Superhydrophilic surfaces with hierarchical groove structure for efficient fog collection

Many biological surfaces with hierarchical microstructures exhibit obvious fog collection abilities. However, it is difficult to effectively fabricate a microstructured metal surface with fog collection performance using a simple but flexible method. Inspired by the abilities of microstructures of Sarracenia trichomes to capture fog and transport water, a series of hierarchical groove surfaces with the fog collection property were fabricated by wire electrical discharge machining (WEDM) method, and the fabricated surfaces showed the obvious superhydrophilicity. Moreover, the results show that the fabricated surface with the hierarchical groove structure had better water transport performance and higher fog collection efficiency compared with the smooth surface, and the abilities of water transport and fog collection are related to the number of low ribs on the surface with the hierarchical microgroove. The microstructure metal materials obtained in this study not only open up the potential applications of WEDM in fog collection, but also have wide application prospects in the fields of microfluidic system, biomedicine, and biological excitation system.