Bioinspired Fouling-Release Smart Skin Powered by Twisted Spiral Artificial Muscles (TSAMs)

The buildup of marine organisms on submerged surfaces, known as biofouling, poses a major threat to the maritime industry. Biofouling on seafaring vessels increases hydrodynamic drag, fuel consumption, and leads to the spread of invasive species. Despite considerable research, a cost-effective and environmentally friendly strategy for preventing biofouling remains elusive. Silicone-based fouling release coatings (FRCs) that rely on hydrodynamic shear forces to remove attached biofilms have recently been proposed as a non-toxic solution for biofouling. However, FRCs are susceptible to fouling in still water or near-still water conditions. In this study, a smart skin bioinspired by the shape-changing behavior of octopi for removing biofilms in near-still water conditions is proposed. Active deformation of the smart skin powered by twisted spiral artificial muscles (TSAMs) leads to the detachment of biofilms. The efficacy of the smart skin is evaluated in both a laboratory setting and a field environment. A maximum of 87% of a laboratory grown and 79% of a heterogeneous field biofilm is detached by the active motion of the skin surface. The results indicate that the actively deformed smart skins bioinspired by octopi are a promising candidate for removing marine biofilms in still or near-still water environments.