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神野 伊策大学院工学研究科 機械工学専攻教授
研究活動情報
■ 受賞- 2019年10月 経済産業省, 国際標準化貢献者表彰（産業技術環境局長表彰）
- 2019年03月 日本機械学会 情報知能精密機器部門, 日本機械学会 情報知能精密機器部門 功績賞, 機械工学国内学会・会議・シンポジウム等の賞
- 2019年 International Electrotechinical Commission (IEC), 1906 Award
- 2018年 電気学会センサ・マイクロマシン部門, 優秀ポスター発表賞, 第35回「センサ・マイクロマシンと応用システムシンポジウム」発表題目：機械的ストレス下における植物の根系発達過程の解析手法国内学会・会議・シンポジウム等の賞
- 2017年 日本機械学会, 日本機械学会フェロー, 日本機械学会フェロー国際学会・会議・シンポジウム等の賞
- 2006年 日本AEM学会, 日本AEM学会 論文賞, 圧電アクチュエータを用いた進行波型バルブレスマイクロポンプの開発論文賞, 日本国国内外の国際的学術賞
- 2003年10月 Microsystem Technologies, Microsystem Technologies: Best Poster Award, Low-Voltage actuation of RF-MEMS switch using Piezoelectric PZT thin filmsBest Poster Award, ドイツ連邦共和国国際学会・会議・シンポジウム等の賞
- 2025年02月, Journal of Ocean Engineering and Technology研究論文（学術雑誌）
- Elsevier BV, 2024年06月, Journal of the European Ceramic Society, 44(6) (6), 3887 - 3894研究論文（学術雑誌）
- Abstract Lead zirconate titanate (Pb (Zrx, Ti1−x)O3: PZT) is a well-known ferroelectric compound, in which long-range polar order is usually developed. In the present study, it was clarified by distortion-corrected atomic-scale scanning transmission electron microscopy imaging that long-range polar order is disrupted in PZT by utilizing composition-modulated superlattice. Shape of unit cell was unusual both in the Pb(Zr0.65Ti0.35)O3 (PZT65) and Pb(Zr0.30Ti0.70)O3 (PZT30) layers, which was due to mutual in-plane lattice constraint. By taking account of this, first-principles calculations clarified that multiple directions can be energetically favorable for lead-ion displacement, which explains a reason why long-range polar order was disrupted.Springer Science and Business Media LLC, 2024年05月, Journal of Materials Science, 59(19) (19), 8134 - 8146研究論文（学術雑誌）
- 2024年, Sensors and Actuators A: Physical研究論文（学術雑誌）
- 2024年, Sensors and Actuators A: Physical研究論文（学術雑誌）
- Abstract In this study, we introduced Ce and Mn as new substitution elements to develop ferroelectricity in wurtzite-type ZnO thin films on Pt/Ti/SiO2/Si. By substituting (Ce,Mn) for Zn, we observed a decrease in the c/a ratio, which reached its minimum value of 1.582. The relative permittivity increased from 12 to 20 with increasing (Ce,Mn) concentration (2%–15%), while the dielectric loss remained low at about 0.01. The Zn(Ce,Mn)O thin films exhibited clear ferroelectric behavior with a remanent polarization of more than 80 μC cm−2 and a coercive field of about 2.5 MV cm−1.IOP Publishing, 2023年12月, Japanese Journal of Applied Physics, 63(1) (1), 010902 - 010902研究論文（学術雑誌）
- Abstract In this study, Piezoelectric energy harvesters (PEHs) are fabricated based on epitaxial Pb(Zr,Ti)O3 (PZT) thin films deposited by an RF magnetron sputtering with varied Zr/[Zr+Ti] ratio. For a compatibility with micro‐electromechanical systems, the epitaxial PZT thin films are deposited on Si substrates (PZT/Si). The morphotropic phase boundary (MPB) are formed in the compositional range of 0.44 ≤ Zr/[Zr+Ti] ≤ 0.51 of the epitaxial PZT/Si, which is far broader than that of the bulk PZT. Meanwhile, effective transverse piezoelectric coefficient (|e31,f|) values are evaluated by the direct and converse piezoelectric effects using the unimorph cantilever method. Among the compositions, the rhombohedral‐dominant MPB (MPB‐R) of Zr/[Zr+Ti] = 0.51 exhibits a direct |e31,f| of 10.1 C m−2 and a relative permittivity (εr) of 285, leading to the maximum figure of merit of 40 GPa in this study. On the other hand, the maximum converse |e31,f| of 14.0 C m−2 is measured from the tetragonal‐dominant MPB (MPB‐T) of Zr/[Zr+Ti] = 0.44. At a resonance frequency, the MPB‐T presents a high output power density of 301.5 µW−1/(cm2 g2) under an acceleration of 3 m−1 s−2, which is very promising for the high‐performance PEH applications.Wiley, 2023年10月, Advanced Materials Interfaces, 11(2) (2)研究論文（学術雑誌）
- In this study, we fabricated limiting current‐type oxygen microsensors capable of sensing a wide range of oxygen concentrations. The oxygen microsensors consist of yttria‐stabilized zirconia thin films on spiral Ta2O5 diffusion layers and high‐temperature micro‐hotplates. At temperatures above 575 °C, we observed a clear limiting current that increased proportionally with oxygen concentration between 0.4% and 94%. This wide‐range linearity is attributed to the Knudsen diffusion of the oxygen gas passing through the small gap in the spiral Ta2O5 diffusion layer. © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.Wiley, 2023年10月, IEEJ Transactions on Electrical and Electronic Engineering, 19(5) (5), 796 - 799研究論文（学術雑誌）
- Springer Science and Business Media LLC, 2023年10月, Bulletin of Materials Science, 46(4) (4)研究論文（学術雑誌）
- Abstract In this study, a physical reservoir computing system, a hardware-implemented neural network, was demonstrated using a piezoelectric MEMS resonator. The transient response of the resonator was used to incorporate short-term memory characteristics into the system, eliminating commonly used time-delayed feedback. In addition, the short-term memory characteristics were improved by introducing a delayed signal using a capacitance-resistor series circuit. A Pb(Zr,Ti)O3-based piezoelectric MEMS resonator with a resonance frequency of 193.2 Hz was employed as an actual node, and computational performance was evaluated using a virtual node method. Benchmark tests using random binary data indicated that the system exhibited short-term memory characteristics for two previous data and nonlinearity. To obtain this level of performance, the data bit period must be longer than the time constant of the transient response of the resonator. These outcomes suggest the feasibility of MEMS sensors with machine-learning capability.IOP Publishing, 2023年08月, Japanese Journal of Applied Physics, 62(SM) (SM), SM1013 - SM1013研究論文（学術雑誌）
- Abstract Lead-free epitaxial (K0.47Na0.53)NbO3 (KNN) thin films were fabricated on (001)SrRuO3/Pt/ZrO2/Si substrates by RF magnetron sputtering at 650 °C and were post-annealed at the same 650 °C by a rapid thermal annealing (RTA) process. The crystal structure of epitaxial KNN thin films were changed by RTA, i.e. the lattice parameter c in the out-of-plane direction decreased instead of an increase of the parameter a in the in-plane direction. The displacement–electric field curve of the RTA-annealed KNN thin films was symmetrical and the shift of the polarization reversal field was smaller than in the KNN thin films annealed by a conventional furnace. This means that RTA is effective in compensating for oxygen vacancies as well as suppressing the generation of A-site vacancies at the interface between the thin film and the substrate. The converse piezoelectric coefficient ∣e31,f∣ of the epitaxial KNN/Si unimorph cantilever was found to improve by up to 7.7 C m−2 due to the decrease in defect density resulting from RTA.IOP Publishing, 2023年07月, Japanese Journal of Applied Physics, 62(SM) (SM), SM1010 - SM1010研究論文（学術雑誌）
- Springer Science and Business Media LLC, 2023年06月, Microsystem Technologies, 29(8) (8), 1181 - 1188研究論文（学術雑誌）
- In the quaternary system PbTiO3-PbZrO3-SrTiO3-SrZrO3, compositions that lie close to the antiferroelectric tetragonal and ferroelectric rhombohedral (AFET-FER) phase boundary have potential applications in micro-actuators. However, in thin films, this phase boundary is reported to shift significantly to the zirconium-rich region. Hence, it is necessary to seek alternative approaches to stabilize the tetragonal AFE phase in such compositions. Therefore, this study explores the effect of B-site Mn3+-doping on their structure. Dielectric, ferroelectric, and piezoelectric characteristics of such thin films have been compared with those with increasing Zr/Ti ratios to understand the efficacy of this approach. Transverse piezoelectric coefficient, e31,f, and bipolar strain are found to be higher in Mn3+-doped thin films. Furthermore, large strains and e31,f in thin films have been correlated with structural modifications revealed by systematic Raman spectroscopic investigations.AIP Publishing, 2023年04月, Journal of Applied Physics, 133(16) (16)研究論文（学術雑誌）
- Lead zirconate titanate (PZT) films have shown great potential in piezoelectric micro-electronic-mechanical system (piezo-MEMS) owing to their strong piezoelectric response. However, the fabrication of PZT films on wafer-level suffers with achieving excellent uniformity and properties. Here, we successfully prepared perovskite PZT films with similar epitaxial multilayered structure and crystallographic orientation on 3-inch silicon wafers, by introducing a rapid thermal annealing (RTA) process. Compared to films without RTA treatment, these films exhibit (001) crystallographic orientation at certain composition that expecting morphotropic phase boundary. Furthermore, dielectric, ferroelectric and piezoelectric properties on different positions only fluctuate within 5%. The relatively dielectric constant, loss, remnant polarization and transverse piezoelectric coefficient are 850, 0.1, 38 μC/cm2 and −10 C/m2, respectively. Both uniformity and properties have reached the requirement for the design and fabrication of piezo-MEMS devices. This broadens the design and fabrication criteria for piezo-MEMS, particularly for piezoelectric micromachined ultrasonic transducers.MDPI AG, 2023年04月, Materials, 16(8) (8), 3185 - 3185研究論文（学術雑誌）
- Artificial superlattice thin films of lead zirconate titanate (PZT) were epitaxially grown on silicon substrates, and the influence of superlattice strain on their piezoelectric properties was investigated. The c-axis oriented PZT superlattice thin film consists of two different PZT layers, Pb(Zr0.65Ti0.35)O-3 (PZT-65) and Pb(ZrxTi1-x)O-3 (PZT-X: x = X/100 = 0.3-0.9), with a 4 nm period. Satellite peaks were clearly observed in x-ray diffraction patterns, and cross-sectional composition measurements confirmed the superlattice structure with good interfaces, showing an alternate change in Zr and Ti compositions. Ferroelectric properties varied significantly depending on the PZT-X composition, and in particular, the PZT-65/PZT-30 superlattice thin film showed nearly the same ferroelectricity as the tetragonal phase under a large compressive strain of PZT-65 from the PZT-30 layer. For the PZT-65/PZT-X (X = 30-58) superlattice thin films, the PZT-65 layers received a compressive strain, and a relatively large piezoelectric coefficient, which did not depend on the PZT-X composition, was obtained. However, a decrease in piezoelectricity was observed in PZT-65/PZT-X (X = 70 and 90), where the PZT-65 layers experienced tensile strain. This result indicates that the piezoelectric properties of PZT superlattice thin films can be controlled by the interlayer strain.AIP Publishing, 2023年03月, Applied Physics Letters, 122(12) (12), 122902-1 - 122902-6, 英語[査読有り]研究論文（学術雑誌）
- AIP Publishing, 2023年02月, APPLIED PHYSICS LETTERS, 122(9) (9), 英語
- In this study, we investigated the piezoelectric characteristics of the sol-gel Pb(Zr0.52Ti0.48)O3 (PZT) films deposited on two different types of substrates. Epitaxial PZT piezoelectric thin films were grown on ZrO2-buff-ered Si substrates, while polycrystalline PZT thin films were grown on conventional Pt/Ti/Si substrates by the sol-gel method. X-ray diffraction measurements revealed a cube-on-cube epitaxy on the buffered Si substrate. The piezoelectric coefficient (e31,f) of the epitaxial PZT thin films was investigated by measuring the tip displacement of PZT cantilevers, and the |e31,f | values were in the range of 8.9-12 C/m2. The voltage depen-dence of the |e31,f | values was more constant than that of the polycrystalline sol-gel PZT/Si cantilever. The epitaxial sol-gel PZT films thus exhibited good piezoelectric properties for applications in micro -electromechanical systems devices.ELSEVIER SCIENCE SA, 2023年01月, THIN SOLID FILMS, 764, 英語研究論文（学術雑誌）
- Epitaxial (K,Na)NbO3 (KNN) thin films were deposited on (001)SrRuO3/Pt/ZrO2/Si substrates by RF magnetron sputtering, and post-annealing effects on the as-deposited epitaxial KNN thin films were investigated. According to the findings, by annealing, the crystal system of these thin films changes from a tetragonal to an orthorhombic system because of the release of internal stress. The asymmetry of polarization-electric field hysteresis loops along the electric field changes from a positive to a negative side by annealing. This means that stable spontaneous polarization P (s) changes from the upward to downward direction with an increase in the number of A-site vacancies. In addition, the displacement-electric field curves of epitaxial KNN/Si unimorph cantilevers exhibit asymmetric behaviors. A relatively high converse piezoelectric coefficient divide e (31,f ) divide = 6.4 C m(-2) is obtained for 5 h annealed epitaxial KNN thin films.IOP Publishing Ltd, 2022年11月, JAPANESE JOURNAL OF APPLIED PHYSICS, 61(SN) (SN), 英語研究論文（学術雑誌）
- Pb(Zr,Ti)O3 (PZT) thin films with rhombohedral composition of Zr/Ti = 58/42 were epitaxially grown on SrRuO3/Pt/ZrO2/Si(001) substrates by radio frequency (RF) magnetron sputtering and their temperature dependence was investigated. In situ high-temperature X-ray diffraction measurements were conducted by the synchrotron radiation X-ray (SPring-8). The as-deposited PZT thin film showed a tetragonal structure due to a clamping effect from substrates. On heating, the diffraction spot was split into two peaks from 600 °C to 750 °C, while the split peaks were maintained on cooling to room temperature. This result indicates that tetragonal and cubic structures coexisted above 600 °C, whereas cubic to rhombohedral phase transition occurred on cooling. After the high-temperature measurement, the PZT thin films showed large voltage dependence of the converse piezoelectric coefficients (∣e 31, f ∣) due to the drastic change of the crystallographic structure by the high-temperature treatment.IOP Publishing Ltd, 2022年11月, Japanese Journal of Applied Physics, 61(SN) (SN), 英語[査読有り]研究論文（学術雑誌）
- Epitaxial growth of lead-free (K,Na)NbO3 (KNN) thin films on (001)SrRuO3/Pt/ZrO2/Si substrates was achieved by using RF magnetron sputtering. X-ray diffraction measurements revealed that lattice constants (a1 = 0.3987 nm, a2 = 0.3959 nm, a3 = 0.4011 nm) of epitaxial KNN thin films with a pseudo cubic system were close to KNN single crystals. Vertical piezoelectric force microscopy observation indicated that the spontaneous polarization Ps with a downward direction was dominant, and the epitaxial KNN thin films were naturally polarized. The epitaxial KNN thin films exhibited low relative dielectric constant (ϵr ∼267). In addition, piezoelectric coefficients |e31,f| showed a constant value of about 6.5 C m-2 with the increase in applied positive voltages. Relatively high converse |e31,f| values were obtained at low applied voltages due to an intrinsic piezoelectric effect. Therefore, the epitaxial KNN thin films might enable piezoelectric microelectromechanical systems driven at low applied voltages.AIP Publishing, 2022年10月, Applied Physics Letters, 121(17) (17), 英語研究論文（学術雑誌）
- For a high power density in piezoelectric energy harvesters, both a large direct piezoelectric coefficient ( e31, f) and a small relative permittivity constant ( εr,33) are required. This study proposed an energy harvesting device made of an epitaxial Pb(Zr, Ti)O3 (PZT) thin film grown on a Si substrate. The epitaxial PZT thin film is deposited on the Si substrate by RF magnetron sputtering. The epitaxial PZT thin film grown on Si substrate has a εr,33 constant of 318. The output voltage as a function of input displacement was measured using a shaker to evaluate the direct e31, f coefficients and energy harvester output characteristics. According to the figure of merit defined as ( e31, f)2/ ε0 εr,33, the epitaxial PZT/Si cantilever is 32 GPa. At a resonant frequency of 373 Hz under an acceleration of 11 m/s2, the epitaxial PZT/Si cantilever has a high output power of 40.93 μW and power density of 108.3 μW/cm2/g2 without any damage, which is very promising for high power energy harvester applications.AIP Publishing, 2022年10月, Applied Physics Letters, 121(16) (16), 161901 - 161901, 英語[査読有り]研究論文（学術雑誌）
- A-site Sr-substituted Pb(Zr0.80Ti0.20)O-3 composition (PSZT) with different Sr2+ content in the range, 0.15 <= x <= 0.20, and located near the AFE-FE phase boundary hold promise for microactuator applications. Thin films of PSZT with 1.0 mu m thickness were fabricated on silicon substrates by chemical solution deposition by spin coating. The structure and texture of the thin films were determined through Raman spectral and XRD studies. We report, for the first time, the existence of the monoclinic phase in the AFE(T)-FER morphotropic phase boundary (MPB) compositions. Correlation of piezoelectric constant, e(31,f) of the thin films and their texture is also reported.TAYLOR & FRANCIS LTD, 2022年10月, INTEGRATED FERROELECTRICS, 230(1) (1), 163 - 170, 英語研究論文（学術雑誌）
- Integration of high-performance lead zirconate titanate (PZT) piezoelectric films onto (111) Si substrates is beneficial for the development of piezoelectric micro-electro-mechanical systems (Piezo-MEMS) because of (111) Si's isotropic mechanical properties and desirable etching characteristics. These features will greatly reduce complications in micro-device fabrication and patterning of PZT/Si heterostructures. However, piezoelectric performance of a PZT film is usually dominated by its preferred crystalline orientation, with (001) being superior than (110) and (111). Such a vectorial dependence seriously restricts applications of PZT films grown on (111) Si, which are usually not (001)-textured. In this work, highly (001)-oriented PZT thick films (& SIM;1.5 mu m) with a 53/47 Zr/Ti ratio were prepared on (111) Si substrates via a multi-layer buffering technique, i.e., through the use of a (111)Pt/Ti bi-layer and a LaNiO3 buffer layer. The PZT films were sputter-deposited at a low temperature (350 & DEG;C) and then crystallized in a (001) texture via a rapid thermal annealing (RTA). The e(31,f) transverse piezoelectric coefficient was up to & SIM;11.6 C/m(2) for PZT films with a RTA time of 2 minutes. Such an e(31,f) value is comparable to that of PZT films grown on (100) Si. This work opens up many possibilities for Piezo-MEMS by demonstrating the desirable combination of a large piezoelectricity in (001) PZT with a good patternability of (111) Si.AIP Publishing, 2022年10月, APPLIED PHYSICS LETTERS, 121(18) (18), 英語研究論文（学術雑誌）
- Piezoelectric BiFeO3 films were successfully prepared on 304 stainless steel (SS) foils via RF-magnetron sputtering at 450 degrees C. By adopting a LaNiO3/Pt/Ti tri-layer bottom electrode, a predominant (100)-orientation and a better crystalline morphology were achieved in the BiFeO3 film, resulting in better ferroelectric and dielectric properties targeted for piezoelectric applications than those directly grown on SS or LaNiO3/SS. These properties include a large remnant polarization (P-r similar to 68 mu C/cm(2)), a large coercive field (E-c similar to 241 kV/cm) and a sizable selfbias (E-bi similar to 158 kV/cm), as well as a low dielectric constant and a reduced dielectric loss (epsilon(r)<= 200 and tan delta <= 0.026 in 1 kHz-1 MHz). Based on this optimal BiFeO3-SS heterostructure, large converse and direct transverse piezoelectric coefficients vertical bar e(31,f)vertical bar similar to 1.7 C/m(2) and 1.07 C/m(2) were achieved in prototype piezoelectric actuator and energy harvester structures, respectively. These results suggest that BiFeO3-SS heterostructures have a great potential for applications in lead-free, metal-based piezoelectric micro-electro- mechanical systems (piezoMEMS).ELSEVIER SCI LTD, 2022年07月, JOURNAL OF THE EUROPEAN CERAMIC SOCIETY, 42(8) (8), 3454 - 3462, 英語研究論文（学術雑誌）
- Recently, photo-electrochemical (PEC) water splitting has been spotlighted as a promising technique for H-2 production using solar energy. To enhance the solar-to-hydrogen (STH) conversion efficiency by preventing the recombination of photogenerated charges inside photoactive materials, investigations have been initiated on ferroelectrics that inherently possess internal electric fields. (Pb,La)TiO3 (PLT) is a renowned material because of its excellent ferroelectric characteristics. We deposited c-axis-oriented epitaxial-PLT thin films on platinized MgO001. Using PLT/Pt/MgO, PEC performances were evaluated and photocathodic responses were verified. In particular, a giant photopotential (V-ph) of more than 2.42 V was obtained, attributing to a highly stabilized polarization in PLT. Such a V-ph was sufficiently larger than the potential required for water splitting (1.23 V + overpotential, eta), and it enabled the hydrogen evolution reaction (HER) under bias-free conditions.AMER CHEMICAL SOC, 2022年02月, ACS APPLIED ENERGY MATERIALS, 5(2) (2), 2606 - 2612, 英語研究論文（学術雑誌）
- In this study, we fabricated a limiting current-type microelectromechanical system (MEMS) sensor and evaluated its sensing performance of oxygen and humidity concentration. The MEMS oxygen and humidity sensor consisted of a thin-film YSZ-based sensing element on a cantilever-shaped micro-hotplate. The thin-film YSZ layer was electrically heated by a Pt heater of the cantilever-shaped micro-hotplate. The limiting current characteristics were observed above 575 degrees C. We confirmed the limiting current proportionally increased with oxygen concentration. In contrast, the limiting current increased with humidity at a higher bias voltage. These results indicate that both of oxygen and humidity concentration can be separately measured by selecting the bias voltage to the YSZ thin film.IEEE, 2022年, 2022 IEEE SENSORS, 英語研究論文（国際会議プロシーディングス）
- AIP Publishing, 2021年08月, Journal of Applied Physics, 130(7) (7), 074101 - 074101[査読有り]研究論文（学術雑誌）
- Elsevier BV, 2021年08月, Sensors and Actuators A: Physical, 327, 112786 - 112786研究論文（学術雑誌）
- Elsevier BV, 2021年05月, Sensors and Actuators A: Physical, 322, 112617 - 112617研究論文（学術雑誌）
- Institute of Electrical Engineers of Japan (IEE Japan), 2021年05月, IEEJ Transactions on Sensors and Micromachines, 141(5) (5), 141 - 146研究論文（学術雑誌）
- In this study, we designed, fabricated and evaluated a piezoelectric thin-film loudspeaker. To enhance the acoustic output in the low frequency range, the device design was optimized by finite element analysis. The prototype speaker was fabricated using the piezoelectric PZT thin film deposited on a stainless steel substrate using RF magnetron sputtering. The vibration displacement and output sound pressure of the completed device were measured as a function of frequency. The measured SPL increased in proportion to the frequency below the resonance. Above the resonance frequency, the SPL was constant independent of frequency. It achieved a sound pressure level of 65 dB at the resonance frequency of 726 Hz. SPL was calculated from the displacement and we confirmed that the calculated results of the frequency response of SPL were in good agreement with the measurement results.一般社団法人 日本機械学会, 2021年, IIP情報・知能・精密機器部門講演会講演論文集, 2021, IIP1A3-1, 日本語
- Elsevier BV, 2021年01月, Sensors and Actuators B: Chemical, 327, 128932 - 128932研究論文（学術雑誌）
- IOP Publishing, 2020年11月, Japanese Journal of Applied Physics, 59(SP) (SP), SPPD09 - SPPD09研究論文（学術雑誌）
- IOP Publishing, 2020年11月, Japanese Journal of Applied Physics, 59(SP) (SP), SPPB04 - SPPB04[査読有り]研究論文（学術雑誌）
- 公益社団法人 応用物理学会, 2020年08月, 応用物理学会学術講演会講演予稿集, 2020.2, 878 - 878, 日本語
- American Chemical Society (ACS), 2020年07月, ACS Applied Electronic Materials, 2(7) (7), 2084 - 2089[査読有り]研究論文（学術雑誌）
- Interest in energy harvesters has grown rapidly over the last decade. In this study, we fabricate and evaluate piezoelectric energy harvesters (PEH) fabricated from Pb(ZrTi)O3 (PZT) thin films on stainless steel foils. The PZT thin films were deposited onto (Pb,La)TiO3/Pt/Ti-coated stainless steel substrate by RF-magnetron sputtering. Parallel and series connection of eachPEH enabled the output power increase as high as turning on a LED.一般社団法人 日本機械学会, 2020年, IIP情報・知能・精密機器部門講演会講演論文集, 2020, 2A06, 日本語
- Recently, thin-film lithium-ion batteries have attracted considerable attention as the micro-power sources for micro-sensors. In this study, we fabricated all solid-state thin-film lithium-ion batteries composed of amorphous multilayers and evaluated their charge-discharge characteristics in atmospheric conditions. The thin-film batteries were composed of an amorphous multilayer structure of lithium-doped vanadium oxide, lithium phosphorus oxynitride (LiPON), and Si as cathode, electrolyte, and anode, respectively. To obtain a good interface with the LiPON electrolyte, we deposited a multilayer cell structure by successive deposition in a vacuum chamber with a multi-target sputtering machine equipped with a movable shadow mask. We measured the charge and discharge characteristics of the thinfilm batteries under atmospheric conditions without protection layers on the thin-film batteries. We observed large unit area capacities of 32.8 and 15.7 mu Ah/cm(2) at the first charge and discharge cycle, respectively, in the voltage range of 0.5-3.0 V.ELSEVIER SCIENCE SA, 2020年, Thin Solid Films, 697, 137840, 英語[査読有り]研究論文（学術雑誌）
- We have constructed a time-resolved equivalent circuit model of the piezoelectric vibrational energy harvesters (PVEHs) with the trapezoidal unimorph structure not only to optimize the dimensional parameter of trapezoidal PVEHs but also to anticipate the output power by a variety of external vibrations. To calculate the output responses by arbitrary mechanical input accelerations such as impulses or sinusoidal, we have formulated simultaneous first order differential equations based on this model. In order to express dynamics with large amplitudes enough to drive actual devices such as micro-sensors with BLEs, we have considered the nonlinear effects, and successfully reproduced experiments by our calculations.Institute of Physics Publishing, 2019年12月, Journal of Physics: Conference Series, 1407(1) (1), 英語研究論文（国際会議プロシーディングス）
- In this study, we report the effect of Zr/Sn ratio on the Antiferroelectric (AFE) → Ferroelectric (FE) phase transition and transverse piezoelectric characteristics on AFE thin films of compositions having the general formula Pb0.97La0.02(Zr1- x + ySnxTiy)O3, where y = 0.10 and 0.10 ≤ x ≤ 0.15 along the phase boundary in the ternary system Pb(Zr0.50Ti0.50)O3-Pb(Zr0.50Sn0.50)O3-PbZrO3. Thin films having a thickness of 2.0 µm were fabricated on platinised silicon substrates by sol–gel method. Data obtained from dielectric, ferroelectric and structural studies have been combined to explain the mechanism of AFE → FE switching.Taylor and Francis Ltd., 2019年09月, Integrated Ferroelectrics, 201(1) (1), 86 - 93, 英語研究論文（学術雑誌）
- 2019年05月, ケミカルエンジニヤリング, 64(5) (5), 335 - 342, 日本語有機強誘電体薄膜を利用した圧電振動発電
- Piezoelectric thin-film vibration energy harvesters (PVEHs) are one of the key technologies to be used as a power sources of the sensor nodes. In order to optimize the dimensional parameters of PVEHs, we have derived theoretical equations for the output power of the PVEHs with the cantilever structure using time-resolved equivalent circuit models which can be applicable to a variety of vibration with arbitrary waves. In this study, we have calculated the output power of the PVEHs with trapezoidal stainless-steel cantilevers on which Pb(Zr,Ti)O3 (PZT) thin films are deposited. Theoretical formula of the output power enables the optimization of not only the geometry of the trapezoidal cantilever, but also electrode length and substrate thickness. We fabricated the PVEHs of PZT thin films on stainless steel foils. The calculation results of the output power were in good agreement with those of the experiments. The theoretical formula indicated that the generated power was maximized when the electrode length was 2/3-5/6 of cantilever length, and piezoelectric film thickness was about 40% of substrate thickness. The optimum electrode length is equal to 2/3 of the beam length if the cantilever shape is a rectangle but becomes larger than 2/3 when it is close to a triangle. With these electrical optimum solutions, we will be able to determine optimal design of the PVEH according to the specific vibration environments.Elsevier, 2019年02月, Nanoscale Ferroelectric-Multiferroic Materials for Energy Harvesting Applications, 161 - 179, 英語論文集(書籍)内論文
- In this study, we fabricated the piezoelectric microelectromechanical systems (MEMS) speakers with Pb(Zr,Ti)O3 (PZT) thin films. In order to improve the performance of piezoelectric speakers, we fabricated the 2 mm square MEMS speaker with a diaphragm structure of PZT/Si and photosensitive polyimide. The optimal structure was investigated by finite element method (FEM) simulation. The 2 μm thick PZT thin films were deposited on SOI wafers by radio frequency (RF) magnetron sputtering, and microfabricated into unimorph diaphragm. We measured the vibration amplitude of the piezoelectric MEMS speakers as a function of frequency. We confirmed that the resonance frequency was 25.6 kHz that is out of audible range. In addition, the speaker could generate large sound pressure level (SPL) of 82 dB at 6 Vpp.一般社団法人 日本機械学会, 2019年, マイクロ・ナノ工学シンポジウム, 2019.10, 19pm5PN312, 日本語
- In this research, we designed, fabricated and evaluated a PZT thin-film piezoelectric MEMS transformer. First, the disk-shaped device with the ring-dot structure was designed using Finite Element Method (FEM) analysis. At this time, since the piezoelectric transformer is driven in resonance, we confirmed resonance frequency and vibration mode of the transformer. Next, a PZT thin film was deposited on a silicon on insulator (SOI) substrate using RF magnetron sputtering method, and then microfabricated into a piezoelectric transformer. Finally, we measured the impedance and transformation properties of the piezoelectric MEMS transformer. The resonance frequency was observed at 4.57 MHz, and the transformation ratio was found to be about 0.3.一般社団法人 日本機械学会, 2019年, マイクロ・ナノ工学シンポジウム, 2019.10, 19pm5PN318, 日本語
- 2019年, Sensors and Actuators A: Physical, 296, 286 - 291, 英語Ultrahigh temperature platinum microheater encapsulated by reduced-TiO2 barrier layer[査読有り]研究論文（学術雑誌）
- 2019年, Scientific Reports, 9, 7309, 英語Crystallographic contributions to piezoelectric properties in PZT thin films[査読有り]研究論文（学術雑誌）
- This paper describes high flexible piezoelectric vibration energy harvesters (PVEHs) composed of PZT thin films on stainless steel (SS) mesh. The PZT thin films were deposited on Pt/Ti-coated SS mesh substrates which were plain-woven with the SS wire diameter of 15 μm and 30 μm, respectively. Relative dielectric constant of the PZT thin films on the SS mesh of 15 and 30 was measured to be 475, 263, respectively. In 15 device, the remnant polarization and the coercive field was 11.9 μC/cm2 and 48.7 kV/cm, respectively. For the measurement of the piezoelectric response, we attached conductive rubber sheets to the rectangular top electrode. The maximum output voltage of about 30 mV was measured in each bending motion. We confirmed the capability of the PZT thin films on SS mesh for the PVEH applications.Institute of Physics Publishing, 2018年07月, Journal of Physics: Conference Series, 1052(1) (1), 英語研究論文（国際会議プロシーディングス）
- © Published under licence by IOP Publishing Ltd. Piezoelectric MEMS energy harvesters based on multilayer (ML) Pb(Zr,Ti)O3(PZT) thin films with interdigitated electrodes (IDE) as their internal and top electrodes are proposed and designed. Thick PZT thin films with good piezoelectric characteristics can be deposited by using multilayer deposition technique. Furthermore, IDE is adopted to the harvester design in order to take advantage of the longitudinal piezoelectric effect, which typically has twice piezoelectric constant as large as transverse effect. The energy harvesters with two electrode configurations, parallel plate electrodes (PPE) and IDE, are designed and estimate these output power. According to the result of finite element analysis, the output power per gravitational acceleration is about 124 μW for the PPE configuration. On the other hand, the output power per gravitational acceleration for the IDE configuration is about three times as large as that for PPE. Moreover, the influence of IDE patterns and the number of PZT layers were investigated. The larger number of layers results in the larger output power.2018年07月, Journal of Physics: Conference Series, 1052
- 2018年07月, Journal of Physics: Conference Series, 1052(1) (1), 1 - 4, 英語, 国際誌, 国際共著していない[査読有り]研究論文（学術雑誌）
- 2018年07月, Journal of Physics: Conference Series, 1052(1) (1), 012094, 英語[査読有り]研究論文（国際会議プロシーディングス）
- 2018年07月, Journal of Physics: Conf. Series, 1052, 012112 - 1-4, 英語[査読有り]研究論文（学術雑誌）
- 2018年, Integrated Ferroelectrics, 192, 113 - 120, 英語Transverse piezoelectric properties of {110}-oriented PLZT thin films[査読有り]研究論文（学術雑誌）
- 2018年, Japanese Journal of Applied Physics, 57, 11UD06, 英語Numerical designs of piezoelectric thin-film vibration energy harvesters[査読有り]研究論文（学術雑誌）
- 2018年, Neuroscience Research, [kuid20190610.xls]論文!E2, [kuid20190610.xls]論文!G2, 英語Immediate elimination of injured white matter tissue achieves a rapid axonal growth across the severed spinal cord in adult rats[査読有り]研究論文（学術雑誌）
- 2018年, Japanese Journal of Applied Physics, 57, 040101, 英語Piezoelectric MEMS: Ferroelectric thin films for MEMS applications[査読有り][招待有り]
- 2018年, 日本機械学会誌, 121(12) (12), 22 - 25, 日本語IoT電源としての振動発電技術[査読有り][招待有り]
- 2017年11月, The 17th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (Power MEMS 2017), 271 - 274, 英語Development of Piezoelectric Vibration Energy Harvesters for Batteryless Smart Shoes[査読有り]研究論文（国際会議プロシーディングス）
- 2017年10月, The 21st International Conference on Miniaturized Systems for Chemistry and Life Sciences (MicroTAS 2017), 英語ON-CHIP MECHANICAL STRESS TEST ON PLANT ROOT GROWTH[査読有り]研究論文（国際会議プロシーディングス）
- 2017年10月, The 21st International Conference on Miniaturized Systems for Chemistry and Life Sciences (MicroTAS 2017), 英語METHODS FOR PHYSHICAL CHARACTERIZATION OF GROWING PLANT ROOTS[査読有り]研究論文（国際会議プロシーディングス）
- We fabricated the piezoelectric bimorphs composed of Pb(Zr,Ti)O-3 (PZT) thin films on metal foil substrates. To efficiently inexpensively manufacture piezoelectric bimorphs with high flexibility, 1.2-mu m-thick PZT thin films were directly deposited on both surfaces of 10- and 20-mu m-thick bare stainless-steel (SS) foil substrates by dip coating with a sol-gel solution. We confirmed that the PZT thin films deposited on the SS foil substrates at 500 degrees C or above have polycrystalline perovskite structures and the measured relative dielectric constant and dielectric loss were 323-420 and 0.12-0.17, respectively. The PZT bimorphs were demonstrated by comparing the displacements of the cantilever specimens driven by single-and double-side PZT thin films on the SS foil substrates under the same applied voltage. We characterized the piezoelectric properties of the PZT bimorphs and the calculated their piezoelectric coefficient |theta(31), r| to be 0.3-0.7 C/m(2). (C) 2017 The Japan Society of Applied PhysicsIOP PUBLISHING LTD, 2017年10月, JAPANESE JOURNAL OF APPLIED PHYSICS, 56(10) (10), 10PF08, 英語[査読有り]研究論文（学術雑誌）
- Epitaxial Pb(Zr0.53Ti0.47)O-3 films were grown on (001) Pt/(001) MgO via rf-magnetron sputtering. Switching dynamics of 90 degrees and 180 degrees domains under bi-polar electric fields were probed by using small-field e(31f) measurements in which the evolution of the transverse piezoelectric response with the bias voltage represents a set of fingerprints of the evolving domain structure. Furthermore, the asymmetric e(31,f) - V curves revealed a strong built-in electric field, which was verified by the standard polarization-electric field hysteresis measurement. Finally, X-ray 2 theta-scan patterns under DC bias voltages were collected for the piezoelectric specimen. The domain switching sequence indicated by the XRD results is consistent with that revealed by the e(31,f) measurement. Published by AIP Publishing.AMER INST PHYSICS, 2017年07月, APPLIED PHYSICS LETTERS, 111(2) (2), 英語[査読有り]研究論文（学術雑誌）
- The airflow energy harvesters (AFEHs) of piezoelectric Pb(Zr,Ti)O-3 (PZT) thin films were developed. Electric power was generated by self-excited vibration of the piezoelectric bimorph cantilevers induced by a continuous airflow. To enhance the vibration in low wind speed, we used very thin stainless-steel (SS) foils with thickness of 20 inn as base substrates, and the PZT thin films were deposited on both surface of SS foils by radio-frequency (rf) magnetron sputtering. When the angle of attack (AOA) was 20 degrees and above, stable self-excited vibration was generated at wind speeds larger than 4.5 m/s. When the wind speed was 8 m/s, the maximum output power reached 36.4 mu W at the AOA of 20 degrees. From the evaluation of the thickness effect of the base cantilevers, it was confirmed that the thinner substrate reduced not only cut-in wind speed but also maximum output voltage. (C) 2017 Elsevier B.V. All rights reserved.ELSEVIER SCIENCE SA, 2017年07月, SENSORS AND ACTUATORS A-PHYSICAL, 261, 295 - 301, 英語[査読有り]研究論文（学術雑誌）
- 公益社団法人 応用物理学会, 2017年03月, 応用物理学会学術講演会講演予稿集, 2017.1, 1271 - 1271, 日本語
- This paper presents a novel microfluidic device for high throughput ion-channel analysis. To analyze the electrophysiological properties of cells efficiently, we designed the electrically independent microchannels on the microfluidic device. The microfluidic device is composed of a silicon-on-insulator (SOI) layer having the trap holes with 9 or 12 μm diameter, poly-dimethylsiloxane (PDMS) microchannel chips and glass substrate with Pt electrodes. We successfully trapped the multiple cells on one device without damage by applying negative pressure to the microchannels with a syringe pump. Finally, we confirmed that the each trap hole was strongly sealed with the cell by measuring the electrical impedance, which was more than 1 GΩ, namely gigaseal.一般社団法人 日本機械学会, 2017年, マイクロ・ナノ工学シンポジウム, 2017.8, PN-27, 日本語
- In this study, we fabricated the microelectromechanical systems (MEMS) microphones composed of piezoelectric Pb(Zr,Ti)O3 (PZT) thin-film bimorphs. To improve the sensitivity of the piezoelectric MEMS microphone, we designed the PZT bimorph cantilevers by using a finite element method (FEM) simulation. The dimensions of the PZT bimorphs are 1000 μm in width and 280 μm in length. The two layers of 1-μm-thick PZT thin films were deposited on Si substrates by radio frequency (RF) magnetron sputtering and formed into the cantilevers by dry etching. To evaluate the frequency responses, we measured the vibration amplitude of the PZT bimorphs oscillated by applying the negative AC voltage. The piezoelectric microphone was demonstrated by detecting the output signal owing to the direct piezoelectric effect when the sound pressure was applied. We confirmed that the output signal of the piezoelectric microphone was proportionally increased by increasing the applied sound pressure.一般社団法人 日本機械学会, 2017年, マイクロ・ナノ工学シンポジウム, 2017.8, PN-97, 日本語
