Modeling of a Bridge-Shaped Nonlinear Piezoelectric Energy Harvester

Abstract

Abstract: Piezoelectric microelectromechanical systems (MEMS) energy harvesting is an attractive technology for harvesting small energy from ambient vibrations. Increasing the operating frequency bandwidth of such devices is one of the major challenges to be solved for real-world applications. A MEMS-scale doubly clamped nonlinear beam resonator has demonstrated very wide bandwidth and high-power density among the energy harvesters reported. In this paper, a first complete theoretical discussion of nonlinear resonance-based piezoelectric energy harvesting is provided. The sectional behavior of the beam has been studied through the Classical Lamination Theory (CLT) specifically modified to introduce the piezoelectric coupling and nonlinear Green-Lagrange strain tensor. A lumped parameter model has been built through Rayleigh–Ritz method and the resulting nonlinear coupled equations have been solved in the frequency domain through the Harmonic Balance Method (HBM). Finally, the influence of external load resistance on the dynamic behavior has been studied. The theoretical model shows that nonlinear resonant harvesters have much wider power bandwidth than that of linear resonators but their maximum power is still bounded by the mechanical damping as is the case for linear resonating harvesters. ©2014