A Broadband Energy Harvester With Internal Resonance Induced by Two Resonators

Nonlinear energy harvesting has a better performance than linear resonators, because realistic ambient vibrations are spread over a wide frequency spectrum. We present a broadband nonlinear energy harvester with internal resonance induced by two resonators. Each resonator contains a cantilever beam with a magnet tip, and one is partially covered by piezoelectric material. The perturbation method of multiple scales is used to solve coupled partial different equations by applying internal resonance of ratio 2:1. The shooting method validates the analytical solutions of the frequency response and output voltage numerically. Output voltage for different excitation levels and distances are investigated. Simulations show the design, by applying internal resonance and nonlinearity, increases the bandwidth of frequency response.