Analysis, Design, and Implementation of an Elastomer Generator Based Energy Harvesting Scheme

Dielectric elastomer generator (DEG) is a special variable capacitor generator used to harvest electrical energy from ambient mechanical vibrations, such as waves, building vibrations, wind, and human movement. The DEG, by virtue of its variable capacitance, converts the applied mechanical energy into electrical form. For successful energy harvesting, the DEG requires controlled charging and discharging operations. Thus, the energy harvesting circuits, used to charge and discharge the DEG, must work in tandem with the mechanical vibrations. The energy harvested during a single cycle of DEG operation increases with an increase in the DEG operating voltage. Hence, energy harvesting circuits must drive the DEG at high voltage levels. These two requirements make the energy harvesting circuit design a challenging job. In this paper, a novel energy harvesting system is proposed to drive the DEG without needing a position sensor, a high-voltage source, or a high turns ratio transformer. The theory of the proposed scheme is explained and validated with experiments performed on a prototype DEG. The control implemented leads to a special intermittent operation of the energy recovery circuit, which is also introduced. 2.597 mJ energy was harvested from a single elastomer film of 10 cm diameter with 2.3 nF capacitance in relaxed condition.