Bio-inspired self-replenishing and self-reporting slippery surfaces from colloidal co-assembly templates

Abstract Functional materials with specific wettability have broad technological implications in various fields. Herein, inspired by the rapid replenishment of Nepenthes nectaries, we present novel lubricant infused hierarchical porous surfaces with self-replenishing and self-reporting capacities. As the porous surfaces were replicated from colloidal co-assembly templates, they were composed of an inverse opal nano-porous structured outer surface layer to lock the lubricant and maintain the surface stability, together with an embedded macro-porous network as reservoirs to store and supply the lubricant for self-healing. We have demonstrated that the hierarchical inverse opal films are in possess of liquid-repelling feature on liquids with different surface tensions (22.3 mN/m to 72.8 mN/m) and favorable self-replenishment capacity for stable droplet manipulation. In addition, the structural colors arisen from the periodic nanostructure could serve as an optical indicator to monitor the wettability of the resultant slippery surfaces, thus greatly expanding their practical values. These features make the self-replenishing slippery surfaces ideal candidates for various applications such as optical sensing, fluid transportation, medical self-cleaning, and so on.