An energy harvesting scheme for dielectric elastomer generators

Energy harvesting is an attractive option to generate power for different low power stand-alone electronic devices. Dielectric Elastomer Generator (DEG) is a special variable capacitor generator which, by virtue of its variable capacitance property, can convert vibrational mechanical energy to electrical energy. Hence the DEGs can be used as a means to harvest electrical energy from various environmental vibrations, like waves, building vibrations, and human movements, etc. To drive the DEG, in synchronism with the periodic mechanical vibration, Energy Harvesting Circuits are used. In this paper, a novel energy harvesting scheme is proposed. The proposed energy harvesting scheme does not require a position sensor or a high voltage transformer for its operation. It can also harvest energy from mechanical vibrations continuously without needing an auxiliary voltage source. Complete theory of the proposed scheme is explained at length and is validated with experiments performed on a prototype DEG. We are able to harvest 2.57 mJ energy from a single elastomer film of 10 cm diameter and 2.3 nF capacitance in relaxed condition. The experimental results show good match with the proposed theory.