Thickness-dependent fast wetting transitions due to the atomic layer deposition of zinc oxide on a micro-pillared surface.

Smart surfaces promote the fundamental understanding of wetting and are widely used in practical applications for energy and water collection. Light-induced switchable wettability facilitated by ZnO coatings, for instance, was developed for liquid manipulation at the surface. However, the transition of wetting states was reported to follow a hydrophobic-hydrophilic cycle in an hour, which is very long and may limit its future applications.