泵用两叠片圆形压电振子的弯曲振动分析

VIBRATION ANALYSIS OF A DOUBLE-LAYER PIEZOELECTRIC ACTUATOER FOR MICROPUMP

为提高微型压电泵的输出能力,采用瑞利法对固定边界条件下两叠片压电振子进行了理论研究。以压电晶片与金属基板的厚度比α、直径比β(称结构参数)为变量,推导出了压电振子谐振频率及有效机电耦合系数的计算方法。通过编程计算即可获得压电振子的有效机电耦合系数和谐振频率,进而优选压电振子的结构参数。以日本产压电振子为例进行了谐振频率的计算,并与阻抗分析仪的测试的谐振频率进行了比较,二者比较接近。研究结果表明,结构参数的变化对压电振子的谐振频率和机电耦合系数影响较大,当结构参数α、β分别为0.3和0.6时,压电振子的最大有效机电耦合系数为0.52。

In order to enhance the performance of piezoelectric micropumps, the Rayleigh method is utilized to investigate the fixed-edge double-layer piezoelectric actuator for micropumps. As a result of it, the relationship between the performance parameters (the resonant frequency and effective electromechanical-coupling parameter) and the structural parameters (the diametric ratio β and thickness ratio α of piezoelectric membrane to metal plate) is figured out. Given the correlative material parameters, the performance parameters with the structural parameters as variable can be worked out to obtain an optimal actuator. The natural frequency of the actuator made in Japan is calculated and tested, and the results show great agreement with each other. When the thickness ratio α and the diametric ratio β are 0.3 and 0.6 respectively, the effective electromechanical-coupling parameter reaches its maximum value (0.52).