Research On Micropump Based On MEMS Technology

How to drive the flow of solution is a crucial issue in Microfluidic system. In this paper, we studied two types of piezoelectric micropumps: valveless piezoelectric micropump and cantilever piezoelectric micropump. They are fabricated using MEMS technology. The pumping mechanism is also been studied. The optimization design of a piezoelectric micropump is presented. After that, we studied the performance of the valveless piezoelectric micropump. The dependence of the flow rate on pump parameters, such as, excitation voltage, frequency and component geometry, are each discussed. Optimal geometries and operating parameters have been determined. For a fixed frequency actuation, the flow rate and back pressure increase as the voltages increases. The optimization frequency is 1250Hz. The maximum of the back pressure is 153Pa. And the maximum flow rate of the valveless piezoelectric micropump is 1.695 ul/min. The cantilever piezoelectric micropump will not start to work until the input pressure is larger than 228Pa. The valveless piezoelectric micropump is more reliable and stable in contrast to the cantilever piezoelectric. It will has broader application in Microfluidic system.In this paper, we also studied the Electroosmotic Pump (EOP), which is based on the Electroosmosis principle. The EOP is made of PDMS (polymethylsiloxane) and glass. Firstly, we fabricate PDMS EOP using photolithographic replica molding and bond techniques. Then we treat the EOP with dynamic coating. To investigate the effect of EOP, we use fluorescence dye (Rodamine B) as indicator, and examine the results through the fluorescent microscope. The result shows that solution in microchannels can be driven well by EOP. We studied the effect of the dynamic coating on the performance of the PDMS EOP. The result shows it is crucial to the PDMS EOP.