Analytical modeling of piezoelectric vibration-induced micro power generator

In this article, a novel piezoelectric cantilever bimorph micro transducer electro-mechanical energy conversion model is proposed. Based on the curvature basis approach, the relationship between the deduced voltage and the mechanical strain induced piezoelectric polarization is formulated. In addition to the working equation for piezoelectric sensors, the damping effect is included to enable the resonance frequency, the maximum induced voltage at the resonance, the conversion energy density and the dimensions of the piezoelectric micro power generator to be analytically estimated. The analytical model shows that the vibration-induced voltage is proportional to the excitation frequency and the width of the device but is inversely proportional to the length of the cantilever beam and the damping factor. To verify the theoretical analysis, two micro transducer clusters are fabricated. The experimental results demonstrate that the maximum output voltage coincides with the energy conversion analytical model. (C) 2006 Elsevier Ltd. All rights reserved.