- Recently, development of insect scale robots has been attracting attention. These robots are expected to be used for inspection or sensing in narrow and danger places where human cannot enter. In this study, we fabricated and evaluated piezoelectric thin film actuators intended for flapping wing insect scale robot. We firstly report a FEM analysis results of piezoelectric PZT thin-film actuators. To verify this analysis results, we deposited PZT thin films on micro-fabricated stainless steel substrates and evaluated their crystal structure, electrical properties, and piezoelectric properties of PZT thin films. X-ray diffraction measurements reveal that the PZT thin films have a polycrystalline perovskite structure. The relative dielectric constant of the PZT thin films was 240. FEM analysis results are in good agreement with the resonant frequency. The angular displacement are less than 1° in all measurement points driven by resonant frequency (5Vpp, 2.095 and 2.257 kHz).一般社団法人 日本機械学会, 2017年, 年次大会, 2017, G1600102, 日本語
- We fabricated a new diaphragm micropump composed of the piezoelectric Pb(Zr,Ti)O3 (PZT) thin films on the stainless-steel (SS) foil substrates to reduce the driving voltage. To miniaturize and simplify the micropump structure, the diaphragm and microchannel with diffusers were monolithically formed on the 30-μm-thick SS substrates by photolithography and wet etching. We directly deposited the 1-μm-thick PZT thin films on the SS diaphragm by dip coating with a sol-gel solution. To evaluate the driving characteristics of the fabricated micropump, the SS diaphragm was actuated by applying AC voltage to the PZT thin films. The displacement of the 9-μm-thick SS diaphragm was 1.7 μm with 10 Vpp-driving voltage at 1 Hz.一般社団法人 日本機械学会, 2017年, マイクロ・ナノ工学シンポジウム, 2017.8, PN-8, 日本語
- Lithium ion batteries are widely used in a variety of portable products because of their high energy density. Recently solid-state lithium ion batteries have been studied to solve the safety issue of liquid electrolyte. In order to realize solid state thin film batteries, we prepared electrode thin films by RF magnetron sputtering on Pt/Ti/Si substrates. In this study, LiCoO2(LCO) cathode thin films were deposited. After annealing at 620°C, clear diffraction of (003) and (101) orientation was detected in XRD measurements. Si anode, Cyclic voltammgram showed oxidation and reduction peaks at 0.6 V, 0.01 V, respectively. We also measured the capacity of the Si thin film by the discharge-charge curves. The discharge-charge capacity of 660 μAh/(cm2・μm) and 609 μAh/(cm2・μm) could be obtained for the Si anode thin films, respectively.一般社団法人 日本機械学会, 2017年, IIP情報・知能・精密機器部門講演会講演論文集, 2017, I - 1, 日本語
- This paper describes piezoelectric vibration energy harvester (PVEH). The PVEH was fabricated from Pb(ZrTi)O3 (PZT) thin films which were deposited onto (Pb,La)TiO3/Pt/Ti-coated stainless steel substrate by rf-magnetron sputtering. We measured output power of the PVEH as well as theoretical calculation. The output power showed maximum at the calculated optimal load resistance of 73.2 kΩ, where the output power was 1.0 μW. For the purpose of predicting output power, we tried to derive electromechanical coupling coefficient. Applying an equivalent circuit model of the energy harvester, we succeeded in deriving electromechanical coupling coefficient.一般社団法人 日本機械学会, 2017年, IIP情報・知能・精密機器部門講演会講演論文集, 2017, I - 2, 日本語
- We investigated piezoelectric vibration energy harvesters with poly(vinylidene fluoride/trifluoroethylene) films and the improved power generation from using multistacked and stretched ferroelectric films on the cantilevers. The energy harvesters generated electric power with a resonant frequency of approximately 25 Hz, which corresponded to the ambient vibration. The power density of four-layered harvesters was estimated to be 2.5 mu W/m(3), which was larger than the power density of previous harvesters. The output power of stretched-film harvesters was 3.6 times the output obtained from unstretched films. In addition, because organic ferroelectric films are flexible, the resonant frequency of each harvester was practically constant even when using the techniques of multistacking and stretching. (C) 2017 The Japan Society of Applied PhysicsIOP PUBLISHING LTD, 2017年, Japanese Journal of Applied Physics, 56(4) (4), 04CL04, 英語[査読有り]研究論文（学術雑誌）
- (1-x)BaTiO3-xBaSnO(3) (BT-xBS, 0 <= x <= 0.20) perovskite thin films were deposited on Pt/Ti/Si substrates with uniaxial graded composition by using a dual-target combinatorial sputtering technique. These films were highly (101)-oriented and showed strong composition dependence in their electromechanical properties. The maximum value of the relative dielectric constant was 925 at around x=0.028, where the transverse piezoelectric coefficient vertical bar e(31,f)vertical bar also peaked at about 1.5-1.9 C/m(2). This vertical bar e(31,f)vertical bar value is higher than those of epitaxial BaTiO3 thin films. Our results indicate that BT-xBS is a promising substitute of lead-based perovskites for applications in piezoelectric MEMS devices.ELSEVIER SCI LTD, 2017年01月, CERAMICS INTERNATIONAL, 43(1) (1), 1597 - 1601, 英語[査読有り]研究論文（学術雑誌）
- We investigated the piezoelectric properties of a vibration energy harvester using large-area, flexible cantilevers composed of polyurea thin films. The piezoelectric constant d(31) of the polyurea films was measured based on the relationship between the displacement and applied voltage of large-aspect-ratio cantilevers. Centimeter-scale unimorph cantilevers were fabricated, and their energy harvester performance was evaluated by vibrating them. The power generation of the cantilevers with controlled forms was 2.2mV at 50.5Hz (i.e., vibration generation could be efficiently realized at environmental vibrations under 100 Hz).TAYLOR & FRANCIS LTD, 2017年, MOLECULAR CRYSTALS AND LIQUID CRYSTALS, 653(1) (1), 188 - 193, 英語[査読有り]研究論文（学術雑誌）
- 表面技術協会, 2017年, 表面技術, 68(7) (7), 387 - 391, 日本語圧電薄膜アクチュエータ[査読有り][招待有り]
- {110}-preferentially oriented thin films of lead based perovskite solid solutions consisting of lead indium niobate (PIN) and lead titanate (PT), (1-x) PIN-x PT, x = 0.36-0.40 having compositions near the morphotropic phase boundary (MPB), and having a thickness of 2.0 mm, were prepared on silicon substrates (111) Pt/Ti/SiO2/Si by a chemical solution deposition technique. In the thin films, crystallographic orientation and crystalline phase were analysed by X-ray diffraction and Raman spectroscopy respectively. In this study, we also report through Raman spectral investigation, stabilisation of discrete rhombohedral, monoclinic and tetragonal crystalline phases as the thin film composition is varied across the morphotropic phase boundary. The electric field induced mechanical strain and polarisation characteristics of the {110}-oriented PIN-PT thin films have been determined under unipolar and bipolar excitation. Transverse piezoelectric coefficient, e(31,f) of the thin films have been correlated with their crystal structure. (C) 2016 Elsevier B.V. All rights reserved.ELSEVIER SCIENCE SA, 2016年12月, Journal of Alloys and Compounds, 688(PB) (PB), 863 - 867, 英語[査読有り]研究論文（学術雑誌）
- Pb(Hf,Ti)O-3 (PHT) thin films were deposited by combinatorial sputtering, and their precise piezoelectric properties were evaluated as a function of Hf/Ti composition. The PHT thin films showed typical ferroelectric characteristics, and the relative dielectric constant epsilon(r) was as high as 700. The piezoelectric coefficient of {100}-oriented PHT thin films reached vertical bar e(31,f)vertical bar = 6.5 C/m(2) around Hf/Ti = 50/50, at which epsilon(r) was also maximized. The piezoelectric characteristics of the PHT thin films were similar to those of PZT thin films, indicating that the PHT thin films are promising alternatives to PZT thin films in piezoelectric micro-electromechanical systems (MEMS). (C) 2016 Elsevier B.V. All rights reserved.ELSEVIER SCIENCE SA, 2016年10月, THIN SOLID FILMS, 616, 444 - 448, 英語[査読有り]研究論文（学術雑誌）
- 2016年10月, Proc. of 20th International Conference on Miniaturized Systems for Chemistry and Life Sciences(MicroTAS 2016), 英語ANALYTICAL METHODS OF ROOT GROWTH BEHAVIOR USING AN ARTIFICIAL SOIL DEVICE[査読有り]研究論文（国際会議プロシーディングス）
- 公益社団法人 応用物理学会, 2016年09月, 応用物理学会学術講演会講演予稿集, 2016.2, 1236 - 1236, 日本語
- In this study, we fabricated multilayer ceramics (MLCs) composed of multilayered Pb(Zr,Ti)O-3 (PZT) piezoelectric thin films with internal electrodes and evaluated their dielectric and piezoelectric properties. The stack of PZT ferroelectric layers (550 nm) and SrRuO3 (SRO, 80 nm) electrodes were alternatively deposited on Pt/Ti-coated silicon-on-insulator substrates by radio-frequency magnetron sputtering. The MLCs composed of one, three, and five PZT layers were fabricated by the alternate sputtering deposition of PZT ferroelectric layers and SRO electrodes through the movable shadow mask. The capacitances of MLCs were proportionally increased with the number of PZT layers, while their relative dielectric constants were almost same among the each MLC. The MLCs exhibited symmetric and saturated P-E hysteresis loops similar to the conventional PZT thin films. We estimated that the piezoelectric properties of MLCs by FEM simulation, and confirmed that the effective transverse piezoelectric coefficients (d (31,eff) ) increased with the number of PZT layers. The piezoelectric coefficients calculated to be d (31,eff) = -2964 pC/N at 25 PZT layers, which is much higher than those of conventional single-layer piezoelectric thin films.SPRINGER, 2016年06月, MICROSYSTEM TECHNOLOGIES-MICRO-AND NANOSYSTEMS-INFORMATION STORAGE AND PROCESSING SYSTEMS, 22(6) (6), 1275 - 1283, 英語[査読有り][招待有り]研究論文（学術雑誌）
- We have developed a piezoelectric-driven millimeter-scale robot with a simple structure. This millimeter-scale robot, which consists of a titanium (Ti) body and front/back legs integrated with a Pb(Zr, Ti)O-3 (PZT) piezoelectric thin film actuator, is driven by using mechanical resonance. To simply fabricate the millimeter-scale robot, the PZT thin film was directly deposited on an H-shaped Ti substrate by radio frequency magnetron sputtering and the shape of the robot was completed by plastic deformation of the monolithic Ti substrate. We obtained the transverse piezoelectric coefficient d (31) of the deposited PZT thin film was -21.3 pm/V, which was sufficient for driving the fabricated millimeter-scale robot with a low driving voltage a parts per thousand currency sign10 V. We also evaluated the resonant characteristics of the fabricated robot and confirmed that the front/back legs of robot were oscillated in primary and secondary resonance modes at around 4.5 and 11 kHz, respectively. We demonstrated that the millimeter-scale robot with asymmetric structure in the front-back direction was controlled by changing driving voltage conditions and a bending angle formed by the front/back legs. The moving speed of the millimeter-scale robot was 13.6 cm/s by applying negative unipolar voltage of 10 V-pp at 10.6 kHz when the bending angle was set to 109A degrees. We experimentally confirmed that the millimeter-scale robot can be driven forward and backward by optimizing the shape of the robot and mechanical resonant modes.SPRINGER, 2016年06月, MICROSYSTEM TECHNOLOGIES-MICRO-AND NANOSYSTEMS-INFORMATION STORAGE AND PROCESSING SYSTEMS, 22(6) (6), 1429 - 1436, 英語[査読有り]研究論文（学術雑誌）
- In this study, we fabricated multilayer ceramics (MLCs) composed of multilayered Pb(Zr,Ti)O-3 (PZT) piezoelectric thin films with internal electrodes and evaluated their dielectric and piezoelectric properties. The stack of PZT ferroelectric layers (550 nm) and SrRuO3 (SRO, 80 nm) electrodes were alternatively deposited on Pt/Ti-coated silicon-on-insulator substrates by radio-frequency magnetron sputtering. The MLCs composed of one, three, and five PZT layers were fabricated by the alternate sputtering deposition of PZT ferroelectric layers and SRO electrodes through the movable shadow mask. The capacitances of MLCs were proportionally increased with the number of PZT layers, while their relative dielectric constants were almost same among the each MLC. The MLCs exhibited symmetric and saturated P-E hysteresis loops similar to the conventional PZT thin films. We estimated that the piezoelectric properties of MLCs by FEM simulation, and confirmed that the effective transverse piezoelectric coefficients (d (31,eff) ) increased with the number of PZT layers. The piezoelectric coefficients calculated to be d (31,eff) = -2964 pC/N at 25 PZT layers, which is much higher than those of conventional single-layer piezoelectric thin films.SPRINGER, 2016年06月, MICROSYSTEM TECHNOLOGIES-MICRO-AND NANOSYSTEMS-INFORMATION STORAGE AND PROCESSING SYSTEMS, 22(6) (6), 1275 - 1283, 英語[査読有り]研究論文（学術雑誌）
- 2016年06月, Proc. of Asia-Pacific Conference of Transducers and Micro-Nano Technology 2016 (APCOT2016), 英語FABRICATION OF FORCE SENSOR FOR STUDYING SEED GERMINATION OF PLANTS[査読有り]研究論文（国際会議プロシーディングス）
- 応用物理学会, 2016年03月, 応用物理, 85(3) (3), 207, 日本語圧電MEMSの基礎技術と応用展開[査読有り][招待有り]
- In this study, we fabricated a microelectromechanical systems (MEMS) cylindrical gyroscope integrated with piezoelectric thin-film for sensing/driving elements. The cylindrical gyroscope has several advantages: (1) the sensitivity can be improved due to the high Q-factor. (2) we can eliminate an initial output signal from the sensing electrodes. We characterized the resonant characteristics of the cylindrical gyroscope in wine-glass mode and the Q-factor was 723 at 36.13 kHz under atmospheric pressure. In addition, we experimentally confirmed that the mechanical vibration of the gyroscope can be measured by detecting the electrical signal due to the piezoelectric effect of Pb(Zr,Ti)O3 (PZT).一般社団法人 日本機械学会, 2016年, 年次大会, 2016, J2230103, 日本語
- This paper describes shoe-mounted piezoelectric vibration energy harvesters (PVEHs). The PVEHs were fabricated from Pb(ZrTi)O-3 (PZT) thin films which were directly deposited onto Pt/Ti-coated stainless steel foil by rf-magnetron sputtering. We experimentally and theoretically evaluated impulse responses of the PVEHs by applying a simple impulse input on the energy harvesters, typical damped free vibration behaviour was clearly observed, and the output signal was in good agreement with the theoretical value. We measured the output power by applying the impulse input with an optimal load resistance of 33.9 k Omega. The maximum output power was approximately 20 mu W, which correspond with the calculated value based on theoretical equation. From these results, the theoretical equation we derived might be helpful for design purposes of the shoe-mounted PVEHs.IOP PUBLISHING LTD, 2016年, 16TH INTERNATIONAL CONFERENCE ON MICRO AND NANOTECHNOLOGY FOR POWER GENERATION AND ENERGY CONVERSION APPLICATIONS (POWERMEMS 2016), 773, 英語[査読有り]研究論文（国際会議プロシーディングス）
- Superior piezoelectric properties of lead-based perovskite type solid solution systems such as PLZT, having compositions near morphotropic phase boundary (MPB) make them ideal candidates for MEMS. The dielectric and piezoelectric characteristics in such perovskite based thin films are related to their structure and texture. In this study, we report the influence of aliovalent B-site acceptor dopants (Fe3+, Cu2+ and Mn3+) on the structure, dielectric and piezoelectric properties of {110}- preferentially oriented PLZT (8/65/35) thin films. Thin films having a thickness of 2.0 mu m were prepared on silicon substrates (111) Pt/Ti/SiO2/Si by Sol-gel spin coating technique. The preferential crystallographic orientation and crystalline phase formation in the thin films were analysed by X-ray diffraction and Raman spectroscopy respectively. The improved transverse piezoelectric coefficient, e(31,f) and electric field induced bipolar strain characteristics of the acceptor doped PLZT films have been correlated with their crystal structure. Mechanism for higher bipolar strain in Cu2+ and Mn3+ doped PLZT films have also been studied and are reported.TAYLOR & FRANCIS LTD, 2016年, INTEGRATED FERROELECTRICS, 176(1) (1), 210 - 219, 英語[査読有り]研究論文（学術雑誌）
- 表面技術協会, 2016年, 表面技術, 67(7) (7), 348 - 352, 日本語振動エネルギーによる環境発電（振動発電）[査読有り][招待有り]
- 2016年, 日本電子材料技術協会会報, 47, 26 - 29, 日本語金属基板上圧電薄膜による振動発電技術[査読有り][招待有り]
- 2015年11月, Proceedings of The 8th Plant Biomechanics International Conference, 英語Development of on-chip physical characterization method for root growth[査読有り]研究論文（国際会議プロシーディングス）
- We evaluated the effective transverse piezoelectric coefficients (e(31,f)) of Pb(Zr,Ti)O-3 (PZT) thin films from both the direct and converse piezoelectric effects of unimorph cantilevers. (001) preferentially oriented polycrystalline PZT thin films and (001)/(100) epitaxial PZT thin films were deposited on (111)Pt/Ti/Si and (001)Pt/MgO substrates, respectively, by rf-magnetron sputtering, and their piezoelectric responses owing to intrinsic and extrinsic effects were examined. The direct and converse vertical bar e(31,f)vertical bar values of the polycrystalline PZT thin films were calculated as 6.4 and 11.5-15.0C/m(2), respectively, whereas those of the epitaxial PZT thin films were calculated as 3.4 and 4.6-4.8C/m(2), respectively. The large vertical bar e(31,f)vertical bar of the converse piezoelectric property of the polycrystalline PZT thin films is attributed to extrinsic piezoelectric effects. Furthermore, the polycrystalline PZT thin films show a clear nonlinear piezoelectric contribution, which is the same as the Rayleigh-like behavior reported in bulk PZT. In contrast, the epitaxial PZT thin films on the MgO substrate show a piezoelectric response owing to the intrinsic and linear extrinsic effects, and no nonlinear contribution was observed. (C) 2015 The Japan Society of Applied PhysicsIOP PUBLISHING LTD, 2015年10月, JAPANESE JOURNAL OF APPLIED PHYSICS, 54(10) (10), 1 - 10, 英語[査読有り]研究論文（学術雑誌）
- 2015年10月, Proceedings of 19th International Conference on Miniaturized Systems for Chemistry and Life Sciences (MicroTAS 2015), 英語METHODS OF PLANT ROOT CHARACTERIZATION UNDER VARIABLE ENVIRONMENTAL CONDITIONS TOWARD IMPROVING CROP PRODUCTIVITY[査読有り]研究論文（国際会議プロシーディングス）
- In this study, we evaluate the compositional dependence of Ba(Zr0.2Ti0.8)O-3-(Ba0.7Ca0.3)TiO3 (BZT-BCT) thin films prepared by combinatorial sputtering. Compositional gradient polycrystalline (1 - x)BZT-xBCT thin films oriented along the < 001 > and < 111 > directions were deposited on Si substrates by co-sputtering BZT and BCT targets and the composition x was varied from 0.16 to 0.82. Over the whole composition range, the BZT-BCT thin films exhibited smooth surfaces and columnar structure. The temperature dependence of the dielectric properties was measured and the tricritical phase transition point of BZT-BCT thin films was determined to be the same composition as that of bulk ceramics, while its temperature was approximately 100 degrees C higher. The maximum relative dielectric constant (epsilon(r) = 778) was obtained for x = 0.50. The piezoelectric coefficients also peaked at around x = 0.50, and the maximum value (vertical bar e(31, f vertical bar) = 0.48 C/m(2)) was compatible with other Ba-based piezoelectric epitaxial thin films. These results indicate that polycrystalline BZT-BCT thin film is a promising material as a substitute for lead-based piezoelectric materials. (C) 2015 Elsevier B.V. All rights reserved.ELSEVIER SCIENCE SA, 2015年08月, THIN SOLID FILMS, 588, 34 - 38, 英語[査読有り]研究論文（学術雑誌）
- 2015年06月, Proceedings of 2015 JSME-IIP ASME-ISPS Joint Conference on Micromechatronics for Information and Precision Equipment (MIPE 2015), 英語[査読有り]研究論文（国際会議プロシーディングス）
- 2015年06月, Proceedings of 2015 JSME-IIP ASME-ISPS Joint Conference on Micromechatronics for Information and Precision Equipment (MIPE 2015), 英語[査読有り]研究論文（国際会議プロシーディングス）
- 2015年06月, Proceedings of 2015 JSME-IIP ASME-ISPS Joint Conference on Micromechatronics for Information and Precision Equipment (MIPE 2015), 英語[査読有り]研究論文（国際会議プロシーディングス）
- In this study, multilayer ceramics (MLCs) composed of La-modified PbTiO3 layers with internal Pt electrodes were fabricated by radio frequency (RF) magnetron sputtering. Multiple (Pb-0.9,La-0.1)Ti0.975O3 (PLT) layers with thicknesses of approximately 500 nm were deposited on Pt/Ti-coated Si substrates through a square movable shadow mask. The isolated internal Pt electrodes were prepared by sliding the movable shadow mask. The MLCs composed of one, three, and five PLT layers were fabricated by alternate sputtering deposition of Pt electrodes and PLT ferroelectric layers with the movable shadow mask. The MLCs had a smooth and crack-free surface, and dense PLT layers could be prepared between the internal Pt electrodes. The MLCs exhibited excellent dielectric properties and their capacitances increased with the number of PLT layers, while the dielectric losses were lower than 3.5 %. The P-E hysteresis loops of MLCs showed symmetric loops because of the alternating direction of external electric field on the ferroelectric PLT layers.SPRINGER, 2015年05月, JOURNAL OF MATERIALS SCIENCE, 50(10) (10), 3631 - 3637, 英語[査読有り]研究論文（学術雑誌）
- Preferentially {100}-oriented thin films of lead lanthanum zirconate titanate, (Pb1-xLax) (Zr0.65Ti0.35)(1-x/4)O-3[PLZT(x/65/35)] with compositions near the morphotropic phase boundary (MPB) were prepared on silicon substrates (111)Pt/Ti/SiO2/Si by sol-gel spin coating technique. The structural, micro structural and electrical characteristics have been studied as a function of thin film composition. Crystalline orientation and microstructure of the thin films have been determined by X-ray diffraction, Scanning electron microscopy, respectively. The transverse piezoelectric coefficient, e(31)* of the PLZT thin films have been evaluated by tip deflection of unimorph cantilevers. The influence of thin film composition on e(31)* have been determined. PLZT (7/65/35) thin film exhibited the optimum dielectric and piezoelectric characteristics with a dielectric permittivity, epsilon(r) = 917; dielectric loss, tan delta = 0.03 and average e(31)* = -4.2 C/m(2). (C) 2014 Elsevier B.V. All rights reserved.ELSEVIER SCIENCE SA, 2015年02月, MATERIALS CHEMISTRY AND PHYSICS, 151, 308 - 311, 英語[査読有り]研究論文（学術雑誌）
- Recently, piezoelectric MEMS have been intensively investigated to create new functional microdevices, and some of them have already been commercialized such as MEMS gyrosensors or miropumps of inkjet printer head. Piezoelectric energy harvesting is considered to be one of the promising future applications of piezoelectric MEMS. In this report, we introduce the deposition of the piezoelectric PZT thin films as well as lead-free KNN thin films. We fabricated piezoelectric energy harvesters of PZT and KNN thin films deposited on stainless steel cantilevers and compared their power generation performance.IOP PUBLISHING LTD, 2015年, 15TH INTERNATIONAL CONFERENCE ON MICRO AND NANOTECHNOLOGY FOR POWER GENERATION AND ENERGY CONVERSION APPLICATIONS (POWERMEMS 2015), 660, 英語[査読有り]研究論文（国際会議プロシーディングス）
- 2015年, Energy Harvesting and Systems, 3, 61, 英語Fabrication of high-efficiency piezoelectric energy harvesters of epitaxial Pb(Zr,Ti)O3 thin films by laser lift-off[査読有り]研究論文（学術雑誌）
- This paper reports a simple and high-productive fabrication method of flexible piezoelectric substrate. To achieve a low-cost fabrication process of the substrate, we developed a novel transfer technique of piezoelectric thin films which were formed on temporary stainless-steel substrate to target PDMS (Poly-dimethylsiloxane) substrate by using wet etching process. We experimentally clarified that Pb(Zr,Ti)O-3 (PZT) thin films transferred on PDMS substrate, which is developed flexible piezoelectric substrate, have piezoelectric properties by evaluating crystal structures and an inverse piezoelectric effect. This fabrication method might allow us to efficiently develop novel MEMS (micro-electro-mechanical systems) devices such as wearable sensors and artificial muscle in large quantities at a low cost.IEEE, 2015年, 2015 28TH IEEE INTERNATIONAL CONFERENCE ON MICRO ELECTRO MECHANICAL SYSTEMS (MEMS 2015), 28th Vol.1, 377 - 380, 英語[査読有り]研究論文（国際会議プロシーディングス）
- This paper reports an on-chip analytical method for studying physical mechanisms of plant root growth in soil environments. To quantitatively evaluate physical interaction between root and soil, we developed a silicon-based microchannel device integrated with force displacement sensor which mimics a barrier in soil. By using developed microsystem, we successfully characterized the driving forces of root growth in three kinds of plants including Arabidopsis thaliana, which is known as a model organism. This analytical method allows us to efficiently characterize potential adaptability of root system to soil environments at early growth stage. The gaining knowledge might contribute for breed improvement, in terms of increasing crop productivity and plant biomass.IEEE, 2015年, 2015 28TH IEEE INTERNATIONAL CONFERENCE ON MICRO ELECTRO MECHANICAL SYSTEMS (MEMS 2015), 28th Vol.2, 702 - 705, 英語[査読有り]研究論文（国際会議プロシーディングス）
- We fabricated UV-light driven micro-actuators utilizing epitaxial piezoelectric thin films. We prepared Pb(Zr,Ti)O-3 (PZT) epitaxial thin films on cantilever-shaped Pt/MgO substrates, and observed light-induced deformation. When the UV-LED light was irradiated to the surface of PZT thin film, the cantilever deflected due to the coupling of photovoltaic and piezoelectric properties. The deflection of the cantilever was proportionally increased with the UV-light intensity, while the time constant was less than 2 sec, which was much shorter than that of bulk ceramics. These results indicate that UV-light driven piezoelectric thin-film actuators will open a new avenue for remote controlled micro-actuators.IEEE, 2015年, 2015 TRANSDUCERS - 2015 18TH INTERNATIONAL CONFERENCE ON SOLID-STATE SENSORS, ACTUATORS AND MICROSYSTEMS (TRANSDUCERS), 973 - 976, 英語[査読有り]研究論文（国際会議プロシーディングス）
- 2014年12月, Proc. of The International Conference on Small Science (ICSS 2014), 英語MEMS Applications in Agriculture[査読有り][招待有り]研究論文（国際会議プロシーディングス）
- 2014年10月, Proc. of the 4th International Workshop on Piezoelectric MEMS, 英語Power generation reliability of PZT thin films on stainless-steel cantilevers[査読有り]研究論文（国際会議プロシーディングス）
- HIGH-THROUGHPUT CHEMOTAXIS ASSAY OF PLANT-PARASITIC NEMATODE TOWARD GREEN AGRICULTURE© 14CBMS. This paper presents a new microsystem for simple and high-throughput chemotaxis assay of plant-parasitic nematodes Meloidogyne incognita. To improve an efficiency of chemotaxis assay, we developed a PDMS (Polydimethylsiloxane) microsystem, which can generate various chemical conditions in multiple microchannels at once. By using this system, we successfully identified a lower limitation of the concentration gradient of KNO2014年10月, Proc. of 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences(MicroTAS 2014), 276 - 278, 英語
3 solution, which can act as a repellent for the nematode M. incognita.[査読有り]研究論文（国際会議プロシーディングス） - 2014年10月, Proc. of the 4th International Workshop on Piezoelectric MEMS, 英語Compositional dependence of (1-x)Ba(Zr0.2Ti0.8)O3-x(Ba0.7Ca0.3)TiO3 piezoelectric thin films prepared by combinatorial sputtering[査読有り]研究論文（国際会議プロシーディングス）
- We evaluated the compositional dependence of Pb(MgInstitute of Physics, 2014年09月, Jpn. J. Appl. Phys., 53(9) (9), 09PA06, 英語
1/3 ,Nb2/3 )O3 –PbTiO3 (PMN–PT) polycrystalline thin films by combinatorial sputtering. We prepared compositional gradient (1 − x)PMN–xPT polycrystalline thin films with preferential orientation along the 〈001〉 direction in the composition range of x = 0–0.62. We determined that the morphotropic phase boundary (MPB) composition of PMN–PT polycrystalline thin film existed at around x = 0.35, from the X-ray diffraction (XRD) measurements. The maximum value of relative dielectric constants (εr = 1498) was obtained at approximately x = 0.23. On the other hand, the piezoelectric coefficients (|e31,f | = 14.1 C/m2) peaked at the determined MPB composition of x = 0.35. From the results of the compositional dependence of dielectric and piezoelectric characteristics, the FOM ([Formula: see text]) of the PMN–PT (x = 0.35) thin film reached 21 GPa, which is much higher than that of the other polycrystalline piezoelectric thin films. These results suggest that PMN–PT (x = 0.35) thin film is a promising material for high-efficiency piezoelectric MEMS energy harvesters. - We evaluated the compositional dependence of Pb(Mg-1/3,Nb-2/3)O-3-PbTiO3 (PMN-PT) polycrystalline thin films by combinatorial sputtering. We prepared compositional gradient (1 - x)PMN-xPT polycrystalline thin films with preferential orientation along the < 001 > direction in the composition range of x = 0-0.62. We determined that the morphotropic phase boundary (MPB) composition of PMN-PT polycrystalline thin film existed at around x = 0.35, from the X-ray diffraction (XRD) measurements. The maximum value of relative dielectric constants (epsilon(r) = 1498) was obtained at approximately x = 0.23. On the other hand, the piezoelectric coefficients (vertical bar e(31,f)vertical bar = 14.1 C/m(2)) peaked at the determined MPB composition of x = 0.35. From the results of the compositional dependence of dielectric and piezoelectric characteristics, the FOM (e(31,f)(2)/epsilon(0)epsilon(r)) of the PMN-PT (x = 0.35) thin film reached 21 GPa, which is much higher than that of the other polycrystalline piezoelectric thin films. These results suggest that PMN-PT (x = 0.35) thin film is a promising material for high-efficiency piezoelectric MEMS energy harvesters. (C) 2014 The Japan Society of Applied PhysicsIOP PUBLISHING LTD, 2014年09月, Japanese Journal of Applied Physics, 53(9) (9), 1 - 9, 英語[査読有り]研究論文（学術雑誌）
- 2014年08月, Proc. of the 10th Japan-Korea Conference on Ferroelectrics, 英語Measurement of Transverse Piezoelectric Coefficient e31,f of Pb(Zr,Ti)O3 Thin Film with Stripe Electrodes[査読有り]研究論文（国際会議プロシーディングス）
- 2014年08月, Proc. of the 10th Japan-Korea Conference on Ferroelectrics, 英語Fabrication of Multi-layered PZT Piezoelectric Thin Film[査読有り]研究論文（国際会議プロシーディングス）
- 公益社団法人 応用物理学会, 2014年03月, 応用物理学会学術講演会講演予稿集, 2014.1, 141 - 141, 日本語
- システム制御情報学会, 2014年, システム・制御・情報 = Systems, control and information : システム制御情報学会誌, 58(11) (11), 443 - 448, 日本語振動発電によるMEMSエナジーハーベスト技術
- This paper describes the reliability of piezoelectric vibration energy harvesters (PVEHs) of Pb(Zr,Ti)O-3 (PZT) thin films on metal foil cantilevers. The PZT thin films were directly deposited onto the Pt-coated stainless-steel (SS430) cantilevers by rf-magnetron sputtering, and we observed their aging behavior of power generation characteristics under the resonance vibration condition for three days. During the aging measurement, there was neither fatigue failure nor degradation of dielectric properties in our PVEHs (length: 13 mm, width: 5.0 mm, thickness: 104 mu m) even under a large excitation acceleration of 25 m/s(2). However, we observed clear degradation of the generated electric voltage depending on excitation acceleration. The decay rate of the output voltage was 5% from the start of the measurement at 25 m/s(2). The transverse piezoelectric coefficient (e(31,f)) also degraded with almost the same decay rate as that of the output voltage; this indicates that the degradation of output voltage was mainly caused by that of piezoelectric properties. From the decay curves, the output powers are estimated to degrade 7% at 15 m/s(2) and 36% at 25 m/s(2) if we continue to excite the PVEHs for 30 years.IOP PUBLISHING LTD, 2014年, 14TH INTERNATIONAL CONFERENCE ON MICRO AND NANOTECHNOLOGY FOR POWER GENERATION AND ENERGY CONVERSION APPLICATIONS (POWERMEMS 2014), 557(1) (1), 英語[査読有り]研究論文（国際会議プロシーディングス）
- In this paper, we present a novel microsystem for investigating mechanisms of plant-root growth. To measure a generative force by plant-root growth efficiently, we developed a silicon-based microchannel integrated with MEMS force sensors. We have also developed a protocol for sowing a plant seed onto the micro device and experimentally confirmed that plant-roots can grow through the microchannel filled with agarose-gel medium. By using the microsystems, we successfully estimated the generative force by plant-root growth.IEEE, 2014年, 2014 INTERNATIONAL SYMPOSIUM ON MICRO-NANOMECHATRONICS AND HUMAN SCIENCE (MHS), 英語[査読有り]研究論文（国際会議プロシーディングス）
- We developed self-excited vibration energy harvesters of Pb(Zr,Ti)O-3 (PZT) thin films using airflow. To enhance the self-excited vibration, we used 30-mu m-thick stainless steel (SS304) foils as base cantilevers on which PZT thin films were deposited by rf-magnetron sputtering. To compensate for the initial bending of PZT/SS304 unimorph cantilever due to the thermal stress, we deposited counter PZT thin films on the back of the SS304 cantilever. We evaluated power-generation performance and vibration mode of the energy harvester in the airflow. When the angle of attack (AOA) was 20 degrees to 30 degrees, large vibration was generated at wind speeds over 8 m/s. By FFT analysis, we confirmed that stable self-excited vibration was generated. At the AOA of 30 degrees, the output power reached 19 mu W at wind speeds of 12 m/s.IOP PUBLISHING LTD, 2014年, 14TH INTERNATIONAL CONFERENCE ON MICRO AND NANOTECHNOLOGY FOR POWER GENERATION AND ENERGY CONVERSION APPLICATIONS (POWERMEMS 2014), 557(1) (1), 英語[査読有り]研究論文（国際会議プロシーディングス）
- We fabricated piezoelectric MEMS energy harvesters (EHs) of lead-free (K,Na)NbO3 (KNN) thin films on microfabricated stainless steel cantilevers. The use of metal substrates makes it possible to fabricate thin cantilevers owing to a large fracture toughness compared with Si substrates. KNN films were directly deposited onto Pt-coated stainless steel cantilevers by rf-magnetron sputtering, thereby simplifying the fabrication process of the EHs. From XRD measurement, we confirmed that the KNN films on Pt-coated stainless steel cantilevers had a perovskite structure with a preferential (001) orientation. The transverse piezoelectric coefficient e31,f and relative dielectric constant εr were measured to be -3.8C/m 2 and 409, respectively. From the evaluation of the power generation performance of a KNN thin-film EH (length: 7.5 mm, width: 5.0 mm, weight of tip mass: 25 mg), we obtained a large average output power of 1.6 μW under vibration at 393 Hz and 10 m/s2. © 2013 The Japan Society of Applied Physics.2013年09月, Japanese Journal of Applied Physics, 52(9) (9), 1 - 9, 英語[査読有り]研究論文（学術雑誌）
- 日本セラミックス協会, 2013年07月, セラミックス, 48(7) (7), 542 - 545, 日本語圧電薄膜を用いた振動発電素子技術[招待有り]
- カンチレバーを機械要素とする圧電薄膜エナジーハーベスターの振動発電特性は，圧電特性だけでなく，共振周波数や振動Q値など素子の振動特性にも依存する．そこで，本研究ではエナジーハーベスターの発電性能と，素子形状及び基板材料との関係を明らかにすることを目的として，異なる金属材料を基板とするPZT薄膜エナジーハーベスターを作製し，振動発電評価を行った．公益社団法人 精密工学会, 2013年, 精密工学会学術講演会講演論文集, 2013, 505 - 506, 日本語
- The field of microfluidics has drastically contributed to downscale the size of benchtop experiments to the dimensions of a chip without compromising results. However, further miniaturization and the ability to directly manipulate individual molecules require a platform that permits organized molecular transport. The motor proteins and microtubules that carry out orderly intracellular transport are ideal for driving in vitro nanotransport. Here, we demonstrate that a reconstruction of the cellular kinesin/dynein microtubule system in nanotracks provides a molecular total analysis system (MTAS) to control massively parallel chemical reactions. The mobility of kinesin and a microtubule dissociation method enable orientation of a microtubule in an array for directed transport of reactive molecules carried by kinesin or dynein. The binding of glutathione S-transferase (GST) to glutathione (GSH) and the binding of streptavidin to biotin are visualized as colocalizations of quantum dots (Q-dots) when motor motilities bring them into contact. The organized nanotransport demonstrated here suggests the feasibility of using our platform to perform parallel biochemical reactions focused at the molecular level.AMER CHEMICAL SOC, 2013年01月, ACS NANO, 7(1) (1), 447 - 455, 英語[査読有り]研究論文（学術雑誌）
- In this study, we propose a reliable measurement method for the effective transverse piezoelectric coefficient for thin films especially on anisotropic substrate. This coefficient for piezoelectric Pb(Zr, Ti)O-3 (PZT) thin films was calculated by measuring the electric field-induced tip displacement of unimorph cantilevers composed of PZT thin films and Si substrates. We evaluated the reliability of the proposed measurement method by comparing it with numerical analysis and confirmed that the relative error of the piezoelectric coefficient (e(31,f)) was less than 1%. We prepared 16 different unimorph cantilevers composed of identical PZT films on different Si beam geometries that had various substrate thicknesses and cantilever widths. Although the effective transverse piezoelectric coefficient e(31,f) of PZT thin films ranged from - 6.5 to - 14 C/m(2) as a function of the applied voltage, the difference among the 16 samples with an applied voltage of 25V was within 10%. These results demonstrate that the proposed measurement method has sufficient reliability and can be used to evaluate the effective transverse piezoelectric coefficient e(31,f) of thin films. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4789347]AMER INST PHYSICS, 2013年01月, JOURNAL OF APPLIED PHYSICS, 113(4) (4), 英語[査読有り]研究論文（学術雑誌）
- In this study, we propose a practical microfabrication method of lead-free sodium potassium niobate [(K, Na)NbO3, KNN] thin films by dry etching for the first time. We found that Ar/C4F8 plasma etching was very effective for high etching rate of KNN thin film as well as excellent selectivity of KNN and Cr metal mask. We successfully fabricated unimorph micro-cantilevers of KNN thin films without process damage and confirmed excellent piezoelectric properties of the microfabricated KNN thin film. These results indicate that Ar/C4F8 plasma etching enables to fabricate various lead-free piezoelectric MEMS applications. © 2013 IEEE.2013年, 2013 Transducers and Eurosensors XXVII: The 17th International Conference on Solid-State Sensors, Actuators and Microsystems, TRANSDUCERS and EUROSENSORS 2013, 1051 - 1054, 英語[査読有り]研究論文（国際会議プロシーディングス）
- We fabricated piezoelectric MEMS energy harvesters (EHs) of lead-free (K, Na)NbO3 (KNN) thin films on microfabricated stainless steel cantilevers. The 2.2-μm-thick KNN thin films were directly deposited by rf-magnetron sputtering onto the cantilevers, thereby we could simplify fabrication process of the EHs. Because of the strong fracture toughness of stainless steel, the thickness of the cantilevers can be as thin as 30 μm. We obtained large averaged output power of 1.6 μW at 393 Hz and 10 m/s 2 for the lead-free unimorph cantilever. © 2013 IEEE.2013年, 2013 Transducers and Eurosensors XXVII: The 17th International Conference on Solid-State Sensors, Actuators and Microsystems, TRANSDUCERS and EUROSENSORS 2013, 474 - 477, 英語[査読有り]研究論文（国際会議プロシーディングス）
