Multi-directional multi-modal multi-stable piezoelectric vibration energy harvester

Abstract Vibration energy harvesting technology promotes the development of self-powered sensors. In response to the existing issues in piezoelectric energy harvesting, this paper designs a multi-directional multi-modal multi-stable piezoelectric vibration energy harvester (MDMMMS-PVEH). The device consists of a support base and four multi-modal and multi-stable structures. By adopting an inclined beam array design, it achieves multi-directional vibration energy capture. Meanwhile, a composite beam-magnetic coupling multi-stable design is employed to achieve wideband response and high power density energy output. Firstly, theoretical analysis and simulation parameter optimization were conducted on the prototype. The COMSOL software was used to analyze the cantilever beam structure, calculating the natural frequencies and vibration modes of different beams. Then, the simulation optimization of the inclined beam angle affecting multi-directional energy collection was carried out, determining the optimal inclination angle to be 45°. The open-circuit voltage values of the beam structure were analyzed, and the arrangement of permanent magnets was also simulated. Finally, a prototype was developed and an experimental system was set up for testing. The experimental results show that the prototype can collect multi-dimensional vibration energy in the low-frequency range. Compared with the non-magnetic coupling, when excited in the Z -axis direction, the open-circuit voltage of the prototype increased by 36.1% and 61.2% at 12 Hz and 26 Hz excitation frequencies, respectively, and the maximum power density reached 21.50 mW cm −3 , providing a solution for self-powered technology in the Internet of Things era.