This paper presents an impact-based piezoelectric vibration energy harvester using freely movable spherical proof mass and MFC (Macro Fiber Composite) beams as piezoelectric cantilevers. When external vibration is applied, a metal sphere moves freely along the channel and collides with both ends of the cavity, which induces the vibration of parallel- connected MFCs and generates electric power. A proof-of-concept device having the form- factor of a wristwatch has been designed and tested. Moreover, spherical proof mass made of different materials has been tested to analyze the relationship between output power, long-term reliability, and audible noise level during operation. Maximum peak-to-peak open circuit voltage of 41.2V and average power of 908.7 μW have been obtained in response to a 3g vibration at 17Hz for device with parallel-connected MFC beams.
|Journal||Journal of Physics: Conference Series|
|State||Published - 10 Dec 2015|
|Event||15th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications, PowerMEMS 2015 - Boston, United States|
Duration: 1 Dec 2015 → 4 Dec 2015