Performance of piezoelectrically actuated micropump with different driving voltage shapes and frequencies

The effects of driving voltage waveform and frequencies on the performance of piezoelectrically actuated micropump are investigated in details. A full three-dimensional piezoelectric micropump was modeled numerically and tri electro-mechanical-fluidic coupling effects have been taken into account on its interface boundaries. Standard excitation waveforms including sinusoidal, triangle, sawtooth and square shapes were implemented and the results were compared with each other. The real time pump flow behavior was studied in each case for different membrane positions. The analysis predicts that the more sharp jump in the wave form, the more pump flow can be attained at the outlet. Square shape excitation with the sharpest instantaneous slope has the most notable overall flow rate compared to the other types in the examined range of frequencies. The behavior can be explained by considering the generated vortices in the flow. Due to sudden jump in membrane position, the flow forms strong vortices which magnify the diodicty of valves.