An experimental study on the structure of the internal impact type vibration energy harvester

To increase the vibration energy-harvesting capability of the piezoelectric generator based on a cantilever beam, the authors´ research group had proposed the internal impact type vibration energy harvester (IITVEH) that employs a proof mass at the tip of a cantilever beam to hit the frames of the IITVEH on the two sides of the proof mass. In this work, we study the effect of the structure topology of IITVEH on its output power. Two structural designs of IITVEH utilizing both electromagnetic and piezoelectric elements are introduced, which are named as U & Y type structures, respectively. In the experiment, the output electric power of the U and Y type structures is compared for the same vibration excitation conditions. It is concluded that the Y type structure has a larger total output power than the U type structure.