Theory and Experimental Verification on Cymbal-shaped Slotted Valve Piezoelectric Pump

Valve piezoelectric pumps usually have larger flow rate than that of valveless ones. However, the traditional cantilever valve easily induces stress concentration which impacts the reliability of pumps. Therefore, a cymbal-shaped slotted check valve is proposed to be applied in a piezoelectric pump in order to reduce the stress concentration of the valve and thus improve the reliability of the piezoelectric pump. The structure and working principle of the piezoelectric pump are analyzed; the stress analysis of the cymbal-shaped slotted valve diaphragm is conducted. In addition, finite element software is employed to analyze the difference of the Von-Mises stress between the cymbal-shaped slotted diaphragm and the slotted flat diaphragm. The simulation results show that, the Von-Mises stress of cymbal-shaped slotted diaphragm is smaller than that of the slotted flat one. Furthermore, the cymbal-shaped slotted valve piezoelectric pump is also fabricated, and flow rate experiment is performed. The experimental results indicate that the flow rate of piezoelectric pump working in low frequencies (0 Hz < f < 50 Hz) is larger than that working in high frequencies (200 Hz < f < 2000 Hz). When driven at voltage of 160 V and frequency of 5 Hz, the pump reaches its maximum flow rate of 6.6 g/min. The experimental results validate the feasibility of the cymbal-shaped slotted check valve. This research can effectively solve the problem of stress concentration of valve piezoelectric pumps and is helpful for improving the reliability of them.