- We fabricated a piezoelectric MEMS energy harvester (EH) of Pb(Zr, Ti)O-3 (PZT) thin film on stainless steel cantilever. The use of metal substrates makes it possible to fabricate thin cantilevers owing to a large fracture toughness compared with Si substrates. The PZT thin film was directly deposited onto 50-mu m-thick stainless steel substrate by rf-magnetron sputtering. By attaching a tip mass (weight: 480 mg) to the substrate, the resonant frequency of the cantilever (length: 10 mm, width: 10 mm) was dropped to about 75 Hz. From X-ray diffraction (XRD) measurement, we confirmed that the PZT thin film on Pt-coated stainless steel substrate had a perovskite structure with a random orientation. The relative dielectric constant epsilon(r) and transverse piezoelectric coefficient e(31,f) were measured to be 650 and -1.7 C/m(2), respectively. From the evaluation of the power generation performance of the PZT thin-film EH, we obtained a large average output power of 1.1 mu W under vibration at a low frequency of 75 Hz (acceleration amplitude: 5 m/s(2), load resistance: 20 k Omega). Moreover, the experimental output voltages with open circuit state were in good agreement with the theoretical values calculated using theoretical equation.IEEE, 2013年, 2013 INTERNATIONAL SYMPOSIUM ON MICRO-NANOMECHATRONICS AND HUMAN SCIENCE (MHS), 英語[査読有り]研究論文（国際会議プロシーディングス）
- In this study, we proposed a new Si-based cylindrical MEMS (microelectromechanical system) gyroscope integrated with piezoelectric thin-film for sensing/driving elements. The cylindrical-resonator based gyroscope has several advantages by using the symmetrical structure (1) sensitivity can be improved due to high Q-factor by fixing at a vibration node easily. (2) An initial bias signal can be reduced by setting the sensing elements at the vibration nodes. To further improve the sensitivity the proposed gyroscope, we evaluated the efficiency of the thickness ratio between a disk and a cylinder sidewall by using FEM (finite element method) analysis. Also, we numerically confirmed that the sensitivity of the cylindrical gyroscope can be improved by forming the holes on the disk. These simulation results might contribute to design guide for developing a novel MEMS cylindrical gyroscope. © 2013 IEEE.IEEE Computer Society, 2013年, 2013 International Symposium on Micro-NanoMechatronics and Human Science, MHS 2013, 英語[査読有り]研究論文（国際会議プロシーディングス）
- Micro fabrication has been conducted for sodium potassium niobate [(K, Na) NbO3, KNN] thin films by dry etching and Pt/KNN/Pt unimorph micro cantilevers have been fabricated as a lead-free piezoelectric micro electro mechanical system (MEMS). KNN etching by Ar/C4F8 plasma showed a high etching rate of about 60 nm/min and KNN/Cr selectivity of over 5. Tip displacement of the Pt/KNN/Pt micro cantilevers was measured and the frequency response and piezoelectric properties were evaluated. Young's modulus and piezoelectric coefficients d(31) of the KNN thin film were estimated to be 115 GPa and -99 to 219 pm/V, respectively. These results indicate that Ar/C4F8 plasma etching does not degrade the piezoelectric properties of KNN thin films and enables one to fabricate various lead-free piezoelectric MEMS applications.INST ENGINEERING TECHNOLOGY-IET, 2012年12月, MICRO & NANO LETTERS, 7(12) (12), 1223 - 1225, 英語[査読有り]研究論文（学術雑誌）
- Piezoelectric microelectromechanical systems (MEMS) have been proven to be an attractive technology for harvesting small magnitudes of energy from ambient vibrations. This technology promises to eliminate the need for replacing chemical batteries or complex wiring in microsensors/microsystems, moving us closer toward battery-less autonomous sensors systems and networks. To achieve this goal, a fully assembled energy harvester the size of a US quarter dollar coin (diameter = 24.26 mm, thickness = 1.75 mm) should be able to robustly generate about 100 mu W of continuous power from ambient vibrations. In addition, the cost of the device should be sufficiently low for mass scale deployment. At the present time, most of the devices reported in the literature do not meet these requirements. This article reviews the current state of the art with respect to the key challenges such as high power density and wide bandwidth of operation. This article also describes improvements in piezoelectric materials and resonator structure design, which are believed to be the solutions to these challenges. Epitaxial growth and grain texturing of piezoelectric materials is being developed to achieve much higher energy conversion efficiency. For embedded medical systems, lead-free piezoelectric thin films are being developed, and MEMS processes for these new classes of materials are being investigated. Nonlinear resonating beams for wide bandwidth resonance are also being developed to enable more robust operation of energy harvesters.CAMBRIDGE UNIV PRESS, 2012年11月, MRS BULLETIN, 37(11) (11), 1039 - 1050, 英語[査読有り][招待有り]研究論文（学術雑誌）
- Numerous microfluidic devices have been applied to bioassays. Decreasing amount of liquid solutions helps to reduce sample waste and reagent consumption. Increasing sensitivity with fast reactions is another advantage. However, further downsizing of microfluidic devices brings difficulties in perfusing solutions due to a pressure drop, which is essential in bioassays. Here, we report a perfusable channel array in submicrometer to micrometer scale fabricated by integrating nanoimprint lithography (NIL) and UV lithography (UVL). Two lithography techniques are used to fabricate multiscale SU-8 mother mold for poly(dimethylsiloxane) (PDMS) replicas. SU-8 is an appropriate material as a mold due to mechanical stability and chemical resistance. However, it causes problems in a NIL process such as SU-8 residue on a silicon mold after demolding from a patterned SU-8 surface. To keep the compatibility of SU-8 in NIL process, UV-assisted NIL is employed to fabricate the line-and-space pattern for the channel array and microscale structures for microchannels were defined by UVL. NIL provides high throughput and high resolution patterns for the channel array, while UVL defines micrometer scale channels as interface between a user and the channel array. The fabricated device consists of a channel array (w = 0.5-2 mu m, h = 1-2 mu m, l = 200 mu m) and 2 mu m scale channels (w = 250 mu m, h = 50 mu m, l = 5 mm). These micrometer scale channels are used for inlet or outlet of the channel array to deliver solutions. We demonstrated exchanging solutions using fluorescent solutions. Repetitive increase and decrease of fluorescent intensity proved the solution exchange in channel array. (C) 2012 Elsevier B.V. All rights reserved.ELSEVIER SCIENCE BV, 2012年10月, MICROELECTRONIC ENGINEERING, 98, 58 - 63, 英語[査読有り]研究論文（学術雑誌）
- We examined the composition and orientation dependences of the piezoelectric properties by combinatorial sputtering. PbTiO3 and PbZrO3 were simultaneously sputtered to prepare composition gradient Pb(Zr, Ti)O-3 (PZT) films on Pt/Ti/Si substrates, and an almost linear composition gradient was observed in a range of Zr/(Zr + Ti) ratios from 0.33 to 0.76. Dielectric and piezoelectric properties attained maximum at the Zr/ Ti composition close to the morphotropic phase boundary (MPB), which is consistent with that of PZT ceramics. {100}-oriented PZT films showed a higher dielectric constant than the PZT films with the other orientations, while the PZT films with {111} + {100} mixed orientation showed larger values of e(31,f). These results suggest that the a-axis orientation is dominant in the {100}-oriented PZT films. In this study, we demonstrated that the combinatorial sputtering method enables the precise evaluation of the composition dependence of piezoelectric and dielectric properties. (c) 2012 The Japan Society of Applied PhysicsIOP PUBLISHING LTD, 2012年09月, JAPANESE JOURNAL OF APPLIED PHYSICS, 51(9) (9), 1 - 9, 英語[査読有り]研究論文（学術雑誌）
- We fabricated an integrated blood cell counting system composed of planar blood preparation and blood cell counting devices. The planar blood preparation and counting devices were made of injection-molded polystyrene. 2 mu L and 0.125 mu L of whole blood were separated by hydrophobic passive valves and mixed with 50 mu L of diluting fluid in the preparation device to accurately dilute the blood 25-fold and 400-fold, as primary and secondary dilution. We found that the hydrophobic fluoric resin surface treatments for the passive valves and the wall of the channels were effective for diluting whole blood. After the diluted blood was transferred into the blood counting devices, the number of blood cells was counted based on the change in electrode conductance at flow rate about 1 mu L/s (50-500 cells/s). The coefficient of variation for the reproducibility of the blood cell counting was <2%, which is a desirable value for clinical use. (C) 2012 Elsevier B.V. All rights reserved.ELSEVIER SCIENCE SA, 2012年08月, SENSORS AND ACTUATORS B-CHEMICAL, 171, 1321 - 1326, 英語[査読有り]研究論文（学術雑誌）
- A microfluidic device integrated with a Total Internal Reflection (TIR)-based chip for cell observation and analysis was developed. This integrated device enables in situ Total Internal Reflection Fluorescence Microscopy (TIRFM) on adherent cells cultured under continuous medium perfusion. This TIR-based chip, allows TIRFM to be easily performed on cells without the assembly of complicated optical components and cell culture chambers. The integrated device was evaluated by tracking the movement of fluorescent beads and monitoring the location of insulin granules in mouse pancreatic beta-cells. This system offers higher signal-to-noise (S/N) ratio than epi-fluorescence microscopy (EPIFM), and comparable image quality to commercial TIRFM systems when imaging insulin granules. We also detected repetitive changes in intracellular Ca2+ concentration in MIN6-m9 cells stimulated with KCl, which demonstrates quick perfusion for cell analysis while maintaining high S/N ratio.SPRINGER, 2012年08月, BIOMEDICAL MICRODEVICES, 14(4) (4), 791 - 797, 英語[査読有り]研究論文（学術雑誌）
- With increasing concerns of environmental issues in manufacturing process, energy efficient and waste free manufacturing processes have been widely studied. In the field of nano/micro manufacturing, many research results of direct writing processes such as ink jet printing, gravure printing, and rapid prototyping processes have been reported to remove waste-producing conventional lift-off process for patterning. In addition, the use of toxic solvents such as acetone, toluene, xylene and so on has been decreased. At the same time, energy efficiency becomes one of environmental issues in manufacturing process. In this research, Nano particle deposition system (NPDS), a dry spray deposition process for fabrication of meta and ceramic direct patterning at room temperature, was introduced according to the environmental aspects. In previous studies, NPDS has shown the feasibility of the depositions of metals such as Sn and Ni, and the depositions of ceramics such as Al2O3, and TiO2 by spraying powders under low vacuum condition. The advantages of NPDS are 1) solvent free dry deposition process, 2) relatively low energy consumption with room temperature and low vacuum process condition, and 3) direct patterning process. The energy consumption in NPDS was briefly compared with similar processes including aerosol deposition and cold spray. The direct patterning results with 200 mu m width line pattern using micro-nozzle were fabricated without any post-processes. These results confirmed NPDS can become a solvent-free energy efficient direct patterning process for metals and ceramics.KOREAN SOC PRECISION ENG, 2012年07月, INTERNATIONAL JOURNAL OF PRECISION ENGINEERING AND MANUFACTURING, 13(7) (7), 1107 - 1112, 英語[査読有り]研究論文（学術雑誌）
- We investigated the dry-etching characteristics of lead-free (K,Na)NbO3 (KNN) thin films by inductively coupled plasma-reactive ion etching (ICP-RIE) using Ar/C4F8 as the reactive gas mixture. The KNN etching depth showed a linear relationship as a function of the etching time with a few minutes' delay at the beginning. The etching rate increased with increasing antenna power and bias power. The antenna and bias dependences of the etching rate showed good linearity. The KNN/Pt selectivity increased with increasing antenna power and decreasing bias power. Thus, a high KNN/Pt selectivity was obtained under conditions of a high antenna power and a low bias power. The maximum KNN/Pt selectivity was 86. These etching results enable device fabrication using KNN thin films. (C) 2012 The Japan Society of Applied PhysicsIOP PUBLISHING LTD, 2012年07月, JAPANESE JOURNAL OF APPLIED PHYSICS, 51(7) (7), 1 - 76202, 英語[査読有り]研究論文（学術雑誌）
- We fabricated piezoelectric energy harvesters with lead-free (K,Na)NbO3 (KNN) thin films and compared their power-generation performance with that of Pb(Zr,Ti)O-3 (PZT) thin film energy harvesters. The KNN and PZT thin films were deposited on Pt/Ti/Si substrates by rf-magnetron sputtering. The transverse piezoelectric properties of the KNN and PZT films were essentially the same, e(31,f) similar to -11 C/m(2). The peak average output power of the unimorph cantilevers of KNN/Si and PZT/Si were 1.1 and 1.0 mu W, respectively. Thus, the performance of lead-free KNN thin films as a piezoelectric energy harvester is comparable to that of PZT films. (C) 2012 Elsevier B.V. All rights reserved.ELSEVIER SCIENCE SA, 2012年06月, SENSORS AND ACTUATORS A-PHYSICAL, 179, 132 - 136, 英語[査読有り]研究論文（学術雑誌）
- We have developed a titanium (Ti)-based piezoelectric microelectromechanical systems scanner driven by a Pb(Zr, Ti)O-3 (PZT) thin film for the development of laser scanning displays. The 2-mu m-thick PZT thin film was directly deposited on a 50-mu m-thick Ti substrate by radio frequency magnetron sputtering. Prior to PZT deposition, the Ti substrate was microfabricated into the shape of a horizontal scanner by wet etching; therefore, we could fabricate a piezoelectric microactuator without using the photolithography process. We confirmed the growth of the polycrystalline PZT film with perovskite structures on the Ti substrate. We achieved an optical scanning angle of 22A degrees at a resonant frequency of 25.4 kHz using a driving voltage of 20 V (pp). These horizontal scanning properties can be applicable for laser displays.SPRINGER, 2012年06月, MICROSYSTEM TECHNOLOGIES-MICRO-AND NANOSYSTEMS-INFORMATION STORAGE AND PROCESSING SYSTEMS, 18(6) (6), 765 - 771, 英語[査読有り]研究論文（学術雑誌）
- Thin films of undoped and lithium-doped Zinc oxide, (Zn1-xLix)O; x = 0, 0.05, 0.10 and 0.20 were prepared by sol-gel method using spin-coating technique on silicon substrates [(111)Pt/Ti/SiO2/Si)]. The influence of lithium doping on the structural, electrical and microstructural characteristics have been investigated by means of X-ray diffraction, leakage current, piezoelectric measurements and scanning electron microscopy. The resistivity of the ZnO film is found to increase markedly with low levels (x <= 0.05) of lithium doping thereby enhancing their piezoelectric applications. The transverse piezoelectric coefficient, e(31)* has been determined for the thin films having the composition (Zn0.95Li0.05)O, to study their suitability for piezoelectric applications. (C) 2012 Elsevier B.V. All rights reserved.ELSEVIER SCIENCE SA, 2012年06月, THIN SOLID FILMS, 520(17) (17), 5797 - 5800, 英語[査読有り]研究論文（学術雑誌）
- Ferroelectric PZT-based perovskite thin films are widely studied for fabrication of compact piezoelectric energy harvesting (EH) power microelectromechanical systems (MEMS) due to their large piezoelectric coefficients. Output energy of the piezoelectric EH power MEMS is chiefly governed by their energy conversion rate, k(2) and/or (e(2)/epsilon), where e and e denote their piezoelectric coefficient and dielectric constant. The values of (e(2)/epsilon) are considered as figures of merit (FOM) for the piezoelectric EH power MEMS. At present nonferroelectric AlN thin films are considered as a candidate for a better piezoelectric EH power MEMS due to their high FOM values. These PZT-based thin films are mostly polycrystalline thin films of binary perovskite compounds, Pb(Zr, Ti)O-3 (PZT). We have proposed single crystal thin films of PZT-based ternary perovskite compounds, Pb(Mn, Nb)O-3-PZT (PMnN-PZT), instead of the binary perovskite PZT. The single crystal PMnN-PZT thin films have been successively fabricated by rf-magnetron sputtering. It is found that the FOM values of single c-domain/single crystal PMnN-PZT thin films are one order of magnitude higher than those of AlN thin films. This suggests output powers of the PMnN-PZT thin-film EH power MEMS are one order of magnitude higher than those of the AlN thin-film EH power MEMS.IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2012年04月, JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, 21(2) (2), 451 - 457, 英語[査読有り]研究論文（学術雑誌）
- Pb(ZrxTi1-x)O3 [PZT] thin films of morphotropic phase boundary (MPB) composition having {001}, {110}, and {111}-orientations were fabricated on silicon substrates (111)Pt/Ti/SiO2/Si using a metal organic decomposition spin-coating technique. The influence of crystallographic orientation on the transverse piezoelectric coefficient e31* of the films have been determined. The largest e31* was found in {110}-oriented film. The differences observed in e31* have been explained on the basis of domain wall contributions which are dependent on film texture. The influence of thin film texture on polarization switching characteristics have also been studied. © 2012 VBRI Press.2012年04月, Advanced Materials Letters, 3(2) (2), 102 - 106, 英語[査読有り]研究論文（学術雑誌）
- We fabricated composition gradient sodium potassium niobate [(K,Na)NbO3, KNN] thin films on (111)Pt/Ti/SiO2/Si by multi-target RF magnetron sputtering to optimize KNN film composition by combinatorial method. We successfully obtained c-axis oriented KNN thin films with perovskite structure on 6-inch Si wafers. The KNN film composition was measured by energy dispersive x-ray spectroscopy (EDX) and we confirmed composition gradient of K/(K+Na) ratio of the KNN thin film on Si wafer along with the line between KNbO3 and NaNbO3 targets. This result indicates that the combinatorial sputtering is useful for precise optimization of the deposition condition and film composition of the lead-free KNN thin films.IEEE, 2012年, PROCEEDINGS OF THE 2012 FIFTH INTERNATIONAL CONFERENCE ON EMERGING TRENDS IN ENGINEERING AND TECHNOLOGY (ICETET 2012), 44 - 47, 英語[査読有り]研究論文（国際会議プロシーディングス）
- 2012年, セラミックス, 47, 日本語スパッタリング法によるKNN 系非鉛強誘電体薄膜の作製とその加工技術[査読有り][招待有り]研究論文（学術雑誌）
- With increasing concerns of environmental issues in manufacturing process, energy efficient and waste free manufacturing processes have been widely studied. In the field of nano/micro manufacturing, many research results of direct writing processes such as ink jet printing, gravure printing, and rapid prototyping processes have been reported to remove waste-producing conventional lift-off process for patterning. In addition, the use of toxic solvents such as acetone, toluene, xylene and so on has been decreased. At the same time, energy efficiency becomes one of environmental issues in manufacturing process. In this research, Nano particle deposition system (NPDS), a dry spray deposition process for fabrication of meta and ceramic direct patterning at room temperature, was introduced according to the environmental aspects. In previous studies, NPDS has shown the feasibility of the depositions of metals such as Sn and Ni, and the depositions of ceramics such as Al 2O 3, and TiO 2 by spraying powders under low vacuum condition. The advantages of NPDS are 1) solvent free dry deposition process, 2) relatively low energy consumption with room temperature and low vacuum process condition, and 3) direct patterning process. The energy consumption in NPDS was briefly compared with similar processes including aerosol deposition and cold spray. The direct patterning results with 200μm width line pattern using micro-nozzle were fabricated without any post-processes. These results confirmed NPDS can become a solvent-free energy efficient direct patterning process for metals and ceramics. © KSPE and Springer 2012.2012年, International Journal of Precision Engineering and Manufacturing, 13(7) (7), 1107 - 1112, 英語[査読有り]研究論文（学術雑誌）
- In-plane unstrained single-c-domain/single-crystal thin films of PZT-based ternary ferroelectric perovskite, xPb(Mn,Nb)O-3-(1 - x)PZT, were grown on SrRuO3/Pt/MgO substrates using magnetron sputtering followed by quenching. The sputtered unstrained thin films exhibit unique ferroelectric properties: high coercive field, E-c > 180 kV/cm, large remanent polarization, P-r = 100 mu C/cm(2), small relative dielectric constants, epsilon* = 100 to 150, high Curie temperature, T-c = similar to 600 degrees C, and bulk-like large transverse piezoelectric constants, e(31,f) = -12.0 C/m(2) for PZT(48/52) at x = 0.06. The unstrained thin films are an ideal structure to extract the bulk ferroelectric properties. Their micro-structures and ferroelectric properties are discussed in relation to the potential applications for piezoelectric MEMS.IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2012年01月, IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL, 59(1) (1), 6 - 13, 英語[査読有り]研究論文（学術雑誌）
- We developed a method to measure the adhesion force between the motor protein, kinesin, and a microtubule. Compared with conventional methods that use optical tweezers, our method employs the fluid force that acts on the interaction between a kinesin-coated microbead and a microtubule in a microfluidic channel. When the fluid force just exceeds the kinesin-microtubule adhesion force, the beads are released from the microtubules. Having modeled the kinesins that are bound to the microtubules and the beads as mechanical springs, adhesion forces were measured as 31.3 or 362.9 pN for fluid containing 1 mM ATP or 0 M ATP, respectively. These forces are much larger than those measured when optical tweezers were used to measure the adhesion force between a single kinesin and a microtubule. For our multi-kinesin system we elucidated the relationship between the binding force of a single kinesin molecule and that of all kinesin molecules in a contact area by varying one of two parameters: either the contact area length or the kinesin density on a bead. This study provides insight into the behavior of a bead that is supported by several kinesins in a microfluidic system, which is essential knowledge if a motor protein is to be used as a nanoactuator for in vitro molecular transport.SPRINGER HEIDELBERG, 2011年11月, MICROFLUIDICS AND NANOFLUIDICS, 11(5) (5), 519 - 527, 英語[査読有り]研究論文（学術雑誌）
- A novel microfabrication method of lead-free piezoelectric sodium potassium niobate [(K,Na)NbO3, KNN] thin films was proposed, and the piezoelectric characteristics of the KNN microactuators were evaluated. The KNN thin films were directly deposited on microfabricated Si microcantilevers. The transverse piezoelectric coefficient d(31) of the KNN films was calculated as -53.5 pm/V at 20 V-pp from the tip displacement of the microcantilevers. However, the tip displacement showed large electric-field dependence because of the extrinsic piezoelectric effect, and the intrinsic piezoelectric effect of the KNN microcantilevers was smaller than that of KNN on unprocessed thick substrates. In contrast, the extrinsic piezoelectric effect was almost independent of the microfabrication of the KNN films. (C) 2011 Elsevier B.V. All rights reserved.ELSEVIER SCIENCE SA, 2011年11月, SENSORS AND ACTUATORS A-PHYSICAL, 171(2) (2), 223 - 227, 英語[査読有り]研究論文（学術雑誌）
- This paper proposes a polystyrene microdispenser to meter and discharge 200 nl of plasma solution with high reproducibility. To produce at low cost, hydrophobic passive valves with a simple structured fabricated by injection molding were used for the metering principle. After evaluation using a plasma solution, the microdispensers coated with fluoric resin showed reproducibility of discharged fluid volume with a coefficient of variance of 1.25%. On the other hand, those coated with dimethyl silicone caused a backflow of the discharged fluid to the metering channel, resulting in the degradation of reproducibility. To evaluate the dynamic behavior of the fluid in the channels, we measured not only the static contact angle, but also repeatedly measured the contact angles and various kinds of dynamic contact angle, e.g. the extension advancing angle and the sliding angle. We show the possibility that repeatedly measuring the contact angle can be used for selection of a surface treatment which does not cause backflow. In addition, we propose a method of estimating the discharge pressure, using an extension of the advancing angle and the sliding angle. This method enables closer estimation to the actual measurements than the conventional method based on the static contact angle. (C) 2010 Elsevier B.V. All rights reserved.ELSEVIER SCIENCE SA, 2011年10月, SENSORS AND ACTUATORS A-PHYSICAL, 169(2) (2), 274 - 281, 英語[査読有り]研究論文（学術雑誌）
- In this study, we fabricate multilayer ceramic capacitors (MLCCs) composed of dielectric layers with Pt internal electrodes by single sputtering deposition. We deposited approximately 300-nm-thick BaTiO3 (BT) layers on Pt/Ti-coated SiO2/Si substrates through a movable shadow mask. The separated internal Pt electrodes are prepared by sliding the shadow mask. Multilayered BT thin films are uniformly deposited on a Si substrate with external electrodes on both sides of the BT films. The MLCCs with five BT layers have excellent dielectric properties; a relative dielectric constant of approximately 320 and a dielectric loss of around 2% regardless of the number of dielectric layers. (C) 2011 The Japan Society of Applied PhysicsIOP PUBLISHING LTD, 2011年09月, JAPANESE JOURNAL OF APPLIED PHYSICS, 50(9) (9), 1 - 9, 英語[査読有り]研究論文（学術雑誌）
- 養賢堂, 2011年06月, 機械の研究, 63(6) (6), 459 - 466, 日本語機能性薄膜のマイクロデバイス応用--圧電薄膜を用いたMEMSデバイス
- This paper reports on piezoelectric micro-electro-mechanical systems deformable mirrors with high-density actuator array for low-voltage and high-resolution retinal imaging with adaptive optics. The deformable mirror was composed of unimorph structure of lead zirconate titanate (PZT) thin film deposited on Pt-coated silicon on insulator substrate and a diaphragm of 10 mm in diameter formed by backside-etching the Si handle wafer. 61 hexagonal electrodes were laid out on the PZT thin film for the high-density actuator array. In order to reduce the dead space for the lead lines between the electrodes and connecting pads, a polyimide layer with through holes on the electrodes was patterned as an electrical insulator. To confirm the application feasibility of the fabricated DMs, displacement profiles of the actuators were measured by a laser Doppler vibrometer. Independent applications of voltages on individual actuators were confirmed.SPRINGER, 2011年06月, MICROSYSTEM TECHNOLOGIES-MICRO-AND NANOSYSTEMS-INFORMATION STORAGE AND PROCESSING SYSTEMS, 17(5-7) (5-7), 931 - 935, 英語[査読有り]研究論文（学術雑誌）
- We fabricated piezoelectric energy harvesters composed of c-axis-oriented Pb(Zr,Ti)O(3) (PZT) films transferred onto stainless steel cantilevers for improved energy conversion efficiency and toughness. PZT films were epitaxially grown on Pt/MgO substrates using rf-magnetron sputtering and transferred to 50-mu m-thick stainless steel cantilevers. The transferred PZT films had a low dielectric constant (epsilon(r) = 166) and high transverse piezoelectric coefficient (e(31)* = d(31)/s(11) = -4.5 C/m(2)); these values are almost the same as those of the as-grown epitaxial PZT films on MgO substrates. Because of the small thickness of the cantilever, the first resonant frequency could be as low as 126 Hz without a seismic mass at the tip of the cantilever. At an acceleration of 5 m/s(2), the energy harvester generated an average output power of 5.3 mu W at the optimal load resistance of 50 k Omega. The output power increased monotonically with the acceleration, reaching 244 mu W under an acceleration of 50 m/s(2) without damage to the cantilever. (C) 2010 Elsevier B.V. All rights reserved.ELSEVIER SCIENCE SA, 2010年09月, SENSORS AND ACTUATORS A-PHYSICAL, 163(1) (1), 428 - 432, 英語[査読有り]研究論文（学術雑誌）
- This paper presents a novel technique of positioning heterotypic cells using electroosmotic flow (EOF). Positioning heterotypic cells is a key technique toward the development of single cell analysis. Several techniques for positioning cells have been developed, such as using dielectrophoresis and physical trapping in microchannel. These techniques, however, require additional methods for subsequent biological experiments after arraying cells. In this study, we demonstrated the positioning of two kinds of cells at designated pocket-like microstructures. In this method, cells were positioned using multi-directional EOF in open-to-air flow chamber which would allow easy handling for further biological experiments. After positioning heterotypic cells, we cultivated them and observed cell-cell interactions via gap junctions by the transfer of a fluorescent dye.一般社団法人日本機械学会, 2010年, 年次大会講演論文集, 2010, 239 - 240, 日本語
- Recently, motor protein such as kinesin or dynein has been used as a nano actuator. Previous works have achieved the control of the movement of microtubules (MT) and the transport of molecular cargo. However, the movement of microtubules was led by minus-end because only kinesin was used as an actuator. In this paper, we patterned motor proteins selectively by surface modification and control the location of microtubules by electrophoresis. Selective patterning of motor proteins and actively control of the MT location enables MTs to move with minus-end and plus-end as leading heads by kinesin and dynein motors.一般社団法人日本機械学会, 2010年, 年次大会講演論文集, 2010, 135 - 136, 日本語
- 多重マスク回転傾斜露光法による3次元複雑マイクロ構造の作製Fabrication method of complex 3D structures becomes more important for improvement of soft-MEMS. Then, we propose a new fabrication method that can fabricate complex 3D micro-structures by the inclined rotated UV lithography with an optional fixed mask. A simulation method of the proposed lithography was developed on the basis of electromagnetic theory to calculate fabricated structures in order to assist design of the main and the optional masks. The validity of the proposed lithography and the simulation method were confirmed by demonstrations of the comparison of complex 3D structures between fabricated structures and simulated ones. The proposed method shows the potential to fabricate novel micro-structures and to improve the performance of micro-devices.日本AEM学会, 2010年, 日本AEM学会誌, 18(4) (4), 377 - 382, 日本語
- Pb(ZrxTi1-x)O-3 [PZT] thin films of thickness 2.0 mu m were fabricated on silicon substrates (111)Pt/Ti/SiO2/Si using a sol-gel spin-coating technique. PZT films on substrates with a strontium titanate bottom layer are preferentially {110}-oriented with a columnar structure. The PZT films exhibit good dielectric properties with a dielectric permittivity, epsilon(r)=1545 and dielectric loss, tan delta=0.04. Excellent piezoelectric characteristics are also exhibited by the {110}-oriented films with an average effective transverse piezocoefficient, e(31)(*) of -8.4 C/m(2). The influence of film texture and composition on the transverse piezocoefficient have also been studied.AMER INST PHYSICS, 2010年01月, APPLIED PHYSICS LETTERS, 96(3) (3), 31909, 英語[査読有り]研究論文（学術雑誌）
- The orientation dependence of the piezoelectric properties of epitaxial BaTiO3 (BTO) films was investigated. The (001), (101), and (111)-oriented BTO films of 2-2.5 mu m thickness were deposited on SrRuO3/Pt/MgO or SrRuO3/SrTiO3 substrates by rf magnetron sputtering. X-ray diffraction measurements showed that (001), (101), and (111) BTO films were epitaxially grown on the substrates. The lattice parameters of each BTO film were different from those of the bulk single crystal, and the unit cell volume of the BTO films was larger than that of bulk BTO. The transverse piezoelectric coefficients e(31)* = d(31)/s(11) of (001)BTO films was almost independent of applied electric field, whereas e(31)* of (111)BTO increased with voltage owing to the domain motion. The piezoelectric properties of (101)BTO films strongly depended on the in-plane alignment of the crystal structure, and a relatively large e(31)* of -1.3C/m(2) could be achieved by enhancement of the domain motion. Although the absolute values of e(31)* are smaller than theoretical calculation values, we could demonstrate that the optimization of crystal orientation is effective for enhancing BTO-based lead-free piezoelectric films. (C) 2010 The Japan Society of Applied PhysicsJAPAN SOC APPLIED PHYSICS, 2010年, JAPANESE JOURNAL OF APPLIED PHYSICS, 49(9) (9), 1 - 9, 英語[査読有り]研究論文（学術雑誌）
- The orientation dependence of shear mode piezoelectric properties has been investigated for epitaxial Pb(Zr,Ti)O-3 (PZT) thin films with composition near the morphotropic phase boundary. (101)- and (111)-oriented PZT films were epitaxially grown on SrTiO3 (STO) substrates by rf magnetron sputtering and microfabricated into rectangular-shaped specimens to apply a horizontal electric field using lateral electrodes. The application of a sinusoidal input voltage of 100 kHz generated in-plane shear vibration, which was measured using a laser Doppler vibrometer. In-plane displacement proportionally increased with applied voltage for each PZT film. When a horizontal electric field was applied to (101)PZT along the directions parallel and perpendicular to [110] STO, the shear piezoelectric coefficient d(15) was calculated to be 110 and 305 pm/V, respectively. On the other hand, d(15) of (111)PZT under the electric field parallel to [110]STO was calculated to be 160 pm/V. These results indicate that the shear mode piezoelectric coefficients of the epitaxial PZT films not only show large values compatible with bulk ceramics, but also strongly depend on the crystallographic orientation and the direction of the electric field. (C) 2010 The Japan Society of Applied PhysicsJAPAN SOC APPLIED PHYSICS, 2010年, JAPANESE JOURNAL OF APPLIED PHYSICS, 49(9) (9), 1 - 9, 英語[査読有り]研究論文（学術雑誌）
- Piezoelectric shear strain was measured for c-axis oriented epitaxial Pb(Zr,Ti)O-3 (PZT) thin films. The PZT films, with a composition near the morphotropic phase boundary (MPB), were epitaxially grown on (001) MgO substrates and then microfabricated into a rectangular shape by wet etching of the films. Lateral electrodes were deposited on both sides of the PZT films, to apply an external electric field perpendicular to the polarization. A sinusoidal input voltage of 100 kHz was applied between the lateral electrodes, and in-plane shear vibration was measured by a laser Doppler vibrometer. In-plane displacement due to shear mode piezoelectric vibration was clearly observed and increased proportionally with the voltage. Finite element method (FEM) analysis was conducted to determine the horizontal electric field in the PZT film, and the piezoelectric coefficient d(15) was calculated to be 440 x 10(-12) m/V. The d(15) of the PZT film represents the intrinsic shear piezoelectric effect, which is slightly smaller than that of bulk PZT, due to the absence of extrinsic effects such as longitudinal and transverse piezoelectric strain or domain rotation. (C) 2009 The Japan Society of Applied PhysicsJAPAN SOC APPLIED PHYSICS, 2009年09月, APPLIED PHYSICS EXPRESS, 2(9) (9), pp.091402, 英語[査読有り]研究論文（学術雑誌）
- Piezoelectric Pb(Zr, Ti)O-3 (PZT) thin films were directly deposited on cantilever-shaped titanium substrates and evaluated for their piezoelectric properties and actuator performance. Because of the small difference in the thermal expansion coefficient between the PZT and the substrate, and the mitigation of the residual stress, large piezoelectric properties could be obtained for PZT/Ti unimorph actuators. X-ray diffraction measurements clearly revealed that the PZT thin films have a polycrystalline perovskite structure with a random orientation. Observations using a scanning electron microscope (SEM) demonstrated that PZT films, which were 3.8 mu m thick, were densely deposited on Pt-coated Ti substrate without pores or cracks. The polarization-electric field (P-E) hysteresis of the PZT film clearly indicates ferroelectricity. The piezoelectric properties of the PZT films were evaluated from the tip displacement of PZT/Ti unimorph cantilevers. Simplified transverse piezoelectric coefficients (e(31)* = d(31)/S-11(E), where d(31) and S-11(E) are piezoelectric coefficient and elastic compliance, respectively) were measured, which ranged from -3.6 to 4.3 C/m(2)-about three times larger than those of the PZT thin films deposited on stainless-steel substrates. Measurement of resonant frequencies of the cantilevers shows a clear dependence on the cantilever length, which obeys the theoretical equation. This indicates that these cantilevers can be reliably applied as sensors and actuators in a resonance mode. [2008-0100]IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2009年06月, JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, 18(3) (3), 610 - 615, 英語[査読有り]研究論文（学術雑誌）
- In this paper, we propose innovative valveless pumping devices for microfluidic systems. The liquid in the microchannel was transported by generating a traveling wave on the channel wall, which was composed of a piezoelectric Pb(Zr,Ti)O(3) (PZT) thin film actuator array. The PZT thin films were deposited on the silicon-on-insulator (501) substrates where microchannels, 200 and 500 mu m wide, were fabricated by deep reactive ion etching (DRIE). The displacement profiles and frequency response of the vibrating wall were measured using a laser Doppler vibrometer. The maximum displacements of the 200 and 500 mu m wide empty channels at 10 V(PP) were about 62 and 229 nm, respectively. Minor displacement reductions were observed when the channel was filled with liquid, although the resonant frequencies dropped remarkably. On generating a traveling wave on the channel wall, clear liquid flow could be induced with a mean flow velocity of about 118 and 172 mu m/s for the 200 and 500 mu m wide channels, respectively. (C) 2009 Elsevier B.V. All rights reservedELSEVIER SCIENCE SA, 2009年06月, SENSORS AND ACTUATORS A-PHYSICAL, 152(2) (2), 211 - 218, 英語[査読有り]研究論文（学術雑誌）
- We have deposited nearly stress-free single-crystal thin films of (001) Pb(Mn,Nb)O-3-Pb(Zr,Ti)O-3 (PMnN-PZT) on (001)MgO substrates by rf-magnetron sputtering using a quenching process after the film growth. It is found that single c-domain/single-crystal thin films of PMnN-PZT containing 5%-10% PMnN show a strong hard ferroelectric response with 2E(c)congruent to 400 kV/cm and P-s congruent to 70 mu C/cm(2). GHz-range film bulk acoustic resonators incorporating PMnN-PZT thin films have been fabricated with microelectromechanical system technology. The maximum electromechanical coupling coefficient k(t) and mechanical quality factor Q(m) were 0.7 and 185 in the 4 GHz range, respectively.AMER INST PHYSICS, 2009年04月, APPLIED PHYSICS LETTERS, 94(17) (17), 172903, 英語[査読有り]研究論文（学術雑誌）
- In this paper, we propose a novel microfabrication technique without assembling process including alignment and bonding for significant 3-D microstructures and microfludic networks. The proposed process can integrate embedded microchannels with free path, orifices, openings and nozzles into a complicated microfluidic network by using the inclined/rotated UV lithography with a characteristic single-mask of whole image exposure in a short period of time. ©2009 IEEE.2009年, TRANSDUCERS 2009 - 15th International Conference on Solid-State Sensors, Actuators and Microsystems, 1900 - 1903, 英語[査読有り]研究論文（国際会議プロシーディングス）
