Slippery liquid-infused surface with micro/nano hierarchical structures: Highly efficient fog harvesting

The lack of freshwater resources is a global problem. Fast and efficient water capture from fog is a good solution for many organisms living in arid regions. Compared with superhydrophobic surfaces, slippery liquid-filled porous surfaces (SLIPS) exhibit excellent droplet transport and shedding properties with very low sliding angles (SAs). It is not easy to produce a water film which can effectively improve the efficiency of fog collection. The shape and size of the micro/nanostructure are flexibly adjusted by laser etching, the nanowires on the micron-scale pillars and groove structure are uniformly covered by ammonia etching, and silicone oil is injected by spin-coating to obtain a slippery liquid-infused surface with a micro/nanostructure. Under the synergistic effect of our constructed micro/nanostructure, the superhydrophobic surface injected with lubricant exhibited efficient droplet capture, aggregation, and removal properties, which greatly improved the fog collection efficiency (107% higher than that of the original sample). More importantly, the surface has excellent stability, ice resistance, and acid/alkali resistance and is expected to be used in various extreme adjustments.