An impact-driven frequency up-converter without coupling phase for electret-based vibration energy harvester

One critical issue of electret-based vibrational energy harvesters (eVEHs) for wearable applications is to improve their adaptability for low-frequency ambient environments. This paper exploits the impact-driven frequency up-converter without coupling phase to improve the power output of an electret-based vibration energy harvester. A vibro-impact model is established, solved numerically by SIMULINK, and verified by SOLIDWORKS/motion study tool. The frequency up-conversion mechanism with delicately avoided coupling phase is demonstrated to improve the power output of the eVEH significantly. According to our analysis, the proposed technique improves the energy harvesting efficiency of eVEH by 40%, for an ultra-low frequency excitation of 2 Hz. By and large, the work of this paper could potentially extend the application of eVEH in low frequency scenarios.