Grant-in-Aid for Scientific Research (A)
|Research Institution||Tohoku University|
NAKAMURA Kiyoshi Graduate shool of Engineering, Tohoku University, Professor, 大学院・工学研究科, 教授 (00005365)
佐藤 良夫 (株)富士通研究所, 部長 (研究職)
SONE Hideaki Graduate School of Information Sciences, Tohoku University Associate Professor, 大学院・情報科学研究科, 助教授 (40134019)
TAMAI Teruo Hyogo University of Teacher Education, Professor, 教授 (70053668)
WAKATSUKI Noboru School of Science and Engineerign, Ishinomaki Senshu University, Professor, 理工学部, 教授 (40275615)
SAWA Koichiro Faculty of Science and Technology, Keio University, Professor, 理工学部, 教授 (10051674)
SATO Yoshio Fujitsu Laboratory
|Project Fiscal Year
1996 – 1998
Completed(Fiscal Year 1998)
|Budget Amount *help
¥11,200,000 (Direct Cost : ¥11,200,000)
Fiscal Year 1998 : ¥2,500,000 (Direct Cost : ¥2,500,000)
Fiscal Year 1997 : ¥4,300,000 (Direct Cost : ¥4,300,000)
Fiscal Year 1996 : ¥4,400,000 (Direct Cost : ¥4,400,000)
|Keywords||electromechanical device / piezoelectric actuator / polarization-inverted layer / piezoelectric crystal / relay / electrical contact / accelerometer / proximity sensor / 機構デバイス / 圧電アクチュエータ / 分極反転 / 圧電単結晶 / リレー / 電気接点 / 加速度センサ / 近接センサ / アーク放電 / 電極損傷 / 有限要素法|
To realize integrated electromechanical devices with higher performance, instead of conventional electromagnetic actuators, piezoelectric actuators consisting of single crystals with a polarization-inverted layer have been studied for application with new electromechanical devices. Bending actuators for miniaturization and electrical drive methods for quick response were proposed, and contact phenomena were examined experimentally for high reliability. The following results were obtained.
1. The formation of a LiNbO_3 polarization-inverted layer and the fabrication technique of the actuators were improved. A power-saving precision actuator with no hysteresis and no creep was developed.
2. The defect of electrical contact due to oxidation or contamination in the atmosphere containing silicone was investigated. The effect on an electrode surface membrane and electric resistance of a heat treatment and a surrounding area atmosphere was studied. Moreover, the change of resistance due to surf
ace impurities on the electrode caused by repeated contact was examined.
3. To design new electromechanical actuators using a piezoelectric crystal, a computer simulation technique using a three-dimensional finite element method was improved. The results of the numerical analysis for displacement, resonant frequency, and electromechanical coupling coefficient were experimentally confirmed.
4. A piezoelectric actuator with a integrated displacement sensor was proposed and examined to evaluate electrical contact phenomena such as an insulation destruction voltage and a locking phenomena.
5. A servo accelerometer using a LiNbO_3 bending actuator was proposed and its potential was experimentally confirmed as a highly sensitive sensor in a frequency range of less than 1Hz.
6. A proximity sensor utilizing an evanescent acoustic field formed by the LiNbO_3 bending vibrator with a polarization-inverted layer is proposed. It was demonstrated that when an object approached the surface of the vibrator, resonance frequency of the bending vibrator decreased sharply. Less