一种新型静电斥力微驱动器的设计与仿真

摘要

Electrostatic attraction actuator is the most common method in capacitive MEMS actuators. But dielectric charging can lead to an adhesion failure of the devices and other reliability problems in actuator of electrostatic attraction .However,actuator of electrostatic repulsion does not have these reliability problems.At first,the different generation mechanism of electrostatic attrac-tion and repulsion with COMSOL Multiphysics were analysed and compared in this paper.Aiming at the disadvantages of large volt-age,small deformation and difficult to meet the requirement of practical application in MEMS actuator of electrostatic repulsion,a kind of electrostatic repulsive force micro-actuator with the four-terminal support structure based on the basic structure was pro-posed.The influence of the key structure parameters on the deformation of the movable plate was studied,and the optimal structure size was obtained. By optimizing structure parameters, the maximum deformation of the movable plate can be increased from 0.271μm to 0.399 μm under the driving voltage of 80 V,thus the maximum deformation can be significantly improved.%在电容式MEMS微驱动器中,静电引力驱动最为常见,但介质充电会引起"粘连失效"等可靠性问题,而静电斥力驱动不存在这样的可靠性问题.首先通过有限元仿真软件了分析对比了静电引力和斥力的不同产生机理.针对静电斥力微驱动器驱动电压大、形变量小、难以满足实用化要求的缺点,在基本结构基础上设计一种四段支撑结构的静电斥力微驱动器结构,并研究了关键结构参数对可动极板变形量的影响,确定了最优结构尺寸.通过结构优化,可动极板最大变形量可以在80 V的驱动电压下从0.271μm增加到0.399μm,形变量得到显著提高.