Light-Designed Shark Skin-Mimetic Surfaces

Sharks, marine creatures that swim fast and have an antifouling ability, possess dermal denticle structures of micrometer-size. Because the riblet geometries on the denticles reduce the shear stress by inducing the slip of fluid parallel to the stream-wise direction, shark skin has the distinguished features of low drag and antifouling. Although much attention has been given to low-drag surfaces inspired from shark skin, it remains an important challenge to accurately mimic denticle structures in the micrometer scale and to finely control their structural features. This paper presents a novel method to create shark skin-mimetic denticle structures for low drag by exploiting a photoreconfigurable azopolymer. The light-designed denticle structure exhibits superior hydrophobicity and an antifouling effect as sharks do. This work suggests that our novel photoreconfiguration technology, mimicking shark skin and systematically manipulating various structural parameters, can be used in a reliable manner for diverse applications requiring low-drag surfaces.