Study on New Small-Size High-Performance Electromechanical Devices using Piezoelectric Single Crystals

为了实现更高性能的机电一体化器件，取代传统的电磁驱动器，研究了具有极化反转层的单晶压电驱动器在新型机电器件中的应用。提出了用于小型化的弯曲驱动器和用于快速响应的电驱动方法，并通过实验验证了接触现象的高可靠性。取得了以下研究成果：1.改进了LiNbO_3极化反转层的形成和致动器的制作工艺。研制了一种无迟滞、无蠕变的节能型精密执行器。对有机硅气氛中因氧化或污染造成的电接触缺陷进行了研究。研究了热处理工艺和周围气氛对电极表面膜和电阻的影响。此外，SURF…引起的阻力变化检查了电极上因反复接触而产生的更多的王牌杂质。为了设计新型的压电晶体机电执行器，改进了基于三维有限元方法的计算机仿真技术。对位移、共振频率和机电耦合系数的数值分析结果进行了实验验证。提出了一种带有集成位移传感器的压电致动器，并对其进行了测试，以评估绝缘破坏电压和锁定现象等电接触现象。提出了一种基于LiNbO_3弯曲驱动器的伺服加速度计，并通过实验验证了其在小于1 Hz的频率范围内具有高灵敏度的潜力。提出了一种利用极化反转LiNbO_3弯曲振子形成的瞬变声场作为接近传感器的传感器。结果表明，当物体接近振子表面时，弯曲振子的共振频率急剧下降。较少

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 … More 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