Abstract: Based on the characteristic of planar valveless piezoelectric micropumps thickness-averaged shallow water model and finite element method are employed to develop a liquid-diaphragm coupled equation of the micropump. The mode analysis of coupled equation is carried out for the first-order natural frequency, vibration shape and the amplitude-frequency relation of the silicon diaphram. After mode analysis, piezoelectric force is imposed to investigate diaphragm response, flow behavior and flow rate of micropump. The effects of the structure parameters (the length, the minimum width and the diffuse angle of the micro-diffuser, and the radius of piezoelectric patch) on the natural frequency of liquid-solid coupled system, the diaphragm amplitude and the flow rate of the micropumps are studied. Significant results are obtained for optimal design of the micropumps.

Key words: Liquid-diaphragm coupled equation, Piezoelectric micropumps, Shallow water equation model