Mechanisms and applications of bioinspired underwater/wet adhesives

In nature, many organisms can effectively fix to contact substrates and move and prey in complex living environments, such as underwater, seawater, and tidal environments, owing to special secreted chemical components and/or special micro/nanostructures on the adhesive surface of these organisms. Inspired by the adhesive performance of organisms, extensive research related to adhesive components and adhesive surfaces has been conducted recently. To better understand the underlying adhesive mechanisms and facilitate further continuous inspiration, a brief overview of recent wet/underwater adhesive materials is provided herein. First, the adhesive processes and underlying mechanisms of commonly researched organisms, such as mussels, octopuses, clingfish, and tree frogs, are discussed, and the corresponding bioinspired artificial adhesives are presented. Then, the applications of these bioinspired adhesives, such as intelligent robots (signal monitoring and sensing devices), wearable devices (including wet climbing and electronic skin), biomedicines (including wound dressings, bone adhesion, and rapid hemostasis), are presented and summarized. Finally, we offer our perspective on the future challenges and development of bioinspired artificial adhesives.