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, we report semi‐transparent, flexible, and water‐responsive shrinkable films, composed of poly(ethylene oxide) and α‐cyclodextrin. These films exhibit remarkable stability under ambient conditions and demonstrate significant contraction (∼50%) within 6 seconds 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 of conventional hydrogel and 25 times larger than that of skeletal muscles. Remarkably, upon hydration, these films are capable of lifting objects 10,000 times their own weight. Leveraging this technology, we further developed water‐shrink tapes, which, upon contact with water, effectively constrict human skin and autonomously close bleeding wounds in animal models within 10 seconds. Our work offers a novel approach to skin wound management, showing significant potential for emergency and self‐care scenarios.This article is protected by copyright. All rights reserved