A multi-frequency piezoelectric vibration energy harvester with liquid filled container as the proof mass

Abstract

The performance of a vibration energy harvester consisting of a beam with a water-filled container as the tip mass is investigated. Particular attention is paid to the capability of this system to harvest energy over a broader range of frequencies compared to the traditional beam with a solid tip mass system. The broadening is due to geometric, inertial, damping, flow nonlinearities, or a combination of them. These nonlinearities cause energy exchange between the system's modes through internal resonances leading to nonlinear periodic, or periodically or chaotically modulated responses over a relatively broad range of excitation frequencies. The results show an output voltage response that has two or more resonance peaks in comparison to the traditional harvester, which has only one peak near the resonance frequency. The system's parameters including the excitation frequency and amplitude and the water depth to container diameter ratio can be used to control the frequency bandwidth over which energy is harvested.