Analytic Modeling and Experimental Verification of Thin-Film Piezoelectric Vibration-Induced Micro Power Generator

In this article, a novel electromechanical energy conversion model of a piezoelectric cantilever bimorphs micro transducer is proposed. In this new piezoelectric-base power generator modeling, the coupling relationship between the mechanical strain and the piezoelectric polarization, rather than the curvature basis approach, is adopted to deduce the vibration-induced voltage and electrical power. 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 power, and the dimensions of the piezoelectric micro power generator to be analytic estimated. The analytic model shows that the vibration-induced voltage is proportional to the excitation frequency and the width of the device but is inverse proportional to the length of cantilever beam and the damping factor. To verify the theoretical analysis, two clusters of micro transducers are fabricated. Experimental results demonstrate that the maximum output voltages and the power conversion are only little derivations from the analytic model.