- 2009年, 日本AEM学会誌, Vol.17.(No.2) (No.2), pp.253 - 258, 日本語積層型圧電アクチュエータを用いた進行波型マイクロポンプによる流体輸送制御[査読有り]研究論文（学術雑誌）
- 回転傾斜露光法による複雑マイクロ構造作製とバイオデバイスへの応用Fabrication of complex 3D structures becomes more important for improvement of soft-MEMS. Then, we propose the new fabrication method that can fabricate complex 3D structures with inclined rotated UV lithography on only one process. The simulation of the proposed method was developed to calculate the fabricated structures to assist design of masks. The validity of the method and the simulation were confirmed by demonstration of fabrication of the complex 3D structures and by similarity between fabricated structures and simulated ones. In addition, to indicate the availability of fabricated complex structures, the fabricated structures were applied to the FISH (Fluorescence In Situ Hybridization) process that is the method of observation for chromosomes. In this study, the proposed method showed the potential to fabricate the novel structures and to improve the performance of micro-device.日本AEM学会, 2009年, 日本AEM学会誌, Vol.17.(No.2) (No.2), pp.274 - 278, 日本語[査読有り]研究論文（学術雑誌）
- 2009年, Journal of Physics D: Applied Physics, Vol.141., pp.115507, 英語Effects of fluid dynamic stress on fracturing of cell-aggregated tissue during purification for islets of Langerhans transplantation[査読有り]研究論文（学術雑誌）
- We have previously reported (K,Na)NbO3 (KNN) films, whose piezoelectric properties are the highest reported thus far. In this study, we investigate the detailed crystalline structures of these KNN films after deposition oil Pt/MgO and Pt/Ti/SiO2/Si substrates by RF magnetron sputtering. The KNN film on Pt/MgO was epitaxially grown on the Pt lower electrode with a perfect (001) orientation in the perovskite structure. The KNN film on Pt/Ti/SiO2/Si was polycrystalline with a preferential (001) orientation in the perovskite structure having dense columnar grains. X-ray diffraction measurements revealed that the KNN films grown on Pt/MgO and Pt/Ti/SiO2/Si were tetragonal; the lattice parameters c and a were related as c/a > 1. The KNN film oil Pt/MgO had a higher c/a value than the KNN film oil Pi/Ti/SiO2/Si, indicating that the former had more compressed strain. We conclude that this difference in compressed strain may contribute to the difference in piezoelectric properties of the KNN films oil Pt/MgO and Pt/Ti/SiO2/Si. [DOI: 10.1143/JJAP.47.8909]JAPAN SOC APPLIED PHYSICS, 2008年12月, JAPANESE JOURNAL OF APPLIED PHYSICS, 47(12) (12), 8909 - 8913, 英語[査読有り]研究論文（学術雑誌）
- Soft piezoelectrics based on niobium-doped lead zirconate titanate (PZT-5H) are used for actuator applications. Through careful control of particle dispersion in thick-film ink formulations, crack-free and dense PZT thick-films of thickness 40 mu m have been fabricated on alumina substrates by screen-printing method. The transverse piezoelectric coefficient, e*(31) (=d(31)/s(11)) have been determined from the tip deflection of the unimorph cantilevers. The PZT films on alumina substrates exhibited good linear piezoelectric deflection to the applied voltage with the stable piezoelectric coefficient, e*(31) of -4.0 C/m(2). (C) 2008 Elsevier B.V. All rights reserved.ELSEVIER SCIENCE SA, 2008年11月, SENSORS AND ACTUATORS A-PHYSICAL, 148(1) (1), 134 - 137, 英語[査読有り]研究論文（学術雑誌）
- ＲＦ‐ＭＥＭＳスイッチ用圧電薄膜型マイクロアクチュエータの開発A piezoelectric RF-MEMS switch driven by PZT thin films was investigated for low-voltage actuation. PZT thin films with composition of Zr/Ti=53/47 were grown on the (111) Pt/Ti/Si substrates by RF-sputtering. In the previous paper, the cantilever type actuators composed of PZT thin films and Cr elastic layers have been successively fabricated as unimorph structure, but large initial bending arose due to the residual stress in the PZT and Cr layers. In this paper, we optimized the deposition condition for Cr elastic layer in order to reduce the initial bending. Then, new structures of piezoelectric actuators having cantilever and four edges supported beam types were fabricated, and evaluated for the driving property. The deflection of cantilever and four edges supported beam type actuators applied the voltage of 5V were 2.6μm and 1.3μm, respectively. As a result, it is confirmed that the proposed actuators can be adopted for RF-MEMS switches with low-voltage actuation.日本AEM学会, 2008年06月, 日本AEM学会誌, 16(2) (2), 82 - 87, 日本語[査読有り]
- The externally driven micropump, is common means of transporting liquid on the microscale. It is usually difficult to evaluate the oscillation characteristics with the influence of the liquid inside the micropump taken into account. In this study, modal analysis with an additional mass effect of liquid is carried out for the evaluation of the influences of miniaturization and internal liquid. Analyses under three typical conditions of microfluidics devices were carried out: (1) cantilever-type actuator vibrates a flexible microchannel, (2) film-type actuator vibrates a microchannel, and (3) oscillation of single microchannel. The results indicate that the liquid inside the microchannel and the microchannel shape greatly influence the oscillation characteristics. The microchannel should be designed to have a small aspect ratio, a large cross-sectional area of the upper wall. and a cross-sectional area of channel smaller than that of the upper wall. These effects should be taken into account in the design of the externally driven micropunp.JAPAN SOCIETY APPLIED PHYSICS, 2008年06月, JAPANESE JOURNAL OF APPLIED PHYSICS, 47(6) (6), 5226 - 5230, 英語[査読有り]研究論文（学術雑誌）
- The 4 GHz bulk acoustic wave (BAW) resontors have been fabricated by thin films of Pb(Zr,Ti)O3 based ternary perovskite compounds. The Pb(Mn1/3Nb2/3)O3-Pb(Zr,Ti)O3 (PMnN-PZT) thin films were deposited on (100)MgO substrates by RF magnetron sputtering. The PMnN-PZT thin films showed tetragonal crystal structure and highly (001) orientation. The surface roughness of the thin films was about 2nm. The cross section TEM image of PMnN-PZT thin films showed single cdomain/ single crystal structure. The bulk acoustic wave (BAW) resonators composed by PMnN-PZT thin films were fabricated by MEMS technology. The RF properties of the resonator were evaluated by VNA (Vector Network Analyzer). The BAW resonator by 0.1PMnN-0.9PZT(55/45) thin film exhibited high electro-mechanical coupling constant kt and high Q value at 3.87GHz. Values of kt, Q, and k t 2Q were found to be 0.56, 185 and 58, respectively. These values are highest, in our knowledge, comparing with those of previously reported PZT-BAW resonators. © 2008 IEEE.2008年, Proceedings - IEEE Ultrasonics Symposium, 1920 - 1923, 英語[査読有り]研究論文（国際会議プロシーディングス）
- Piezoelectric MEMS deformable mirror resolution is studied for an adaptive optics device. In previous study, we have developed the piezoelectric MEMS deformable mirrors which have 19 actuator away. To improve the resolution of the deformable mirror, we designed hexagonal 61-element actuator array. In order to reduce the dead space for the lead lines between the actuators, they were prepared on the polyimide insulating layer. The displacement of each actuator was measured by using a lasor Doppler vibrometer and we confirmed a relatively large displacement of more than 1pm by applying a voltage of 10Vpp. Furthermore, we measured the relationship input voltage and displacement and fabricated DMs actuated linearly when applied -20〜20Vpp.一般社団法人日本機械学会, 2008年, 年次大会講演論文集, 2008, 17 - 18, 日本語
- In this paper, we propose and study innovative liquid pimping devices for microfluidic systems such as pTAS. In our study, microchaimels with vibrating wall were fabricated on silicon on insulator (SOI). The vibrating wall was composed of piezoelectric PZT thin films deposited on the microchannel wall. The microchannel can transport liquid by traveling wave induced on channel wall by applying sinusoidal voltages to each patterned top electrodes with different phase. The active microchannel of 200μm wide was fabricated by the deep reactive ion etching(DRIE) process. The displacement profiles of the vibrating wall and frequency response were measured by a laser Doppler vibrometer. We examined the difference of the characteristics that were the to the effect of the structure of channel wall.一般社団法人日本機械学会, 2008年, 年次大会講演論文集, 2008, 19 - 20, 日本語
- 2008年, 日本AEM学会誌, Vol.16.(No.2) (No.2), pp.82 - 87, 日本語鈴木孝明，田澤慶朗，神野伊策，小寺秀俊[査読有り]研究論文（学術雑誌）
- High-piezoelectricity lead-free films of (K,Na)NbO3 (KNN) were successfully deposited on Pt/MgO and Pt/Ti/SiO2/Si substrates by RF magnetron sputtering. The KNN film was epitaxially grown on Pt/MgO with a high < 001 > orientation in the pseudo-cubic perovskite structure. The KNN film on Pt/Ti/SiO2/Si was polycrystalline with a preferential < 001 > orientation in the pseudo-cubic perovskite structure. The piezoelectric properties of the KNN films were determined from the tip displacement of KNN/Pt/MgO or KNN/Pt/Ti/SiO2/Si unimorph cantilevers. The transverse piezoelectric coefficients e(31)* (d(31)/s(11)(E)) of the KNN films on Pt/MgO and Pt/Ti/SiO2/Si were calculated to be -3.6 and -5.5 C/m(2), respectively, which are amongst the highest values for KNN films ever reported. (c) 2008 The Japan Society of Applied Physics.JAPAN SOC APPLIED PHYSICS, 2008年01月, APPLIED PHYSICS EXPRESS, 1(1) (1), 1 - 11501, 英語[査読有り]研究論文（学術雑誌）
- (K-x,Na1-x)NbO3 (KNN) thin films were deposited on (001)SrRuO3/(001)Pt/(001)MgO substrates by RF-magnetron sputtering, and their piezoelectric properties were investigated. The x-ray diffraction measurements indicated that the KNN thin films were epitaxially grown with the c-axis orientation in the perovskite tetragonal sys tem. The lattice constant of the c-axis increased with in creasing concentrations of potassium. The KNN thin films showed typical ferroelectric behavior; the relative dielectric constant Er was 270 similar to 320. The piezoelectric properties were measured from the tip displacement of the KNN/MgO unimorph cantilevers; the transverse piezoelectric coefficient e(31)* (= d(31)/S-11(E)) of KNN (x = 0) thin films was calculated to be -0.9 C/m(2). On the other hand, doping of potassium caused an increase in the piezoelectric properties, and the KNN (x = 0.16) films showed a relatively large transverse piezoelectricity of e(31)* = -2.4 C/m2.IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2007年12月, IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL, 54(12) (12), 2562 - 2566, 英語[査読有り]研究論文（学術雑誌）
- Sodium niobate (NaNbO3, NN) thin films were deposited on (001)SrRuO3/Pt/MgO substrates by rf magnetron sputter deposition. The X-ray diffraction (XRD) pattern of the sputtered NN thin films showed epitaxial growth with a (001)-oriented perovskite structure. From the reciprocal space maps, the lattice parameters of the in-plane and out-of-plane directions were a = 0.392 nm and c = 0.395 nm, respectively. The relative dielectric constant E, and the range of the dielectric loss tan 6 were about 270 and 0.05-0.13 at 1 kHz, respectively. The P-E hysteresis loop showed clear ferroelectricity with spontaneous polarization P-s of 20 mu C/cm(2) and coercive electric field E-c of 50kV`/cm. The transverse piezoelectric properties were evaluated from the tip displacement of NN/MgO unimorph cantilevers. The transverse piezoelectric coefficient e(31)(*) (= d(31)/S-11(E)) was -0.9 C/m(2). which is almost compatible with that of the bulk NN ceramics. The tip deflection showed typical butterfly curves owing to the polarization reversal, indicating that the sputtered NN thin films had a high piezoelectric performance.INST PURE APPLIED PHYSICS, 2007年10月, JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS, 46(10B) (10B), 6960 - 6963, 英語[査読有り]研究論文（学術雑誌）
- This paper presents a new microfluidic check valve well suited for low Reynolds number flow rate sensing, micropump flow rectification, and flow control in lab-on-a-chip devices. The valve uses coupling between fluid movement in a channel and an elastomeric column (flap) suspended in the fluid path to generate a strong anisotropic flow resistance. Soft lithography-based molding techniques were used to fabricate the valve, allowing for a low-cost, single-step fabrication process. Three valves-having heights of 25, 50, and 75 mu m, respectively-were fabricated and experimentally evaluated; the best of them demonstrated a maximum fluidic diodicity of 4.6 at a Reynolds number of 12.6 and a significant diodicity of 1.6 at the low Reynolds number of 0.7. The valve's notable low Reynolds number response was realized by adopting a design methodology that balances the stiffness of the elastomer flap and adhesion forces between the flap and its seat. A pair of elastomer check valves integrated with a miniature membrane actuator demonstrated a flow rectification efficiency of 29.8%. The valve's other notable features include a wide bandwidth response, the ability to admit particles without becoming jammed, and flow rate sensing capability based on optical flap displacement measurements.SPRINGER HEIDELBERG, 2007年08月, MICROFLUIDICS AND NANOFLUIDICS, 3(4) (4), 427 - 435, 英語[査読有り]研究論文（学術雑誌）
- In this study, we report piezoelectric microactuators composed of Pb(Zr,Ti)03 (PZT) films for low-voltage RF-MEMS switches. In order to realize a flat beam shape as well as a large displacement, we have adopted an X-shaped connector at the center of the beam. Finite element method (FEM) simulation indicates that the bending motion of the beam is almost same as two connected cantilevers, and the maximum displacement reaches 3.2 mu m/5 V. To fabricate the microactuators, piezoelectric PZT films were deposited on Si substrates using rf-sputtering and microfabricated into the PZT/Cr unimorph actuators of 800 mu m in length and 200 mu m in width, respectively. Although the X-shaped connector effectively releases the stress of the multilayered beam so that the beam shape is almost flat, small residual stress caused slight concave curvature along the width. The displacement at the center of the beam was measured using a laser Doppler vibrometer. The measurement revealed that the displacement was 0.5 mu m/5 V which was lower than the FEM result. The reduction of the displacement is attributed to the increase of the stiffness of the beam due to the concave curvature of the beam width.SPRINGER, 2007年05月, MICROSYSTEM TECHNOLOGIES-MICRO-AND NANOSYSTEMS-INFORMATION STORAGE AND PROCESSING SYSTEMS, 13(8-10) (8-10), 825 - 829, 英語[査読有り]研究論文（学術雑誌）
- In this paper, we propose a cell encapsulation and hydrogel-beads production method using droplet formation in a microchannel. The hydrogel-beads produced by the microfluidic device developed here have smaller diameter and narrower distribution in their diameter compared to the conventional method, such as the droplet extrusion and the emulsification. The effects of the flow velocity and microchannel wall were analyzed based on fluid dynamical analysis. The results revealed that the wall effect of the microchannel strongly affected to the diameter of the droplet and the shape of the hydrogel-beads.SPRINGER, 2007年05月, MICROSYSTEM TECHNOLOGIES-MICRO-AND NANOSYSTEMS-INFORMATION STORAGE AND PROCESSING SYSTEMS, 13(8-10) (8-10), 951 - 958, 英語[査読有り]研究論文（学術雑誌）
- Since most of miniaturized surface plasmon resonance (SPR) sensing systems need commercially available peristaltic or syringe pumps, it is difficult to reduce the system size, biosample volume, and the production cost. In this paper, a compact biochip for clinical diagnosis is presented. The proposed biochip is integrated traveling wave micropumps and SPR imaging sensors on one chip. The micropump is composed of flexible microchannel and piezoelectric bimorph actuator array, and achieved the maximum flow rate 336 mu l/min. The SPR imaging biosensor can quantitatively measure biosamples with multi microchannels, i.e. one biosample and two reference flows to obtain an analytical curve. The SPR imaging measurements with bovine serum albumin solutions were carried out using the prototype of the proposed diagnostic system composed of a pair of the micropump and the sensor. Since the clear SPR signal curve was observed, it was confirmed that the proposed system can be applicable to the clinical diagnosis.SPRINGER, 2007年05月, MICROSYSTEM TECHNOLOGIES-MICRO-AND NANOSYSTEMS-INFORMATION STORAGE AND PROCESSING SYSTEMS, 13(8-10) (8-10), 1391 - 1396, 英語[査読有り]研究論文（学術雑誌）
- In this paper, we report a piezoelectric deformable mirror composed of piezoelectric thin films for low-voltage adaptive optics (AO). A 2-mu m-thick piezoelectric Pb(ZrTi)O-3 (PZT) film was deposited on a Pt-coated silicon-on-insulator (SOI) substrate, and a diaphragm structure of 15 mm in diameter was fabricated by etching a Si handle wafer. A 19-element unimorph actuator array was produced on the PZT films with an Al reflective layer over the backside of the diaphragm. Measurements of the displacement profile using a laser Doppler vibrometer demonstrated that a large displacement of approximately 1 mu m was obtained by applying a voltage of 10 V-PP on one actuator. To examine the application feasibility of the deformable mirror to AO, we reproduced low-order Zernike modes by calculating the voltage on each individual electrode using an influence function matrix. The measurements demonstrated that the deformable mirror could produce the Zernike modes up to the seventh term. Considering the low-voltage actuation as well as the capability for miniaturization of the electrode size, deformable mirrors (DMs) actuated by PZT films are desirable for low-cost AO.IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2007年03月, IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS, 13(2) (2), 155 - 161, 英語[査読有り]研究論文（学術雑誌）
- Micropumps are one of the most important microfluidic components in Micro Total Analysis System (mu TAS). The authors have developed a traveling wave micropump that demonstrates high energy efficiency and does not require valves. A prototype valveless micropump was fabricated using microfabrication techniques to validate the pumping principle. The micropump uses piezoelectric bimorph cantilevers to deform a flexible microchannel wall. Traveling waves are induced on the surface of the microchannel by applying property phased sinusoidal voltage to the piezoelectric cantilevers. The resulting peristaltic motion of the channel wall transports the fluid. The fluid flow in the micropump was numerically simulated with the computational fluid dynamics code, FLUENT. Comparing the experimental and numerical results confirmed that the proposed modeling method can accurately evaluate the performances of the traveling wave micropump. Based on the flow obtained in numerical analysis, an improvement in the pump efficiency is expected with optimization of the shape of the moving wall.SPRINGER, 2007年, COMPLEX MEDICAL ENGINEERING, 3 - +, 英語[査読有り]研究論文（国際会議プロシーディングス）
- 2007年, 日本AEM学会誌, Vol.15.(No.2) (No.2), pp.70 - 75, 日本語低電圧駆動型指向性可変ミリ波アンテナのための基礎的研究（誘電体の局所温度場を制御するマイクロヒータ）[査読有り]研究論文（学術雑誌）
- The piezoelectric MEMS deformable mirrors for adaptive optics have been developed to realize low voltage and large stroke deformable mirrors. The PZT film was deposited on a Pt-coated silicon-on-insulator (SOI) substrate and the 19 segmented electrodes were prepared on it. The circular diaphragm structure was fabricated by etching the Si substrate from the back side and the unimorph actuator array composed of a PZT film and a Si layer was accomplished. Finally a Al reflective layer was coated over the backside of the membrane as a mirror surface. The displacement profiles measurements by a laser Doppler vibrometer showed that the each actuator generated large displacement of approximately 5μm at 10V. Furthermore we could successfully reproduce the Zernike modes up to 4th order by applying the voltage calculated by control function matrix. © 2007 The Institute of Electrical Engineers of Japan.2007年, 電気学会論文誌E, 127(12) (12), 1 - 523, 日本語[査読有り]研究論文（学術雑誌）
- We have successfully transferred heteroepitaxial Pb(Zr,Ti)O-3 (PZT) thin films from MgO substrates on to glass substrates. The transferred PZT thin films exhibit single crystal structure with ferroelectric properties similar to the as grown epitaxial films. The transferring process comprises coating of Cr-metallized surface of epitaxial PZT thin films, pressing and cementing the Cr-metallized surface on to the glass substrates by silicone rubber, and removing the MgO substrates by chemical etching. This process realizes a fabrication of high-temperature processed PZT thin films onto the glass at room temperature. The process is also available for the transformation of PZT thin films on organic film sheet. The present transfer process reduces the effects of the inevitable strain and/or constraint to rigid substrates for heteroepitaxial growth and has a potential for integration of single crystal piezoelectric PZT devices onto a wide variety of MEMS. (c) 2005 Published by Elsevier Ltd.PERGAMON-ELSEVIER SCIENCE LTD, 2007年01月, VACUUM, 81(5) (5), 571 - 578, 英語[査読有り]研究論文（学術雑誌）
- We propose two-dimensional (2D) thermo-elastic model to predict the temperature variation of the lattice constants and volume loss of the epitaxial (001)PbTiO3 (PT) thin films grown on (100)SrTiO3 substrates under specific biaxial stress conditions. The stresses resulted from the induced thermal stress and thermo-elastic bending of the PT film and ST substrate are used together with the external stresses to calculate the Landau-Ginsburg-Devonshire (LGD) formalism for PT at any temperature. The dielectric constant and spontaneous polarization could be accurately determined under compound effect of 2D state of stress and temperature variation. Because this study combines thermodynamic with thermo-elastic mechanics; it would be very useful for design and simulate the performance of piezoelectric micro-sensors and micro-actuators which are usually subjected to a various heat and stress under actual working conditions. The present predictions are applicable for a fabrication of piezoelectric MEMS on Si wafers. (c) 2006 Elsevier Ltd. All rights reserved.PERGAMON-ELSEVIER SCIENCE LTD, 2006年11月, VACUUM, 81(4) (4), 459 - 465, 英語[査読有り]研究論文（学術雑誌）
- In this paper, we report an electric field-induced strain of antiferroelectric (AFE) PbZrO3 (PZ) films deposited by rf-sputtering. The PZ films grown on the (001)Pt/(001)MgO substrate are preferentially oriented along the c axis in a tetragonal system which is perpendicular to the AFE polar direction. On the other hand, the PZ films on the (111)Pt/Ti/Si substrate have a random orientation, and they show, clear double P-E hysteresis loops, representing the AFE-ferroelectric (FE) phase transition caused by the Application of an electric field. The transverse strain induced by the electric field is evaluated by the measurements of tip displacement of PZ/substrate unimorph cantilevers. The PZ films on the Pt/Ti/Si substrate exhibit clear strain jump corresponding to the AFE-FE phase transition, and a maximum transverse strain of 5 x 10(-5) is obtained at an electric field of -150 kV/cm.JAPAN SOC APPLIED PHYSICS, 2006年09月, JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS, 45(9B) (9B), 7258 - 7261, 英語[査読有り]研究論文（学術雑誌）
- Single-crystal lead titanate [(00l)PbTiO3 (PT)] thin films were heteroepitaxially grown on a miscut strontium titanate [(001)SrTiO3 (ST)] substrate by radio frequency magnetron sputtering. The PT thin films were grown via a step-flow growth. The step-flow growth enhanced the layer growth resulting in the continuous (001) single-crystal structure without a dislocated interface for the film thickness below 200 to 250 nm. The PT thin films show a small temperature variation of the lattice parameters unlikely to the bulk PT crystals due to the substrate clamping. The temperature variation of the lattice constants is discussed in terms of the thermo-elastic deformation analysis for the PT/ST heterostructure.CAMBRIDGE UNIV PRESS, 2006年05月, JOURNAL OF MATERIALS RESEARCH, 21(5) (5), 1261 - 1268, 英語[査読有り]研究論文（学術雑誌）
- Heteroepitaxial growth of stress free single crystal perovskite thin filmsThin films of single c-domain/single crystal (PbMg1/3Nb2/3O3)(1-x)(PbTiO3)(x), x = 0-0.4 (PMNT) were heteroepitaxially grown on (001)SrTiO3 and (001)MgO substrates by magnetron sputtering using a quenching process. The lattice parameters of the quenched PMNT thin films were almost the same to the bulk values independently to the lattice parameters of substrates. The quenched PMNT thin films showed stress free structural properties, although the crystal structure of thin films is modified from bulk PMNT. The electromechanical properties are the same to the bulk single c-domain single crystals.WORLD SCIENTIFIC PUBL CO PTE LTD, 2006年04月, SURFACE REVIEW AND LETTERS, 13(2-3) (2-3), 167 - 172, 英語[査読有り]研究論文（学術雑誌）
- Thin films of single c-domain/single-crystal (1-x)Pb(Mg1/3Nb2/3)O-3-xPbTiO(3) (PMN-PT) with x congruent to 0.33 near a morphotropic boundary composition were heteroepitaxially grown on (110)SRO/(001)Pt/(001)MgO substrates. The heteroepitaxial growth was achieved by rf-magnetron sputtering at the substrate temperature of 600 degrees C. After the sputtering deposition, the substrates were rapidly cooled from 600 degrees C to room temperature by atmospheric air gas at a cooling rate of 100 degrees C/min. The rapid cooling process enhanced the heteroepitaxial growth of the single c-domain/single crystal PMN-PT thin films. Their electromechanical coupling factor k(t) measured by a resonance spectrum method was 45% at resonant frequency of 1.3 GHz with phase velocity of 5500 to 6000 m/s for the film thickness of 2.3 mu m. The d(33) and d(31) were 194 pC/N and -104 pC/N, respectively. The observed k(t), d(33), and d(31) were almost the same to the bulk single-crystal values. The present PMN-PT thin films are applicable for a fabrication of GHz planar bulk acoustic wave transducers. (c) 2006 American Institute of Physics.AMER INST PHYSICS, 2006年03月, APPLIED PHYSICS LETTERS, 88(12) (12), pp.122903, 英語[査読有り]研究論文（学術雑誌）
- 2006年, Advances in Science and Technology, Vol.45., pp.1212 - 1217, 英語Structure and Electromechanical Properties of Quenched PMN-PT Single Crystal Thin Films[査読有り]研究論文（学術雑誌）
- This paper presents a polymer-based micropump addressing the cost, performance, and system compatibility issues that have limited the integration of on-chip micropumps into microanalysis systems. This pump uses dielectric elastomer actuation to periodically displace fluid, and a pair of elastomeric check valves to rectify the fluid's resulting movement. Its significant features include the use of a transparent substrate, self-priming capability, insensitivity to gas bubbles, and the ability to admit particles. A pump occupying less than 10 mm 2 of chip space produced a 77 mu l min(-1) flow rate. The pump has a high thermodynamic efficiency and exhibits little performance degradation over 10 hours of operation. In addition to its notable performance, the pump can be fabricated at low cost and directly integrated into microfluidic chips that use planar softlithography-formed structures. The new pump concept, fabrication, and experimental performance are discussed herein.ROYAL SOC CHEMISTRY, 2006年, LAB ON A CHIP, 6(9) (9), 1147 - 1154, 英語[査読有り]研究論文（学術雑誌）
- Piezoelectric Pb(Zr,Ti)O-3 (PZT) thin films with a composition near the morphotoropic phase boundary were deposited directly on cantilever-shaped stainless steel (SUS) substrates using RF-magnetron sputtering for application of micro-electromechanical systems (MEMS). X-ray diffraction measurements reveal that the PZT thin films have a polycrystalline perovskite structure with a preferential orientation of (101). Cross-section morphology - observed using a scanning electron microscope - indicates that the PZT films exhibit a dense columnar structure without pores or clacks. The films' P-E hysteresis loops indicate clear ferroelectricity. Based on the deflection characteristics of the cantilever, the effective piezoelectric coefficient e(31) of the PZT films is measured to be -1.35 C/m(2). (c) 2005 Elsevier B.V. All rights reserved.ELSEVIER SCIENCE SA, 2006年01月, SENSORS AND ACTUATORS A-PHYSICAL, 125(2) (2), 382 - 386, 英語[査読有り]研究論文（学術雑誌）
- We report on the intrinsic crystalline structure of epitaxial ferroelectric Pb(Zr,Ti)O-3 (PZT) films, which are fully relaxed from the stress of the substrate. The PZT films with the rhombohedral composition of Zr/Ti=68/32 were epitaxially grown on (001)Pt/(001)MgO substrates. Four-circle x-ray diffraction measurements revealed that the films showed not only perfect c-axis orientation, but also a tetragonal phase due to a clamping effect of the substrate. Successively, x-ray diffraction measurements using synchrotron radiation were carried out to examine the intrinsic structure of stress-free PZT films, which were powdered after substrate removal. The structure refinement by Rietveld analysis demonstrated that the films without substrates returned to a rhombohedral phase, however, 19% of the B site in the perovskite structure was occupied by Pb atoms. The phase-transition temperature from rhombohedral to cubic slightly decreased due to the anomalous structure of the stress-free PZT films. These results suggest that the deviation of the thin-film properties from the bulk ones is caused not only by in-plane epitaxial stress as an extrinsic factor, but also by the anomalous crystalline structure of the stress-free thin films. (C) 2005 American Institute of Physics.AMER INST PHYSICS, 2005年04月, JOURNAL OF APPLIED PHYSICS, 97(7) (7), pp. 074101, 英語[査読有り]研究論文（学術雑誌）
- The interface strength of Pb(Zr,Ti)O-3 (PZT) thin films on a silicon substrate is studied experimentally and theoretically in this work. The focus is put on crack initiation from the free edge of the interface. A novel method of sandwiched cantilever specimen is utilized to perform the delamination tests. Theoretical analyses are performed on the singular behavior of the stress in the vicinity of the free edge along the interface between Cr layer and PZT layer, and on the distribution of normal stress at the delarnination loads. Based on these results, a delamination criterion involving stress intensity parameter is adopted to estimate the interface toughness for crack initiation at the free edge along the interface Cr/PZT. (C) 2004 Elsevier Ltd. All rights reserved.PERGAMON-ELSEVIER SCIENCE LTD, 2005年03月, INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES, 42(5-6) (5-6), 1729 - 1741, 英語[査読有り]研究論文（学術雑誌）
- Development of peristaltic soft micropump driven by electrostatic actuatorWe have developed a valveless micropump driven by electrostatic actuators. The micropump was composed of flexible wall of microchannel with electrodes for the electrostatic force. Traveling wave was induced on the surface of the microchannel by applying sinusoidal voltages to each electrode with the different phase. The fluid can be moved by the peristaltic motion of the channel wall. The sinusoidal voltages of 150 V were applied at the frequency of 5.0 kHz to the electrostatic actuators under the microchannel filled with the water. The fluid flow was measured with micro particle's motion in the fluid by the peristaltic actuation of electrostatic force.ROYAL SOC CHEMISTRY, 2005年, MICRO TOTAL ANALYSIS SYSTEMS 2004, VOL 2, (297) (297), 13 - 15, 英語[査読有り]研究論文（国際会議プロシーディングス）
- We have successfully transferred epitaxial single crystal PZT (Pb (Zr, Ti) O thin films from MgO substrates onto glass substrates by using micro fabrication process. The internal compressive stress of about 200 MPa in the epitaxial PZT thin films was released after the transference. The relative dielectric constant of the PZT thin films increased from 239.4 to 332.9 after the transference with a small decrease of polarization. The crystallinity and crystal orientation of the PZT thin films on the glass substrates were the same to those of epitaxial virgin PZT thin films on the MgO substrates. The transfer process is useful for a fabrication of PZT thin film MEMS devices on any substrates.Vacuum Society of Japan, 2005年, Shinku/Journal of the Vacuum Society of Japan, 48(3) (3), 133 - 135, 日本語[査読有り]研究論文（学術雑誌）
- 2005年, Journal of the Japan Society of Applied Electromagnetics, vol. 13, pp. 310-315, 英語Development of Valveless Micropump Piezoelectrically Driven by Traveling Wave[査読有り]
- 2005年, 日本AEM学会誌, Vol.13.(No.4) (No.4), pp.310 - 315, 日本語圧電アクチュエータを用いた進行波型バルブレスマイクロポンプの開発[査読有り]研究論文（学術雑誌）
- A new atomization method in W/O (water in oil) system was developed for liquid sampling system of μTAS (micro total analysis systems). This device was masufactured using soft MEMS (micro electro mechanical systems) technology and comprised of simple rectangular microchannels made of PDMS (polydimethylsiloxane). Using this device, picoliter-sized cylindrical liquids were generated successfully and sequentially. To investigate the breakup motion of cylindrical liquid in microchannel, a light emitting diode system was developed for the function of the strobe light. Furthermore, theoretical analysis was carried out to predict the size of cylindrical liquids. The effects of continuous phase velocity and microchannel wall on the diameter of cylindrical liquids were clarified experimentally and numerically. The numerical results of cylindrical liquid diameter quantitatively agreed with the experimental results. According to this theoretical model developed here, the device can be optimized to generate smaller and uniform cylindical liquids.Japan Society of Mechanical Engineers, 2005年, 日本機械学会論文集B, 71(708) (708), 2007 - 2012, 日本語[査読有り]研究論文（学術雑誌）
- Single crystal thin films of relaxor PMNT, (1-x)PbMg1/3Nb2/3O3-xPbTiO(3), x = 0 to 0.35, were hetero-epitaxially grown on (001) SrTiO3 by a magnetron sputtering. XRD study showed the unit cell of the PMNT thin films was a c-enlongated tetragonal with highly strained structure at the film thickness below 50 nm. As the film thickness increased above a critical film thickness of around 300 nm, the PMNT thin films evolved from the tetragonal phase to the pseudo-cubic of relaxed structure. We have evaluated the dielectric properties of the relaxed single crystal PMNT thin films. The dielectric constant increased with the increase of the PT as expected: The room temperature dielectric constants at 100 kHz were 800 for PMN and 2700 for PMN-35PT. The PMN-35PT thin films, however, showed a broad temperature anomaly with low maximum dielectric constants of 4800. The d(33) piezoelectric coefficients estimated were 290 pC/N which were different from bulk single crystal values by half order of magnitude, although the dielectric and piezoelectric properties of the relaxed structure were expected to be compatible to bulk materials. The low dielectric constant was not simply attributed to the stress and/or interfacial effect.TAYLOR & FRANCIS LTD, 2005年, INTEGRATED FERROELECTRICS, 70, 131 - 140, 英語[査読有り]研究論文（学術雑誌）
- Thin films of (1-x)PbMg1/3 Nb-2/3 O-3 -xPbTiO(3) (PMNT) with x = 0 to 0.35 were epitaxially grown on (100)SrTiO3 (ST) and (100) MgO substrates by magnetron sputtering. Typical film thickness was 300 to 2000 nm. La-doped conductive (100) ST and Pt coated MgO, (100) Pt/MgO, were used for their dielectric measurements. XRD and cross-sectional TEM studies suggested that the hetero-epitaxial PMNT thin films comprised single crystal-like structure with (001) orientation. The dielectric response showed frequency dispersion similar to bulk relaxor-like behavior except extremely broad temperature anomaly. The maximum relative dielectric constant, epsilon(m)*, for PMNT thin films at x = 0.23 was 900 to 2000. The epsilon(m)* ncreased with the increase of PbTiO3. For PMNT thin films at bulk morphotropic phase boundary condition, x = 0.35, the epsilon(m)* was 5000 which was still lower than bulk values. The low dielectric constant is probably due to the presence of strained hetero-epitaxial layer having temperature independent dielectric properties. The strained PMNT thin films of 1800 nm thick showed d(33) = 120 pC/N at ac applied voltage of 50 V.TAYLOR & FRANCIS LTD, 2005年, FERROELECTRICS, 328, 69 - 77, 英語[査読有り]研究論文（学術雑誌）
- In this study, we evaluated transverse piezoelectric properties of c -axis oriented PbTiO3 (PT) thin films from the actuation of the PT/MgO unimorphs. The PT films were grown on Pt/MgO substrates using rf-sputtering technique. X-ray diffraction measurements revealed that the PT films exhibited highly c -axis orientation with a -axis domains, suggesting epitaxial growth of the PT films. The piezoelectric characteristics of the PT films were estimated by the measurements of tip deflection of the unimorph cantilevers composed of PT films and MgO substrates. The PT cantilevers showed excellent linear piezoelectric deflection even with the application of large reverse voltage to the polar direction. The stable piezoelectricity of the PT films is attributed to not only large coercive field larger than their break down field but the highly c -axis orientation of PT films. We estimated piezoelectric coefficient e(31) of the PT thin films and obtained large transverse piezoelectricity of e(31) = - 1.77 C/m(2) which is two times larger than that of the PT single crystals.TAYLOR & FRANCIS LTD, 2005年, FERROELECTRICS, 327, 91 - 95, 英語[査読有り]研究論文（学術雑誌）
- High-quality (K,Na)NbO3 thin films were successfully deposited on a (100) SrTiO3 (STO) substrate by pulsed laser deposition. High-density KNbO3 (KN), (K0.5Na0.5)NbO3 (KNN) and NaNbO3 (NN) ceramic targets were prepared by spark plasma sintering (SPS). The crystallographic analyses of the film were performed by conventional X-ray diffraction (XRD) analysis and rocking curve measurement. The XRD reciprocal space map was also measured to determine the lattice constants of the film and analyze the crystallographic relationship between the grown film and the STO substrate. The fluctuation change in the orientation of crystals in the grown film decreased and the smoothness of the film surface improved with increasing sodium content of the film. For the NN films, the full width at half maximum (FWHM) of the rocking curve was as small as 0.12degrees. The XRD reciprocal space map measurements showed that the lattices of the KN and KNN films relaxed on the STO substrate but the NN film was restricted to it.JAPAN SOC APPLIED PHYSICS, 2004年09月, JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS, 43(9B) (9B), 6627 - 6631, 英語[査読有り]研究論文（学術雑誌）
- Thermodynamic characteristics of single crystalline Pb(Zr0.52Ti0.48)O3 (PZT) were investigated using c-axis oriented PZT films. The PZT films were epitaxially grown on Pt/MgO substrate and dielectric and ferroelectric properties were measured as a function of one-dimensional stress. The stress dependence of dielectric and ferroelectric properties was examined on the basis of the Landau-Devonshire’s phenomenological theory and the free energy coefficients of single crystalline PZT films were obtained. The dielectric stiffness coefficients and electrostrictive coefficient of epitaxial PZT films were obtained to be α1=-1.30×108(m/F), α11=3.07×108(m5/C2F), α111=-3.11×107(m9/C2F), and Q12=-5.70×10-2(m4/C2), which are different from the values derived from the analysis of polycrystalline PZT. The temperature dependence of dielectric constant of the PZT films showed clear Curie-Weiss law and the dielectric stiffness coefficient α1 derived from this measurement was almost same value from the analysis of stress dependence of the dielectricity of the epitaxial PZT films. © 2004 The American Physical Society.2004年02月, Physical Review B - Condensed Matter and Materials Physics, 69(6) (6), 英語[査読有り]研究論文（学術雑誌）
