Light-driven actuators with self-healing capability: A supramolecular core-shell elastomer approach

Soft actuators for flexible electronics and soft robotics have garnered significant interest, while achieving rapid actuation, mechanical robustness, and self-healing capacity within a single system remains challenging. Here we disclosed an interfacial supramolecular strategy by incorporating polydopamine (PDA) decorated Liquid metal (EGaIn) microdroplets into an aqueous polyurethane (WPU) matrix to construct a dynamic supramolecular interface. The formation of multiple hydrogen bonds and metal-catechol coordination markedly enhances interfacial adhesion and energy dissipation without sacrificing chain mobility. Consequently, the WLMP film achieves complete crack closure and mechanical recovery within 12 h at room temperature, demonstrating autonomous self-healing. Moreover, the composites exhibit excellent strength (7.6 MPa), low modulus (3.03 MPa), high stretchability (1054.2%), and notch resistance. Furthermore, the broadband light absorption of PDA endows the composite with outstanding photothermal performance (96.2 °C in 240 s) under simulated sunlight irradiation at 100 mW cm^-2, enabling NIR-driven actuators with rapid response and sophisticated biomimetic movement (0.5 and 1 W cm^-2). The proposed strategy has opened new avenues for the development of highly integrated, stimuli-responsive soft materials.