The role of superhydrophobicity in the adhesion of a floating cylinder

Abstract

Horizontal cylinders floating on liquid surfaces are mundanely observed, whose examples include the legs of aquatic arthropods and floating larvae, twigs and hairs. We study the force and energy required to lift the cylinder clear from the water surface, to evaluate the role of wettability, especially superhydrophobicity, in the adhesion of floating cylinders. We find that a drastic degree of energy saving is achieved when lifting a superhydrophobic cylinder as compared with a cylinder with moderate wettability. This can serve as a starting point to understand how the superhydrophobicity of the legs of water-walking insects help to propel them efficiently.