Tough and mechanically damage-resistant polysiloxane-polyacrylate elastomers for dielectric elastomer actuators

Dielectric elastomer actuators offer considerable potential for artificial muscles and soft robots. However, the soft and ultra-thin elastomers are susceptible to mechanical damage, which can lead to rapid failure of the actuator. Herein, the dimethacryloxy-terminated polydimethylsiloxane was synthesized and copolymerized with acrylate monomers to prepare a tough polysiloxane-polyacrylate dielectric elastomer. Through systematic optimization, we constructed a synergistic elastomer network combining covalent crosslinks and a topologically interlocked structure. Upon mechanical damage, physical entanglements dissipate fracture energy while permanent covalent crosslinks preserve network stability, endowing the elastomer with a fracture toughness of 3.89 kJ/m². Moreover, the optimized elastomer exhibits satisfactory dielectric actuation performance (actuation area strain of 76%, energy density of 178.5 J/kg). Therefore, actuators fabricated from this elastomer maintain effective actuation even under mechanical damage. Furthermore, we designed and demonstrated the actuator's application as a flexible vector-control device, thereby broadening its potential for use. This work offers an effective strategy for developing mechanically reliable soft actuating materials, which is expected to further promote the practical applications of dielectric elastomers.