Rapid‐Response Water‐Shrink Films with High Output Work Density Based on Polyethylene Oxide and α‐Cyclodextrin for Autonomous Wound Closure

Abstract Conventional wound closure methods, including sutures and tissue adhesives, present significant challenges for self‐care treatment, particularly in the context of bleeding wounds. Existing stimuli‐responsive contractile materials designed for autonomous wound closure frequently lack sufficient output work density to generate the force needed to bring the wound edges into proximity or necessitate stimuli that are not compatible with the human body. Here, semi‐transparent, flexible, and water‐responsive shrinkable films, composed of poly(ethylene oxide) and α‐cyclodextrin, are reported. These films exhibit remarkable stability under ambient conditions and demonstrate significant contraction (≈50%) within 6 s upon exposure to water, generating substantial contractile stress (up to 6 MPa) and output work density (≈1028 kJ m −3 ), which is 100 times larger than that…