A study on high-output piezoelectric micropumps for application in DMFC

摘要

In order to supply liquid fuel in DMFC (Direct Methanol Fuel Cell) system, a small but high-output micropump is needed. This study presents a design concept, fabrication and experimental results of the newly devised piezoelectric micropump by using resonance and fluid inertia. The micropump consists of a resonantly-driven pumping unit, an inlet check valve, and a pipeline element with a small diameter employed in an outlet. The resonance mechanism is used to oscillate the pumping chamber. It simply magnifies a small displacement of the used multilayer-piezoelectric actuator. The fluid inertia effect uses a fast flow through a narrow pipeline element employed instead of the outlet check valve. First, an analysis on each element such as a diaphragm and a check valve is performed. Based on the obtained analysis results, a prototype micropump is designed, and fabricated. Then, pumping characteristics such as frequency-dependent displacement, and flow rate without load pressure are experimentally investigated. Finally, a refabrication of the micropump is carried out to improve load characteristics, and the obtained experimental results are presented and discussed.