- Thermodynamic characteristics of single crystalline Pb(Zr0.52Ti0.48)O-3 (PZT) were investigated using c-axis oriented PZT films. The PZT films were epitaxially grown on Pt/MgO substrate and dielectric and ferroelectric properties were measured as a function of one-dimensional stress. The stress dependence of dielectric and ferroelectric properties was examined on the basis of the Landau-Devonshire's phenomenological theory and the free energy coefficients of single crystalline PZT films were obtained. The dielectric stiffness coefficients and electrostrictive coefficient of epitaxial PZT films were obtained to be alpha(1)=-1.30x10(8) (m/F), alpha(11)=3.07x10(8) (m(5)/(CF)-F-2), alpha(111)=-3.11x10(7) (m(9)/(CF)-F-2), and Q(12)=-5.70x10(-2) (m(4)/C-2), which are different from the values derived from the analysis of polycrystalline PZT. The temperature dependence of dielectric constant of the PZT films showed clear Curie-Weiss law and the dielectric stiffness coefficient alpha(1) derived from this measurement was almost same value from the analysis of stress dependence of the dielectricity of the epitaxial PZT films.AMER PHYSICAL SOC, 2004年02月, PHYSICAL REVIEW B, 69(6) (6), pp.64103, 英語[査読有り]研究論文（学術雑誌）
- Mixing of samples and reagents in microchannels is a key technology in realizing a μTAS. Turbulence is not practically attainable in micro-scale since Reynolds number is extremely low. Therefore, introducing oscillations or electrical force to disturb liquid flow is necessary to enhance the mixing in microchannels. Some researchers reported mixing method by the use of time pulsating cross-flow into main channel. In those systems, complex actuators are necessary and the efficiency is not so high due to the difficulties in the optimization. In this paper, we present a simple mixing method using an asymmetric pulsating flow.一般社団法人日本機械学会, 2004年, 年次大会講演論文集, 2004, 67 - 68, 日本語
- Structure and ferroelectric properties of sputtered PMNT thin filmsThin films of strain free single c-domain / single crystal (PbMg1/3Nb2/3O3)(1-x) (PbTiO3)(x), x=0-0.4 were epitaxially grown on (001)SrTiO3 and (001)MgO substrates by magnetron sputtering. The sputtered PMNT thin films showed bulk relaxor-like frequency dispersion in their dielectric properties but exhibited strongly diffused temperature anomaly unlikely to bulk PMNT. The d(33) and d(31) values at MPB composition lied 200-300pC/N and 70-100pC/N, respectively. These values were larger than those of PZT ceramics, but 10 to 15% of PMNT single crystal's values.IEEE, 2004年, 2004 14th IEEE International Symposium on Applications of Ferroelectrics-ISAF-04, 11 - 16, 英語[査読有り]研究論文（国際会議プロシーディングス）
- 2004年, Produktion von Leiterplatten Und Systemen, Vol.6.(No.3.) (No.3.), pp457 - 459, 英語Low-Voltage Actuation of RF-MEMS Switch Using Piezoelectric PZT Thin-Films[査読有り]研究論文（学術雑誌）
- Transverse piezoelectric properties of Pb(Zr, Ti)O-3 (PZT) films were estimated using a simple measuring method we developed. The c-axis oriented PZT films were epitaxially grown on Pt/MgO substrates, while the polycrystalline PZT films with the preferential orientation of <111> were deposited on Pt/Ti/Si substrates using rf sputtering technique. The piezoelectric characteristics of the PZT films with different crystalline structures were evaluated by the tip deflection of the unimorph cantilevers of the strip specimen just cleaved out from the substrates. The PZT films on MgO substrates showed excellent linear piezoelectric deflection to the applied voltage with the stable piezoelectric coefficient e(31) of -4.7 to -4.9 C/m(2) which is caused by the ideal lattice motion of the single domain structure. On the other hand, the PZT films on Si substrates showed large hysteresis of the deflection and the value of e(31) ranged from -4.3 to -7.5 C/m(2) according to the applied voltage. The non-linear as well as large piezoelectric response of the PZT films on Si is similar to conventional bulk PZT ceramics, indicating that the reorientation of domains whose polar axes are not parallel to the electric field is superimposed on the lattice motion. (C) 2003 Elsevier B.V. All rights reserved.ELSEVIER SCIENCE SA, 2003年10月, SENSORS AND ACTUATORS A-PHYSICAL, 107(1) (1), 68 - 74, 英語[査読有り]研究論文（学術雑誌）
- Crystallographic structure of as-grown epitaxial Pb(Zr,Ti)O-3 (PZT) films was investigated with regard to the Zr/Ti ratio and crystalline orientation. PZT films with (001) and (111) orientation were epitaxially grown on (100) and (111)SrTiO3 substrates respectively using radio-frequency (rf) sputtering. Four circle x-ray diffraction measurements revealed that the crystallographic dependence on Zr/Ti composition in PZT films was much different from bulk PZT. In particular, (001)-oriented PZT films showed tetragonal structure even in the Zr/Ti composition of 70/30 where the bulk PZT ceramics are rhombohedral phase. In addition, although (001)-oriented PZT films with Zr/Ti ratio of 53/47 and 70/30 showed tetragonal structure, (111)-oriented PZT films with the same Zr/Ti ratio were identified as the rhombohedral structure. The cell volume of the PZT films with both orientations increased, suggesting the excess Pb atoms in the films due to the impinging energetic sputtered particles induces the anomalous crystalline structure of the PZT films. Dielectric properties of the PZT films exhibited stable value independent of Zr/Ti ratio and characteristic increase of dielectric constant near Zr/Ti=53/47 could not be observed. These results suggest that the internal stress due to the sputter deposition plays an important roll in the unique characteristics of crystallographic and electrical properties of the epitaxial PZT films. (C) 2003 American Institute of Physics.AMER INST PHYSICS, 2003年04月, JOURNAL OF APPLIED PHYSICS, 93(7) (7), 4091 - 4096, 英語[査読有り]研究論文（学術雑誌）
- Anomalous cystalline structure of epitaxial Pb(Zr,Ti)O-3 films grown on (100)Pt/(100)MgO by RF-magnetron sputteringCompositional dependence of crystallographic structure of the epitaxial Pb(Zr,Ti)O-3 (PZT) films was investigated. The c-axis oriented PZT films with Zr/Ti ratio ranging from 10/90 to 70/30 were epitaxially grown on (100)Pt/(100)MgO substrates using rf-sputtering. Four-circle x-ray diffraction measurements revealed that the PZT films exhibited anomalous crystalline structure which was considerably different from the phase diagram of bulk PZT. In particular, the PZT films showed tetragonal structure even with the Zr/Ti composition above 53/47 and rhombohedral phase could not be identified even for the PZT films of 70/30. The lattice constants of the PZT films were independent of the film thickness. The sputtering process accompanies non-thermal equilibrium reactions with the bombardment of the energetic sputtered particles to the growing films and might induce isotropic internal stress across the films. The anomalous crystalline characteristics are attributed to the sputter-induced stress of the PZT films.KOREAN PHYSICAL SOC, 2003年04月, JOURNAL OF THE KOREAN PHYSICAL SOCIETY, 42, S1317 - S1321, 英語[査読有り]研究論文（学術雑誌）
- Thin films of PbMg1/3 Nb2/3O3 (PMN) and (1 - x)PbMg1/3 Nb O-2/3(3) -xPbTiO(3) (PMNT) with x = 0.1 to 0.3 were epitaxially grown on (100) MgO and (100) SrTiO3 (ST) substrates by magnetron sputtering. Typical film thickness was 300 to 900 nm. Pyrochlore free (001) PMN and (001) PMNT thin films were grown on the ST and MgO substrates at narrow temperature window of 500 +/- 20degreesC. The cross-sectional TEM image showed that the sputtered PMN and PMNT thin films comprised high density and continuous structure. These sputtered films showed 3-dimensional epitaxy. The dielectric response of the sputtered thin films showed frequency dispersion similar to bulk relaxor-like behavior with a broad temperature anomaly. PMN-23PT (x = 0.23) thin films showed the temperature of maximum, Tm, at 80degreesC. The Tm coincided with that of corresponding bulk materials. However, the obtained maximum dielectric permittivity, epsilon(m) , epsilon(m) = 900 to 1000, was considerably smaller than that in the bulk. The relatively low dielectric permittivity was probably due to the presence of strained hetero-epitaxial layer having temperature independent dielectric properties.TAYLOR & FRANCIS LTD, 2003年, INTEGRATED FERROELECTRICS, 55, 781 - 793, 英語[査読有り]研究論文（学術雑誌）
- オ-ム社, 2003年, New Diamond, Vol. 19.(No.2) (No.2), pp.29 - 14, 日本語DLC・ダイヤモンド薄膜のMEMSおよびμ-TASへの応用[招待有り]研究論文（学術雑誌）
- We performed structural studies on PZT thin films, Pb-y(Zr0.57Ti0.43)(2-y)O-3; y=0.97, 1.07, 1.15. The thin films were deposited on Pt (001)/MgO (001) substrates by rf-magnetron sputtering. Every film grew epitaxially in a tetragonal phase with the "cube on cube" relationship to the substrate, and contained no other crystalline phases, such as PbO or pyrochlore. It is known that PZT bulk ceramic with Zr/Ti of about 57/43, the composition of which is on the Zr-rich side of the morphotropic phase boundary (MPB), has a rhombohedral structure at room temperature. These PZT films, however, had tetragonal perovskite structures (space group: P4mm). The Pb atoms mainly occupy the A (1a) site, and the Zr and Ti atoms occupy the B (1b) site at random. When y is less than unity in Pb-y(Zr0.57Ti0.43)(2-y)O-3, the excess Zr/Ti tends to enter the Pb (A) sites and randomly occupy the sites together with Pb; and when y is more than unity, the excess Pb tends to mix with the Zr and Ti at Zr/Ti (B) sites. In all these films, the atomic positions of Zr/Ti, O(1), and O(2) shift mutually along the c axis in the tetragonal structure. With increasing y, c/a approaches unity and the crystal structure shifts toward the rhombohedral phase, especially in the O(2) atomic position, where a large shift was observed. The PZT thin films were grown under the restraint of a Pt (001) square lattice, and under isotropic compressive plane stress. These are the major reasons that the film crystallizes into tetragonal perovskite and polarizes spontaneously in the c-axis direction perpendicular to the substrate surface.AMER PHYSICAL SOC, 2002年08月, Physical Review B, 66(6) (6), pp. 064102, 英語[査読有り]研究論文（学術雑誌）
- 2002年, Micro Total Analysis Systems 2002, No. 1,, pp. 88 - 90, 英語Development of Micomixer Based on Instability of Interface Between Two Immiscble Liquids（共著）[査読有り]研究論文（学術雑誌）
- 2002年, Micro Total Analysis Systems 2002, No.1,, pp. 148 - 150, 英語Bi-directional Valve-less Micropumu using Piezoelectric Micro-array Actuators（共著）[査読有り]研究論文（学術雑誌）
- 2001年, The Society of Materials Science, B, pp. 193-196, 英語Piezoelectric Properties of Pzt Thin Film[査読有り]
- This study shows the possibility of controlling dielectric or piezoelectric properties of PZT thin film by applying strain after the deposition. We investigate the relationship between applied strain and relative dielectric coefficient of PZT films deposited on SUS304 and SUS430 stainless steel. The results show that the relative dielectric coefficient increases with decreasing compressive strain. While the crystal orientation of PZT film deposited on SUS304 coincide with that on SUS430, the residual compressive strain in the former is different from the latter. We compare the dielectric properties of PZT film deposited on SUS304 with that on SUS430 at the same strains in the films. Dielectric properties of the former agree fairly well with those of the latter. © 2000, The Institute of Electrical Engineers of Japan. All rights reserved.2000年, IEEJ Transactions on Sensors and Micromachines, 120(12) (12), 559 - 564, 英語[査読有り]研究論文（学術雑誌）
- This study shows the possibility of controlling dielectric or piezoelectric properties of PZT thin film by applying strain after the deposition. We investigate the relationship between applied strain and relative dielectric coefficient of PZT films deposited on SUS304 and SUS430 stainless steel. The results show that the relative dielectric coefficient increases with decreasing compressive strain. While the crystal orientation of PZT film deposited on SUS304 coincide with that on SUS430, the residual compressive strain in the former is different from the latter. We compare the dielectric properties of PZT film deposited on SUS304 with that on SUS430 at the same strains in the films. Dielectric properties of the former agree fairly well with those of the latter. © 2000, The Institute of Electrical Engineers of Japan. All rights reserved.2000年, Trans. IEE of Japan, 120(12) (12), 559 - 564, 英語[査読有り]研究論文（学術雑誌）
- The wafer flexure technique was used to characterize the d(31) coefficient of a number of sol-gel and radio frequency (rf) sputtered lead zirconate titanate (PZT) thin films with thicknesses between 0.6 and 3 mu m. Typical d(31) values for well-poled 52/48 sol-gel films were found to be between -50 and -60 pC/N. The rf sputtered films possessed large as-deposited polarizations which produced d(31) coefficients on the order of -70 pC/N in some unpoled films. The subsequent poling of the material, in a direction parallel to the preferred direction increased the d(31) coefficient to values of about -85 pC/N. The aging behavior of the d(31) coefficient was also investigated. For sol-gel films the aging rate was found to be independent of poling direction and to range from 4% per decade for a 2.5 mu m film to 8% per decade for a 0.6 mu m film. In contrast, the aging rate of sputtered films was strongly dependent on poling direction, with maximum and minimum rates of 26% and 2% per decade recorded. These aging rates are very high in light of the limited twin wall motion in PZT films, and are believed to result from the depolarizing effects of internal electric fields in the rf sputtered films and interfacial defects in the sol-gel films. (C) 1999 American Institute of Physics. [S0021-8979(99)04609-5].AMER INST PHYSICS, 1999年05月, Journal of Applied Phisics, 85(9) (9), 6711 - 6716, 英語[査読有り]研究論文（学術雑誌）
- 1999年, Advances in Information Storage Systems, Vol.10, pp.347 - 355, 英語Piezoelectric Property of CVD ZnO Film for Pressure Micro Sensor（共著）[査読有り]研究論文（学術雑誌）
- Interfacial Structure and Ferroelectric Properties of PZT/SrRuO3 Heterostructures on MISCUT (001)SrTiO3 （共著）A heterostructure of (001)PZT(53/47)/(110)SrRuO3(SRO) was deposited on a miscut (001)SrTiO3(ST) substrate by a magnetron sputtering. The film thickness of the PZT and SRO ranged from 100nm to 200nm. The miscut angles were typically 1.7 degrees. The heterostructure was grown on the miscut ST substrates under a step-flow growth. The heterostructure was tightly bonded to the ST substrate without an interfacial layer. The sputtered PZT thin films were tetragonally deformed with c=4.16 Angstrom (bulk c-lattice parameter, 4.14 Angstrom). A room temperature dielectric constant of the PZT thin films was 200 to 300 at 1 kHz. The P/E hysteresis measurements indicated that the saturation polarization P-s was 40 mu C/cm(2) with a coercive field E-c of 400 kV/cm to 500 kV/cm. The E-c observed was one order of magnitude higher than a bulk value for PZT The high values of E-c were observed in a perfect c-domain orientation without an interfacial layer or 90 degrees domains.GORDON BREACH SCI PUBL LTD, 1999年, Integrated Ferroelectrics, 26(1-4) (1-4), 741 - 748, 英語[査読有り]研究論文（学術雑誌）
- Piezoelectric characteristics of c-axis oriented Pb(Zr,Ti)O3 thin films（共著）Piezoelectric properties as well as crystalline structures of the c-axis oriented Pb(Zr,Ti)O-3 (PZT) thin films were investigated. The PZT films with a composition near the morphotropic phase boundary were deposited on (100)Pt/MgO substrates using rf-magnetron sputtering. Cross-sectional TEM observation demonstrated that the PZT films were single-crystalline structures without 90 degrees domains. Using the PZT films of 3.2 mu m in thickness, unimorph cantilevers with PZT/polyimide structure were microfabricated and their piezoelectric behavior was observed. For the microcantilevers of 500 mu m in length, large deflection about 6 mu m at 30 V could be obtained without a poling treatment for the PZT films. The excellent piezoelectric coefficient d(31) of 84 similar to 105 x 10(-12) m/V was derived from the deflection of the cantilevers.KOREAN PHYSICAL SOC, 1998年02月, Journal of Korean Physical Society, 32, S1481 - S1484, 英語[査読有り]研究論文（学術雑誌）
- Continuous Single Crystal PbTiO3 Thin Films Epitaxially Grown on Miscut (001)SrTiO3（共著）Continuous single crystal (001)PbTiO3 (PT) thin films, 5 to 300 nm in thickness, were epitaxially grown on miscut (001)SrTiO3 (ST), miscut angle 1.7 degree, by rf-planar magnetron sputtering. The surface of the miscut substrates comprised periodic striped patterns with periodic step lines and terraces; the step height was 0.4 nm and terrace width was 14 nm. The surface of PT thin films also comprised periodic striped patterns; the step height was 1 to 3 nm and the terrace width was 50 to 150 nn. The film growth was governed by a step-flow growth with step-bunching. The layer growth mode of Frank-van der Merwe type was predominant and the surface was extremely hat on an atomic scale. The resultant epitaxial films showed a single crystal/single c-domain structure. Epitaxial growth on miscut substrate is essential to fabricate perovskite thin films with controlled microstructure.KOREAN PHYSICAL SOC, 1998年02月, Journal of Korean Physical Society, 32, S1344 - S1348, 英語[査読有り]研究論文（学術雑誌）
- Basic Sputtering Process and Ferroelectric Properties of Single-Domain Single-Crystal Thin Films of PbTiO3 （共著）Single c-domain single crystal PbTiO3 (PT) thin films were prepared by sputtering on both miscut (001)SrTiO3 (ST) and (110)SrRuO3/miscut (001)ST substrates with a miscut angle of 1.7 degrees. Film thickness ranged from 5 nm to 250 nm. The film growth was governed by step-flow growth and the film surface was atomically flat. The lattice misfit strain induced during the film growth was quenched. The PT films were tetragonally deformed and tightly bonded to the ST. The PT films showed no anomaly on the curves of lattice parameter in terms of temperature (temperature range, room temp. to 600 degrees C), due to their excellent interfacial quality, although anomalies are expected at the Curie temperature (around 490 degrees C in bulk PT). The P/E loops suggest that the saturation polarization P-s was 40 mu C/cm(2) with a high coercive field of 400 to 500 kV/cm and a dielectric constant of 60 to 70 at 1 KHz. The P-s of the PT thin film is about half that of bulk PT.GORDON BREACH SCI PUBL LTD, 1998年, Integrated Ferroelectrics, 21(1-4) (1-4), 451 - 460, 英語[査読有り]研究論文（学術雑誌）
- The c-axis oriented Pb(Zr, Ti)O-3 (PZT) thin films, which have a tetragonal structure and a composition near the morphotropic phase boundary, have been obtained on (100)MgO substrates with (100)Pt electrodes by rf-magnetron sputtering. These PZT thin films have a remarkably low relative dielectric constant of 240. The intrinsic piezoelectric and mechanical properties of the thin films were evaluated. The velocity of sound and the mechanical compliance s(11)(E) were measured by the piezoelectric resonance of the cantilever. The piezoelectric coefficient d(31) was measured directly from the transverse expansion of the cantilever beams. Even without a poling treatment, dal of the PZT thin films was -100 pC/N and almost the same as that of bulk ceramics. The extremely large piezoelectric coefficient gar of -57 x 10(-3) Vm/N was also estimated because of the large d(31) and remarkably low dielectric constant. These PZT thin films are suitable for micro sensor and actuator applications.JAPAN J APPLIED PHYSICS, 1997年09月, JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS, 36(9B) (9B), 6065 - 6068, 英語[査読有り]研究論文（学術雑誌）
- The composition and crystalline quality of ferroelectric thin films formed on Pt covered MgO(100) substrates have been investigated with combined use of O-16(alpha,alpha)O-16 3.045 MeV resonant backscattering and channelling techniques, Oxygen depth profiling has been estimated by the resonant backscattering, and crystalline quality was estimated by the channelling method. The ferroelectric thin films of PbTiOy (PTO) and La-modified PTO (PbxLa1-xTiOy; PLT) (y approximate to 3) oi 750 Angstrom thick were formed on Pt covered MgO substrates by multi-target ion beam sputtering method with introducing oxygen gas, Pt thin films beneath the film due to the under-electrode were also fabricated by the same method. For both PTO and PLT films, depth profiling of Pb and Ti elements showed relatively constant concentrations for whole film thicknesses, whereas the oxygen concentrations varied drastically, The extent of variation of oxygen concentration was larger for the PTO film than for the PLT film. This led to better crystalline quality of PLT, compared with PTO, The effect of oxygen depth profiling and crystalline quality on the electric properties is also discussed.ELSEVIER SCIENCE BV, 1997年06月, Applied Surface Science, 117, 453 - 458, 英語[査読有り]研究論文（学術雑誌）
- Piezoelectric properties of the c-axis oriented Pb(Zr,Ti)O-3 (PZT) thin films were investigated. The PZT films with a composition near the morphotropic phase boundary were epitaxially grown on (100)Pt-coated MgO substrates by rf-magnetron sputtering. The PZT films exhibited excellent ferroelectricity with a remanent polarization more than 50 mu C/cm(2). In order to examine intrinsic piezoelectric properties, cantilever structures were microfabricated with the PZT films. The piezoelectric coefficient d(31) Of PZT films, which were not subjected to poling treatments, was measured directly from the transverse expansion of the cantilever beams. The measurements revealed that the PZT films were naturally polarized and had a relatively large piezoelectric coefficient d(31) of 100 x 10-(12) m/V without poling. (C) 1997 American Institute of Physics.AMER INST PHYSICS, 1997年03月, Applied Physics Letters, 70(11) (11), 1378 - 1380, 英語[査読有り]研究論文（学術雑誌）
- Ferroelectric thin films of PbTiO3, (Pb,La)TiO3 (PLT) and Pb(Zr,Ti)O-3 (PZT) were successfully fabricated using a multi-ion-beam sputtering technique. X-ray diffraction (XRD) measurements demonstrated that the films with perovskite structure were grown on (100)Pt/MgO and (111)Pt/Ti/SiO2/Si substrates at a low substrate temperature of 415 degrees C. The PZT films about 630 Angstrom in thickness exhibited a high dielectric constant of 675 and an excellent ferroelectric P-E hysteresis loop. In order to promote the surface reactions, the substrates were irradiated with XeCl excimer laser beam during the deposition at a room temperature, The results of XRD revealed the formation of perovskite PZT thin films.ELSEVIER SCIENCE BV, 1996年05月, Nuclear Instruments and Methods in Physics Research B, 112(1-4) (1-4), 125 - 128, 英語[査読有り]研究論文（学術雑誌）
- Artificial superlattices consisting of antiferroelectric PbZrO3 (PZO) and ferroelectric PbTiO3 (PTO) have been fabricated by a multi-ion-beam sputtering technique. The epitaxial PZO and PTO layers were sequentially grown on (100)Pt/MgO substrates at a low substrate temperature of 415 degrees C with a periodicity from 5 to 100 perovskite unit cells. X-ray diffraction studies revealed the superlattice structures with a-axis oriented PTO layers on a-axis oriented PZO layers. The dielectric and ferroelectric properties of the superlattice films were enhanced with increasing periodicity. (C) 1996 American Institute of Physics.AMER INST PHYSICS, 1996年01月, Applied Physics Letters, 68(3) (3), 328 - 330, 英語[査読有り]研究論文（学術雑誌）
- Pb-based ferroelectric thin films of PbTiO3, (Pb, La)TiO3 and Pb(Zr, Ti)O-3 were fabricated on Pt/MgO and Pt/Ti/SiO2/Si substrates using an excimer-laser-assisted multi-ion-beam sputtering technique. During the deposition at room temperature, the surface of the films was irradiated with XeCl excimer laser pulses in order to promote surface reactions. X-ray diffraction and in situ reflection high-energy electron diffraction measurements demonstrated that the films with perovskite structure were epitaxially grown with preferential a-axis orientation. The prepared PZT films exhibited the dielectric constant of 248 and ferroelectric P-E hysteresis loops.JAPAN J APPLIED PHYSICS, 1995年09月, Japanese Journal of Applied Physics, 34(9B) (9B), 5211 - 5215, 英語[査読有り]研究論文（学術雑誌）
- AMER INST PHYSICS, 1995年01月, Applied Physics Letters, 66(2) (2), 145 - 147, 英語[査読有り]研究論文（学術雑誌）
- Lead-zirconate-titanate (PZT) thin films with lead-lanthanum-titanate (PLT) buffer layer prepared by multiion-beam sputtering were characterized from the structural and electrical viewpoints. Cross-sectional transmission electron microscopy (TEM) observation demonstrated the epitaxial growth of the films without intermixing layers or misfit dislocations. Nominal interdiffusion of PZT/PLT/substrates was found in the depth profiles obtained from secondary ion mass spectroscopy (SIMS). The PZT films over the entire compositional range of Zr/Ti ratio exhibited relative dielectric constant which was consistent with the dependence of bulk PZT; however, obvious changes of lattice spacings at phase boundaries were not found from X-ray diffraction (XRD) measurement.JAPAN J APPLIED PHYSICS, 1994年01月, Japanese Journal of Applied Physics, 33(1B) (1B), 574 - 577, 英語[査読有り]研究論文（学術雑誌）
- Ferroelectric lead-zirconate-titanate (PZT) thin films were successfully fabricated by the multi-ion-beam sputtering technique in an oxygen ambient at a low substrate temperature of 415-degrees-C. By inserting lead-lanthanum-titanate (PLT) buffer layers between substrates and PZT films, the perovskite-PZT thin films could be epitaxially grown on (100)MgO, (100)Pt/MgO and (111)Pt/Ti/SiO2/Si substrates. These films, even at thickness values of as low as 630 angstrom, showed excellent ferroelectric properties with a remanent polarization of 20 muC/cm2, coercive field of 200 kV/cm, and a relative dielectric constant of 700.JAPAN J APPLIED PHYSICS, 1993年09月, Japanese Journal of Applied Physics, 32(9B) (9B), 4057 - 4060, 英語[査読有り]研究論文（学術雑誌）
- Ferroelectric PbTiO3 Thin Films Prepared by Multi-Ion-Beam Sputter and Ion-Assisted Deposition（共著）Very thin PbTiO3 films of approximately 350 angstrom were synthesized in situ on MgO substrates by multi-ion-beam sputter deposition using metal targets. Crystalline films in a perovskite phase were obtained at a low substrate temperature of 415-degrees-C by means of reactive sputtering in an oxygen ambient. The formation of crystal phases was studied as a function of deposition parameters, and ion-beam-assisted deposition using an electron cyclotron resonance (ECR) plasma was also employed to improve the film growth. Low-energy (<300 eV) oxygen ion bombardment was found to enhance c-axis orientation and crystallization at a lower substrate temperature of 400-degrees-C.JAPAN J APPLIED PHYSICS, 1993年07月, Japanese Journal of Applied Physics, 32(7A) (7A), L950 - L953, 英語[査読有り]研究論文（学術雑誌）
- Tribological properties of aluminum modified with nitrogen ion implantation and plasma treatment（共著）Surface modification of Al by a combination of ion implantation and plasma treatment has been investigated from the tribological viewpoint. Nitrogen ions were implanted into pure Al specimens at 90 keV and then ion-nitrided at a few kV for 6 h. The wear test was carried out using a wheel-on-plate-type testing machine. It was shown that these treatments reduce the friction coefficient, the wear rate and increase the hardness. The surface of the Al specimen was observed by optical microscopy and SEM. A lot of blisters emerged on the surface of the treated Al specimen. The TEM observation revealed the detailed surface structure of the modified layer. These results suggest that the combination of the treatments is effective for the modification of tribological properties of the Al surface.ELSEVIER SCIENCE BV, 1991年07月, Nuclear Instruments and Methods in Physics Research B, 59(60) (60), 920 - 924, 英語[査読有り]研究論文（学術雑誌）
- 2020年, 応用物理学会春季学術講演会講演予稿集(CD-ROM), 67thSi基板上エピタキシャルPb(Zr,Ti)O3薄膜の結晶構造と圧電特性の評価
- 2019年02月25日, 応用物理学会春季学術講演会講演予稿集(CD-ROM), 66th, ROMBUNNO.9a‐PA2‐29, 日本語有機圧電エナジーハーベスターにおける振動発電特性の膜厚依存性研究発表ペーパー・要旨（全国大会，その他学術会議）
- 2019年, フッ素化学討論会講演要旨集, 42ndフッ素系高分子圧電体を用いたユニモルフカンチレバー型振動発電デバイスの特性評価
- [東京] : Institute of Electrical Engineers of Japan, 2018年, 「センサ・マイクロマシンと応用システム」シンポジウム論文集 電気学会センサ・マイクロマシン部門 [編], 35, 4p, 日本語機械的ストレス下における植物の根系発達過程の解析手法—Analytical method for developmental process of growing root systems under mechanical stress
- 2018年, 応用物理学会春季学術講演会講演予稿集(CD-ROM), 65thPb(Zr,Ti)O3薄膜の電圧印加結晶構造変化の組成依存性
- 2017年, 応用物理学会秋季学術講演会講演予稿集(CD-ROM), 78thPb(Zr,Ti)O3圧電薄膜の逆圧電効果による結晶構造変化のその場観察
- 30pm1-E-4 圧電薄膜アクチュエータを用いたインセクトスケール圧電ロボットの作製と評価This paper describes the fabrication and characterization on insect-scale piezoelectric thin-film robots. Recently, many insect-scale robots are being developed for medical and engineering field. However, they need a power source and are expensive due to complex structures. In this study, we fabricated an insect-scale robot driven at low voltage and characterized them. We deposited PZT thin films on cantilever-shaped stainless steel (SUS304) substrates, and assembled them into a three-leg insect-scale robot. From experimental results, a robot with no load moved at 2.25 mm/s by applying 13 V_一般社団法人日本機械学会, 2015年10月21日, マイクロ・ナノ工学シンポジウム, 2015(7) (7), "30pm1 - E-4-1"-"30pm1-E-4-2", 日本語
unipolar square-wave voltage at 190 Hz. In contrast, a robot with 72.8 mg mass moved at 3.03 mm/s by applying 20 V_ voltage at 156 Hz. We successfully realized an insect-scale piezoelectric thin-film robot driven at low voltage. - 2A2-R08 圧電薄膜の転写技術を用いたソフトアクチュエータの開発We developed novel soft actuators using piezoelectric thin films. To realize low-cost fabrication method, we also developed a new transfer technique of piezoelectric thin films, which was deposited on temporary stainless steel substrate, to PDMS substrate by using wet etching process. By characterizing crystal structure and driving performance as actuators, we experimentally clarified that transferred Pb(Zr,Ti)O_3 (PZT) thin films have piezoelectric properties. This method might allow us to develop novel MEMS (micro-electro-mechanical systems) devices such as artificial muscle at low-cost fabrication in future.一般社団法人日本機械学会, 2015年05月17日, ロボティクス・メカトロニクス講演会講演概要集, 2015, "2A2 - R08(1)"-"2A2-R08(2)", 日本語
- 2015年, セラミックス基礎科学討論会講演要旨集, 53rdスパッタ法を用いたLi4Ti5O12薄膜の作製とその評価
- 22am2-E3 金属基板上PZT薄膜を用いた振動発電素子の信頼性評価に関する研究This paper describes the reliability of vibration energy harvesters of metal-based Pb(Zr,Ti)O_3 (PZT) thin films. Metal foil cantilevers have attracted attention to improve the lifetime of vibration energy harvesters because of their strong fracture strength. However, the long-term reliability of vibration energy harvesters has not been investigated intensively. In this study, we fabricated the PZT thin-film vibration energy harvesters based on metal foil cantilevers (length: 10 mm, width: 2.5 mm, thickness: 30 μm) and measured their output power for one thousand minutes. From the experimental results, we confirmed that the vibration energy harvester showed quite low degradation of approximately 0.31% by every decade on a logarithmic time scale at the acceleration of 1 m/s^2. On the other hand, we could not demonstrate the precise relationship between the output power and excitation acceleration because of the variation in measured data.一般社団法人日本機械学会, 2014年10月20日, マイクロ・ナノ工学シンポジウム, 2014(6) (6), "22am2 - E3-1"-"22am2-E3-2", 日本語
- 22am2-E1 圧電薄膜を用いた自励振動型気流発電素子の作製および評価We fabricated self-excited vibration energy harvesters of Pb(Zr, Ti)O_3 (PZT) thin films using air flow. To generate a large self-excited vibration, we use 30-μm-thickness stainless steel (SS304) foils as base substrates of PZT thin films. The PZT thin films were deposited directly by rf-magnetron sputtering. To compensate the initial bending of PZT/SS304 substrates due to the thermal stress, we deposited the counter PZT thin films on the backside of SS304 substrates. When the angle of attack was 30°, the energy harvester generated the self-excited vibration above the wind speed of 8 m/s, and the output power reached 19 μW at the wind speed of 12 m/s.一般社団法人日本機械学会, 2014年10月20日, マイクロ・ナノ工学シンポジウム, 2014(6) (6), "22am2 - E1-1"-"22am2-E1-2", 日本語
- 20pm1-E3 金属基板上圧電薄膜アクチュエータを用いたミリメータスケールロボットの作製We fabricated the millimeter-scale robot by metal-based PZT thin-film actuator. PZT thin films were directly deposited on 50-μm-thick Ti substrates by rf-magnetron sputtering. Piezoelectric actuators have simple structure and drive by low voltage. Therefore, in recent year, the robot using piezoelectric materials have been studied. However, piezoelectric actuators cannot generate a large displacement. In this study, we fabricated the millimeter-scale robot(7.5×2.5 cm^2) actuated using resonance since the largest displacement can be generated at the resonance. The movement of the robot depends on the angle between front and rear legs θ and the frequency f of the applied voltage. Under the condition of θ = 123° and f = 10.6 kHz, the robot moved forward at a speed of 6.74 cm/s. On the other hand, under the condition of θ = 123° and f = 5.4 kHz, the robot moved backward at a speed of 1.21 cm/s.一般社団法人日本機械学会, 2014年10月20日, マイクロ・ナノ工学シンポジウム, 2014(6) (6), "20pm1 - E3-1"-"20pm1-E3-2", 日本語
- 20pm1-F3 PZT圧電薄膜および圧電MEMSデバイスの信頼性評価Piezoelectric thin films have attracted attention for MEMS applications. In addition to the deposition of the high-quality piezoelectric thin films, establishment of the measurement technique of the piezoelectric properties, including the evaluation of the reliability, is strongly demanded. In this presentation, we will discuss the characteristics of the proper and inverse piezoelectricity of the thin films, and related properties of the reliability.一般社団法人日本機械学会, 2014年10月20日, マイクロ・ナノ工学シンポジウム, 2014(6) (6), "20pm1 - F3-1"-"20pm1-F3-2", 日本語
- 21am2-A8 ウエットエッチングによる圧電薄膜のPDMS基板上への転写技術This paper reports a simple and high-productive fabrication method of flexible piezoelectric substrate. To realize low-cost fabrication method, we developed a novel transfer technique of piezoelectric thin films onto PDMS substrate based on metal wet etching process. We experimentally clarified that transferred Pb(Zr,Ti)O3 (PZT) thin films by using our developed method have piezoelectric property. This method might allow us to develop novel MEMS (micro-electro-mechanical systems) devices such as wearable sensors and flexible energy harvesters at low-cost fabrication.一般社団法人日本機械学会, 2014年10月20日, マイクロ・ナノ工学シンポジウム, 2014(6) (6), "21am2 - A8-1"-"21am2-A8-2", 日本語
- 20pm1-E2 正・逆圧電効果によるPZT薄膜の圧電定数e_<31,f>の評価We evaluated the transverse piezoelectric coefficient e_<31,f> of Pb(Zr,Ti)O_3 (PZT) thin films from direct and inverse piezoelectric effects using cantilever methods. The PZT/Si unimorph cantilevers (length: 17.8 mm, width: 2.0 mm, thickness: 628 μm) were fabricated by depositing the PZT thin films and the stripe-shaped Pt top electrodes on Pt/Ti/Si substrates by rf-magnetron sputtering. From the e_<31,f> measurement, we confirmed that e_<31,f> largely depended on frequency in both direct and inverse effects. In cases where evaluated from direct piezoelectric effect, e_<31,f> was independent of position and size of electrode and input displacement, and calculated to be -6 C/m^2 above 20 Hz. On the other hand, e_<31,f> evaluated from inverse piezoelectric effect increased with applied voltage, and calculated to be as high as -12 C/m^2 below 500 Hz.一般社団法人日本機械学会, 2014年10月20日, マイクロ・ナノ工学シンポジウム, 2014(6) (6), "20pm1 - E2-1"-"20pm1-E2-2", 日本語
- 2014年, 応用物理学会春季学術講演会講演予稿集(CD-ROM), 61stスパッタ法を用いたLi4Ti5O12薄膜の作製とその評価
- 2014年, 応用物理学会秋季学術講演会講演予稿集(CD-ROM), 75thポリ尿素薄膜を用いた焦電・圧電特性および振動発電評価
- 6AM2-A-8 スパッタ法で作製したPZT薄膜積層アクチュエータ(6AM2-A マイクロナノプロセス技術I(センサシンポジウムとの合同セッション))We fabricated multilayer ceramic actuator (MLCA) composed of piezoelectric layers with SrRuO_3 (SRO) internal electrodes by single sputtering deposition. We deposited approximately 500-nm-thick Pb(Zr,Ti)O_3 (PZT) layers on SiO_2/Si substrates through a movable shadow mask. The separated internal SRO electrodes are prepared by sliding the shadow mask and multilayered PZT thin films are deposited on a Si substrate with external electrodes on both sides of the PZT films. The PZT layers of MLCA have perovskite structure. The MLCA with five PZT layers have high-dielectric properties; a relative electric coefficient of approximately 1100 regardless of the number of PZT layers. The piezoelectric displacement of Si cantilever with MLCA increased with the number of PZT layers.一般社団法人日本機械学会, 2013年11月04日, マイクロ・ナノ工学シンポジウム, 2013(5) (5), 107 - 108, 日本語
- 5PM1-C-6 植物寄生性センチュウの行動分析用マイクロ流路デバイス : 流路規格および流路内物質濃度分布の検証(5PM1-C 細胞工学とマイクロ流体デバイス)We present a novel method for chemotaxis assay of plant-parasitic nematode, Meloidogyne incognita by using a PDMS (polydimethylsiloxane) microchannel device. For allowing the nematodes to swim in a simple microchannel, we also developed a protocol by loading an agarose gel into microchannel with power-free pumping method. A 5-μm-wide microchannel array, which is narrower than the body width of the nematodes, can efficiently confine the nematodes in analyzed area. We numerically evaluated the chemical concentration distribution in developed microchannel and successfully related the time-dependent chemical condition to the behavior of nematodes.一般社団法人日本機械学会, 2013年11月04日, マイクロ・ナノ工学シンポジウム, 2013(5) (5), 35 - 36, 日本語
- J212011 コンビナトリアル成膜法によるPMN-PT薄膜の組成依存性評価([J212-01]マイクロ・ナノ材料創成とそのデバイス応用(1))In this study, we deposited Pb(Mg_<1/3>Nb_<2/3>)03-PbTi03 (PMN-PT) thin films on PbTiO_3/Pt/Ti/Si substrates by combinatorial sputtering to optimize the composition ratio of PMN-PT thin films. Compositional gradient PMN-PT thin films were deposited by multi target co-sputtering, namely combinatorial sputtering, and pyrocholre-free PMN-PT thin films with rondom orientation were prepared on PbTiO_3/Pt/Ti/Si substrates. PT compositional ratio is ranging from 0.25 to 0.57, which coverd MPB composition of bulk PMN-PT ceramics (PT = 0.33). We confirmed that relative dielectric constants increase with decreasing PT ratio in PMN-PT films. On the other hand, the PMN-PT thin films showed the maximum piezoelectric coefficients|e_<31,f>| = 7〜8 C/m^2 around PMN-0.45PT, which is shifted from MPB composition of PMN-PT bulk ceramics.一般社団法人日本機械学会, 2013年09月08日, 年次大会 : Mechanical Engineering Congress, Japan, 2013, "J212011 - 1"-"J212011-4", 日本語
- J161013 ステンレス基板上圧電薄膜を用いたMEMSエナジーハーベスター([J161-01]マイクロナノメカトロニクス(1))We developed piezoelectric thin-film MEMS energy harvesters using stainless steel (SUS430) cantilevers to improve fracture toughness as well as to lower the resonant frequency. The large fracture toughness of SUS430 cantilevers overcomes the breakdown of the cantilevers and ensures the long lifetime of the energy harvesters. To simplify the fabrication process, the piezoelectric Pb(Zr,Ti)O_3 (PZT) thin film was directly deposited on the microfabricated SUS430 cantilevers with a 30-μm-thick beam and a tip mass by rf-magnetron sputtering. The X-ray diffraction (XRD) measurement revealed that the PZT thin film has perovskite structure with random orientations. The relative dielectric constant ε_r and the transverse piezoelectric coefficient е_<31,f> were respectively evaluated to be 325 and -4.0 C/m^2, which indicates the figure of merit (FOM) of 0.049. From the evaluation of power generation performance for the PZT thin-film energy harvester (beam length: 5.5 mm, width: 5.0 mm, mass length: 2.0 mm), its maximum output power was 6.8 μW (power density: 1.7 μW/mm^3) under conditions of 367 Hz and 10 m/s^2.一般社団法人日本機械学会, 2013年09月08日, 年次大会 : Mechanical Engineering Congress, Japan, 2013, "J161013 - 1"-"J161013-5", 日本語
