A hybrid piezoelectric device combining a tri-stable energy harvester with an elastic base for low-orbit vibration energy harvesting enhancement

Abstract

How to efficiently harvest the low-orbit vibration energy over a wide frequency range is one main challenge of the piezoelectric energy harvester. In this paper, combining the advantages of elastic base (EB) and the interaction of coupled elastic system, a hybrid piezoelectric device combining a tri-stable piezoelectric energy harvester (TPEH) with an EB is presented to enhance the harvesting ability of the low-orbit vibration energy. The EB composed of a mass and spring can amplify the low-orbit vibration and provide the TPEH enough kinetic energy to overcome the potential barrier and jump to the high-orbit oscillation, resulting in an even better operating bandwidth and higher power generation. The nonlinear electromechanical model describing the dynamic responses of the presented harvester is derived. The effects of the mass ratio and stiffness ratio on the dynamic performances of the hybrid energy harvester are numerically investigated with dynamic bifurcation diagrams method. The results show that the presented harvester has wider frequency bandwidth and higher power generation than those of the TPEH with rigid base by properly selecting the mass ratio and stiffness ratio, and it can more easily snap-through from low-orbit oscillation to high-orbit oscillation to reach larger dynamic response at lower excitation levels. Experiments are conducted to validate the simulations, and the experimental results are in good agreement with the theoretical results. Finally, fluencies of the load resistance on the power generation are also experimentally studied, and an optimum load resistance to achieve the peak power is obtained.