Curvature‐Driven Reversible In Situ Switching Between Pinned and Roll‐Down Superhydrophobic States for Water Droplet Transportation

Abstract

Precise tuning of surface wettability – by means of curvature-driven reversible switching from the pinned to the roll-down superhydrophobic state (see figure) – is reported for for the first time. The adhesion force and sliding behaviors of superhydrophobic poly(dimethylsiloxane) (PDMS) pillar arrays show strong dependence on surface curvature. Alteration of the curvature of the surface allows a water droplet to be easily adjusted from the “ pinned” to the “roll-down” state, which provides the possibility of precise, in situ control of the movements of water droplets.