QCM传感器性能的有限元仿真分析

Finite element simulation analysis method of QCM sensor

由于QCM传感器频率高、振幅小的振动难以观察,无法分析电极对传感器性能的影响.针对这一问题,通过引入了通用有限元分析软件ANSYS,在Workbench平台上建立石英晶片厚度剪切振动模式模型,分析了不同尺寸电极对QCM传感器性能的影响.仿真结果表明:电极直径增加会导致石英晶体的谐振频率下降;电极尺寸过大过小都容易导致寄生模干扰加强.

The principle of QCM sensor for micro measurement is based on the inverse piezoelectric effect,which states that when the quartz crystal is applied with alternating voltage,it will generate high frequency thickness-shear vibration.Since it is hard to observe the vibration with high frequency and small amplitude,it is difficult to analyze the effect of electrodes on the performance of QCM sensors.To solve this problem,the finite element analysis software ANSYS is introduced and the thickness shear vibration model of quartz wafer is created on the Workbench platform to analyze the effect of different electrodes sizes on the performance of QCM sensors.The simulation results show that the increase of the electrodes diameter may cause the decrease of the resonant frequency and on the other hand,too big or too small electrodes size may strengthen the parasitic mode.So the reasonable choice of electrodes size is necessary.This research provides new approach for the analysis and design of QCM sensors.