Effect of seawater diffusion on the dielectric properties of silicone elastomer

This study investigates the diffusion kinetics of seawater into silicone dielectric elastomers and examines their detrimental effects on electromechanical performance in energy harvesting applications. Encapsulated dielectric elastomer samples are prepared and immersed in water to correlate DC resistivity changes with water content diffusing through the membrane. Results demonstrate that water ingress induces significant conduction losses, which appear similar in both seawater and deionized water. When considering the use of these materials for ocean energy harvesting, conduction losses reduce transducer efficiency. Therefore, the dielectric properties of water-saturated samples are analyzed under typical electro-mechanical harvesting schemes, highlighting severe limitations at low stretch amplitudes. Furthermore, water-saturated samples exhibit a 22% reduction in dielectric breakdown strength, substantially diminishing the achievable energy density of submerged generators such as wave energy converters.