Skeletal-Muscle-Inspired Superstrong Dynamic Covalent Liquid-Crystal Elastomers With Exceptional Actuation Performance.

Abstract

As an emerging actuator material for artificial muscles and soft robotics, dynamic covalent liquid-crystal elastomers (DCv-LCEs) enable network reorganization through dynamic bond exchange, allowing actuator reprogramming, actuation-mode tuning, and material recycling. Despite these distinctive advantages, existing DCv-LCEs still suffer from limited actuation performance for practical applications. Inspired by the critical role of noncovalent interactions in natural skeletal-muscle actuation, we develop a superstrong DCv-LCE (SS-DCv-LCE) by deliberately engineering a dynamic covalent liquid-crystal network that simultaneously incorporates hydrogen-bonding and metal-coordination crosslinks. The dual noncovalent crosslinks synergistically reinforce SS-DCv-LCE, giving rise to a remarkably high Young's modulus (∼27.6 MPa) and a superhigh strength (∼30.7 MPa) at room temperature, while also imparting significantly enhanced mechanical robustness at elevated temperatures. As a result, SS-DCv-LCE delivers an actuation stress of up to 1.6 MPa and a work capacity of up to 486.1 kJ m^-3, which are ∼4.5- and ∼12.1-fold higher than those of human skeletal muscle, respectively, and also far exceed those of existing state-of-the-art elastomeric DCv-LCEs. Moreover, SS-DCv-LCE exhibits reprogrammability and reprocessability, enabling reshaping and recycling into actuators with diverse geometries and actuation modes. This work establishes a new network-architecture design for high-actuation-performance DCv-LCEs, opening opportunities for practical applications in artificial muscles and soft robotics.