Multiphysical modeling of a contact-type piezotransducer for the analysis of micro-energy harvesting from ambient vibrations

Abstract

The paper presents development of a coupled-field finite element model of a contact-type piezoelectric transducer, which acts as a micropower source for MEMS sensors by harvesting energy from ambient vibrations. The proposed FE model of the cantilever-type piezotransducer couples three different physical domains: mechanical, piezoelectrical and fluidic. Both linear and nonlinear piezoelectric models are implemented. The fluid-structure interaction is modeled as viscous air damping, which manifests in the form of squeeze-film damping governed by the nonlinear compressible isothermal Reynolds equation. Vibro-impact interaction is modeled through implementation of a special adhesive-repulsive contact model that is suitable for contact simulations at the micro-scale. Performance of the FE model is demonstrated by representative dynamic simulations including parametric studies that reveal the influence of structural, excitation and ambient pressure parameters on dynamical and electrical performance of the device.