A novel approach to deliver liquids from a solid coating is both location- and time- controlled. The sponge-like coating can repeatedly absorb liquids and release them again. The type of release, either droplets or film, can be initiated by a short exposure with UV light. The uptake is accelerated by exposure with blue light. The principle of this coating is based on a photoresponsive liquid-filled smectic crystal network (LCN).
On-demand liquid release from a sponge-like coating