Design of a multi-directional piezoelectric energy harvester with spring and magnetic coupling
At present, with the efforts of worldwide researchers, harvesting energy from low-frequency vibrations has been realized. However, low-frequency vibrations usually come from various directions. So a piezoelectric energy harvester (PEH) can scavenge vibration energy from multi-directions with a simple structure is urgently needed. This paper proposes a piezoelectric elastic energy harvester consisting of a spring, a piezoelectric cantilever beam, a proof mass and two magnets scavenging multi-directional vibration energy with one cantilever beam. The piezoelectric cantilever beam and the spring are employed to sense vibrations from two orthogonal directions. The magnetic interaction is designed to transfer energy from the spring to the beam. In this paper, experimental study is carried out to verify the function of the multi-directional PEH. The experimental result indicates that the multi-directional energy harvester proposed in this paper is a high-performance way to harvest energy form two orthogonal directions.