A universal method to create surface patterns with extreme wettability on metal substrates.

Extreme wettability surfaces have attracted more and more attention due to their practical applications, however, few reports have shown a universal method to create surface patterns with extreme wettability on a variety of metals. In this paper, a mask-assisted dual-chemical-processing approach without special modification is used to prepare the extreme wettability patterns on various metal substrates. Fabrication of superhydrophilic-superhydrophobic patterns on five kinds of metal substrates of Al, Ti, steel, Zn and Mg alloy proved the versatility of this method. The extreme wettability patterns prepared by this method were applied to fog harvest and we found the big differences in the collection efficiency of various metal surface patterns.