Modeling and Simulation of a Piezoelectric Micro-Power Generator

E. Abdel-Rahman, M. Pallapa, M.A.S. Aly, L. Wong, A.I.H. Chen, K.W. Wong, and J.T. Yeow
University of Waterloo, Waterloo, ON, Canada

Micro-power generators (MPGs) harvest and store small amounts of ambient energy. The motivation of this paper is to compare the MPG modeling and simulation results obtained from COMSOL Multiphysics® with those obtained using three other approaches: CoventorWare®, ANSYS® and lumped element analysis. The MPG is composed of two identical micro-cantilever beams made of a piezoelectric layer (Aluminum Nitride) deposited on top of structural Polysilicon layer and a seismic mass (Gold) attached to the free ends of the beams. Firstly, static deflection of the mass and maximum stress in the beams are obtained as functions of the voltage across two electrodes placed on top and bottom of the piezoelectric layer. Then, the eigenvalue problem of the MPG is solved to obtain four lowest natural frequencies and mode shapes. These results are used to determine the MPG operating frequency and verify that spurious modes are placed far away from that frequency range. ANSYS is a registered trademark of ANSYS, Inc. CoventorWare is a registered trademark of Coventor, Inc.