Design and Simulation of a Valveless Piezoelectric Micropump for Fuel Delivery in Fuel Cell Devices

Yasser Rihan

doi:10.12816/0010292

Abstract

Micro- and nano-electromechanical systems (MEMS or NEMS)-based fuel delivery in direct methanol fuel cell (DMFC) devices offer opportunities to address unmet fuel cells related to fuel delivery. By applying an alternating electrical field across the actuator, the resultant reciprocating movement of the pump diaphragm can be converted into pumping effect. Nozzle/diffuser elements are used to direct the flow. To make the power system applicable for portable electronic devices, the micropump (...)

Highlights

The piezoelectric effect is the ability of certain materials to produce an electric charge proportional to an applied mechanical stress
Piezoelectric thick films are of major interest in the actuation of active structures in MEMS, they have been widely applied to micropumps, ultrasonic motors, resonators, microfluidic separators, high-frequency transducers, and energy harvesting, [1] because they exhibit properties such as larger displacement and quick response, high frequency, and can be precisely controlled
This system mainly consists of the following parts: fuel cell membrane electrode assembly (MEA), fuel chamber, nozzle/diffuser, micropump and pump chamber, and fuel supply manifold

Summary

Introduction

The piezoelectric effect is the ability of certain materials to produce an electric charge proportional to an applied mechanical stress. Piezopumps have been considerably developed over the past several years They have many excellent abilities such as liquid handling in small and precise volume, providing a high actuation force with a relative fast mechanical response at high operation frequency, and miniaturization in a small size, etc. This system mainly consists of the following parts: fuel cell membrane electrode assembly (MEA), fuel chamber, nozzle/diffuser, micropump and pump chamber, and fuel supply manifold. When applying an alternating electrical field across the PZT layer, it will generate a reciprocating deflection in the direction vertical to the surface of the actuator This deflection is transferred to the pumping effect that drives the fluid inside the pump chamber flowing through the inlet/outlet. The modeling process can be simplified assuming the whole structure is circumferentially symmetrical, the bonding between the PZT disk and the passive plate is perfect and the outer edge of the passive plate is fixed

E pzt hpzt

Model validation and predicted results

Ring-type deflection

Conclusions