Synergistic piezoelectric and electromagnetic vibration energy harvester via a lever structure

Vibration energy can be converted into electrical power through energy conversion mechanisms. However, improving the conversion efficiency remains a major challenge. In this study, we developed a hybrid electromagnetic and piezoelectric lever vibration energy harvester to promote the harvesting efficiency. In this system, the quasi-zero stiffness and lever structures are introduced to increase the relative motion between the magnets and coils. The beam-tip coils is designed to travel in a magnet corridor, which can improve the harvesting performance effectively. The models of magnetic field and potential energy are established and studied. Then, the coupling equations are derived and corresponding simulations are performed. Finally, the verification experiments are carried out. The experimental results prove that the hybrid harvester could achieve a good harvesting performance under weak random excitations. Under the excitation with a power spectral density of 0.07 g² Hz⁻¹, the root-mean-square output power can exceed 4.028 mW.