Traveling-Wave Micropumps

In this chapter, a valveless piezoelectric and magnetic micropump driven by travelling wave is presented. The micropump, fabricated with polydimethylsiloxane (PDMS) and polymethylmethacrylate (PMMA), consists primarily of a saw-tooth microchannel, substrates, and two kinds of integrated actuator arrays (piezoelectric bimorph arrays and NdFeB permanent magnetic arrays). The travelling wave beneath the top wall of the elastic microchannel can be induced by the actuator arrays, and the liquid particles are then transported along with the travelling wave in the microchannel. The micropumps are designed and fabricated with different microchannels (the saw-tooth and the straight microchannels). Appropriate geometry of the saw-toothed microchannel was also studied for optimizing the performance of the micropump. Experimental characterization of the micropump has been performed in terms of the frequency response of the flow rate and back pressure. The results demonstrate that this micropump is capable of generating a stable flow rate in microfluidic systems.