Semiseparated biphasic bicontinuous dielectric elastomer for high-performance artificial muscle.

Electrically driven dielectric elastomer artificial muscles represent a transformative advancement in the field of soft robotics. However, their output performance has encountered a bottleneck owing to the insufficient electromechanical sensitivity of dielectric elastomers. We present a hetero-cross-linking–induced phase separation strategy to design semiseparated biphasic bicontinuous dielectric elastomers with a high electromechanical sensitivity of 360 per megapascal. Our strategy harnesses varying silicone elastomer cross-linking mechanisms to form an interconnected dielectric phase within a soft mechanical phase in the resultant elastomers. These elastomer-based artificial muscles simultaneously exhibit high energy density and power density, as well as ultralong life span under low-driving fields. Applications involve a robotic arm with large stroke and untethered soft crawling robots with multimodal locomotion, showcasing their versatility. Editor's summary: Dielectric elastomers use electroactive polymers to convert electrical energy into mechanical work and vice versa. Although they are stretchable and lightweight, they require high electric fields and can be slow to respond. Shi et al. developed a silicone elastomer with a biphasic bicontinuous structure. Commercial silicone elastomers are cross-linked to form an interconnected dielectric phase within a soft silicone rubber. These composite materials can be actuated under low fields while still showing high energy and power density, which the authors exploited in a number of robotic devices. —Marc S. Lavine [ABSTRACT FROM AUTHOR]