A broadband compressive-mode vibration energy harvester enhanced by magnetic force intervention approach

Abstract

This letter presents a magnetic force intervention approach to enhance the performance of a broadband compressive-mode vibration energy harvester. The magnetic force intervention promotes a magnetic oscillator to vibrate within a desired work area. A magnetic stator drives the magnetic oscillator away by employing a repulsive magnetic force, while two magnetic stoppers (upper and lower magnets) limit the unwanted large displacement of the magnetic oscillator and drive it back toward the magnetic stator. Numerical and experimental results show that the performances of a compressive-mode bistable vibration energy harvester under low-frequency (<10 Hz) weak excitation can be significantly enhanced by using magnetic stoppers. Moreover, the magnetic force that acting against the magnetic stopper can also generate electricity.