Finite element analysis of piezoelectric microgenerator - towards optimal configuration

Abstract

The paper provides results of dynamic numerical analysis of piezoelectric cantilever-type microgenerator intended for wireless MEMS applications. This analysis constitutes an initial phase of ongoing research work aimed at microgenerator optimal design. It is based on beneficial utilization of higher vibration modes, which may offer significant benefits in terms of dynamic performance. Here we report preliminary results of simulations that were performed with a developed 3-D finite element model of the microgenerator that constitutes a bilayer cantilever structure with proof mass at the free end. The structure was subjected to harmonic base excitation by applying vertical acceleration through body load. The resulting characteristics reveal strong dependence of magnitude of generated voltage on design and excitation parameters (frequency, acceleration). Initial findings indicate the necessity to develop microgenerator design with self-tuning of the resonance frequency, i.e. the device should adapt to varying excitation frequency so as to be driven in resonance thereby achieving maximal electrical power output.