Mussel Adhesion

Abstract

Nature has developed many fascinating species mastering in adhesion through the evolution of millions of years. Geckos have developed an extraordinary ability of climbing on vertical surfaces with various surface roughness and textures. Similar abilities have also been observed on many insects such as fliers and ants. Both geckos and insects apply hierarchical foot structures to maximize the real contact area and achieve reversible adhesion force via weak but universal van der Waals forces and sometimes capillary forces. The remarkable climbing ability of geckos and insects has inspired numerous studies on developing structured dry adhesives. On the other hand, many marine creatures use special adhesive proteins as super “glues” in ocean. Barnacles attach themselves permanently on various hard surfaces through adhesive plaques containing amyloid-like nanofibrils. Sandcastle worms build their palaces by secreting special complex coacervate to glue together sand granules on the ocean floor. Marine mussels are masters in wet adhesion, achieving strong and stable wet adhesion in the ocean through adhesive plaques mainly composed by various proteins. The wet adhesion of barnacles, sandcastle worms, and mussels has been interesting to many scientists for the ability to overcome water and moisture, which are big enemies for many artificial adhesives.