Static and dynamic analysis of bistable piezoelectric- composite plates for energy harvesting

This paper presents an arrangement of bistable composite plates with bonded piezoelectric patches to perform broadband vibration-based energy harvesting from ambient mechanical vibrations. These bistable nonlinear devices have the potential to exhibit improved power generation compared to conventional resonant systems and can be designed to occupy smaller volumes than bistable magnetic cantilever systems. In this paper we initially present the results of an optimization study to generate greater electrical power by discovering the correct geometric configuration for energy harvesting based on the static states of the device. The results consider the optimal choice of device aspect ratio, laminate thickness, laminate stacking sequence, and piezoelectric surface area. Increased electrical output is found for geometries and piezoelectric configurations which have not been considered previously. This study is then extended to include dynamic considerations of both the static shapes and the snap-through transition. Optimum designs are shown to be sensitive to the vibration pattern that is being harvested. The optimum geometric configurations based on the static analysis alone are not optimal under all dynamic conditions.