Adaptive gas pumping by controlled timing of active microvalves in peristaltic micropumps

Abstract

We report theoretical and experimental results on adaptive gas pumping by actively controlling microvalve timing in a multi-stage peristaltic micropump. Since gas is compressible, control of timing of the valve actuation relative to pump membrane actuation can modulate gas compression and transfer periods, resulting in adaptive and programmable pumping. A peristaltic 18-stage electrostatic gas micropump that utilizes fluidic resonance for high flow rate and multi-stage peristaltic configuration for high pressure is fabricated and tested. It includes 10 inlet and 9 outlet microvalves. When the duration of time when microvalves are opened is changed between 0.05 and 0.35 cycles, the micropump produced wide ranges of pressure between 7.3 and 3.3 kPa and flow rates between 0.29 and 0.07 sccm. These results correspond to a variation of pressure and flow rate by 110% and 400%, respectively.