压电检测陀螺薄膜材料分析及仿真研究

Analysis and simulation of piezoelectric detecting gyroscope in piezoelectric thin film materials

理论分析了影响压电微机电系统(MEMS)陀螺检测电压输出幅值的因素,结合MEMS领域常用的氮化铝(AlN)、氧化锌(ZnO)和锆钛酸铅(PZT)这3种压电薄膜材料,设计了一种微梁构型的检测陀螺。利用有限元软件COMSOL进行了陀螺的模态、功能的仿真分析。仿真结果显示:使用AlN柔度系数的陀螺结构驱动与检测模态固有频率频差为22 Hz;陀螺结构可以敏感z轴角速度输入;ZnO、AlN和PZT陀螺电压灵敏度分别为2.23,2.16,0.79μV/((°)·s^(-1)),AlN和ZnO的电压灵敏度大于PZT,且AlN的工艺性好于ZnO;因此,AlN在3种压电材料中最适合用于压电检测MEMS陀螺。

The piezoelectric MEMS gyroscope detecting voltage output amplitude inflencing factors are analyzed theoretically,and a detection gyroscope with microbeam configuration is designed by combining AlN,ZnO and PZT piezoelectirc thin film materials commonly used in MEMS field.The modal and function of gyroscope are simulated and analyzed by using COMSOL finite element software.The results of simulations show that the natural frequency difference between the driving mode and detecting mode of the gyroscope structure is 22 Hz.z-axis angular velocity input can be sensed by gyroscope structure,and ZnO,AlN and PZT gyroscope voltage snsitivities are 2.23μV/(°)/s,2.16μV/(°)/s and 0.79μV/(°)/s,respectively.The voltage sensitivity of AlN and ZnO is higher than that of PZT,and the manufacturability of AlN is better than that of ZnO.Therefore,AlN is the most suitable material for piezoelectric detecting MEMS gyroscope among three piezoelectirc materials.