Bioinspired Underwater Adhesive With Spontaneous, Rapid, Stable, and Robust Adhesion in Dynamic Water Environment

Marine mussels exhibit remarkable adhesive capabilities, providing key inspiration for developing underwater adhesives. However, most existing underwater adhesives fail to replicate the convenient, robust, rapid, and stable adhesion of marine mussels. In this work, we developed a biomimetic underwater adhesive (BMUA) that combines catechol group with solvent-responsive curing mechanism. BMUA was synthesized via a straightforward one-step free radical polymerization in dimethyl sulfoxide (DMSO), using methacrylic acid (MA) and N-isopropylacrylamide (NIPAM) as hydrogen bond (H-bond) components, methyl methacrylate (MMA) as a hydrophobic monomer, and DOPA-functionalized methacrylate as the adhesive unit. Upon water contact, BMUA undergoes solvent exchange rapidly, triggering the formation of a H-bond and hydrophobic crosslinked network. This process effectively displaces interfacial water and enables solidification, resulting in strong underwater adhesion. The BMUA demonstrates high adhesive strength on various substrates under flowing water and maintains robust bonding stability across a range of pH, salinity, and temperature conditions. Notably, BMUA retains efficient adhesion (>1.4 MPa) even after 45 days and shows promising performance in practical applications such as underwater sealing, targeted bonding, and rapid hemostasis in a rat liver injury model. This work offers a new design strategy for high-performance underwater adhesives that closely mimic the advantageous adhesion of marine mussels.