- E-2-2 エピタキシャルPZT薄膜を用いた高効率圧電型振動発電素子に関する研究(マイクロナノメカトロニクス(2),口頭発表)We fabricated piezoelectric energy harvesters composed of c-axis oriented Pb(Zr,Ti)O_3 (PZT) thin films transferred onto stainless steel substrates.In order to improve resonance frequency,we designed a cantilever with a tip mass.PZT thin firms were epitaxially grown on MgO substrates using rf-magnetoron sputtering and transferred onto stainless steel substrate by eximer laser liftoff.Transferred PZT thin firms had a low dielectric constant (ε_r=340) and high piezoelectric coefficient(e_<31.1>=-4.76 C/m^2).The energy harvester had a resonance frequency of 143.2 Hz.At the optimal load resistance of 90 kΩ and resonance frequency of 143.2 Hz, theenergy harvester generated output power of 2.02μW at an acceleration of 1m/s^2 and 49μW at acceleration of 7.5 m/s^2.一般社団法人日本機械学会, 2013年03月20日, IIP情報・知能・精密機器部門講演会講演論文集, 2013, 46 - 49, 日本語
- E-2-1 金属基板上PZT薄膜を利用したジャイロセンサーの開発に関する研究(マイクロナノメカトロニクス(2),口頭発表)We developed piezoelectric MEMS gyrosensors composed of PZT thin films. The PZT thin films were directly deposited on the microfabricated metal cantilevers by RF sputtering method.To evaluate basic performance of the gyrosensor,we measured resonance frequency of horizontal and vertical directions.We clearly observed horizontal and vertical resonances at 48.46kHz and 28.77 kHz respectively.Then we calculated the sensitivity analytically.一般社団法人日本機械学会, 2013年03月20日, IIP情報・知能・精密機器部門講演会講演論文集, 2013, 43 - 45, 日本語
- E-1-4 非鉛圧電薄膜(K, Na)NbO_3の微細加工技術(マイクロナノメカトロニクス(1),口頭発表)In this study,we developed microfabrication process of lead-free sodium potassium niobate [(K,Na)NbO_3,KNN]thin films by dry etching.We deposited KNN thin films on Si substrate and evaluated its etching characteristics.We found that Ar/C_4F_8 plasma dry etching was effective for high etching rate 63 nm/min of KNN as well as excellent selectivity of KNN and Cr metal mask 5.7.We conducted fabrication of Pt/KNN/Pt unimorph microcantilevers through KNN etching process.We could fabricate micro-cantilevers without initial deflection and they show high piezoelectric coefficients d_31=110 pm/V.These results suggest that Ar/C_4F_8 plasma dry etching enable to apply for various lead-free piezoelectric MEMS fabrication processes.一般社団法人日本機械学会, 2013年03月20日, IIP情報・知能・精密機器部門講演会講演論文集, 2013, 40 - 42, 日本語
- This thoroughly updated new edition includes an entirely new team of contributing authors with backgrounds specializing in the various new applications of sputtering technology. It forms a bridge between fundamental theory and practical application, giving an insight into innovative new materials, devices and systems. Organized into three parts for ease of use, this Handbook introduces the fundamentals of thin films and sputtering deposition, explores the theory and practices of this field, and also covers new technology such as nano-functional materials and MEMS. Wide varieties of functional thin film materials and processing are described, and experimental data is provided with detailed examples and theoretical descriptions. A strong applications focus, covering current and emerging technologies, including nano-materials and MEMS (microelectrolmechanical systems) for energy, environments, communications, and/or bio-medical field. New chapters on computer simulation of sputtering and MEMS completes the update and insures that the new edition includes the most current and forward-looking coverage available. All applications discussed are supported by theoretical discussions, offering readers both the "how" and the "why" of each technique. 40% revision: the new edition includes an entirely new team of contributing authors with backgrounds specializing in the various new applications that are covered in the book and providing the most up-to-date coverage available anywhere.Elsevier Inc., 2012年11月20日, Handbook of Sputter Deposition Technology: Fundamentals and Applications for Functional Thin Films, Nano-Materials and MEMS: Second Edition, 1 - 644, 英語その他
- OS4-1-1 金属基板を用いたPZT圧電薄膜エナジーハーベスト(OS4 電池レス・デバイスのためのエネルギーハーベストの展開)We fabricated piezoelectric MEMS energy harvesters of PZT thin films on the microfabricated stainless steel cantilevers. The 2.5-μm-thick PZT thin films were directly deposited by RF-magnetron sputtering. Direct deposition of PZT thin films can reduces the complexity of the fabrication process of the piezoelectric MEMS energy harvesters. Furthermore, because of strong fracture toughness of stainless steel, the thickness of the cantilevers could be as thin as 30 μm. We confirmed strong diffraction peaks corresponding to pervskite PZT without a pyrochlore phase by XRD, which indicates that the polycrystalline PZT films with pervskite structures were grown on stainless steel cantilevers. We evaluated the power generation performance of the unimorph cantilever (7.5 mm-long, 5.0 mm-wide) with the tip mass of 2.5×10^<-5> kg. The averaged output power reached 6.0 μW at 10 m/s^2 and a low resonant frequency of 367 Hz.一般社団法人日本機械学会, 2012年10月21日, マイクロ・ナノ工学シンポジウム, 2012(4) (4), 91 - 92, 日本語
- P-OS4-2 Fabrication and characterization of lead-free piezoelectric thin filmsWe fabricated composition gradient sodium potassium niobate [(K,Na)NbO_3, KNN] thin films on (111)Pt/Ti/SiO_2/Si by multi-target RF magnetron sputtering to optimize KNN film composition by combinatorial method. We successfully obtained c-axis oriented KNN thin films with perovskite structure on 6-inch Si wafers. The KNN film composition was measured by energy dispersive x-ray spectroscopy (EDX) and we confirmed composition gradient of K/(K+Na) ratio of the KNN thin film on Si wafer along with the line between KNbO_3 and NaNbO_3 targets. This result indicates that the combinatorial sputtering is useful for precise optimization of the deposition condition and film composition of the lead-free KNN thin films.一般社団法人日本機械学会, 2012年10月21日, マイクロ・ナノ工学シンポジウム, 2012(4) (4), 273 - 274, 英語
- OS7-3-6 RFマグネトロンスパッタリング法によるPMN-PT薄膜の圧電特性(OS7 最先端材料が拓くマイクロ・ナノ工学の新展開(3))We evaluated compositional dependence of piezoelectric and dielectric properties of Pb(Mg_<1/3>Nb_<2/3>)_<1-x>Ti_x(O_3(PMN-PT) films by using combinatorial sputtering method. Compositional gradient PMN-PT films were deposited on Pt/Ti/Si substrates by using multi-target sputtering. Piezoelectric and dielectric properties of PMN-PT films were evaluated as a function of composition x in Pb(Mg_<1/3>Nb_<2/3>)_<1-x>Ti_xO_3. Relative dielectric constant and remnant polarization (P_r) increased with decreasing PT ratio.一般社団法人日本機械学会, 2012年10月21日, マイクロ・ナノ工学シンポジウム, 2012(4) (4), 63 - 64, 日本語
- 2011年12月27日, International Workshop on Micro/Nano engineering, 英語Integrated Microfluidic Device for Molecular Transport by Kinesin-Microtubule System[査読有り]
- 2011年12月27日, International Workshop on Micro/Nano engineering, 英語Fabrication of Multi-scale Channels Applicable to Bio-assays[査読有り]
- 2011年12月27日, International Workshop on Micro/Nano engineering, 英語Multilayer Thin-Film Ceramics Fabricated by RF Magnetron Sputtering[査読有り]
- 3-7 圧電薄膜を用いた振動エナジーハーベスターの特性評価(OS3 電池レス・デバイスのためのエネルギーハーベストの展開)We fabricated piezoelectric vibration energy harvesters composed of PZT and lead-free KNN thin films on Si cantilevers and characterized the output voltage and power of those piezoelectric films. Both of the PZT and KNN films were deposited on Pt-coated Si substrates by rf-magnetron sputtering. The harvesters had a simple unimorph cantilever structure with the almost same dimensions, and the characteristics of power generation were examined. When we applied the acceleration of 10m/s^2 on the PZT and KNN energy harvesters, they generated the output power of 1.11 and 1.01μW at the resonant frequency under 10m/s^2, indicating lead-free KNN films are comparable to PZT films for the performance for power generation.一般社団法人日本機械学会, 2011年09月25日, マイクロ・ナノ工学シンポジウム, 2011(3) (3), 35 - 36, 日本語
- MP-50 Ti基板上に成膜したPZT薄膜駆動の圧電MEMSスキャナーミラーに関する研究(ポスターセッション)We have developed Ti-based piezoelectric MEMS scanner mirrors driven by PZT thin films. The 2μm-thick PZT thin films were directly deposited on 50μm-thick Ti substrates by RF-magnetron sputtering. The Ti substrates were preliminary microfabricated into the shape of the horizontal scanner by wet etching, therefore we could fabricate piezoelectric microactuators without photolithographic process. We could confirm strong diffraction peaks corresponding to perovskite PZT without a pyrochlore phase by XRD, which indicates that the polycrystalline PZT films with perovskite structures were grown on Ti substrates. We achieved a mechanical tilt angle of 10.0° at resonant frequency of 23.7kHz by driving voltage of 10V_一般社団法人日本機械学会, 2011年09月25日, マイクロ・ナノ工学シンポジウム, 2011(3) (3), 167 - 168, 日本語
. These horizontal scanning properties would be applicable for the laser displays. - MP-14 KNN非鉛圧電薄膜の微細加工(ポスターセッション)We conducted inductively coupled plasma reactive ion etching (ICP-RIE) for sodium-potassium niobate (KNN) thin films by Ar/ C_4F_8 mixture gas in order to develop lead-free piezoelectric MEMS devices. We prepared Cr metal masks on KNN thin films deposited on Si substrate. The etching rate of the KNN films was about 63nm/min, which is about third times faster than Ar dry etching. The ferroelectric properties of KNN thin films were not changed by etching process. This result suggests that the lead-free piezoelectric MEMS devices can be fabricated by dry etching of KNN thin films without damage to the KNN films.一般社団法人日本機械学会, 2011年09月25日, マイクロ・ナノ工学シンポジウム, 2011(3) (3), 95 - 96, 日本語
- J161041 (K,Na)NbO_3圧電薄膜の微細加工技術([J16104]マイクロナノメカト口ニクス(4))It was investigated that the etching characteristics of lead-free (K,Na)Nb03 (KNN) thin films by the ICP-RIE (Inductive Coupled Plasma ・Reactive Ion Etching) with Ar-C4F8 mixture for the reactive gas. The Ar-C4F8 mixing ratio fixed 10:1, and the chamber pressure was 0.5Pa during the etching. The KNN etching depth has linear relationship as the function of the etching time. The etching rate increased with increasing the antenna power and the bias power. The antenna and the bias dependence of the etching rate show good linearity. These linear relationships indicate the good controllability of the etching. The KNN/Pt selectivity increased with increasing antenna power and decreasing bias power. Thus, the high KNN etching rate was obtained at high antenna power and high bias power condition. The high KNN/Pt selectivity was obtained at high antenna power and low bias power condition. The maximum KNN etching rate and KNN/Pt selectivity were 371.6nm/min. and 85.8, respectively. These results are comparable to that of the conventional piezoelectric PZT films.一般社団法人日本機械学会, 2011年09月11日, 年次大会 : Mechanical Engineering Congress, Japan, 2011, "J161041 - 1"-"J161041-3", 日本語
- 2011年04月25日, 2011 MRS Spring Meeting and Exhibit, pp. AA5.1, San Francisco, USA,, 英語Parallel Microtuble Array with Defined Polarity by Nanotracks and Selective Microtuble Immobilization[査読有り]
- 2011年04月15日, 8th Annual Conference on Foundations of Nanoscience (FNANO11), pp. 44-45, Snowbird, USA, 英語Experimental and Numerical Analysis of Polar Oriented Microtubule Array in Nanotracks[査読有り]
- D-2-1 ナノインプリントリソグラフィとUVリソグラフィの融合によるバイオアッセイ用サブマイクロ灌流デバイスの作製(D-2 設計・プロセス,口頭発表:マイクロナノメカトロニクス)Recently, micro/nano fabrication techniques are applied to bio-assay for detailed biochemical analysis. For example, studies about single molecule enzymology by femtoliter PDMS chambers and real-time imaging of single molecule fluorescence in quartz nano wells are reported. But, these conventional devices for nano-bio assays have difficulties in perfusing solutions in nano structures, so we developed a simple fabrication process of sub-microchannel and microchannel by integrating nanoimprint lithography and UV lithography. The fabricated device consists of sub-microchannel array and two microchannels. These microchannels are used as inlet or outlet of sub-microchannel to deliver solutions. We achieved water injection and solution exchange in 2-μm channels. Water injection pressure was 100 kPa for 1-μm channels and 120 kPa for 2-μm channnels.一般社団法人日本機械学会, 2011年03月18日, IIP情報・知能・精密機器部門講演会講演論文集, 2011, 28 - 29, 日本語
- D-1-4 金属基板上に成膜したPZT薄膜による圧電MEMSスキャナーミラーの研究(D-1 マイクロアクチュエータ,口頭発表:マイクロナノメカトロニクス)In this study, we have developed metal-based MEMS scanner mirrors driven by PZT piezoelectric thin films not only to simplify fabrication process but also to improve fracture toughness of the micro-actuators. The 2 μm-thick PZT thin films were directly deposited on preliminarily microfabricated metal-based substrates of titanium or stainless steel by RF-magnetron sputtering. We could achieve a large mechanical angle tilt of 6.21° at high resonant frequency of 35.02 kHz by low application voltage of 10V_一般社団法人日本機械学会, 2011年03月18日, IIP情報・知能・精密機器部門講演会講演論文集, 2011, 20 - 25, 日本語
. Use of microfabricated metal-based substrates for the PZT deposition enables simpler process and stronger toughness of scanner mirrors compared with the conventional Si-based ones. - We present a method to make microtubules (MTs) glide bidirectionally depending on their polarities in a closed chamber, in which kinesin and dynein are coated on top and bottom glass surfaces, respectively. Once top Au-coated and bottom ITO-coated glass coverslip were assembled to a flow chamber, surface modification and sequential protein injections realized selective dynein and kinesin coatings. Therefore, plus ends of MTs lead on the top dynein/Au-coated surface, and minus ends lead on the bottom kinesin/ITO-coated surface. These gliding MTs were removed one surface and collected to the other surface by applying voltage for controlling MT gliding directions. These fundamental techniques are essential to drive MTs back and forth in a microfluidic system.IEEE, 2011年, 2011 IEEE 24TH INTERNATIONAL CONFERENCE ON MICRO ELECTRO MECHANICAL SYSTEMS (MEMS), 24th Vol.2, 1373 - 1376, 英語
- We fabricated piezoelectric MEMS deformable mirror (DM) with high-density actuator array for adaptive optics to realize low-voltage and high-resolution retinal imaging. 61-element actuator array composed of lead zirconate titanate (PZT) thin film was deposited on the mirror diaphragm, and the diaphragm was deformed by applying control voltage onto the individual actuator through lead lines prepared on a polyimide insulating layer with through holes. The deformation characteristics of the fabricated DM were measured with a laser Doppler vibrometer, and independent application of a voltage on the individual actuator was confirmed. We also confirmed relatively large stroke of 0.23 mu m under low-voltage of 20 V without displacement hysteresis.IEEE, 2011年, 2011 IEEE 24TH INTERNATIONAL CONFERENCE ON MICRO ELECTRO MECHANICAL SYSTEMS (MEMS), 24th Vol.2, 1265 - 1268, 英語
- In this study, we fabricate multilayer ceramic capacitors (MLCCs) composed of BaTiO3 (BT) dielectric layers with Pt internal electrodes by radio frequency magnetron sputtering. We deposited BT layers with thickness of approximately 300 nm on Pt/Ti-coated SiO2/Si substrates through a movable shadow mask. The isolated internal Pt electrodes are prepared by sliding the shadow mask. Multilayered BT thin films are uniformly deposited on a Si substrate with external electrodes on both sides of the BT films. The formation of a polycrystalline perovskite structure was confirmed by XRD measurement. The MLCCs with five BT layers exhibit excellent dielectric properties: a relative dielectric constant of approximately 320 and a dielectric loss of around 2% regardless of the number of dielectric layers.IEEE, 2011年, 2011 INTERNATIONAL SYMPOSIUM ON APPLICATIONS OF FERROELECTRICS (ISAF/PFM) AND 2011 INTERNATIONAL SYMPOSIUM ON PIEZORESPONSE FORCE MICROSCOPY AND NANOSCALE PHENOMENA IN POLAR MATERIALS, 英語
- Development of Miniaturized Piezoelectric Energy HarvestersWe have developed miniaturized piezoelectric vibration-type energy harvesters with piezoelectric thin films fabricated by MEMS technologies. Harvesters of several resonant frequencies revealed very high energy density. The module including a harvester and electrical circuit lighted up a LED for vibration of 510Hz and 3m/s(2).INST IMAGE INFORMATION & TELEVISION ENGINEERS, 2011年, IDW'11: PROCEEDINGS OF THE 18TH INTERNATIONAL DISPLAY WORKSHOPS, VOLS 1-3, 2, 1227 - 1230, 英語
- Piezoelectric shear strain was measured for c-axis oriented epitaxial Pb(Zr,Ti)O-3 (PZT) thin films. The PZT films, with a composition near the morphotropic phase boundary (MPB), were epitaxially grown on (001) MgO substrates and then microfabricated into a rectangular shape. Lateral electrodes were deposited on both sides of the PZT films to apply an external electric field perpendicular to the polarization. A sinusoidal input voltage of 100 kHz was applied between the lateral electrodes and in-plane shear vibration was measured by a laser Doppler vibrometer. In-plane displacement due to shear mode piezoelectric mode vibration was clearly observed and increased proportionally with the voltage. Finite element method (FEM) analysis was conducted to determine the horizontal electric field in the PZT film, and the piezoelectric coefficient d(15) was calculated to be 440x10(-12)m/V.IEEE, 2011年, 2011 INTERNATIONAL SYMPOSIUM ON APPLICATIONS OF FERROELECTRICS (ISAF/PFM) AND 2011 INTERNATIONAL SYMPOSIUM ON PIEZORESPONSE FORCE MICROSCOPY AND NANOSCALE PHENOMENA IN POLAR MATERIALS, 英語[査読有り]
- In contrast to optical tweezers methods, we established a method to evaluate the adhesion force between a bead carried by multiple kinesins and a microtubule. The method also enables us to estimate the number of kinesins involved in the bead transport. Torque Gamma and drag force F-D applied by the shearing flow were derived theoretically by the flow rate necessary to break kinesin-microtubule bindings in the bead detachment assay. Based on mechanical modeling, the adhesion force, F-Adh, was calculated as 362.9 pN without ATP and 31.3 pN with 1 mM ATP. Furthermore, we found out 5.5-11.9 kinesins are cooperatively working to carry the bead, which is consistent with other results. Our method is advantageous in analyzing multi-kinesin transport system reconstructed in microfluidic systems.IEEE, 2011年, 2011 IEEE 24TH INTERNATIONAL CONFERENCE ON MICRO ELECTRO MECHANICAL SYSTEMS (MEMS), 1365 - 1368, 英語
- We present a microfluidic device integrated with a Total Internal Reflection (TIR)-based chip for cell observation and analysis, which enables Total Internal Reflection Fluorescence Microscopy (TIRFM). By integrating the microfluidic device with optical components, the assembly becomes unnecessary. An evanescent field generated by the TIR-based chip was demonstrated by observation of fluorescent beads and insulin granules in mouse pancreatic beta cells, MIN6-m9. Comparing with epi-fluorescence microscopy (EPIFM), high S/N ratio of 4-fold was realized by the TIR-based chip. To demonstrate the utility of the device integration, we analyzed intracellular Ca2+ concentration change in MIN6-m9 cells in response to KCl stimulation. We found out our integrated device realized quick perfusion for cell analysis with keeping high S/N ratio.IEEE, 2011年, 2011 IEEE 24TH INTERNATIONAL CONFERENCE ON MICRO ELECTRO MECHANICAL SYSTEMS (MEMS), 956 - 959, 英語[査読有り]
- This paper reports a fundamental study on a force measurement and mechanical modeling of a microbead coated with multiple motor proteins, kinesins, which moves on a cytoskeletal filament, microtubules (MTs). We utilized a laminar flow in a microfluidic channel to apply torque λ and drag force F D to the bead, whose values can be derived theoretically. As a result, the adhesion force F Adh was determined based on the mechanical modeling. Here, the flow rate necessary to break kinesin-MT bindings was experimentally measured, and two models were applied to derive fluid forces that was also calculated by a simulation software, FLUENT. Consequently, adhesion forces of 363 pN and 31 pN were obtained under no ATP and 1 mM ATP conditions, respectively. The proposed measurement methodology is advantageous in analyzing multiple microbeads transported by kinesin-MT interaction in a microfluidic system.2010年12月01日, 14th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2010, MicroTAS 2010, 1, 372 - 374
- MNM-5B-1 Ti基板上に成膜したPZT薄膜による振動発電特性(セッション 5B マイクロエネルギー)We fabricated piezoelectric energy harvesters of PZT thin films on Ti cantilevers. The PZT films were directly deposited on Pt-coated Ti substrates using rf-magnetron sputtering. Although the harvester had a simple cantilever structure without seismic mass, the resonant frequency was as low as 272 Hz because of its thin Ti thickness of 50 μm. Output power had a peak at optimal load resistance of 19 kΩ. When we applied the acceleration of 50 m/s^2 on the harvester, it could generate electric power of 15.7 μW at the resonant frequency without serious damage to PZT/Ti harvesters.一般社団法人日本機械学会, 2010年10月12日, マイクロ・ナノ工学シンポジウム, 2010(2) (2), 207 - 208, 日本語
- MNM-3B-3 高密度圧電MEMS可変ミラーの開発(セッション 3B 情報・精密機器におけるマイクロ・ナノテクノロジー2)This paper reports on a piezoelectric micro-electro-mechanical systems (MEMS) deformable mirrors with high-density actuator array for low-voltage and high-resolution retinal imaging with adaptive optics. The deformable mirror was composed of unimorh structure of piezoelectric zirconate titanate (PZT) thin film deposited on Pt-coated silicon on insulator (SOI) substrate and a diaphragm of 10 mm in diameter formed by backside-etching the Si handle wafer. 61 hexagonal electrodes were laid out on the PZT thin film for the high-density actuator array. In order to reduce the dead space for the lead lines between the electrodes and connecting pads, a polyimide layer with through holes on the electrodes was patterned as an electrical insulator. To confirm the application feasibility of the fabricated DMs, the displacement profile of the actuators were measured by a laser Doppler vibrometer. Independent applications of voltages on individual actuators were confirmed.一般社団法人日本機械学会, 2010年10月12日, マイクロ・ナノ工学シンポジウム, 2010(2) (2), 161 - 162, 日本語
- MNM-1A-2 鏡面・非鏡面X線反射率測定によるタンパク吸着膜構造の統計学的評価(セッション 1A マイクロ・ナノスケールバイオ計測と医用応用)The purpose of this study is to investigate conformations of antibodies immobilized on three kinds of solid surfaces modified with APTES, AEAPTES or GA and their antigen-binding affinities. In the recent developments in biosensors, although the geometric structure of antibodies determines their sensitivity, few studies have focused on their conformations and its effect on their antigen-binding capacity due to a lack of applicable analysis techniques. In this work, specular and off-specular X-ray reflectivity measurement were employed, which enables us to analyze vertical and lateral multilayer structure. The results showed that the antigen-binding affinity on GA was highest among antibodies immobilized on three modified surfaces, although their conformations were almost the same as 'flat-on' analyzed by specular X-ray reflectivity. In contrast, lateral layer structure analysis by off-specular reflection revealed that protein layer on GA before antigen-binding had a relatively-long lateral correlation length and a low fractal dimension which would cause the reduction of steric hindrance for antigens' access to binding sites of antibodies.一般社団法人日本機械学会, 2010年10月12日, マイクロ・ナノ工学シンポジウム, 2010(2) (2), 17 - 18, 日本語
- We propose a new micro-fabrication process of piezoelectric MEMS actuators composed of lead-free KNbO_3-NaNbO_3 (KNN) thin films. The micro-cantilevers were fabricated on silicon on insulator(SOI) substrates, and successively the KNN thin films were directly deposited on them by rf-sputtering. Thus, piezoelectric unimorph micro-cantilevers of lead-free KNN films could be prepared without microfabrication of the KNN films. The dielectric properties of KNN thin films on micro-cantilevers were as good as those on the substrate. When we applied voltage of 20V, we could obtain relatively large tip displacement of up to 5.8μm and the average piezoelectric constant d_<31> was calculated to be -47.4pm/V. This fabrication process is useful for various applications of MEMS devices with new functional materials such as lead-free piezoelectric KNN films.一般社団法人日本機械学会, 2010年09月04日, 年次大会講演論文集 : JSME annual meeting, 2010(8) (8), 193 - 194, 日本語
- 2010年06月18日, 電気学会研究会資料. BMS, バイオ・マイクロシステム研究会 = The papers of Technical Meeting on Bio Micro Systems, IEE Japan, 2010(7) (7), 27 - 32, 日本語電気浸透流を用いた開放型流路内での異種細胞配置と細胞間相互作用の観察
- 2010年06月18日, 電気学会研究会資料. BMS, バイオ・マイクロシステム研究会 = The papers of Technical Meeting on Bio Micro Systems, IEE Japan, 2010(7) (7), 57 - 61, 日本語モータタンパク質の選択的付加による微小管輸送方向制御
- B-4 圧電マイクロミラーアレーによる光通信デバイスの作製(口頭発表:マイクロナノメカトロニクス)We studied a new fabrication process for a micro mirror array device with piezoelectric unimorph actuators and simulated its actuation. In this fabrication process, piezoelectric thin film (PZT ; Pb(Zr,Ti)O_3) is deposited on SOI substrate by sputtering after actuator parts are released by BHF wet etching. Therefore, patterning or etching piezoelectric layer is not necessary, which means that proposed fabrication process can apply to various piezoelectric devices. Furthermore, we confirmed the actuation of proposed micro mirrors by FEM simulation.一般社団法人日本機械学会, 2010年03月16日, IIP情報・知能・精密機器部門講演会講演論文集, 2010(0) (0), 73 - 74, 日本語
- The 4 GHz film resontors have been fabricated by sputtered Pb(Mn,Nb)O-3-Pb(Zr,Ti)O-3 (PMnN-PZT) thin films. The PMnN-PZT thin films were deposited on (100) MgO substrates. The thin films showed tetragonal crystal structure and highly (001) orientation. The film bulk acoustic resonators (FBAR) composed by PMnN-PZT thin films were fabricated by MEMS technology. RF properties of the resonator were evaluated by VNA (Vector Network Analyzer). The electromechanical coupling constant k(t) and Q-value for PMnN-PZT thin films were 0.7 and 157, at 4.17GHz, respectively. These values obtained by sputtered thin films are highest comparing with those of previously reported PZT-BAW resonators.IEEE, 2010年, 2010 IEEE INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM (FCS), 2010, 248 - 251, 英語
- The ferroelectric PZT thin films will be suitable for a fabrication of the piezoelectric energy harvesting (EH) MEMS due to their extremely high piezoelectric coefficients. However, at present the non-ferroelectric AlN thin films with a small piezoelectric coefficients are considered to be suitable for a fabrication of the piezoelectric EH MEMS due to their small dielectric constants. The high dielectric constants of the PZT thin films reduce the power output of the EH MEMS. In this paper it is shown the single crystal thin films of PZT-based ternary compounds Pb(Mn,Nb)O-3-PZT show high piezoelectric coefficients with small dielectric constants. Their output powers of the EH MEMS will be superior to the AlN thin film EH MEMS.IEEE, 2010年, 2010 IEEE INTERNATIONAL SYMPOSIUM ON THE APPLICATIONS OF FERROELECTRICS (ISAF), 英語
- Heteroepitaxial thin films of PZT-based ternary perovskite, xPb(Mn, Nb)O3-(1x)PZT, were fabricated by magnetron sputtering on (001)SrTiO3 and (001)MgO substrates. The heteroepitaxial thin films showed single c-domain/single crystal structure and exhibit hard piezoelectric behavior with high Ec, Ec> 180kV/cm, at x=0.06 for the film thickness, 300nm-5mm. The ternary perovskite thin films showed relaxed structure at the film thickness > 0.5mm. However, Curie temperature Tc is 600C which is 250C higher than bulk ceramic values. The sputtered thin films exhibit remnant polarization being as high as 100μmC/cm2. The in-plane compression model is ruled out for a mechanism of the present higher Tc phenomena, since the sputtered thin films show relaxed structure. The mechanism of the higher Tc is unclear. The present thin films of PZT-based ternary perovskite are exotic materials. This paper describes the structure and the exotic ferroelectric properties in relation to the possible application for piezoelectric MEMS. © 2010 IEEE.2010年, Proceedings - IEEE Ultrasonics Symposium, 2010 Vol.1, 80 - 85, 英語
- 2010年, The 5th Asia-Pacific Conference on Transducers and Micro-Nano Technology, pp. 154A-B, Perth, Australia, 8th July,, 英語Development of Hybrid Bio-Device with Self-Organized Huvec Vessels and Artificial Micro-Channels,[査読有り]
- 2010年, The 5th Asia-Pacific Conference on Transducers and Micro-Nano Technology, pp. 128, Perth, Australia, 7th July,, 英語Surface Modification of Polystyrene by Peo/Ppo Block Copolymer Pluronic to Prevent Blood Adhesion,[査読有り]
- In this study, we fabricated high-efficiency piezoelectric energy harvesters composed of c-axis oriented PZT thin films. The PZT film was epitaxially grown on a Pt/MgO substrate and successively transferred on to a stainless steel sheet so as to prepare the unimorph cantilevers. Although the harvester had a simple cantilever structure without seismic mass, the resonant frequency could be reduced to 126 Hz due to the thin thickness of stainless sheet of 50 mu m. When we applied the acceleration of 5 m/s(2) on the harvester, it could generate large electric power of 5.3 mu W at the resonant frequency. Transferred epitaxial PZT films on the metal sheets are effective not only to enhance the output power, but also to reduce the resonant frequency to around environmental vibration using the simple cantilevers.IEEE, 2010年, MEMS 2010: 23RD IEEE INTERNATIONAL CONFERENCE ON MICRO ELECTRO MECHANICAL SYSTEMS, TECHNICAL DIGEST, 152 - 155, 英語
- M5-3 サーフェスマイクロマシン技術を用いたPZT薄膜アクチュエータの作製に関する研究(M5 アクチュエータ/フィジカルセンサ)Micro-cantilevers with piezoelectric lead zirconate titanate (PZT) thin film have been widely investigated for various MEMS applications. However, most of them are fabricated by bulk micromachine techniques in silicon on insulator substrate. On the other hand, if micro-cantilevers could be fabricated by surface micromachine techniques, it is advantageous to arrange them in the high density array. In this study, we suggested a new simple process for fabricating PZT unimorph cantilevers by surface micromachining process. Through this process, we fabricated micro actuators with PZT thin films deposited using rf magnetron sputtering. Dielectric loss of PZT thin films are 0.02-0.06, and piezoelectric constant d_<31> calculated from measured displacement of cantilevers was -72.6 pm/V The proposed piezoelectric actuator fabrication process can be applied to various MEMS devices.一般社団法人日本機械学会, 2009年10月15日, マイクロ・ナノ工学シンポジウム, 2009(1) (1), 87 - 88, 日本語
- Piezoelectric MEMS deformable mirrors have been developed for high resolution retina imaging using adaptive optics. For the low voltage drive, piezoelectric PZT thin films-were used to actuate the mirror surface. In this study, we fabricated hexagonal 61-element actuator array to enhance the performance of image correction. In order to reduce the dead space for the lead lines between the actuators, the polyimide insulating layer was coated on the surface of the PZT actuators and lead lines were prepared with the connection to each element. The displacement of each actuator was measured by using a lasor Doppler vibrometer and we confirmed a relatively large displacement of more than 1μm by applying a voltage of lOVpp. Furthermore, we measured the relationship input voltage and displacement and fabricated DMs actuated linearly when applied -20〜20Vpp.一般社団法人日本機械学会, 2009年09月12日, 年次大会講演論文集 : JSME annual meeting, 2009(8) (8), 237 - 238, 日本語
- We propose a novel concept that self-organized vasculature integrates artificial orifices on a microfluidic device using inducible protein VEGF (Vascular Endothelial Growth Factor) for fluid induction into vasculature. Micro gel beads containing VEGF immobilized on orifices, it is able to induce angiogenesis to orifices on embedded channels. Endothelial cells (HUVEC) characteristically organize vasculature by themselves in collagen gel and grow along the VEGF concentration gradient. HUVEC were cultured on the device for a day in collagen gel and vasculature was forming on orifices by self-organized. And angiogenetic effect was evaluated quantitatively.一般社団法人日本機械学会, 2009年09月12日, 年次大会講演論文集 : JSME annual meeting, 2009(8) (8), 245 - 246, 日本語
- MCH-01 DEVELOPMENT OF A NOVEL METHOD FOR STRETCHING DNA FIBERS ON MICROBRIDGES FABRICATED BY SINGLE-MASK INCLINED UV LITHOGRAPHY(Micro/Nanomechatronics I,Technical Program of Oral Presentations)In this paper, we proposed the novel method for manipulating DNA fibers on microbridges fabricated by the single mask UV lithography process. Chromosomes were stretched and immobilized on microbridges by the centrifugal force, and the chromosomes could be individually accessible platforms for DNA fiber applications. It was confirmed the validity of the proposed method by applying suspended chromosomes to the FISH analysis.一般社団法人日本機械学会, 2009年06月17日, Proceedings of ... JSME-IIP/ASME-ISPS Joint Conference on Micromechatronics for Information and Precision Equipment : IIP/ISPS joint MIPE, 2009, 325 - 326, 英語
- P-MCH-04 Piezoelectric micropumping system using PZT thin films(Micro/Nanomechatronics,Technical Program of Poster Session)In this paper, we propose innovative valveless pumping devices for microfluidic systems. The liquid in the microchannel was transported by generating a traveling wave on the channel wall, which was composed of a piezoelectric Pb(Zr,Ti)O_3 (PZT) thin film actuator array. The PZT thin films were deposited on the silicon-on-insulator (SOI) substrates where microchannels, 200 and 500μm wide, were fabricated. The maximum displacements of the 200 and 500μm wide filled channels at 10 V_一般社団法人日本機械学会, 2009年06月17日, Proceedings of ... JSME-IIP/ASME-ISPS Joint Conference on Micromechatronics for Information and Precision Equipment : IIP/ISPS joint MIPE, 2009, 387 - 388, 英語
were about 61 and 219 nm, respectively. By generating a traveling wave on the channel wall, clear liquid flow could be induced with a mean flow velocity of about 118 and 172μm/s for the 200 and 500μm wide channels, respectively. - Streching method for DNA fibers using multi ringed microbridgesIn this study, we propose a novel method of separately suspending chromosomes on multi ringed microbridges for DNA fiber applications. The structures of microbridges were 3D resin-based microstructures and fabricated with only one exposure process by a rotated/inclined UV lithography. In order to confirm the availability of the multi ringed microbridges, Fluorescent In Situ Hybridization (FISH) analysis was performed to human chromosomes stretched on the microbridges, and the chromosomes were successfully mapped by the DNA probes. © 2009 CBMS.2009年01月01日, Proceedings of Conference, MicroTAS 2009 - The 13th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 1073 - 1075
- In this paper, we propose a three-dimentional multi-layered flow generator fabricated by inclined UV lithography to expose a single layerded photoresist coated on a patterned mask. The fabricated flow generator can be applied for a passive micromixer with laminated and/or secondary flows, a sheath flow generator, and an multi-layered emulsion system. © 2009 CBMS.2009年01月01日, Proceedings of Conference, MicroTAS 2009 - The 13th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 52 - 54
- Single crystal thin films of the PZT-based ternary perovskite, xPb(Mn,Nb)O-3-(1-x)PZT, were fabricated by a magnetron sputtering on (001)MgO substrates. The sputtered thin films were quenched in air after the deposition. The PZT-based thin films exhibited the hard ferroelectric behavior with high piezoelectric coupling factors k(t), k(t)=70%, measured at GHz range FBAR structure. The PZT-based thin films showed a high mechanical quality factor Q(m), Q(m)=185. The observed k(t) and Q(m) are, to our knowledge, the highest in the reported values. The achievement of the high Q(m) will be owed to the, single crystal-like high density film structure with the doped Mn acceptors and oxygen vacancies achieved by the sputtering deposition followed by the quenching. The figure of merit k(t)(2)Q(m) is almost the same to piezoelectric AlN thin films. It is confirmed the quenched PZT-based ternary perovskite thin films have a potential for a fabrication of FBAR and/or wide band filters at GHz range.IEEE, 2009年, ISAF: 2009 18TH IEEE INTERNATIONAL SYMPOSIUM ON THE APPLICATIONS OF FERROELECTRICS, 189 - +, 英語
- 2009年, 2009 International Conference on Microtechnologies in Medicine and Biology [MMB2009], pp. 52-53, Quebec, CANADA, Apr, 01-03,, 英語Single-Mask Multidirectional Photolithography with Multiple Resist Coat for Multi-Layered Microfluidic Networks,[査読有り]
- 日本工業出版, 2009年, 超音波テクノ, Vol.21.(No.5.) (No.5.), pp39 - 43, 日本語多成分PZT系薄膜の作製と圧電特性[招待有り]記事・総説・解説・論説等（商業誌、新聞、ウェブメディア）
- A novel concept of a liquid transport technique utilizing frequency modulation and local resonance oscillation is proposed and it is applied to a micromixer. Meta-structure distributing local masses for generating local resonant oscillation is developed. Vibration of the meta-structure with sweeping frequency produces changes in the positions with large oscillation amplitude. This complex structural oscillation makes eddy-like disturbance of flow in a microchamber, and it produces high mixing efficiency. Using this technique produced a mixing index of 0.92 with the volumetric flowrate of 1 μL/min, while it was 0.49 for a conventional technique employing a vibration at a fixed frequency.一般社団法人日本機械学会, 2008年08月02日, 年次大会講演論文集 : JSME annual meeting, 2008(8) (8), 35 - 36, 日本語
- Recently, studies of positional relationships of cells are seemed to be very important for cell biology. We proposed a novel concept that self-organized vasculatum integrates artificial orifices on a device by VEGF (Vascular Endothelial Growth Factor), and a method of uniformly plating HUVEC (Human Umbilical Vein Endothelial Cells) for efficient vasculature integration. Sucking and clamping of Alginate Calcium gel beads containing VEGF, it is able to induce angiogenesis to orifices on embedded channels. Endothelial cells characteristically organize vasculature by themselves in collagen gel and grow along the VEGF concentration gradient. HUVEC were cultured on device for about 7 days in the collagen gel and artificial vasculature mere immobilized on orifices by self-organized. And viscosity control of the suspension mixed with HUVEC, collagen gel and medium at low temperature made HUVEC uniformly-plated.一般社団法人日本機械学会, 2008年08月02日, 年次大会講演論文集 : JSME annual meeting, 2008(8) (8), 37 - 38, 日本語
- 2008年08月02日, 日本機械学会年次大会講演論文集, 2008(Vol.8) (Vol.8), 35 - 36, 日本語質量分布型マイクロミキサー
