Multi-resonant vibration energy harvester using a spiral cantilever beam

The vibration energy harvesters are supposed to operate at their resonant frequencies for obtaining a optimum output, while most of the reported devices are single-resonant systems with a narrow working band. In this work, a multi-resonant vibration energy harvester is presented to make up the output limitation of the single-resonant systems. The vibration structure is designed as a spiral cantilever beam, and the proposed configuration is proved to be capable of achieving multi-resonant response and effectively increasing the working bandwidth of the harvester. Experimental results show that there will present five obvious resonant peak values, and the corresponding resonant frequencies are concentrated at around 21.6 Hz, 27.4 Hz, 34.5 Hz, 42.6 Hz, and 65.9 Hz respectively.