Modeling and parametric study on DE-based vibro-impact energy harvesters for performance improvement

Abstract

This paper develops a dynamic electromechanical coupling model to investigate the energy harvesting (EH) performance of the vibro-impact (VI) energy harvester comprising a cylindrical capsule, an internal free moving ball, and two dielectric elastomer (DE) membranes at both ends of the capsule. The developed model can describe the electromechanical properties of the collision between the ball and the membrane, which is verified by the existing experimental data. On this basis, the effect of system parameters, such as the mass and the radium of the ball, the internal radium and the length of the capsule, and the pre-stretch ratio of DEs, on the average power density of the energy harvester is also studied under diverse external stimuli including the inclined angle and the excitation frequency. The results show that at the small excitation frequency, the EH performance of the energy harvester can be improved by increasing the pre-stretch ratio of membranes and the mass of the ball and decreasing the radium of the ball and the internal radium of the capsule. The conclusions can help provide a guide for the optimal design of the energy harvester in the practical application so as to improve the EH performance.