Mechanics and Adhesive Performance of Mussels on Roughness- and Geometry- controlled 3D printed Substrates*

Marine mussels have the remarkable ability to adhere to a variety of natural and artificial surfaces under hostile environmental conditions. Although the molecular composition of mussel adhesives has been well studied, a mechanistic understanding the physical origins of mussels’ impressive adhesive strength remains elusive. Here, we investigated the role of substrate roughness and geometry in the adhesive performance of mussels. Using 3D printing, sandblasting, and laser texturing we created substrates with differing surface treatments and introduced these to mussels, which in turn adhered to the engineered surfaces via plaque-thread byssal structures. Tensile testing with in situ imaging was used to determine the adhesion strength and mechanical properties of the mussel adhesive plaques under various conditions. Our results inform the relationships between adhesive performance and substrate properties, give insight into the physical governing factors of mussel adhesion, and provide design criteria for development of synthetic adhesives for use on complex, textured surfaces.