Submerged Stadium-Shaped Pressure Differential Dielectric Elastomer Generator for Wave Energy Conversion

Oceanwaveenergyisapromisingrenewableresource,butitsexploitation is limited by the cost andcomplexityofconversionsystems.Dielectric Elastomer Generators(DEGs)areemergingaslightweight, corrosion-resistant, and scalable alternatives. This paper introduces a Pressure Differential Wave Energy Converter basedonastadium-shapedsubmergedDEG(SS-PD-DEG).Afiniteelementmodelwasdeveloped to describe thesystemelectroelasticresponse,capturingthenon-axisymmetricdeformationofthemembrane under uniform and hydrostatic loading and to predict capacitance variations. A small-scale prototype was designed, manufactured, and tested both in air and underwater. Results confirmed the capability of the SS-PD-DEG to perform full energy generation cycles while operating in underwater conditions. Besides the demonstration of operation, in-air and submerged tests have confirmed the quality of the modelling approach and theoretical predictions. Underwater tests also demonstrated a hydrostatic-induced negative stiffness effect, enabling extended deformability and potential for broadband frequency response.