- 2106 圧電薄膜を用いた流路壁面振動による送液デバイスの開発(要旨講演,一般セッション:マイクロナノメカトロニクス)In this paper, we propose innovative liquid pumping devices for μTAS. In this system, microchannels were fabricated in silicon substrates of silicon on insulator(SOI). The vibrating wall was composed of piezoelectric PZT thin films deposited on the Si device layer of the microchannel. The active microchannel can transport liquid by traveling wave induced on the surface of the piezoelectric vibrating channel by applying sinusoidal voltages to each patterned top electrodes with different phase. The active microchannel of 200μm wide was fabricated by the deep reactive ion etching(DRIE) process. The displacement profiles of the vibrating wall and frequency response were measured by a laser Doppler vibrometer. Maximum displacement was about 50nm at the applied voltage of 1kHz and 20Vpp. Mean flow velocity of about 16μm/s at primary resonance point of 573kHz and 32μm/s at secondary resonance point of 859kHz were achieved at 20Vpp. Because of the simple structure without valves and diffuser, it is suitable for the integration into μTAS devices.一般社団法人日本機械学会, 2008年03月17日, IIP情報・知能・精密機器部門講演会講演論文集, 2008(0) (0), 225 - 227, 日本語
- 2107 圧電薄膜を用いた高解像度形状可変MEMSミラーに関する研究(要旨講演,一般セッション:マイクロナノメカトロニクス)Piezoelectric MEMS deformable mirror resolution is studied for an adaptive optics device. In previous study, we have developed the piezoelectric MEMS deformable mirrors which have 19 actuator away. To improve the resolution of the deformable mirror, we designed the best electrode size to deflect 5μm when applied 10Vpp. Then, we compared 61CH electrodes with 91CH electrodes in terms of Zernike generation. Zernike polynomials are used to evaluate the mirror surface, and the control system is based on the influence functions for generating Zernike modes. As a result of simulation, we proposed 61CH hexagonal electrodes. The displacement profiles measurements by a laser Doppler vibrometer showed that the each actuator generated displacement of 1.0μm〜1.3μm at 10V. Furthermore we calculated residual RMS of Zernike modes(〜27th) of fabricated deformable mirror.一般社団法人日本機械学会, 2008年03月17日, IIP情報・知能・精密機器部門講演会講演論文集, 2008(0) (0), 228 - 231, 日本語
- 2110 MEMSデバイス上における血管増殖因子を用いた血管構造形成の誘導(要旨講演,一般セッション:マイクロナノメカトロニクス)Recently, studies of positional relationships of cells are seemed to be very important for cell biology. We proposed a novel concept that self-organized vasculature integrates artificial orifices on a device by VEGF (Vascular Endothelial Growth Factor). Sucking and clamping of Alginate Calcium gel beads containing VEGF, it is able to induce angjogenesis to orifices on embedded channels. Endothelial cells have a characteristic property that they organize vasculature by themselves in collagen gel and grow along the VEGF concentration gradient. HUVEC (Human Umbilical Vein Endothelial Cells) were cultured on device for about 7 days in the collagen gel and artificial vasculature were immobilized on orifices by self-organized.一般社団法人日本機械学会, 2008年03月17日, IIP情報・知能・精密機器部門講演会講演論文集, 2008(0) (0), 236 - 237, 日本語
- A novel concept of micromixer proposed in this study provides complex perturbation in a micromixer chamber. The chamber wall has meta-structure, which has multiple local masses on the chamber wall. Oscillation is applied to the metastructure with modulating frequency, resulting on local resonance oscillation. Measured amplitude mapping of the vibration corresponded to harmonic responses obtained from finite-element-analyses. This complex structural oscillation produces high mixing efficiency. Using this technique produced a mixing index of 0.92 with the volumetric flowrate of 1 μL/min, while it was 0.49 for a conventional technique.2008年01月01日, 12th International Conference on Miniaturized Systems for Chemistry and Life Sciences - The Proceedings of MicroTAS 2008 Conference, 1387 - 1389, 英語
- In this paper, we propose a novel integration method for multi-layered microfludic networks without assembling process including alignment and bonding. The proposed process can fabricate complicated arrangement of microfluidic networks in an alternating succession of an inclined/rotated UV lithography with a single-mask. For evaluation of practical performance, a double-layered device for cell manipulation with laminar flow was fabricated to immobilize microsubstances on orifices in the flow order with equivalent circuit analysis. © 2008 CBMS.2008年01月01日, 12th International Conference on Miniaturized Systems for Chemistry and Life Sciences - The Proceedings of MicroTAS 2008 Conference, 363 - 365, 英語
- Stress free heteroepitaxial thin films of PZT-based ternary perovskite, xPb(Mn,Nb)O-3-(1-x)PZT, were fabricated by magnetron sputtering on (001)MgO substrates and evaluated their crystal structure, ferroelectric and piezoelectric properties. The heteroepitaxial thin films showed single c-domain /single crystal structure and exhibit hard ferroelectric behavior with large Pr, Pr=60 mu C/cm(2), and high E-c, 2E(c)=230kV/cm, at x=0.06. The PZT-based thin films exhibited high piezoelectric coupling factors k(t), k(t)=70%, measured at GHz range FBAR structure. High values of mechanical quality factor Q(m), Q(m)=185, were observed at 4Ghz range. The observed k(t) and Q(m) are, to our knowledge, the highest in the reported values. The figure of merit k(t)(2)Q(m) is almost the same to piezoelectric AlN thin films. It is confirmed the PZT-based ternary perovskite thin films have a potential for a fabrication of FBAR and/or wide band filters at GHz range.IEEE, 2008年, 2008 IEEE ULTRASONICS SYMPOSIUM, VOLS 1-4 AND APPENDIX, 2008 Vol.1, 213 - +, 英語
- In this paper, we report a piezoelectric deformable mirror composed of high-density actuator array for low-voltage adaptive optics. A piezoelectric Pb(Zr,Ti)O(3) (PZT) film was deposited on a Pt-coated silicon on insulator (SOI) substrate, and a diaphragm structure of 15 mm in diameter was fabricated by etching a Si handle wafer. A hexagonal 61-element unimorph actuator array was produced with an Al or Au reflective layer over the backside of the diaphragm. In order to reduce the dead space for the lead lines between the actuators, they were prepared on the polyimide insulating layer. The displacement of each actuator was measure by using a laser Doppler vibrometer and we confirmed a relatively large displacement of more than I pm by applying a voltage of 10V(pp).IEEE, 2008年, 2008 IEEE/LEOS INTERNATIONAL CONFERENCE ON OPTICAL MEMS AND NANOPHOTONICS, 132 - 133, 英語
- 2008年, 日本機械学会年次大会講演論文集 ,2008/8/2,8,17-18, 日本語補償光学用高解像度圧電MEMSミラーに関する研究
- 2008年, 日本機械学会年次大会講演論文集 ,2008/8/2,8,19-20, 日本語圧電薄膜を用いた流路壁面振動送液デバイスの特性評価
- 2008年, 日本機械学会年次大会講演論文集 ,2008/8/2,8,37-38, 日本語MEMSデバイスを利用した血管構造への流体導入に関する研究
- 2008年, International Symposium on Microchemistry and Microsystems 2008 [ISMM2008], pp. 30, Kyoto, JAPAN, Dec,7,, 英語Development of Rapid Fiber-Fish Process with Micro-Bridges Fabricated by Inclined Uv Lithography,[査読有り]
- 2008年, 化学工業, Vol.59.(No.8.) (No.8.), pp608 - 613, 日本語圧電薄膜によるMEMSデバイス応用[招待有り]記事・総説・解説・論説等（商業誌、新聞、ウェブメディア）
- 2007年12月07日, 電気学会研究会資料. PHS, フィジカルセンサ研究会, 2007(35) (35), 23 - 27, 日本語PZT圧電薄膜とそのMEMS応用
- This paper describes a method for cell sorting using ultrasonic radiation pressure. In previous research literature, we proposed resin-based device that was superior to silicon-based device in the points of optical transparency and simple process. In this paper, we studied some phenomena different from the silicon device. The sound wave reflectivity of SU-8 is smaller than that of silicon. So first, we verified the influence of the wall using PDMS microchannel which had small reflectivity of sound wave. Then we verified the influence of whole device resonance frequency.一般社団法人日本機械学会, 2007年09月07日, 年次大会講演論文集 : JSME annual meeting, 2007(7) (7), 327 - 328, 日本語
- Recently, studies of positional relationships of cells are seemed to be very important for cell biology. We proposed a novel concept that self-organized vasculature integrate artificial orifices on a device. Using SIMPLE (Single Mask inclined Photo-Lithography Exposure) process, it is easy to fabricate embedded channels with orifices. Endothelial cells have a characteristic property that they organize vasculature by their selves in collagen gel. HUVEC (Human Umbilical Vein Endothelial Cells) are cultured on device for about 10 days in matrigel and artificial vasculature were immobilized on orifices by self-organized.一般社団法人日本機械学会, 2007年09月07日, 年次大会講演論文集 : JSME annual meeting, 2007(7) (7), 319 - 320, 日本語
- Piezoelectric deformable mirror for adaptive optics is studied as an adaptive optics device. We have studied the piezoelectric mirror which have 19 upper electrodes. To improve the accuracy of the deformable mirror, we designed two upper electrode types, hexagonal electrodes 37ch and coaxial electrodes 35ch. To compare two electrode types, we calculated deflection of the designed mirrors by using Finite Element Method analysis simulation software, MSC. Marc. Zernike polynomials are used to evaluate the mirror surface, and the control system is based on the influence functions for generating Zernike modes. To compared with three electrodes types, 37ch, 35ch and 19ch, the residual RMS of hexagonal electrodes 37ch was the smallest, less than 0.005μm.一般社団法人日本機械学会, 2007年09月07日, 年次大会講演論文集 : JSME annual meeting, 2007(7) (7), 295 - 296, 日本語
- In this paper, we propose an innovative fluid transport system for μTAS. In this system, microchannels fabricated on silicon chips have active wall of a piezoelectric thin film directly deposited by sputtering on the outside of the microchannels. The active microchannel can transport the fluid by traveling wave induced on the surface of the piezoelectric moving wall by applying sinusoidal voltages to each patterned top electrode with different phase. Since the active microchannel was fabricated by micromachining process and has simple structure without valves and diffuser, it can be applied to μTAS without occupied area. The fluid transport system can be driven by low electric voltage, and integrated with intricate network design.一般社団法人日本機械学会, 2007年09月07日, 日本機械学会年次大会講演論文集, 2007(Vol.7) (Vol.7), 291 - 292, 日本語
- To evaluate the influence of miniaturization on resonance characteristics of extertnally driven micropumps, the modal analyses for systems consisted of an actuator and microchannel including water was carried out. Scale factor defined in this paper quantified the influence of miniaturizing. When a cantilever-typed actuator was miniaturized, it became clear that the oscillation at a high resonant frequency negatively influence on the pump performance (especially when the scale factor is larger than 100 m-1). The influence of additional mass effect of water was negligible for the scale range in this study. When thin-film actuator was used, negative effect observed in cantilever actuator was not emerged. However, additional mass effect of water produced up to a 67% decrease in resonant frequency. We pointed out the necessity to take the additional mass effect of water into consideration when pump is designed.一般社団法人日本機械学会, 2007年09月07日, 日本機械学会年次大会講演論文集, 2007(Vol.7) (Vol.7), 317 - 318, 日本語
- For analysis of cell-cell interactions, we have proposed a microchip fabricated by SIngle-Mask inclined UV Photo Lithography for Embedded network (SIMPLE process). The microchip is made of thick negative photoresist SU-8. In this study, we carried out the toxicity and proliferative tests of SU-8 to pancreatic islet β cell, MIN6. Then, the validity of the proposed device was confirmed by a suction test for MIN6 cells using the fabricated device.一般社団法人日本機械学会, 2007年09月07日, 日本機械学会年次大会講演論文集, 2007(Vol.7) (Vol.7), 325 - 326, 日本語
- 1101 誘電エラストマーポンプ一体型微小分析システム(要旨講演,マイクロメカトロニクス)Loverich et al. have reported a micropump by dielectric elastomer actuation (DEA). The micropump has been fabricated everything from polymer, and achieved highly efficient and low-cost. A microfluidic chip incorporating the DEA micropumps is designed and fabricated in this paper. Assuming an analytical system that should transport sequentially and independently three liquids, the micro fluidic chip was designed. The microfluidic chip consists of three DEA micropumps and check valves. Fabricated microfluidic system performed independent motion of DEA and fluid control. It is possible to transport fluids without mixing. Actual analysis using the chip is future works.一般社団法人日本機械学会, 2007年03月19日, IIP情報・知能・精密機器部門講演会講演論文集, 2007(0) (0), 4 - 6, 日本語
- 1102 SINGLE-MASK傾斜UVリソグラフィにより作製した細胞機能計測用チップ上での細胞培養(要旨講演,マイクロメカトロニクス)Recently, many single-cell analysis systems have been proposed for electroporation and patch clamp. We have proposed a microchip fabricated by the SIngle-Mask inclined UV PhotoLithography for Embedded network (SIMPLE process). The microchip fabricated by SIMPLE process is made of thick negative photoresist SU-8. In this study, we carried out the toxicity and proliferative tests of SU-8 to living cells. Then, we tried to improve cell adhesiveness of substrates by coating poly-L-lysine.一般社団法人日本機械学会, 2007年03月19日, IIP情報・知能・精密機器部門講演会講演論文集, 2007(0) (0), 7 - 8, 日本語
- 1103 樹脂構造体による超音波放射圧を用いた細胞分離デバイスの開発(要旨講演,マイクロメカトロニクス)This paper describes a resin-based device to separate living cells using ultrasonic standing wave (USW). Heretofore silicon is used for USW device structure because it has high reflection property and vertical wall can be fabricated by wet etching. But the resin-based device is needed for the permeation property and simple fabrication process. First, we fabricated the SU-8 resist microchannel by photolithographic method in order to obtain the vertical side walls. Then we carried out cell sorting test using the 1μm beads. As a result, we observed the micro beads moving to acoustic nodes and different phenomenon for the silicon structure device.一般社団法人日本機械学会, 2007年03月19日, IIP情報・知能・精密機器部門講演会講演論文集, 2007(0) (0), 9 - 12, 日本語
- Drag reduction of laminar flow in microchannel is very important for μ-TAS (Micro Total Analysis Systems). Ceramic substrates which consist of alumina particles have rough surface and it is used as a mold to fabricate PDMS rectangular channel with textured wall. Roughness of the wall is depended on diameter of alumina particles. Velocity profile of laminar flow in a textured channel is measured by micro PIV. The measurements reveal that reduction in textured channel can be achieved relative to the classical smooth channel Stokes flow.一般社団法人 日本機械学会, 2007年, 年次大会講演論文集, 2007(0) (0), 321 - 322, 日本語
- In this paper, we propose a multiple cell treatment array with high-density arrayed micro-orifice having an individually accessible microchannel and electrodes. More than 10000 micro-orifices with the diameter of 2 mu m can be simultaneously fabricated by SIngle-Mask inclined UV PhotoLithography for Embedded network (SIMPLE) process with the oxygen plasma etching. More than 200 living cells immobilized at the arrayed micro-orifices were permeabilized by electroporation and allowed to uptake an foreign impermeant substance.IEEE, 2007年, TRANSDUCERS '07 & EUROSENSORS XXI, DIGEST OF TECHNICAL PAPERS, VOLS 1 AND 2, 687 - 690, 英語
- This paper shows a novel reconfigurable antenna applied by MEMS technique. We design and demonstrate a novel thermal driven meta-structural reconfigurable millimeter wave antenna. As far as we know, there is no reconfigurable antenna for millimeter wave by micro heater.IEEE, 2007年, TRANSDUCERS '07 & EUROSENSORS XXI, DIGEST OF TECHNICAL PAPERS, VOLS 1 AND 2, 667 - 670, 英語
- The scale effect of the actuator was evaluated using FEM. When a cantilever actuator was miniaturized, it became clear that the oscillation at a high resonant frequency negatively influence on the pump performance (especially when the scale factor is larger than 100m-1). The influence of additional mass effect of water was negligible over the scale range in this study. When thin-film actuator was used, negative effect observed in cantilever actuator was not emerged. However, additional mass effect of water produced up to a 67% decrease in resonant frequency. We pointed out the necessity to take the additional mass effect of water into consideration when pump is designed.JAPAN SOCIETY APPLIED PHYSICS, 2007年, MICROPROCESSES AND NANOTECHNOLOGY 2007, DIGEST OF PAPERS, 342 - +, 英語
- Thin films of Pb- free single crystal (K,, Na(1-x)NbO(3), KNN, were epitaxially grown on (001)SrRuO(3) / (001)Pt / (001)MgO substrates by rf-magnetron sputtering. In the pseudo-tetragonal system, c-lattice parameters of the sputtered KNN films were around 1% longer than those of the bulk KNN. The sputtered KNN thin films showed bulk like dielectric properties and/or ferroelectricity. Dielectric constant c, spontaneous polarization P,, and coercive electric field E(c) of KNN (x= 0.1: (K(0.1), Na(0.9))NbO(3)) were 300, 20 mu C/cm(2)) and 50 [kV/cm], respectively. The piezoelectric coefficient e(31)* of NaNbO(3) (NN) films was e(31)* congruent to -0.7 [C/m(2)], which was 60% of e(31) of bulk NN ceramics. On the other hand, the piezoelectric properties increased with the doping of K and KNN (x=0.1) showed relatively large e(31)* of -2.4 [C/m(2)].IEEE, 2007年, 2007 SIXTEENTH IEEE INTERNATIONAL SYMPOSIUM ON THE APPLICATIONS OF FERROELECTRICS, VOLS 1 AND 2, 627 - 630, 英語
- In this study, we propose a Genetic Extended-fiber Network (GEN) separately stretched over microbridges for DNA fiber applications. The microbridges are rapidly and easily fabricated by directly spin-coating a thick negative photoresist on a metal mask patterned glass substrate and exposing it twice from the backside of the substrate for two different exposure angles. The GEN constructed over microbridge array by centrifugal stretching can achieve high throughput stretching-and-positioning of DNA fibers and individually accessible platform for DNA fibers, on which spatial relationships of DNA fibers can be quantitatively analyzed by accurate compartmentalization.IEEE, 2007年, TRANSDUCERS '07 & EUROSENSORS XXI, DIGEST OF TECHNICAL PAPERS, VOLS 1 AND 2, 2163 - 2166, 英語
- 2007年, The 11th International Conference on Miniaturized Systems for Chemistry and Life Sciences (MicroTAS2007), 1498 - 1500, 英語A piezoelectric active microchannel for fluid transport in microTAS[査読有り]
- 2007年, Proc. microTAS2007, 1765 - 1767, 英語A Low-Damage Cell Trapping Array Fabricated by Single-Mask Multidirectional Photolithography with Equivalent Circuit Analysis[査読有り]
- 2007年, セラミックス, Vol.42.(No.3.) (No.3.), pp181 - 187, 日本語強誘電体薄膜のMEMS応用[査読有り]記事・総説・解説・論説等（学術雑誌）
- 806 マイクロチャネルを用いた機能性高分子ゲルの微粒化(2)(OS8-2 医療援用工学における流動ダイナミクス,OS8 医療援用工学における流動ダイナミクス,オーガナイズドセッション)Gel beads containing cells for immunoisolation should be small, monodisperse and spherical enough to ensure the reproducivility of diffusion of nutrients and hormone and to improve biocompatibility. In this paper, we present a new method to generate cell encapsulated micro gel beads for cell transplants. Using water-in-oil (W/O) emulsification and droplet coalescence in a microchannel, presented method generated smaller (less than 300μm in diameter) and more monodisperse gel beads compared to conventional methods. We report the relationships between flow rate and some essential dimensions for cell transplants such as gel beads diameter and circularity.一般社団法人日本機械学会, 2006年10月28日, 流体工学部門講演会講演論文集, 2006, "806 - 1"-"806-4", 日本語
- 804 Single-MASK傾斜UVリソグラフィを用いたエレクトロポレーションチップの開発(2)(OS8-1 医療援用工学における流動ダイナミクス,OS8 医療援用工学における流動ダイナミクス,オーガナイズドセッション)A novel single-mask fabrication method for high-density arrayed micro-orifices and embedded microchannels is proposed for single cell analysis. The process is based on inclined UV lithography to expose a single layered photoresist (SU-8) coated on a patterned mask. Long embedded microchannels with a length/width ratio as high as 1000 can be fabricated by the proposed process. We prepared SU-8 structure with arrayed micro-orifices and embedded microchannels, and carried out an electroporation test with mouse erythroleukemia (MEL) cells to confirm the validity of the proposed system. Nuclear transport factor importinss was fed to the cellular interior by applying the low pulsed voltage.一般社団法人日本機械学会, 2006年10月28日, 流体工学部門講演会講演論文集, 2006(0) (0), "804 - 1"-"804-4", 日本語
- 820 細胞分離における生体細胞の破壊とその評価方法(2)(OS8-5 医療援用工学における流動ダイナミクス,OS8 医療援用工学における流動ダイナミクス,オーガナイズドセッション)In this paper, we propose a fracture model of islets in a shear flow to evaluate the mechanical damage of islets. The fracture model was developed using the relationship between surface area increase and strain energy induced into the islet through the fracture. The islet diameter reduction during the purification process was predicted using the fracture model and numerical calculation using computational fluid dynamics. Comparing experimental and numerical results in terms of the islet size reduction, it is confirmed that the fluid dynamical stress during the islet purification damages islets.一般社団法人日本機械学会, 2006年10月28日, 流体工学部門講演会講演論文集, 2006(0) (0), "820 - 1"-"820-4", 日本語
- In this paper, we investigated the effect of the fluid dynamical stress on islets during islet purification process. Firstly, we developed a fracture model of islets in a shear flow by the fracture test using a cylindrical viscometer. Secondary, we conducted the numerical calculation to estimate the fluid dynamical stress and strain energy during islet purification process. Finally we predicted the islet size reduction during islet purification using the fracture model and the numerical results. Comparing experimental data and numerical result in terms of the islet size reduction, it is confirmed that the fluid dynamical stress during the islet purification damages islets.一般社団法人日本機械学会, 2006年09月15日, 年次大会講演論文集 : JSME annual meeting, 2006(5) (5), 289 - 290, 日本語
- A novel single-mask fabrication method for high-density arrayed micro-orifices and microchannels is proposed and applied for electroporation. The process is based on inclined UV lithography to expose a single layered photoresist (SU-8) coated on a patterned mask. To fabricate the proposed feature precisely, we investigated the inclined angle on exposure process and developing distance of microchannels as a function of time. Using the process, we prepared SU-8 structure with arrayed micro-orifices and microchannels, and carried out electroporation test with MEL cells to confirm the validity of the proposed system. Nuclear transport factor CFP-importinβ was fed to the cellular interior by applying the low pulsed voltage.一般社団法人日本機械学会, 2006年09月15日, 年次大会講演論文集 : JSME annual meeting, 2006(7) (7), 293 - 294, 日本語
- In this paper, a new method to generate cell encapsulated micro Ca-alginate gel beads for cell transplants is presented. Alginate gel beads for immunoisolation should be small, monodisperse and spherical enough to ensure the reproducivility of diffusion of nutrients and hormone and to improve biocompatibility. By using water-in-oil (W/O) emulsification and droplet coalescence in micro fluidic channel, smaller (less than 300μm) and more monodisperse gel beads were obtained compared to conventional methods. We report the relationship of flow rate and some essential dimensions for cell transplants such as gel beads diameter and circularity.一般社団法人日本機械学会, 2006年09月15日, 年次大会講演論文集 : JSME annual meeting, 2006(7) (7), 315 - 316, 日本語
- We have developed piezoelectric RF-MEMS switch using PZT thin films for low-voltage actuation. PZT thin films with composition of Zr/Ti=53/47 were grown on the (111) Pt/Ti/Si substrates by RF-sputtering. The cantilever type actuators composed of PZT thin films and Cr elastic layers were successively fabricated as unimorph structure, but large initial bending arises because of residual stress in the PZT and Cr layers. We optimized the design of the actuators to satisfy flat structure as well as large deflection, and we adopted X type connectors in the middle of the beam. According to FEM simulation (MARC2005) results, the deflection of the optimized actuators composed X type connectors was as high as 3.2μm at a relatively small voltage of 5V. Their resonant frequency was 14.6kHz and larger than cantilever type actuator's one. However, the deflection of the actuators was as high as 400nm at 5V, and the actuators geometry cause the degradation of the deflection characteristic.一般社団法人日本機械学会, 2006年09月15日, 年次大会講演論文集 : JSME annual meeting, 2006(7) (7), 321 - 322, 日本語
- A precise control of various fields is required on local field. The thermal field, that is one of the most general fields, is commonly used, but it is difficult to precise control of the thermal field in local field, because of very small thermal capacity of the micro device. Then, we propose the device for larger thermal gradient and fast response, which has great heat liberation and small heat transfer coefficient. Using MEMS process, this device has TaN heat wear on 6μm SiO_2 membrane. In the experiment, our device achieved the fast response unless 0.2s and thermal gradient over 20℃ between the interval of 250μm.一般社団法人日本機械学会, 2006年09月15日, 日本機械学会年次大会講演論文集, 2006(Vol.7) (Vol.7), 297 - 298, 日本語
- We fabricated a deformable MEMS mirror for adaptive optics. A PZT (Pb (Zr, Ti) O_3) thin film was grown on a (111) Pt/Ti/SOI substrate by RF-sputtering. The Si substrate was etched out up to the buried oxide layer to fabricate a circular membrane. We optimized the design of the upper electrodes using numerical analysis. The size of diaphragm is 15mm in diameter and 22μm thick. Mirror surface whose active area is 8mm in diameter was prepared on the exposed buried oxide layer. We calculated influence function for generating Zernike modes, and observed the deformation of the mirror using a laser Doppler vibrometer. The measurements revealed that the Zernike modes to 7^
terms were generated within the residual of 10〜20%.一般社団法人日本機械学会, 2006年09月15日, 日本機械学会年次大会講演論文集, 2006(Vol.7) (Vol.7), 319 - 320, 日本語 This paper describes a method to separate living cells using ultrasonic standing wave by density difference. Particles in ultrasonic standing wave field are subjected to acoustic force toward the direction corresponding to particles density and compressibility. We fabricated the SU-8 resist microchannel by novel photolithographic method in order to obtain the vertical side walls. We carried out cell sorting test system using the micro beads with diameter of 1μm. As a result, we observed the micro beads moving to acoustic nodes and antinodes by acoustic force in the flowing low or high density medium.一般社団法人日本機械学会, 2006年09月15日, 日本機械学会年次大会講演論文集, 2006(Vol.7) (Vol.7), 305 - 306, 日本語2006年05月15日, 電気学会研究会資料. BMS, バイオ・マイクロシステム研究会 = The papers of Technical Meeting on Bio Micro Systems, IEE Japan, 2006(1) (1), 11 - 14, 日本語マイクロチャネルにおけるせん断流が生体組織に与える影響2006年05月15日, 電気学会マイクロマシン・センサシステム研究会資料, MSS-06(1-27) (1-27), 105 - 108, 日本語圧電ＰＺＴ薄膜を用いた波面補償用形状可変ＭＥＭＳミラーの開発2006年, 化学とマイクロ・ナノシステム研究会講演要旨集, 13thSingle-MASK傾斜リソグラフィを用いた単一細胞機能計測アレイの開発In this paper, we propose a novel bonding technique using soft-cure SU-8 sheet under low pressure and low temperature. The pressure for the bonding process (∼5kPa) was significantly smaller than those of other bonding techniques (∼MPa). This bonding process allows us to select a wide variety of materials such as fragile and low melting point materials. © 2006 Society for Chemistry and Micro-Nano Systems.2006年01月01日, Micro Total Analysis Systems - Proceedings of MicroTAS 2006 Conference: 10th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 681 - 683, 英語We observed the instantaneous fluid flow included in the net continuous flow simultaneously generated by traveling wave micropumps using a micro particle image velocimetry (microPIV) system with a high speed digital video camera and a confocal unit. It was measured that the instantaneous flow velocity was about 2.66 times higher than the time-averaged continuous flow in the traveling wave micropump. © 2006 Society for Chemistry and Micro-Nano Systems.2006年01月01日, Micro Total Analysis Systems - Proceedings of MicroTAS 2006 Conference: 10th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 131 - 133, 英語We propose a high throughput electroporation microchip simply and rapidly fabricated by inclined UV lithography using a single photoresist layer on a mask. To confirm the validity of the proposed single-cell analysis chip, we demonstrated high-yield electroporation for mouse erythroleukemia (MEL) cells with the membrane impermeant substances, Trypan blue and nuclear transport factor CFP-importinβ. © 2006 Society for Chemistry and Micro-Nano Systems.2006年01月01日, Micro Total Analysis Systems - Proceedings of MicroTAS 2006 Conference: 10th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 1498 - 1500, 英語Rapid fabrication process for high aspect-ratio embedded microchannels with orifices using a single SU-8 layer on a maskIn this paper, a novel single-mask fabrication method for high aspect-ratio embedded microchannels and high-density arrayed micro-orifices is presented. The proposed process is based on inclined UV lithography to expose a single layered photoresist coated on a patterned mask. Long embedded microchannels with a length/width ratio as high as 1000 can be fabricated by the proposed process. By a suction test with HeLa-GFP cells, it was experimentally confirmed that the fabricated devices are applicable for single-cell analysis.IEEE, 2006年, MEMS 2006: 19TH IEEE INTERNATIONAL CONFERENCE ON MICRO ELECTRO MECHANICAL SYSTEMS, TECHNICAL DIGEST, 2006, 346 - 349, 英語A compact biosensor chip for clinical diagnosis is presented. The proposed biochip integrated three independent microchannels on one chip partially coated with An thin film as a Surface Plasmon Resonance (SPR) excitation layer. For clinical diagnosis, the affinity binding of unlabeled biological molecules onto the Au surface can be quantitatively analyzed by SPR imaging with the multi-microchannels, i.e. one biosample and two reference flows to obtain an analytical curve.IEEE, 2006年, 2006 INTERNATIONAL CONFERENCE ON MICROTECHNOLOGIES IN MEDICINE AND BIOLOGY, 116 - +, 英語2006年, 日本機械学会年次大会講演論文集 ,2006/9/15,7,315-316, 日本語マイクロゲルビーズ生成法の開発2006年, 流体工学部門講演会講演論文集,一般社団法人日本機械学会,2006/10/28,,806-1-806-4, 日本語マイクロチャネルを用いた機能性高分子ゲルの微粒化(2)2006年, The 17th International symposium on integrated ferroelectrics (ISIF2006), pp. 7A-469-C, Hawaii, USA, Apr,23,, 英語Piezoelectric Deformable Mems Mirror for Adaptive Optics Composed of Pzt Thin Films on Soi,[査読有り]2006年, 2006 ASME/JSME Joint Conference on Micromechatronics for Information and Precision Equipment (MIPE2006), pp. S15_02, Santa Clara, USA, Jun,21-23,, 英語Piezoelectric Microactuators Composed of Pzt Thin Films on Si Substrates,[査読有り]2006年, 2006 International Meeting for Future of Electron Devices, Kansai, pp. D-2, Kyoto, Japan, Apr,26,, 英語Piezoelectric Rf-Mems Switches Using Pzt Thin Films,[査読有り]2006年, Asia-Pacific Conference of Transducers and Micro-Nano Technology 2006 (APCOT2006), pp. 95-BMFS-A0399, Singapore, Jun,25-28,, 英語Multi-Functional Cell Mapping Device,[査読有り]2006年, 2006 ASME/JSME Joint Conference on Micromechatronics for Information and Precision Equipment (MIPE2006), pp. S11_04, Santa Clara, USA, Jun,21-23,, 英語Tissue Encapsulation with Thin Hydrogel Membrame Using Micro-Emulsification System,[査読有り]A novel cell encapsulation method in microchannel was studied. We used W/O emulsion in the rectangle microchannel fabricated by soft MEMS process. The cell encapsulation process and internal flow of the droplet were visualized. The velocity of the droplet and the cell were measured by the use of the digital image processing. Simple model for prediction of the all velocity was proposed. The theoretical result agreed well with the experimental data.一般社団法人日本機械学会, 2005年09月18日, 年次大会講演論文集 : JSME annual meeting, 2005(2) (2), 17 - 18, 日本語Micro-folding culture system is proposed where cells are cultivated on micropatterned substrates. The substrates have a number of pits with diameter of 100, 150 and 200μm, and has low cell-adhesiveness surface. Mesenchymal stem cells (MSCs) were seeded onto the patterned substrates at a density of 1.1×10^5 cells/cm^2. Aggregates of the MSCs were formed in the pits within 48 hours. Diameter of the aggregates and movement of aggregates had positive and negative correlation with diameter of pits respectively. There is a possibility that some function of aggregate can be controlled by the micro-folding culture.一般社団法人日本機械学会, 2005年09月18日, 年次大会講演論文集 : JSME annual meeting, 2005(6) (6), 123 - 124, 日本語We fabricated a deformable MEMS (Micro Electro Mechanical System) mirror for adaptive optics. PZT (Pb(Zr,Ti)O_3) thin films were grown on the (111) Pt/Ti/SOI substrate by RF-sputtering. Then Al was evaporated on PZT and patterned as eight separated upper electrodes. The size of mirror is 8mm in diameter and 12μm thick. The deflection of the mirror was 110nm at 10V, and it's proportional to applied voltage. To increase the deflection of the mirror, we optimized the electrodes structure by FE-Analysis. The optimize mirror with new electrodes achieved 13.6μm deflection at 10V.一般社団法人日本機械学会, 2005年09月18日, 年次大会講演論文集 : JSME annual meeting, 2005(7) (7), 117 - 118, 日本語We have developed piezoelectric RF-MEMS switches using PZT thin films for low-voltage actuation. PZT thin films with composition of Zr/Ti=53/47 were grown on the (111) Pt/Ti/Si substrates by RF-sputtering. The cantilever and double supported beam type actuators, composed of PZT thin films and Cr/Al elastic layers, were successively fabricated as unimorph structure. The deflection of the actuators was measured using a Laser Doppler Vibrometer and we observed the largest displacement of cantilever type actuator was 1μm and one of the double supported beam type actuator was 100nm at a relatively small voltage of 5V. Initial bending of the double supported beam type actuator caused by residual stress in the PZT and Cr/Al layers had smaller than one of cantilever type actuator, however the displacement magnitude of the double supported beam type actuator enough for switching couldn't obtain. We optimized the design of the actuator by FEM analysis. Fig.2 Fabrication process of PZT micro-actuator一般社団法人日本機械学会, 2005年09月18日, 年次大会講演論文集 : JSME annual meeting, 2005(7) (7), 121 - 122, 日本語We study on the measurement of mechanical properties of a living cardiac myocyte. Micro mechanical sensors were made of PDMS using MEMS technique. The device consists of micro posts which work as vertical cantilevers measuring local contractile forces of a single myocyte. The generated force is calculated from the displacement of the top of the post. We also propose the device with through holes on the micro channel to apply negative pressure to the cell. And this device has additional capability to measure the cell responses to the physical and chemical effects simultaneously with molecular localization in the cell. This approach has the potential to measure the physiological properties of a single myocyte to develop a bio-simulator model.一般社団法人日本機械学会, 2005年09月18日, 日本機械学会年次大会講演論文集, 2005(Vol.7) (Vol.7), 127 - 128, 日本語259 PZT/SUS ユニモルフマイクロアクチュエータの開発と進行波型マイクロポンプへの応用The traveling wave micropump with a thin flow layer is suitable for particle separation and quantification without valves, heat and strong electric field. We have proposed a traveling wave micropump driven by the traveling wave, and demonstrated high efficiency. In this paper, we fabricated a traveling wave micropump composed of flexible microchannel wall made of Polydimethylsiloxane (PDMS) with piezoelectric thin-film unimorph actuators. The piezoelectric thin films were deposited directly on cantilever-shaped stainless steel (SUS) substrates using rfagnetron sputtering technique. The active motion of the particles in the fluid was confirmed by the actuation of the microchannel wall by the piezoelectric actuators.一般社団法人日本機械学会, 2005年08月22日, Dynamics & Design Conference, 2005(0) (0), "259 - 1"-"259-4", 日本語2005年06月22日, 電気学会マイクロマシン・センサシステム研究会資料, MSS-05(21-44) (21-44), 63 - 66, 日本語ＰＺＴ薄膜／ＳＵＳユニモルフアクチュエータの開発およびマイクロポンプへの応用2005年06月22日, 電気学会研究会資料. BMS, バイオ・マイクロシステム研究会 = The papers of Technical Meeting on Bio Micro Systems, IEE Japan, 2005(1) (1), 9 - 12, 日本語単一心筋細胞の収縮力を測定する力学センサの開発2005年06月22日, 電気学会マイクロマシン・センサシステム研究会資料, MSS-05(21-44) (21-44), 67 - 70, 日本語μＴＡＳ用アトマイザの高機能化と数値設計1104 Si基板上に成膜したPZT薄膜を用いたアクチュエータ(要旨講演,マイクロメカトロニクス)We have developed micro-piezoelectric actuators using PZT thin films. PZT thin films with composition of Zr/Ti=53/47 were grown on the (111)Pt/Ti/Si substrates by rf-sputtering. Micro-cantilevers, composed of PZT thin films and Cr elastic layers, were successively fabricated as unimorph actuators with a length of 500um and width of 90μm. The tip deflection of the cantilevers was measured using a Laser Doppler Vibrometer and we observed piezoelectric vibration level as high as 0.62μm at a relatively small voltage of 5.0V. However, the micro-cantilevers had large initial bending because of residual stress in the PZT and Cr layers.一般社団法人日本機械学会, 2005年03月21日, IIP情報・知能・精密機器部門講演会講演論文集, 2005(0) (0), 40 - 41, 日本語1115 指向性可変ミリ波アンテナの開発(要旨講演,マイクロメカトロニクス)This paper presents a directivity reconfigurable antenna for millimeter-wave communication. Reconfiguration is carried out by changing the dielectric constant of ferroelectric film. The ferroelectric film is composed of lanthanum modified lead titanate (PLT) and deposited on micro strip line by RF sputtering. The dielectric constant of PLT has temperature dependence, so by using heater elements we can change the dielectric constant of PLT film. Heater elements are laid out beside micro strip line. By switching heater element the dielectric constant is periodically changed, and the characteristic of antenna will be reconfigured. As a first step, we analyzed two kind of antenna device by using FDTD (Finite Difference Time Domain) method, and fabricated them. And we developed a new numerical analysis program using CIP (Cubic Interpolated Peudo-Particle Scheme) method.一般社団法人日本機械学会, 2005年03月21日, IIP情報・知能・精密機器部門講演会講演論文集, 2005(0) (0), 82 - 83, 日本語1117 MEMS技術を用いた単一細胞の電気生理特性の計測に関する基礎研究(要旨講演,マイクロメカトロニクス)Patient-tailored treatments become possible by simulating behavior of organs, which is affected by the change of the environment such as dispensing of drugs. For example, it is necessary to detail the electrical and mechanical properties of a single living cell to build simulation model of heart. This paper proposes a novel planar patch-clamp device integrating electrode, micro-channel and micro-hole.一般社団法人日本機械学会, 2005年03月21日, IIP情報・知能・精密機器部門講演会講演論文集, 2005(0) (0), 86 - 87, 日本語2506 単一心筋細胞の収縮特性を測定するデバイスの開発(要旨講演,生体治療・医療,バイオ操作・検査)This paper is a study on the measurement of mechanical properties of a living cardiac myocyte. We propose micro mechanical sensors made of PDMS using soft lithography technique. The device consists of micro columns arrays and work as vertical cantilevers measuring local forces of a myocyte. The generated force derives from the displacement of the top of column. This approach has the potential to measure 2-dimensional mechanical properties of a single myocyte to develop a viscoelastic constitutive equation for a bio-simulator model.