Impact-enhanced Electrostatic Vibration Energy Harvester

An influence of mechanical impacts between variable capacitor electrodes on the electrostatic vibration energy harvester (e-VEH) operation is studied theoretically. The analysis is carried out for two conditioning circuits with parallel and serial load connection. A relationship between e-VEH parameters and external mechanical force characteristics enabling to assess the possibility of operation in a periodic impact mode is obtained. Dependences of the average power generated by the impact-enhanced e-VEH versus the number of collisions between the electrodes and the load resistor value are calculated. The operation of the harvester for two circuits in impact and non-impact modes is compared and analyzed. It is shown that the average power generated by the e-VEH for the impact mode can exceed the power for the non-impact mode by 1–2 orders of magnitude along with a significant decrease of the harvester optimal load resistance.