Bistable Electromagnetic Vibration Energy Harvester Based on Magnetic Coupling Effect Realizing Watt-level Power Output

A high power output electromagnetic vibration energy harvester based on the bistable magnetic coupling effect is proposed. By introducing a permeable iron core to generate a nonlinear magnetic force on the suspended magnet in the middle, a bistable potential energy trap can be generated to achieve a widening of the operating bandwidth under low frequency vibration. At the same time, the strong magnetic coupling between the permeable core and the suspended magnet can enhance the magnetic flux variation inside the coil and thus increase the output power. The results show that the nonlinear magnetic coupling effect between the suspended magnet and the permeable core drives the magnet to vibrate chaotically or periodically with large amplitude between the two potential energy traps, widening the operating frequency band to 10 Hz. When directly excited by sinusoidal vibration with an acceleration of 4 g, the output power of the energy harvester is as high as 1.082 W, reaching a watt-level high power output. This research will provide a technical support for the self-powered and wireless development of sensor network nodes in the industrial internet of things. © 2022 Editorial Office of Chinese Journal of Mechanical Engineering. All rights reserved.