The development of a valveless piezoelectric micropump

Abstract

Previous studies have indicated that the performance of the micropump is influenced by the driving voltage, frequency, valves, and pump chambers. In this study, an innovative one-side actuating valveless micropump is proposed and developed to actuate liquid in one direction with high flow rates and pump heads. The three-dimensional, transition numerical models of the micropumps were also employed to predict its performance. It was found that the inlet choking phenomenon was the major reason to make the one-side actuating micropump valve-free, with a flow rate of 0.088 mL/s and a pump head of 45.6 Pa. By adding the secondary chamber, the performance can be improved to 0.989 mL/s and 1291.0 Pa. The maximum pump head in this study was obtained at 1522.5 Pa by using the 0.3-mm-thick secondary diaphragm. In addition, the performance of the micropump can be further improved by adding a nozzle/diffuser element, thus enabling it to achieve the maximum flow rate of 1.133 mL/s at the frequency of 150 Hz. Without additional check valves, the one-side actuating piezoelectric valveless micropump with compact design can perform more accurately and reliably in the applications of biomedical and electronics cooling.