Titin-Mimetic Phase Separation Enables a High-Performance Dielectric Elastomer for Artificial Muscles

Dielectric elastomers (DEs) are promising candidates for soft robots to achieve efficient electromechanical conversion and lightweight integration. However, conventional homogeneous DE networks face multiple inherent contradictions among compliance, robustness, and dielectric performance due to the lack of differentiated structural design at the molecular scale. Inspired by the hierarchical responsiveness of titin, we present a phase-separated fluorinated polyacrylate DE that achieves synergistic optimization of electrical and mechanical properties while exhibiting excellent self-healing capability. The proposed elastomer achieves a maximum actuation strain of 235% and an ultrahigh specific energy density of 386 J kg^-1 approximately 9.65 times that of natural muscle. As such, our work demonstrates a remarkably comprehensive performance among contemporary advancements. We further demonstrate a biomimetic swimming robot that achieves efficient aquatic locomotion, highlighting the potential of our DE as a suitable candidate for high-performance artificial muscle.