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

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.