Significant improvements in the electromechanical performance of dielectric elastomers by introducing ternary dipolar groups

Abstract

Dielectric elastomers are intelligent materials, which can be deformed under electric field stimulation and show a variety of application prospects in the fields of intelligent robots and bionic materials. However, traditional dielectric elastomers commonly require high driving field, which severely restricts their applications. Herein, a new type of polyacrylate elastomeric material containing three types of dipolar groups (ester, hydroxyl, and carbamate) is designed, which significantly contribute to the enhanced dielectric constant, and the elastic modulus is optimized by adjusting the amount of crosslinking agent. 2-Hydroxyethyl acrylate (HEA), which contains a hydroxyl group, is used as the monomer to prepare poly(2-hydroxyethyl acrylate) (PHEA), and diphenylmethane diisocyanate (MDI) is used as the crosslinking agent to form a series of PHEA@MDI elastomer films. The synthesized elastomers possess both a high dielectric constant (22.2 at 100 Hz) and a large actuation performance (19.2% at 10 MV/m). This work provides a new strategy for fabricating high performance dielectric elastomers.