Abstract: 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 electrome- chanical-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).

Key words: Vibration analysis, Piezoelectric actuator, Rayleigh method