Light-Triggered Rapid Self-Healing in Natural Melanin-Graft-Polyurethane with Superior Mechanical Properties

Fatigue damage inevitably shortens the material service life. Self-healing polymers offer solutions but typically require harsh triggers (e.g., high temperatures or NIR light), limiting engineering applications. Herein, we creatively employ white light to trigger rapid self-healing. Polyurethane (PU) chains are grafted onto natural melanin nanoparticles extracted from squid ink, forming a "core-shell" structure with melanin cores and surface-linked PU chains. This design effectively enhances the mechanical strength of PU (tensile strength of 62.15 MPa) and enables it to achieve efficient healing. Under room-temperature flashlight illumination for 10 min, the grafted PU can achieve a self-healing efficiency of 97.09%. This dual enhancement of mechanical and self-healing properties advances the engineering application of self-healing elastomers.