Gecko's Toes‐Inspired High‐Adhesive and Self‐Healable Elastomer in Marine Conditions: Humidity‐Triggered Crosslinking and Damage Sensing

ABSTRACT The development of smart materials capable of underwater self‐healing, mechanical robustness and damage‐healing sensing attributes holds great promise for applications in marine energy exploitation. However, achieving excellent humidity self‐healing, superior adhesion, and effective damage sensing and monitoring properties simultaneously is challenging because the disturbance of water molecules to dynamic‐interaction reconstruction. Herein, inspired by gecko's toes, an ultra‐robust environmental adaptative self‐healing supramolecular elastomer is designed by molecular engineering of water‐insensitive dynamic network, which possesses efficient self‐healing and visual damage sensing capabilities. Through coupling design of hierarchical hydrogen bonds, humidity‐tolerant catechol coordination and photothermal sensitivity moiety, the elastomer achieves high Young's modulus (157.72 MPa) and superior self‐healing efficiency (84.68%). Moreover, the autonomous association between catechol groups and steel surface endows the resultant elastomer with outstanding adhesion force (12.82 MPa) in humid conditions. Furthermore, this elastomer can be fabricated as a patch covered on steel substrates. The damage‐healing dynamics and interfacial failure characteristics are visually demonstrated by the reversible fracture and reconstruction of iron‐catechol coordination bonds, realizing real‐time damage sensing and monitoring. This study provides a novel strategy for the design of next‐generation smart protective materials in harsh marine environment, and expected for ensuring the stable operation of marine energy mining equipment.