一般社団法人日本機械学会, 2005年03月21日, IIP情報・知能・精密機器部門講演会講演論文集, 2005(0) (0), 345 - 346, 日本語マグネトロンスパッタ法による（Ｐｂ，Ｌａ）（Ｚｒ，Ｓｎ，Ｔｉ）Ｏ３薄膜の作製及び組成比による特性評価The electrical properties and phase transition behavior of (Pb,La)(Zr,Sn,Ti)O_3 (PLZST) thin films prepared on (100)Pt/(100)MgO substrates by RF-magnetron spattering and investigated by X-ray diffraction, relative dielectric constant and P-E hysteresis loops. From X-ray diffraction all PLZST thin films are polycrystalline. With an increase in composition Ti, electrically field-induced AFE-FE switching field(E_一般社団法人日本機械学会, 2005年03月21日, 日本機械学会情報・知能・精密機器部門講演会講演論文集, 2005, 88 - 89, 日本語) is depressed. But Polarization of ferroelectric state are almost equal. These indicate PLZST components is better around boundary between AFE_T and F_R for micro actuator. マイクロアトマイザの開発とその数値設計Cylindrical droplet formation in a W/O (water in oil) system of microchannel was analyzed experimentally and theoretically. The microchannel shape was modified to generate smaller droplet based on theoretical model. Numerical and experimental investigations were carried out with the novel microchannel. It is found that generated droplet was almost the spherical shape, since the diameter was smaller enough than the depth of microchannel. The results indicated that 3-dimensional and more precise theoretical model should be applied to realize the smaller droplet generation.一般社団法人日本機械学会, 2005年03月21日, 日本機械学会情報・知能・精密機器部門講演会講演論文集, 2005, 90 - 92, 日本語進行波によるバルブレスマイクロポンプの作製及びその応用Micropumps are one of the most important microfluidic components in Micro Total Analysis System (μTAS). We have developed a valveless micropump driven by traveling wave, and obtained high energy efficiency. In this paper, the valveless micropump was fabricated by the microfabricatin technique to verify the validity of the pumping principle. The micropump was composed of flexible walls of a microchannel with piezoelectric bimorph cantilevers. Traveling wave was induced on the surface of the microchannel by applying sinusoidal voltages to each piezoelectric cantilever with the different phase, and the peristaltic motion of the channel wall transports the fluid. The fluid flow of the proposed micropump was measured using Micro particle Image Verocimetry (MicroPIV). The traveling wave micropump driven by the piezoelectric actuators is a simple structure without valves and a low cost disposable device.一般社団法人日本機械学会, 2005年03月21日, 日本機械学会情報・知能・精密機器部門講演会講演論文集, 2005, 64 - 65, 日本語914 PZTエピタキシャル膜のガラス基板上への転写と誘電特性評価(GS-4,16 薄膜(1),研究発表講演)We have successfully transferred epitaxial single crystal PZT thin films from MgO substrates onto glass substrates by using micro fabrication process. The internal compressive stress of about 200MPa in the epitaxial PZT thin films was released after the transference. The relative dielectric constant of the PZT thin films increased from 239.4 to 332.9 after the transference with a small decrease of polarization. The crystallinity and crystal orientation of the PZT thin films on the glass substrates were the same to those of epitaxial virgin PZT thin films on the MgO substrates. The transfer process is useful for a fabrication of PZT thin film MEMS devices on any substrates.一般社団法人日本機械学会, 2005年03月18日, 関西支部講演会講演論文集, 2005(80) (80), "9 - 27"-"9-28", 日本語923 誘電率変化を用いた指向性可変ミリ波アンテナの創製(GS-16 センシング,研究発表講演)This paper presents a directivity reconfigurable antenna for millimeter-wave communication. Reconfiguration is carried out by changing the dielectric constant of ferroelectric film. The ferroelectric film is composed of lanthanum modified lead titanate (PLT) and deposited on micro strip line by RF sputtering. The dielectric constant of PLT has temperature dependence, so by using heater elements we can change the dielectric constant of PLT film. Heater elements are laid out beside micro strip line. By switching heater element the dielectric constant is periodically changed, and the characteristic of antenna will be reconfigured. As a first step, we analyzed two kind of antenna device by using FDTD(Finite Difference Time Domain) method, and fabricated them. And we developed a new numerical analysis program using CIP(Cubic Interpolated Peudo-Particle Scheme) method.一般社団法人日本機械学会, 2005年03月18日, 関西支部講演会講演論文集, 2005(80) (80), "9 - 45"-"9-46", 日本語Low-power implantable micro analysis systems such as blood glucose sensors have received significant interest in recent years. Powering such micro devices with conventional methods is a concern because batteries have a finite life and transcutaneous energy transmission using RF or magnetism requires bulky hardware and frequent charging. To address these issues, this paper proposes a new device that harvests energy in vivo from repetitive loading of bones. The proposed autonomous power supply uses a small patch of piezoelectric material attached to a load-bearing bone and a simple rectification circuit to accumulate electrical charge that develops in the piezoelectric material during each bone loading period. Copyright © 2005 by the Transducer Research Foundation, Inc.2005年01月01日, Micro Total Analysis Systems - Proceedings of MicroTAS 2005 Conference: 9th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 1, 433 - 435, 英語In this paper, DEP (dielectrophoretic) electrode array which can distribute and transport the dielectric objects uniformly in PDF (pressure driven flow) was proposed. The configuration of the electrode array was theoretically designed realizing the force balance between the DEP force and drag force in stream direction. The performance of the configuration was investigated in a DEP filtering device which has the optimized electrode array. Copyright © 2005 by the Transducer Research Foundation, Inc.2005年01月01日, Micro Total Analysis Systems - Proceedings of MicroTAS 2005 Conference: 9th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 1, 1075 - 1077, 英語We observed the fluid flow induced by traveling wave micropumps using micro particle image velocimetry (micro PIV) system. From the comparison between the observed and calculated results, it was confirmed that the energy conversion efficiency can be estimated from experimental and numerical results in order to optimize the structure of the traveling wave micropump. Copyright © 2005 by the Transducer Research Foundation, Inc.2005年01月01日, Micro Total Analysis Systems - Proceedings of MicroTAS 2005 Conference: 9th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 1, 1108 - 1110, 英語We propose a novel single-mask fabrication method for high aspect ratio embedded microchannels with micro-openings using inclined UV lithography. It can easily make into a high-density array, e.g. high-throughput patch-clamp. Copyright © 2005 by the Transducer Research Foundation, Inc.2005年01月01日, Micro Total Analysis Systems - Proceedings of MicroTAS 2005 Conference: 9th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 1, 1183 - 1185, 英語In this paper we present the piezoelectric-driven deformable micro-mirror for optical wavefront correction. The mirror membrane was fabricated on diaphragm structure composed of piezoelectric PZT thin films on Si substrate. The application of voltage induced large deflection of the surface of the diaphragm.IEEE, 2005年, IEEE/LEOS Optical MEMs 2005: International Conference on Optical MEMs and Their Applications, 31 - 32, 英語Development of piezoelectric RF-MEMS switch driven by low operating voltageThis paper presents the possibility of piezoelectric RF-MEMS switches for low voltage operation. The switches we fabricated consist of micro-cantilevers using PZT thin films with the length of 490 gm and the width of 87 mu m. The cantilevers are actuated as unimorph actuators that can be deflected by applying voltage between upper and lower electrodes. We could obtain large tip deflection of 3 mu m even at the low voltage of 5.0V, which is well compatible with conventional IC drivers. This result indicates that the RF-MEMS switches using piezoelectric PZT thin films is advantageous to the low voltage switching devices in RF components compared with conventionally proposed electrostatic ones.AMER SOC MECHANICAL ENGINEERS, 2005年, Advances in Electronic Packaging 2005, Pts A-C, PART C, 2033 - 2036, 英語We have developed piezoelectric micro-actuators for the application of low-voltage RF-MEMS switches. The inicro-cantilevers are composed of piezoelectric PZT thin films deposited on Pt/Ti/Si substrates by rf-magnetron sputtering. The PZT thin films are microfabricated into a unimorph cantilever with the length of 500 mu m and the width of 85 mu m. We could obtain large tip deflection of 1.0 mu m even at the voltage of 5.0V This result suggests that the low-voltage RF-MEMS switches are expected to be realiezed using piezoelectric PZT thin film actuators.IEEE, 2005年, 2005 PACIFIC RIM CONFERENCE ON LASERS AND ELECTRO-OPTICS, 2005, 797 - 798, 英語2005年, 関西支部講演会講演論文集,一般社団法人日本機械学会,2005/3/18,80,11-35-11-36, 日本語MicroTAS用マイクロアトマイザの特性解析2005年, Micro Total Analysis Systems 2005, pp. 160-162, 英語A Novel High Energy Density Dielectric Elastomer Actuator for Micro Anaysis Systems,[査読有り]2005年, Transactions of the Materials Research Society of Japan (MRS-J), pp. 19-22,, 英語Preparation of Pb(Zr,Ti)O3 Thin Films with Graded Composition Profiles by Rf-Sputtering,[査読有り]2005年, The First International Conference on Complex Medical Engineering-CME2005, pp. 103-106,Kagawa International Conference Hall, Takamatsu, Japan, May,15-18,, 英語Improvement on Pump Performance of Traveling Wave Micropump for Fluid Transportation in Microchannel,[査読有り]進行波を用いた薄膜バルブレスマイクロポンプの開発(J22-3 センサ・アクチュエータシステムとその知能化(3),J22 センサ・アクチュエータシステムとその知能化-実環境で活躍するメカトロニクスを目指して)Micropumps play a significant role in fluid transportation system of μ-TAS. We propose a peristaltic micropump system composed of a microchannel made of silicon rubber. Bottom surface of the microchannel is deformed by the electrostatic attraction between upper and lower electrodes made of copper thin films. Since the pump has simple structure using the electrostatic thin film actuators without valves, the fabrication process is also as simple as just stacking organic films or layer on PMMA substrate. The micropump is suitable for low-cost disposable applications. We could observe clear deflection of the channel wall which is proportional to the a square of the applied voltage. In addition, we confirmed active motion of microbeads in the fluid by the peristaltic actuation of electrostatic force.一般社団法人日本機械学会, 2004年09月04日, 年次大会講演論文集 : JSME annual meeting, 2004(7) (7), 357 - 358, 日本語Piezoelectric thin films have attracted considerable attention in micro-electromechanical systems. In this study, PZT thin films were deposited directly on Pt-coated SUS substrates using RF magnetron sputtering technique. SUS plate has high mechanical strength and stability, which are suitable properties as a substrate for the deposition of a piezoelectric film rather than a conventional substrate such as Si. The x-ray diffraction measurements revealed that the PZT thin films show polycrystalline structure with a perovskite strucure. Piezoelectric vibration of PZT/SUS unimorph cantilevers was clearly observed and the piezoelectric constant e_<31> of the films was calculated to be -1.6 C/m^2.一般社団法人日本機械学会, 2004年09月04日, 年次大会講演論文集 : JSME annual meeting, 2004(7) (7), 355 - 356, 日本語We aim for the realization of a low-voltage RF-MEMS switch. The switches, we fabricated, consist of unimorph micro-cantilevers using piezoelectric PZT thin films. The PZT thin films are deposited on Si substrate by RF sputtering. The cantilevers can be deflected by applying voltage between upper and lower electrodes, and can cause short-circuit transmission line and ground (off-state). Dimension of the cantilever is 500μm in length, 70μm in width, and 3.1μm in thickness. We were able to obtain the deflection of 0.8μm at the voltage of 10V. We established the fabrication process of RF-MEMS switch using PZT thin films on Si substrate.一般社団法人日本機械学会, 2004年09月04日, 年次大会講演論文集 : JSME annual meeting, 2004(7) (7), 359 - 360, 日本語This paper presents a directivity reconfigurable antenna for millimeter-wave communication. Reconfiguration is carried out by changing the dielectric constant of ferroelectric film. The ferroelectric film is composed of lanthanum modified lead titanate (PLT) and deposited on micro strip line by RF sputtering. The dielectric constant of PLT has temperature dependence, so by using heater elements we can change the dielectric constant of PLT film. Heater elements are laid out beside micro strip line. By switching heater element the dielectric constant is periodically changed, and the characteristic of antenna will be reconfigured. As a first step, we analyzed two kind of antenna device by using FDTD(Finite Difference Time Domain) method, and fabricated them.一般社団法人日本機械学会, 2004年09月04日, 年次大会講演論文集 : JSME annual meeting, 2004(7) (7), 361 - 362, 日本語Picoliter-sized water droplets are generated for liquid metering system of μTAS using liquid-liquid interface. The dynamics of interfacial wave between two immiscible liquids has an important roll in this system, e.g., controlling droplets size. In this paper, the fluid dynamical study based on the interfacial instability theory is carried out. Comparing experimental and theoretical results, the validity of theoretical approach is discussed in detail.一般社団法人日本機械学会, 2004年09月04日, 年次大会講演論文集 : JSME annual meeting, 2004(2) (2), 69 - 70, 日本語Patient-tailored treatments become possible by simulating behavior of organs, which is affected by the change of the environment such as dispensing of drugs. For example, it is necessary to detail the electrical and mechanical properties of a single living cell to build simulation model of heart. In this paper, we fabricated two kinds of device for cardiac myocyte, the one is for patch-clamp recording and the other is to measure 2-dimensional mechanical forces.一般社団法人日本機械学会, 2004年09月04日, 日本機械学会年次大会講演論文集, 2004(Vol.5) (Vol.5), 341 - 342, 日本語PLD法によるSrTiO_3(100)基板上への(K, Na)NbO_3薄膜のエピタキシャル成長KNbO_3, (K_<0.5>Na_<0.5>)NbO_3 and NaNbO_3 thin films were deposited on (100) SrTiO_3(STO) substrate by Pulsed Laser Deposition (PLD). The obtained (K,Na)NbO_3 films were epitaxially grown on (100)SrTiO_3 with an orientation relationship as (K,Na)NbO_3(001)_日本結晶成長学会, 2004年08月25日, 日本結晶成長学会誌 = Journal of the Japanese Association for Crystal Growth, 31(3) (3), 234 - 234, 日本語∥STO(001) and (K,Na)NbO_3[100]_ ∥STO[100]. The smoothness of the film surface is improved with the increase of the Na content. Thermodynamic characteristics of single crystalline Pb(Zr 0.52 Ti 0.48 )O 3 (PZT) were investigated using c-axis oriented PZT films. The PZT films were epitaxially grown on Pt/MgO substrate and dielectric and ferroelectric properties were measured as a function of one-dimensional stress. The stress dependence of dielectric and ferroelectric properties was examined on the basis of the Landau-Devonshire's phenomenological theory and the free energy coefficients of single crystalline PZT films were obtained. The dielectric stiffness coefficients and electrostrictive coefficient of epitaxial PZT films were obtained to be α 1 = -1.30 × 10 8 (m/F), α 11 = 3.07 × 10 8 (m 5 /C 2 F), α 111 = -3.11 × 10 7 (m 9 /C 2 F), and Q 12 = -5.70 × 10 -2 (m 4 /C 2 ), which are different from the values derived from the analysis of polycrystalline PZT. The temperature dependence of dielectric constant of the PZT films showed clear Curie-Weiss law and the dielectric stiffness coefficient α 1 derived from this measurement was almost same value from the analysis of stress dependence of the dielectricity of the epitaxial PZT films.2004年02月01日, Physical Review B - Condensed Matter and Materials Physics, 69, 641031 - 6410372004年, 日本機械学会年次大会講演論文集 ,2004/9/4,7,357-358, 日本語進行波を用いた薄膜バルブレスマイクロポンプの開発2004年, 日本機械学会年次大会講演論文集 ,2004/9/4,2,67-68, 日本語極低レイノルズ数流れにおける脈動を用いた混合法2004年, Micro Total Analysis Systems 2004, pp. 439-441, 英語A Novel Micro Device for Measuring the Electromechanical Properties of a Single Myocyte,[査読有り]2004年, The 5th Korea-Japan Conference on Ferroelectrics (Invite), pp. 191, 英語Characterization of Transverse Piezoelectric Properties of Pzt Thin Films for Micro-Actuator Applications,[査読有り]2004年, The 5th Korea-Japan Conference on Ferroelectricity, pp. 85, The Hoam Convention Center, Seoul National University, Seoul, Korea, Aug,18-21, 英語Preparation and Characterization of Pb(Zr, Ti)O3 Thin Films Deposited on Sus Substrates by RF Magnetron Sputtering,[査読有り]2004年, 8th International Conference on Miniaturized Systems for Chemistry and Life Sciences(microTAS2004), pp. 234-236, Malmo Exhibition and Convention Center, Malmo, Sweden,Sep,26-30, 英語High-Efficient Micropump with Geometry Optimization of Microchannel Using Computational Fluid Dynamics,[査読有り]Miniaturized biochemical analysis systems, so-called a μTAS, have gained considerable interest for research and development in new-bio-engineering. However, there is a difficulty in mixing fluids in the micro device because of extremely low Reynolds number. So, to develop an effective micromixer which can fully perform at low Reynolds number flow is important to realize integrated μTAS. In our previous experiment based on flow visualization technique, it was found that the diffusion phenomena of two species must play an important role in mixing process in such a creeping flow. The effect of diffusion should be investigated in detail to evaluate the performance of passive mixer. In this paper, we make a numerical study on the suitable flow condition for μTAS and the diffusion characteristics of passive mixer by means of curvilinear coordinate transformation technique.一般社団法人日本機械学会, 2003年08月05日, 年次大会講演論文集 : JSME annual meeting, 2003(5) (5), 325 - 326, 日本語The paper presents the possibility of a low-voltage micro-switch for RF application. The switches, we fabricated, consist of micro-cantilevers using piezoelectric PZT thin films with the length of 300μm and the width of 50μm. The cantilevers are actuated as unimorph actuators that can be deflected by applying voltage between upper and lower electrodes. We could obtain large deflection of 4.3μm even at the low voltage of 6.0V, which is well compatible with conventional IC drivers. This result indicates that the RF-MEMS switch using piezoelectric PZT thin films is much advantageous to the low voltage switching devices compared with conventionally proposed electrostatic ones.一般社団法人日本機械学会, 2003年08月05日, 年次大会講演論文集 : JSME annual meeting, 2003(7) (7), 221 - 222, 日本語In this paper we propose hybrid piezoelectric materials composed of thin film PZT on organic layer. It is well-known that the PZT film shows excellent piezoelectric properties and is easy for microfabrication as MEMS devices. However deposition of PZT films need high process temperature as high as 500℃ which makes it difficult to integrate them on flexible organic materials. In this study we prepared PZT films on epitaxial MgO substrates in advance, and then they were glued onto adhesive polyimide layer. Finally the MgO substrates were etched away and the PZT films combined with the polyimide layer could be obtained as the hybrid materials. We have fabricated microactuators for micropumps using this film. The PZT films on the polyimide layer were integrated on Si substrates with microchannel and pressure cavities, and piezoelectric actuation was evaluated using laser Doppler displacement meter. We have observed clear piezoelectric displacement as high as 250nm at 10V, indicating the hybrid piezoelectric materials is useful for the MEMS applications.一般社団法人日本機械学会, 2003年08月05日, 年次大会講演論文集 : JSME annual meeting, 2003(7) (7), 225 - 226, 日本語This paper presents a frequency and directivity reconfigurable antenna for millimeter-wave communication. Reconfiguration is achieved by actuating conductor matrix element with micro actuator. The conductor matrix elements are arranged in the upper conductor layer and the lower conductor layer. If a distance between the upper and the lower conductor elements is short enough, the separated conductor elements act as continuous antenna line. By actuating the conductor elements, the electrically connected antenna line is easily disconnected. Consequently, the shape of antenna is reconfigured fitting to wavelength and receiving/radiating wave direction. As a first step, we have fabricated a millimeter antenna device and measured its characteristic. We have confirmed the characteristic radiation of the millimeter wave antenna, indicating this structure is effective to control the path of millimeter current.一般社団法人日本機械学会, 2003年08月05日, 日本機械学会年次大会講演論文集, 2003(Vol.7) (Vol.7), 213 - 214, 日本語一般社団法人日本機械学会, 2003年01月20日, バイオエンジニアリング講演会講演論文集, 2003(15) (15), 229 - 230, 日本語221 進行波を用いた圧電バルブレスマイクロポンプの研究一般社団法人日本機械学会, 2003年01月20日, バイオエンジニアリング講演会講演論文集, 2003(15) (15), 231 - 232, 日本語222 界面不安定性を用いたマイクロミキサーの開発2003年, 4th Asian Meeting on Ferroelectrics (AFM-4), pp. 51, 英語Characterization of Transverse Piezoelectric Properties of Epitaxial Pb(Zr,Ti)O3 Thin Films[査読有り]2003年, Micro Total Analysis Systems 2003, pp. 997-1000, 英語Characterization of Piezoelectric Micropump Driven by Traveling Waves Isaku Kanno, Satoyuki Kawano, Shunsuke Yakushiji, Hidetoshi Kotera,[査読有り]2003年, Micro System Technologies, pp. 571-573, 英語Kelvin-Helmholtz Instability Theory in Development of Microfluidic Mixing System,[査読有り]2003年, Micro System Technologies, pp. 526-528,, 英語Frequency and Directivity Reconfigurable Antenna for Millimeter-Wave[査読有り]2003年, The 5th Euromech Solid Mechanics Conference, pp., 英語Crack Initiation at Free Edge of Interface between Piezoelectric Thin Films on a Substrate[査読有り]1998年10月23日, シンポジウム電磁力関連のダイナミックス講演論文集, 10, 483 - 486, 日本語ZnO薄膜を用いたマイクロカンチレバー型アクチュエータ日本表面科学会, 1998年, 表面科学, 19(7) (7), 463 - 468, 日本語[査読有り]記事・総説・解説・論説等（学術雑誌）
■ 書籍等出版物- その他, Elsevier, 2019年, 英語, Chap_8: "Fundamentals of piezoelectric thin films for microelectromechanical systems"Nanostructures in Ferroelectric Films for Energy Applications - Domains, Grains, Interfaces and Engineering Methods -学術書
- その他, Elsevier, 2019年, 英語, Chap9 "Structural optimization of piezoelectric thin-film vibration energy harvesters based on electric equivalent circuit model"Nanoscale Ferroelectric-Multiferroic Materials for Energy Harvesting Applications学術書
- その他, シーエムシー出版, 2014年, 日本語, 第4章 圧電セラミックスの薄膜化と圧電特性測定技術高分子圧電材料と無機圧電セラミックスの基礎から応用学術書
- その他, CRC Press, 2013年, 英語MEMS Fundamental Technology and Applications学術書
- その他, CRC Press, 2013年, 英語, Chap 8"Piezoelectric Thin Films and Their Application to Vibration Energy Harvesters"Energy Harvesting with Functional Materials and Microsystems学術書
- その他, NTS, 2012年, 日本語環境発電ハンドブック学術書
- その他, CRC press, 2012年, 英語Integrated Microsystems学術書
- IEEE IFCS ISAF 2020, 2020年07月Piezoelectric MEMS as a Micro-Power Source[招待有り]口頭発表（基調）
- 第37回強誘電体会議, 2020年05月Piezoelectric PZT Thin-Film Transformer with a Ring-Dot Structure口頭発表（一般）
- 第37回強誘電体会議, 2020年05月両端支持ユニモルフ梁を用いた薄膜の正圧電係数の評価方法口頭発表（一般）
- 第67回応用物理学会春季学術講演会, 2020年03月Si 基板上エピタキシャル(K, Na)NbO3薄膜の結晶構造および圧電特性の組成依存性口頭発表（一般）
- 第67回応用物理学会春季学術講演会, 2020年03月Si基板上エピタキシャルPb(Zr,Ti)O3薄膜の結晶構造と圧電特性の評価口頭発表（一般）
- 第67回応用物理学会春季学術講演会, 2020年03月高温 Pt マイクロヒーターの開発口頭発表（一般）
- 第67回応用物理学会春季学術講演会, 2020年03月Piezoelectric PZT thin-film transformers with a ring-dot structureポスター発表
- 第67回応用物理学会春季学術講演会, 2020年03月スパッタ法による積層誘電体薄膜作製技術口頭発表（招待・特別）
- 第67回応用物理学会春季学術講演会, 2020年03月全固体リチウムイオン薄膜電池の多層化口頭発表（一般）
- 第10回 マイクロ・ナノ工学シンポジウム, 2019年11月圧電薄膜を用いた圧電トランスの設計、試作および評価ポスター発表
- 第80回応用物理学会秋季学術講演会, 2019年09月SSPDの高性能化に向けたNbTiN薄膜の成膜条件の検討口頭発表（一般）
- 第80回応用物理学会秋季学術講演会, 2019年09月Si基板上のエピタキシャル(K,Na)NbO3薄膜の結晶構造および圧電特性の評価口頭発表（一般）
- 第80回応用物理学会秋季学術講演会, 2019年09月(K, Na)NbO3薄膜への添加物効果口頭発表（一般）
- 第80回応用物理学会秋季学術講演会, 2019年09月RFスパッタリング装置を用いたガラス基板上へのPZT薄膜成膜ポスター発表
- 第83回半導体・集積回路技術シンポジウム, 2019年08月圧電薄膜を用いた振動発電技術口頭発表（招待・特別）
- 強誘電体応用会議2019, 2019年05月シンクロトロン放射光X線回折を用いたエピタキシャルPZT薄膜の微視的圧電特性組成依存性評価口頭発表（一般）
- 第66回応用物理学会春季学術講演会, 2019年03月, 日本語, 応用物理学会, 東京都, 国内会議有機圧電エナジーハーベスターにおける振動発電特性の膜厚依存性ポスター発表
- IIP2019 情報・知能・精密機器部門（IIP部門）講演会, 2019年03月, 日本語, 東洋大学, 国内会議圧電薄膜を用いた振動発電素子開発[招待有り]口頭発表（招待・特別）
- 第66回応用物理学会春季学術講演会, 2019年03月, 日本語, 東京工業大学, 国内会議圧電薄膜を用いた振動発電技術[招待有り]口頭発表（招待・特別）
- 第66回応用物理学会春季学術講演会, 2019年03月, 日本語, 東京工業大学, 国内会議V2O5正極を用いた全固体リチウムイオン薄膜電池の作製口頭発表（一般）
- 第66回応用物理学会春季学術講演会, 2019年03月, 日本語, 東京工業大学, 国内会議(K, Na)NbO3薄膜へのドーピング効果口頭発表（一般）
- IIP2019 情報・知能・精密機器部門（IIP部門）講演会, 2019年, 日本語, 国内会議マイクロフォースセンサを用いた根の機械的性質の解析口頭発表（一般）
- PowerMEMS2018, 2018年12月, 英語, FL, USA, 国際会議Equivalent circuit model of piezoelectric vibration energy harvesters composed of trapezoidal unimorph cantileversポスター発表
- 71th ICAT, 2018年10月, 英語, Penn State, USA, 国際会議Sputtering deposition of piezoelectric PZT thin films for MEMS applications[招待有り]口頭発表（招待・特別）
- 第79回応用物理学会秋季学術講演会, 2018年09月, 日本語, 名古屋国際会議場, 国内会議電圧印加における非鉛(K,Na)NbO3薄膜の結晶構造変化その場観察口頭発表（一般）
- 2018年度日本機械学会年次大会, 2018年09月, 日本語, 関西大学, 国内会議圧電薄膜技術：基礎研究から実用化まで口頭発表（基調）
- 第79回応用物理学会秋季学術講演会, 2018年09月, 日本語, 応用物理学会, 名古屋市, 国内会議ユニモルフカンチレバー型有機圧電薄膜の振動発電特性ポスター発表
- 第79回応用物理学会秋季学術講演会, 2018年09月, 日本語, 名古屋国際会議場, 国内会議V2O5正極を用いた全固体リチウムイオン薄膜電池の作製口頭発表（一般）
- The 10th Japan-China Symposium on Ferroelectric Materials and Their Applications (JCFMA10), 2018年09月, 英語, Inuyama, Japan, 国際会議PZT thin-film Piezoelectric Vibration Energy Harvesters[招待有り]口頭発表（招待・特別）
- 第79回応用物理学会秋季学術講演会, 2018年09月, 日本語, 名古屋国際会議場, 国内会議Pb(Zr,Ti)O3圧電薄膜の正圧電特性の温度依存性に関する研究口頭発表（一般）
- The 10th Japan-China Symposium on Ferroelectric Materials and Their Applications (JCFMA10), 2018年09月, 英語, Kobe, Japan, 国際会議In-situ synchrotron diffraction study of epitaxial and polycrystalline Pb(Zr,Ti)O3 thin filmsunder an applied electric fieldポスター発表
- IWPMA2018, 2018年09月, 英語, Kobe, Japan, 国際会議Doping effect of lead-free K0.5Na0.5NbO3 thin films by multi-target RF-magnetron sputtering口頭発表（一般）
- 第79回応用物理学会秋季学術講演会, 2018年09月, 日本語, 名古屋国際会議場, 国内会議(K,Na)NbO3および(Pb,La)TiO3薄膜を用いた光起電力特性評価口頭発表（一般）
- 2018 ISAF-FMA-AMF-AMEC-PFM Joint Conference (IFAAP2018), 2018年05月, 英語, Hiroshima, Japan, 国際会議Numerical Designs of Thin-Film-Formed Piezoelectric Vibration Energy Harvesters口頭発表（一般）
- 2018 ISAF-FMA-AMF-AMEC-PFM Joint Conference (IFAAP2018), 2018年05月, 英語, Hiroshima, Japan, 国際会議Direct Observation of Inverse Piezoelectric Effect of Pb(Zr,Ti)O3 Thin Films Using Synchrotron X-ray Diffraction口頭発表（一般）
- 2018 ISAF-FMA-AMF-AMEC-PFM Joint Conference (IFAAP2018), 2018年05月, 英語, Hiroshima, Japan, 国際会議A Newly Developed High Performance PZT Thin Films by Using Sputtering and Sol-Gel Hybrid Method for Piezo-MEMS Device口頭発表（一般）
- 日本学術振興会 薄膜第131委員会 第283回委員会・第289回研究会, 2018年04月, 日本語, 京都テルサ, 国内会議ナノエネルギ―技術への期待と展望[招待有り]口頭発表（招待・特別）
- IIP2018 情報・知能・精密機器部門（IIP部門）講演会, 2018年03月, 日本語, 東洋大学, 国内会議等価回路モデルを用いた圧電薄膜振動発電素子の設計と評価口頭発表（一般）
- IIP2018 情報・知能・精密機器部門（IIP部門）講演会, 2018年03月, 日本語, 東洋大学, 国内会議V2O5正極を用いた全固体薄膜リチウムイオン電池の作製とその評価口頭発表（一般）
- 第65回応用物理学会春季学術講演会, 2018年03月, 日本語, 早稲田大学, 国内会議Pb(Zr,Ti)O3薄膜の電圧印加結晶構造変化の組成依存性口頭発表（一般）
- 電気学会センサ・マイクロマシン部門 部門大会 第35回「センサ・マイクロマシンと応用システムシンポジウム」, 2018年, 日本語, 国内会議機械的ストレス下における植物の根系発達過程の解析手法ポスター発表
- 日本機械学会2018年度年次大会, 2018年, 日本語, 国内会議マイクロフォースセンサを用いた根の成長挙動解析口頭発表（一般）
- 日本機械学会2018年度年次大会, 2018年, 日本語, 国内会議マイクロピラーアレイを用いた根の機械的ストレス応答の解析口頭発表（一般）
- 6th International Workshop on Piezoelectric MEMS (PiezoMEMS2018), 2018年01月, 英語, Orlando, FL, 国際会議In-situ observation of crystallographic deformation of Pb(Zr,Ti)O3 thin films by synchrotron x-ray diffractionポスター発表
- PowerMEMS2017, 2017年11月, 英語, Kanazawa, Japan, 国際会議THE PIEZOELECTRIC PZT THIN FILMS DEPOSITED ON METAL SUBSTRATESポスター発表
- The 17th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications （Power MEMS 2017), 2017年11月, 英語, 日本機械学会, 金沢市, 国際会議Orientation Dependence of Power Generation on Piezoelectric Energy Harvesting Using Stretched Ferroelectric Polymer Filmsポスター発表
- PowerMEMS2017, 2017年11月, 英語, Kanazawa, Japan, 国際会議MULTILAYER PIEZOELECTRIC MEMS ENERGY HARVESTER BASED ON LONGITUDINAL EFFECT口頭発表（一般）
- PowerMEMS2017, 2017年11月, 英語, Kanazawa, Japan, 国際会議IEZOELECTRIC PZT THIN FILMS DEPOSITED ON STAINLESS STEEL MESH口頭発表（一般）
- PowerMEMS2017, 2017年11月, 英語, Kanazawa, Japan, 国際会議DEVELOPMENT OF PIEZOELECTRIC VIBRATION ENERGY HARVESTERS FOR BATTERY-LESS SMART SHOESポスター発表
- 第78回応用物理学会秋季学術講演会, 2017年09月, 日本語, 応用物理学会, 福岡市, 国内会議分極制御有機圧電薄膜による振動発電素子[招待有り]口頭発表（招待・特別）
- 日本セラミックス協会 第30回秋季シンポジウム, 2017年09月, 日本語, 神戸大学, 国内会議圧電薄膜とMEMSデバイス応用[招待有り]口頭発表（招待・特別）
- 2017年度日本機械学会年次大会, 2017年09月, 日本語, 埼玉大学, 国内会議シューズ埋め込み型圧電振動発電素子の作製・評価口頭発表（一般）
- 017年度日本機械学会年次大会, 2017年09月, 日本語, 埼玉大学, 国内会議インセクトスケールロボットを目的とした圧電薄膜アクチュエータの作製口頭発表（一般）
- 第78回応用物理学会秋季学術講演会, 2017年09月, 日本語, 福岡国際会議場, 国内会議Pb(Zr,Ti)O3圧電薄膜の電気的信頼性評価に関する研究口頭発表（一般）
- 福岡国際会議場, 2017年09月, 日本語, 国内会議Pb(Zr,Ti)O3圧電薄膜の逆圧電効果による結晶構造変化のその場観察口頭発表（一般）
- International workshop on piezoelectric materials and applications (IWPMA2017), 2017年09月, 英語, Virginia, 国際会議Measurement of piezoelectric characteristics of thin films[招待有り]口頭発表（招待・特別）
- 応用物理学会 薄膜・表面分科会 セミナー, 2017年07月, 日本語, 産総研 臨海副都心センター, 国内会議圧電薄膜を利用した振動発電[招待有り]口頭発表（招待・特別）
- 強誘電体応用会議, 2017年06月, 日本語, 京都, 国内会議ディップコート法による金属箔上へのPZT薄膜の作製と評価口頭発表（一般）
- 8th International Conference on Electroceramics (ICE2017), 2017年05月, 英語, Nagoya, 国際会議Evaluation of piezoelectric characteristics of thin films for MEMS applications[招待有り]口頭発表（招待・特別）
- IIP2017 情報・知能・精密機器部門（IIP部門）講演会, 2017年03月, 日本語, 東洋大学 白山キャンパス, 国内会議薄膜型全固体リチウムイオン電池の作製と評価口頭発表（一般）
- 第64回応用物理学会春季学術講演会, 2017年03月, 日本語, パシフィコ横浜, 国内会議ディップコート法によるステンレス箔上へのPZT薄膜の作製口頭発表（一般）
- IIP2017 情報・知能・精密機器部門（IIP部門）講演会, 2017年03月, 日本語, 東洋大学 白山キャンパス, 国内会議PZT薄膜を用いた圧電型エナジーハーベスターの作製と評価口頭発表（一般）
- 第64回応用物理学会春季学術講演会, 2017年03月, 日本語, パシフィコ横浜, 国内会議Pb(Zr,Ti)O3薄膜の斜め成膜およびその特性評価に関する研究口頭発表（一般）
- International Symposium on Micro-Nano Science and Technology 2016, 2016年12月, 英語, Tokyo, 国際会議Design and characterization of cantilever-type piezoelectric MEMS microphones口頭発表（一般）
- 日本機械学会 2016年度年次大会, 2016年09月, 日本語, 国内会議根の成長パターン解析を目的としたマイクロピ ラーデバイスの開発口頭発表（一般）
- 日本機械学会 2016年度年次大会, 2016年09月, 日本語, 国内会議圧電薄膜振動子を用いたシリンダー型 MEMS ジャイロスコープの特性評価口頭発表（一般）
- The 16th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS2016), 2016年09月, 英語, Pari, France, 国際会議Shoe-mounted vibration energy harvester of PZT piezoelectric thin films on metal foils口頭発表（一般）
- 11th Energy harvesting workshop, 2016年09月, 英語, Arlington, Virginia, USA, 国際会議Piezoelectric Thin Films on Metal Substrates for Flexible and Robust Energy Harvesting[招待有り]口頭発表（招待・特別）
- 第8回日中強誘電体応用会議, 2016年09月, 英語, 筑波, 国際会議Measurement method of transverse piezoelectric properties of thin films[招待有り]口頭発表（招待・特別）
- 第77回応用物理学会秋季学術講演会, 2016年09月, 日本語, 朱鷺メッセ, 国内会議KNN 薄膜を用いた光起電力特性評価ポスター発表
- 第8回日中強誘電体応用会議, 2016年09月, 英語, 筑波, 国際会議Compositional dependence of BaTiO3-xBaSnO3 piezoelectric thin films prepared by combinatorial sputtering口頭発表（一般）
- 第77回応用物理学会秋季学術講演会, 2016年09月, 英語, 朱鷺メッセ, 国内会議Compositional dependence of BaTiO3-xBaSnO3 piezoelectric thin films prepared by combinatorial sputtering口頭発表（一般）
- the 13th International Workshop on Piezoelectric Materials and Applications in Actuators & Energy Conversion Materials and Devices 2016, 2016年08月, 英語, Jeju, Korea, 国際会議Sputtering deposition of piezoelectric thin films[招待有り]口頭発表（招待・特別）
- 5th International Workshop on Piezoelectric MEMS, 2016年05月, 英語, Grenoble, France, 国際会議Multilayer piezoelectric thin films[招待有り]口頭発表（招待・特別）
- 第63回応用物理学会春季学術講演会, 2016年03月, 日本語, 東京都, 国内会議薄膜材料の正・逆圧電特性評価口頭発表（一般）
- 第66回応用物理学会春季学術講演会, 2016年03月, 日本語, 東京都, 国内会議積層圧電薄膜の作製およびその実効的圧電特性評価口頭発表（一般）
- 第64回応用物理学会春季学術講演会, 2016年03月, 日本語, 東京都, 国内会議コンビナトリアルスパッタ法を用いたPMN-PZ-PT薄膜の組成依存性評価口頭発表（一般）
- 第65回応用物理学会春季学術講演会, 2016年03月, 日本語, 東京都, 国内会議PZT圧電薄膜の正圧電特性経時変化口頭発表（一般）
- 第20回 関西大学先端科学技術シンポジウム, 2016年01月, 日本語, 吹田市, 国内会議圧電MEMSとエナジーハーベスティング応用[招待有り]口頭発表（招待・特別）
- "The 15th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2015) Journal of Physics: Conference Series", 2015年12月, 英語, Boston, USA, 国際会議PIEZOELECTRIC MEMS FOR ENERGY HARVESTING口頭発表（一般）
- 化学とマイクロ・ナノシステム学会第32回研究会, 2015年11月, 日本語, 国内会議オンチップ力計測手法による根の成長メカニズム解析ポスター発表
- 第 7 回マイクロ・ナノ工学シンポジウム, 2015年10月, 日本語, 新潟県, 国内会議圧電薄膜アクチュエータを用いたインセクトスケール圧電ロボットの作製と評価口頭発表（一般）
- 第76回応用物理学会秋季学術講演会, 2015年09月, 日本語, 名古屋, 国内会議ステンレス基板上PZT薄膜の光誘起ひずみ効果口頭発表（一般）
- 10th Energy Harvesting Workshop, 2015年09月, 英語, Virginia, USA, 国際会議Self-excited vibration energy harvesters of PZT thin films on stainless-steel cantilevers by airflow口頭発表（一般）
- 第76回応用物理学会秋季学術講演会, 2015年09月, 日本語, 名古屋市, 国内会議Pb(Hf,Ti)O3薄膜の作製と組成依存性評価口頭発表（一般）
- the 7th China-Japan Symposium on Ferroelectric Materials and Their Applications, 2015年08月, 英語, Beijin, China, 国際会議Piezoelectric thin films for MEMS口頭発表（一般）
- 2015 JSME-IIP/ASME-ISPS Joint Conference on Micromechatronics for Information and Precision Equipment, 2015年06月, 英語, Kobe, 国際会議Reliability of vibration energy harvesters of PZT thin films on stainless steel cantilevers口頭発表（一般）
- 2015 JSME-IIP/ASME-ISPS Joint Conference on Micromechatronics for Information and Precision Equipment, 2015年06月, 英語, Kobe, 国際会議Development of simple microrob ot using piezoelectric thin film actuator on metal substrate口頭発表（一般）
- 強誘電体応用会議, 2015年05月, 日本語, 京都市, 国内会議正・逆圧電効果によるPZT薄膜の圧電定数e31,fの測定口頭発表（一般）
- 強誘電体応用会議, 2015年05月, 日本語, 京都市, 国内会議圧電薄膜のMEMS応用口頭発表（一般）
- 第62回応用物理学会春季学術講演会, 2015年03月, 日本語, 国内会議自励振動を利用した圧電薄膜気流振動発電素子口頭発表（一般）
- 第62回応用物理学会春季学術講演会, 2015年03月, 日本語, 国内会議UV-LED光駆動の圧電薄膜アクチュエータの作製口頭発表（一般）
- Fourth International Conference on Multifunctional, Hybrid and Nanomaterials (Hybrid Materials 2015), 2015年03月, 英語, Spain, 国際会議Piezoelectric vibration energy harvesters with stretched and multi-stacked organic ferroelectric filmsポスター発表
- 第62回応用物理学会春季学術講演会, 2015年03月, 日本語, 国内会議Pb(Hf,Ti)O3薄膜の作製と圧電特性評価口頭発表（一般）
- 平成26年度応用物理学会関西支部第3回講演会, 2015年02月, 日本語, 国内会議自励振動を利用した圧電薄膜気流発電素子口頭発表（一般）
- 平成26年度応用物理学会関西支部第3回講演会, 2015年02月, 日本語, 国内会議UV-LED光駆動圧電薄膜アクチュエータの作製口頭発表（一般）
- 第53回セラミックス基礎科学討論会, 2015年01月, 日本語, 国内会議積層圧電薄膜を用いた高効率MEMSアクチュエータの開発口頭発表（一般）
- 第53回セラミックス基礎科学討論会, 2015年01月, 日本語, 国内会議スパッタ法を用いたLi4Ti5O12薄膜の作製とその評価口頭発表（一般）
- 第6回マイクロ・ナノ工学シンポジウム, 2014年10月, 日本語, 国内会議正・逆圧電効果による PZT 薄膜の圧電定数 e31,f の評価口頭発表（一般）
- 第6回マイクロ・ナノ工学シンポジウム, 2014年10月, 日本語, 国内会議金属基板上圧電薄膜アクチュエータを用いたミリメータスケールロボットの作製口頭発表（一般）
- 第6回マイクロ・ナノ工学シンポジウム, 2014年10月, 日本語, 国内会議金属基板上 PZT 薄膜を用いた振動発電素子の信頼性評価に関する研究口頭発表（一般）
- 第6回マイクロ・ナノ工学シンポジウム, 2014年10月, 日本語, 国内会議金属基板上 PZT 薄膜を用いた自励振動発電素子の評価口頭発表（一般）
- 第6回マイクロ・ナノ工学シンポジウム, 2014年10月, 日本語, 国内会議ウエットエッチングによる圧電薄膜の PDMS 基板上への転写技術口頭発表（一般）
- 第6回マイクロ・ナノ工学シンポジウム, 2014年10月, 日本語, 国内会議PZT 圧電薄膜および圧電 MEMS デバイスの信頼性評価口頭発表（一般）
- 2014年秋季第76回応用物理学会学術講演会, 2014年09月, 日本語, 応用物理学会, 札幌市, 国内会議有機圧電エナジーハーベスターにおける振動発電特性の分子配向依存性口頭発表（一般）
- 2014年秋季第77回応用物理学会学術講演会, 2014年09月, 日本語, 応用物理学会, 札幌市, 国内会議ポリ尿素薄膜を用いた焦電・圧電特性および振動発電評価口頭発表（一般）
- 2014年 第75回応用物理学会秋季学術講演会, 2014年09月, 日本語, 国内会議コンビナトリアルスパッタ法による BZT-BCT 圧電薄膜の組成依存性評価口頭発表（一般）
- International ERATO Higashiyama Live-Holonics Symposium 2014 "Plant Live-Cell Imaging and Microdevices", 2014年09月, 英語, 国際会議High-throughput Chemotaxis Assay of Plant-parasitic Nematode by Using a Microchannel Deviceポスター発表
- 第60回高分子研究発表会(神戸）, 2014年07月, 日本語, 神戸市, 国内会議延伸処理した強誘電ポリマーの振動発電特性評価口頭発表（一般）
- 応用物理学会関西支部平成26年第1回講演会, 2014年06月, 日本語, 京都市, 国内会議有機圧電型エナジーハーベスターの特性評価ポスター発表
- 化学とマイクロ・ナノシステム学会 第29回研究会, 2014年05月, 日本語, 日本女子大学 目白キャンパス, 国内会議植物寄生性センチュウのハイスループット化学走性分析用デバイスポスター発表
- 第31回強誘電体応用会議, 2014年05月, 日本語, 国内会議コンビナトリアルスパッタ法による PMN-PT 圧電薄膜の組成依存性評価口頭発表（一般）
- 第61回応用物理学会春季学術講演会, 2014年03月, 日本語, 国内会議着脱式マイクロ流路チップを用いたゾル-ゲル法によるPZT薄膜の直接パターニング技術口頭発表（一般）
- 第61回応用物理学会春季学術講演会, 2014年03月, 日本語, 国内会議スパッタ法を用いた Li4Ti5O12薄膜の作製とその評価口頭発表（一般）
- 第61回応用物理学会春季学術講演会, 2014年03月, 日本語, 国内会議コンビナトリアル成膜によるPLZT薄膜の組成依存性評価口頭発表（一般）
- 第5回 マイクロ・ナノ工学シンポジウム, 2013年11月, 日本語, 日本機械学会マイクロ・ナノ工学部門, 仙台国際センター(仙台市), 国内会議植物寄生性センチュウの行動分析用マイクロ流路デバイス:流路規格および流路内物質濃度分布の検証口頭発表（一般）
- 第5回 マイクロ・ナノ工学シンポジウム, 2013年11月, 日本語, 仙台国際センター(仙台市), 国内会議スパッタ法で作製したPZT薄膜積層アクチュエータ口頭発表（一般）
- 日本機械学会 2013 年度年次大会, 2013年09月, 日本語, 岡山大学津島キャンパス(岡山市), 国内会議ステンレス基板上圧電薄膜を用いた MEMS エナジ ーハーベスター口頭発表（一般）
- 日本機械学会 2013 年度年次大会, 2013年09月, 日本語, 岡山大学津島キャンパス(岡山市), 国内会議コンビナトリアル成膜法による PMN-PT薄膜の組成依存性評価口頭発表（一般）
- IEEE 2013 Joint UFFC, EFTF, and PFM Symposium, 2013年07月, 英語, IEEE, プラハ, 国際会議Piezoelectric thin films公開講演，セミナー，チュートリアル，講習，講義等
- IEEE 2013 Joint UFFC, EFTF, and PFM Symposium, 2013年07月, 英語, IEEE, プラハ, 国際会議Composition depndence of PMN-PT thin films prepared by combinatorial sputteringポスター発表
- 第３０回強誘電体応用会議, 2013年05月, 日本語, 京都市, 国内会議ステンレス基板上非鉛KNN薄膜を用いたMEMSエナジーハーベスター口頭発表（一般）
- 3rdInternational PiezoMEMS Workshop, 2013年04月, 英語, ワシントンDC, 国際会議Piezoelectric MEMS of lead-free KNN thin films[招待有り]口頭発表（招待・特別）
- IIP2013情報・知能・精密機器部門講演会, 2013年03月, 日本語, 日本機械学会, 東京, 国内会議非鉛圧電薄膜(K,Na)NbO3の微細加工技術口頭発表（一般）
- IIP2013情報・知能・精密機器部門講演会, 2013年03月, 日本語, 日本機械学会, 東京, 国内会議金属基板上PZT薄膜を利用したジャイロセンサーの開発に関する研究口頭発表（一般）
- 応用物理学会春季学術講演, 2013年03月, 日本語, 応用物理学会, 東京, 国内会議シリコン基板上に作製したPZT薄膜積層アクチュエータ口頭発表（一般）
- 応用物理学会春季学術講演, 2013年03月, 日本語, 応用物理学会, 東京, 国内会議コンビナトリアル成膜によるBZT-BCT薄膜の組成依存性評価口頭発表（一般）
- IIP2013情報・知能・精密機器部門講演会, 2013年03月, 日本語, 日本機械学会, 東京, 国内会議エピタキシャルPZT薄膜を用いた高効率圧電型振動発電素子に関する研究口頭発表（一般）
- he 12th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS2012), 2012年12月, 英語, Atranta, USA, 国際会議PIEZOELECTRIC MEMS ENERGY HARVESTERS OF PZT THIN FILMS ON STAINLESS STEEL CANTILEVERSポスター発表
- 第53回真空に関する連合講演会, 2012年11月, 日本語, 日本真空学会, 甲南大学ポートアイランドキャンパス, 国内会議シリコン基板上に作製したPZT薄膜積層アクチュエータ口頭発表（一般）
- 第53回真空に関する連合講演会, 2012年11月, 日本語, 日本真空学会, 甲南大学ポートアイランドキャンパス, 国内会議コンビナトリアル成膜法によるBZT-BCT非鉛圧電薄膜の作製と圧電特性評価口頭発表（一般）
- International Conference on Emerging Trends in Engineering & Technology (ICETET-12), 2012年11月, 英語, IEEE, 姫路, 国際会議Fabrication and characterization of lead-free piezoelectric thin films口頭発表（一般）
- 第4回マイクロ・ナノ工学シンポジウム, 2012年10月, 日本語, 日本機械学会, 北九州, 国内会議金属基板を用いたPZT圧電薄膜エナジーハーベスト口頭発表（一般）
- 第4回マイクロ・ナノ工学シンポジウム, 2012年10月, 日本語, 日本機械学会, 北九州, 国内会議RFマグネトロンスパッタ法によるPMN－PT薄膜の圧電特性口頭発表（一般）
- 2012 IEEE Nanotechnology Material and Devices Conference (IEEE-NMDC 2012), 2012年10月, 英語, IEEE, Hawaii, USA, 国際会議MEMS Energy Harvesters of Piezoelectric Thin Films[招待有り]口頭発表（招待・特別）
- 第4回マイクロ・ナノ工学シンポジウム, 2012年10月, 英語, 日本機械学会, 北九州, 国内会議Fabrication and characterization of lead-free piezoelectri thin filmsポスター発表
- 2012年秋季 第73回応用物理学会学術講演会, 2012年09月, 日本語, 応用物理学会, 愛媛大学・松山大学, 国内会議非鉛圧電薄膜(K,Na)NbO3を用いたMEMSデバイス作製及び評価口頭発表（一般）
- 日本学術振興会第161委員会第78回研究会 「エネルギーハーベスト」, 2012年09月, 日本語, 日本学術振興会, 名古屋大学, 国内会議PZT圧電薄膜を用いた振動発電素子[招待有り]シンポジウム・ワークショップパネル（指名）
- CMOS Emerging Technologies 2012, 2012年07月, 英語, Vancouver, Canada, 国際会議Piezoelectric Energy Harvesters of Lead-Free (K, Na)NbO3 Thin Films口頭発表（一般）
- 6th Asia-Pacific Conference on Transducers and Micro, 2012年07月, 英語, Nanjin, Chaina, 国際会議Microfabrication of Lead-Free (Ka,Na)NbO3 Piezoelectric Thin Films by Dry Etching[招待有り]口頭発表（一般）
- 6th Asia-Pacific Conference on Transducers and Micro/Nano Technologies, 2012年07月, 英語, Nanjin, Chaina, 国際会議Microfabrication of Lead-Free (Ka,Na)NbO3 Piezoelectric Thin Films by Dry Etching口頭発表（一般）
- International Symposium on Integrated Functionalities 2012 (ISIF2012), 2012年06月, 英語, Hong Kong, 国際会議Compositional Dependence of Piezoelectric PZT Films by Combinatorial Sputtering口頭発表（一般）
- 第29回強誘電体応用会議(FMA29), 2012年05月, 日本語, 京都市, 国内会議圧電薄膜とMEMS応用[招待有り]口頭発表（招待・特別）
- 第29回強誘電体応用会議(FMA29), 2012年05月, 日本語, 京都市, 国内会議コンビナトリアル成膜によるPZT圧電薄膜の組成依存性評価口頭発表（一般）
- 20th IEEE International Symposium on Applications of Ferroelectrics (ISAF) and International Symposium on Piezoresponse Force Microscopy on Nanoscale Phenomena in Polar Materials (PFM), ISAF-PFM-2011, 2011年07月, 英語, IEEE, Vancouver, Canada, 国際会議Multilayer Thin‐Film Capacitors Fabricated by Radio-Frequency Magnetron Sputteringポスター発表
■ Works_作品等- 2002年産業技術研究助成事業 「超格子圧電薄膜材料の開発とマイクロマシンデバイスへの応用」
- 2002年Industrial Technology Research Grant Program "Development of piezoelectric films with super structures and their application for MEMS"
- 日本学術振興会, 科学研究費助成事業, 挑戦的研究(萌芽), 名古屋大学, 2022年06月30日 - 2025年03月31日Development of a living cell-cell battery inspired by electric fishes
- 国立研究開発法人科学技術振興機構, 戦略的創造研究推進事業（CREST）, 2020年04月 - 2023年03月, 研究代表者【CREST】高効率非鉛圧電薄膜発電システムの実証展開
- 科学研究費補助金／基盤研究(B), 2017年04月 - 2021年03月, 研究代表者競争的資金
- 国立研究開発法人科学技術振興機構, 戦略的創造研究推進事業（CREST）, 2016年 - 2020年03月, 研究代表者【CREST】分極制御非鉛圧電薄膜による高効率MEMS振動発電素子の創製競争的資金
- 科学技術振興機構(JST), 研究成果展開事業 研究成果最適展開支援プログラム 戦略テーマ重点タイプ, 2016年, 研究代表者スポーツを対象としたウェアラブル圧電型振動発電モジュールの開発競争的資金
- 研究成果最適展開支援プログラム フィージビリティスタディステージ 探索タイプ, 2012年, 研究代表者A-STEP「高密度・高品質積層誘電体デバイスの開発」競争的資金
- 研究成果最適展開支援プログラム フィージビリティスタディステージ 探索タイプ, 2012年, 研究代表者A-STEP「高効率・高信頼性圧電MEMS振動発電素子の開発」競争的資金
- 科学研究費補助金／基盤研究(C), 2011年, 研究代表者競争的資金
- 研究成果最適展開支援プログラム フィージビリティスタディステージ 探索タイプ, 2011年, 研究代表者A-STEP「高密度・高品質積層誘電体デバイスの開発」競争的資金
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