Advanced Hybridised Dielectric Elastomers With Large Actuation Strain Under Low Electric Field via Crosslinker Molecular Weight

Dielectric elastomer (DE) can transfer electrical energy into mechanical energy, who demonstrates significant application potentiality in flexible actuation, sensing, and power generation. However, DE faces the technical bottleneck of high driving electric fields, limiting its practical applications. In this work, an advanced hybridised DE with silicone oil and acrylate was designed to reduce modulus and increase dielectric constant, and realize the characteristic of high driving strain under low electric field. The polysiloxane crosslinking agent with different molecular weight was prepared through the addition reaction between isocyanate and hydroxyl groups, in which dihydroxy‐terminated silicone oil acted as the matrix, 4,4′‐diphenylmethane diisocyanate acted as a chain extender and isocyanoethyl methacrylate acted as a capping agent. In combination with butyl acrylate (BA) to fabricate the new hybridised DE. As a result, the molecular weight of the crosslinker markedly impacts on the hybridised DE's modulus. The introduction of BA enhances the dielectric constant and reduces the modulus. The as‐fabricated PM 2 I‐BA 1 achieves a high actuation sensitivity factor ( β ) of 34.2 and exhibits an actuation strain of 23% under an electric field of 22.5 kV/mm. The linear actuator obtains an output force of 96.3 mN (11 times its own weight) under 12.5 kV/mm.