Optimization of The Energy Harvested By a Triboelectric Generator Excited With a Small Number of Actuations

This paper ravels how to optimize the harvested energy available at the rectified DC output of a triboelectric generator (TENG) when only a small number of mechanical actuations are required. We report that the harvested energy from the TENG can be improved by selecting an optimal capacitor C
rect
at the output of the rectifier. The available energy can be increased by a factor of ~3 if C
rect
is on the order of the minimum capacitance of the TENG (C
min
), while typical values of C
rect
are on the order of 10 to 100 of C
min
. The optimization study was applied to two different conditioning circuits, showing better energy harvesting capabilities with half-wave diode bridge rectifiers than with full-wave diode bridge rectifiers. SPICE simulations and experiments with a dedicated test bench confirmed the theoretical analysis.