Photoresponsive surfaces with controllable wettability

In this paper, current progress in the area of photoresponsive surfaces with controllable wettability is reviewed, including mainly surface conversion between wetting and anti-wetting, prepared from inorganic oxides (e.g., titanium dioxide, zinc oxide, and tungsten oxide) or/and photoactive organic molecules (e.g., azobenzene, and spiropyran), and movement of liquid droplets driven by molecular machines (e.g., molecular shuttles such as rotaxanes). Photoresponsive controllable wettability originates from a transition between the bistable states of photoresponsive materials. The exploration of the basic mechanisms provides a basis for the construction of novel smart responsive surfaces.