Flexibility-Patterned Liquid-Repelling Surfaces.

Droplets impacting solid surfaces is ubiquitous in nature and of practical importance in numerous industrial applications. For liquid-repelling applications, rigidity-based asymmetric redistribution and flexibility-based structural oscillation strategies have been proven on artificial surfaces; however, these are limited by strict impacting positioning. Here, we show that the gap between these two strategies can be bridged by a flexibility-patterned design similar to a trampoline park. Such a flexibility-patterned design is realized by three-dimensional projection micro-stereolithography and is shown to enhance liquid repellency in terms of droplet impalement resistance and contact time reduction. This is the first demonstration of the synergistic effect obtained by a hybrid solution that exploits asymmetric redistribution and structural oscillation in liquid-repelling applications, paving the rigidity-flexibility cooperative way of wettability tuning. Also, the flexibility-patterned surface is applied to accelerate liquid evaporation.