基于PZT-Si的微机电系统微驱动器的设计与仿真分析

Design and Simulation of Micro-electro-mechanical System Micro-actuator Based on PZT-Si

设计了一种基于PZT和Si的蟹爪型MEMS微驱动器,具有结构简单、响应速度快、输出位移大的特点。为了进一步优化结构、提高使用寿命,根据微驱动器的结构特征,建立了直流电压下PZT蟹爪梁的的力-电耦合数学模型,得到了驱动电压与变形量的关系曲线。采用数值模拟方法开展了压电层材料、厚度等参数对微驱动器驱动性能的影响研究,研究表明:相对于压电层厚度和输入电压的影响,压电材料性能是系统稳定性的主要影响因素。以弹性柔顺系数相对较低的"硬陶瓷"PZT-4作为压电层时,微驱动器的稳定性增强但驱动响应有所降低;而当选用弹性柔顺系数相对较大的"软陶瓷"PZT-5和PZT-5H作为压电层时,微驱动器的驱动效应增强而稳定性降低。在此基础上,对微驱动器的结构参数进行了优化分析,确定了蟹爪梁结构参数的最优组合,为微驱动器的设计和改进提供了理论指导。

A novel crab-clawed type microactuator based on PZT and Si,which has the features of simple structure,fast response and large output displacement was designed.In order to optimize structure and enhance usability,a coupled mathematical model for crab-clawed beam is established,the relation of driving voltage with deformation are achieved by analyzing the structure characteristic of micro-actuator.The influences of different materials and thickness of piezoelectric layer on the transverse actuation capability of crab-clawed type microactuator is investigated using the numerical simulation method.The results indicate that the stability and drive-response of the system is mainly determined by the piezoelectric material,but the thickness of piezoelectric layer and input voltage also play important roles.When the hard ceramic materials PZT-4 which have lower elastic compliance coefficient selected as piezoelectric layer,the structural stability of microactuator enhanced but the drive-response reduced.When piezoelectric layer are replaced by the soft ceramic materials PZT-5 and PZT-5H which have higher elastic compliance coefficient,the drive-response of microactuator increase markedly but the structural stability decreased.And thus the structure parameters of crab-clawed beam are optimized optimal analysis,the optimal combination of three structural parameters with the optimal performance of crab-clawed beam is obtained,which can provide reference for the structure design and improvement.