A dielectric elastomer and electret hybrid ocean wave power generator with oscillating water column

Dielectric elastomer generator (DEG) is promising ocean wave energy harvesting technology with high reliability and low cost. This paper proposes an innovative oscillating water column wave energy harvester based on dielectric elastomer(DE), equipped with a bipolar free-standing electret rotary generator(B-FEG) which concurrently provides the bias voltage for the DEG. The novel idea is to exploit the pressure and airflow generated by the motion of the oscillating water column to inflate the DE-film in each wave period and synchronously rotate the ingenious B-FEG continuously. This hybridized energy harvesting technology is conceived to allow the DEGs to generate electricity from ocean waves without conventional bias-voltage supply. A theoretical model is derived to characterize the output performance of the proposed wave energy harvester and further verified by the finite element simulation. The output energy of the DEGs and B-FEG is then estimated theoretically and verified experimentally. The experimental results show that the B-FEG is capable of producing a bias voltage for DEGs. The proposed hybrid electric power of wave energy harvesters popularizes the DEG more conveniently by utilizing the bias voltage of B-FEG.