A Multi-Frequencies Micro-Electromagnetic Vibration Energy Harvester with Nonlinearity for Expanding the Frequency Band.

In this paper, we proposed a multi-frequencies electromagnetic vibration energy harvester (EVEH) with a wider operating frequency band. The EVEH contains three different vibration picking-up systems with different natural frequencies. A broadened bandwidth was obtained by combining the structural nonlinearity of the vibration picking-up systems with the multi-frequencies, while the vibration energy harvest was increased by adopting two induction coils in the EVEH system. At an acceleration of 1.5g and frequencies of 45.6, 75 and 146.5 Hz, the peak-peak voltages of the prototype were 336, 270 and 39.8 mV, respectively. The corresponding bandwidths were 10.1, 7.8 and 4.2 Hz, respectively.