A Bidirectional Valveless Piezoelectric Micropump With Double Chambers Applying Synthetic Jet

A novel bidirectional valveless piezoelectric micropump with double chambers applying synthetic jet effect was developed. The numerical simulation was applied to study the performance and flow field of the micropump. The micropump consisted of a pump body, a cover and two piezoelectric actuators had a simple structure. The direction of the flow of the micropump could change immediately based on the Coanda effect by controlling the displacement of the two piezoelectric actuators. And the synthetic jet element increase the flowrate greatly. The effects of the Reynolds number and frequency on the flowrate were studied. The size of the throat was 200 μm × 200 μm. The Reynolds numbers were 500 and 1000 in the simulation and the SST turbulence model was chosen. The sinusoidal vibration was applied and the frequency ranged from 10 to 50 Hz. The results showed that the flowrate of jet entrainment accounted for more than 80% of the outlet flowrate. And the outlet flowrates were much larger than the volume changes of the pump chambers. The fluctuation of flowrate decreased with the increase of frequency. The micropump could achieve continuous outflow as the frequency was higher than 30 Hz.