Abstract
In the process of energy harvesting, vibration energy harvesting still has several disadvantages, including a high-threshold excitation and a narrow working bandwidth. Therefore, a 2-degrees-of-freedom piezoelectric energy harvester is proposed. By introducing a nonlinear magnetic force to the system, the working bandwidth and the energy-harvesting efficiency of three magnetically coupled piezoelectric cantilever beams can be effectively improved. In this paper, a mathematical model consisting of three electrically coupled magnetically coupled piezoelectric cantilever beam systems is established, and the governing equations of electric coupling are solved numerically and verified experimentally. The dynamic characteristics under different excitations and frequencies are studied. The experiment shows that the working bandwidth can be increased by controlling the distance between three pairs of circular magnets and changing the excitation and frequency to induce resonance. Thus, the self-power requirement of micro-power devices can be realized. Overall, this study provides a promising solution for improving the performance of piezoelectric energy harvesters and offers theoretical insights for designing vibrating piezoelectric energy harvesters.