Modelling and design of highly coupled piezoelectric energy harvesters for broadband applications

Abstract

This paper reports a method to design highly coupled piezoelectric energy harvesters with frequency tuning capabilities using nonlinear electrical techniques. A cantilever beam with two PMN-PT patches has been optimized thanks to both analytical modelling and Finite Element Methods (FEM). The built prototype exhibits a strong electromechanical coupling (k${}^2$=17.6%) and a figure of merit (km${}^2$Q=12.4) which allow a bandwidth corresponding to 22% of the resonant frequency value.