Fabrication of PDA@SiO₂@rGO/PDMS dielectric elastomer composites with good electromechanical properties

Since dielectric elastomers (DEs) can undergo muscle-like actuation under external electric fields, they show promising applications in fields such as actuators, generators, and biomimetic robots. However, traditional DEs require strong electric fields and pre-stretching to deliver useful deformation, limiting their practical applications. Herein, a novel method for preparing polydimethylsiloxane (PDMS) composites with high actuation under low electric field without pre-stretching is reported. In this method, polydopamine (PDA) is used to modify sandwich-structured silicon dioxide@graphite oxide hybrids (PDA@SiO₂@GO). The inclusion of the SiO₂ layer improves the dielectric constant and reduces the dielectric loss of the composite, while the PDA shell improves the dispersibility of the filler. The PDA@SiO₂@rGO/PDMS composite containing 5 wt% PDA@SiO₂@GO exhibits a large actuated strain of 14.23% under an electric field of 33.19 kV/mm without pre-stretching; this value is 465% larger than that of pure PDMS and superior to those of most reported DEs composites. The results provide a promising new route to prepare high-performance DEs.