Fault-Tolerant and On-Demand Supra Tough Adhesive Natural Albumin-Based Organohydrogels

Abstract

Adhesive hydrogels play a crucial role in numerous applications across fields such as wound dressing, biomedical implants, and flexible electronics. Despite recent efforts on hydrogel design, reconciling the conflicting requirements of adaptability to rough surfaces and intrinsic strength remains elusive for self-adhesive hydrogels. To address this challenge, a novel strategy is proposed where conformal contact between hydrogels and solids is initially established in a weak state, followed by reinforcement to enhance strength and toughness. Illustrating this approach, bovine serum albumin (BSA) is employed to incorporate a flexible synthetic polymer network, resulting in soft and adhesive organohydrogels (OHGs) with instantaneous and reversible adhesion on various substrates, providing fault-tolerant operation convenience. A brief on-demand heating step transforms them into a strong and supra-adhesive state by forming a rigid BSA network and establishing a double network (DN) structure. The resulting BSA based DN OHGs demonstrate remarkably enhanced bulk mechanical strength and exceptional interfacial toughness on diverse nonporous solid substrates, allowing for on-demand permanent fixation. This approach integrates fault-tolerance and permanent fixation into a single material, highlighting the potential of these natural albumin based OHGs as advanced functional materials for diverse applications, including artisanal restoration, and all-season flexible sensors.