Enhanced piezoelectric energy harvesting of a bistable oscillator with an elastic magnifier

Abstract

This paper presents theoretical investigation on a coupling system consisting of bistable oscillator with an elastic magnifier (EM) to improve the output performances in vibration energy harvesting. Lumped-parameter nonlinear equations of the coupling system are derived to describe the broadband large-amplitude periodic displacement responses of the coupling system. The effects of the system mass ratio and stiffness ration on the output performances are studied. It shows that increasing the mass ratio and stiffness ratio can improve the system output performances. The distinct advantage in the coupling system lies in the existence of large-orbit periodic vibration over low level range. With the comparison of the electromechanical trajectories obtained from simulations, it shows that the coupling system can harvest more power at low excitation level with larger bandwidth as compared to the bistable oscillator without an EM.