Stress-Shield Enhanced Fatigue Resistance in Fabric-Hydrogel Composite Coatings

Hydrogel coatings are widely used as functional interfaces, yet are prone to cohesive fatigue under cyclic mechanical loading. Existing fatigue-resistant designs usually rely on complex fabrication or specific material systems, limiting their use in practical coatings. Herein, we propose a stress-shielding-driven strategy to enhance the fatigue resistance of hydrogel coatings by embedding woven fabrics into the polyacrylamide hydrogel model via topological entanglement. The interpenetrated fabric-hydrogel architecture establishes a robust interface that redistributes the applied load from the polymer network to the fabric over a larger process zone. This stress redistribution reduces the true load of polymer chains at the crack tip, while the wrinkled fabric interface forces crack deflection. Elastic Spandex fabrics synergistically deform to reduce interfacial shear stress with the hydrogel, boosting the interfacial fatigue threshold of hydrogel coatings by ∼8-fold. Moreover, by enhancing the intrinsic fatigue threshold of the hydrogel and incorporating multilayer fabrics, interfacial fatigue thresholds exceed 300 J m^-2. This stress-shielding strategy is compatible with diverse hydrogel systems, providing a versatile design principle and simple fabrication approach for fatigue-resistant hydrogel coatings with strong industrial potential.