A VALVELESS MICROPUMP WITH ASYMMETRIC OBSTACLES

A new type of valveless micropump with asymmetric obstacles created through MEMS fabrication using only one photo mask is presented in this study. The valveless micropump, in which the diffuser/nozzle devices are replaced with asymmetric obstacles and the fluid is driven by harmonic oscillation of a piezoelectric disc, successfully improves performance and decreases pressure loss. The performance of the micropump is evaluated by measuring the pressure head difference and the flow rate as the input voltage ranges from 20 to 40 V. The present study reached a maximum pump pressure of 1.2KPa at 3.1KHz and the maximum net volume flow rate was 156 μL/min for water when the inside diameter of the inlet/outlet tube was 10 mm. The device in this study is the smallest piezoelectric type micropump with high pressure head and high net flow rate reported in the literature.

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