High-dielectric-permittivity silicone rubbers incorporated with polydopamine-modified ceramics and their potential application as dielectric elastomer generator

Abstract

Exploiting green energy from environmental resources with high harvesting efficiency has always been an ambitious goal in materials science. Dielectric elastomer generator (DEG) is one of the most promising devices which could draw electrical energy from mechanical stress. However, the need for high deformability and dielectric properties poses great challenge. In this work, high permittivity inorganic fillers, copper calcium titanate (CCTO), were incorporated with a bimodal silicone rubber matrix aiming at improving dielectric, mechanical, and mechanic-electro conversion properties. The surfaces of the inorganic fillers were modified with polydopamine (PDA) layers first to enhance the interfacial interaction between the inorganic and polymer material, leading to better dispersion and greater dielectric property. Results showed at a bias voltage of 1500 V, the energy harvested by the 26 wt% CCTO@PDA incorporated composite was 0.69 mJ/cm3, twice as much as the polymer matrix. The energy conversion efficiency of 20 wt% CCTO@PDA incorporated composite elastomer was at the maximum of 3.36%, increased by 68% compared to the pure matrix.