Lipoic acid-based stable underwater adhesive with repeatable adhesion and recyclability

The development of fast, recyclable, and stable adhesion is crucial across multiple fields. Adhesives based on lipoic acid (LA) as a raw material have garnered significant attention; however, their susceptibility to closed-loop depolymerization after polymerization greatly limits their applications. We have designed a stable underwater adhesive through a straightforward preparation process that exhibits high adhesive strength, excellent mechanical properties, and resistance to swelling, making it suitable for soft tissue repair under high burst pressure. This adhesive effectively seals isolated organ breakage and achieves instant adhesion to a variety of substrates. Notably, repeatable adhesion exceeding one hundred cycles has been accomplished. A simple and effective polymerization reaction is employed to prevent depolymerization, allowing for the long-term storage of the adhesive. The adhesive is degradable, biocompatible, and sustainable, enabling reprocessing multiple times to create a robust adhesive interface. The adhesive can be continuously produced using closed-loop recyclable monomers. Additionally, it is utilized in human electromyogram (EMG) and electrocardiogram (ECG) applications, where it effectively collects stable and realistic physiological signals. This study presents a novel, straightforward, and environmentally friendly strategy for designing a stable LA-based underwater adhesive. Furthermore, it offers new insights for the design and application of conductive underwater adhesives.