Hierarchically structured stainless-steel surfaces with superior superhydrophobicity and anti-reflection

Superhydrophobicity and anti-reflection of stainless-steel surfaces have potential applications in the fields of solar energy absorption and conversion, stray light shielding, and optical stealth. Here, we propose an efficient method for fabricating hierarchically structured stainless-steel surface with superior superhydrophobicity and anti-reflection based on maskless electrochemical machining (maskless ECM) technology. The hierarchically structured surface not only had a contact angle of 154° without chemical modification, but also had an average reflectance of 1.44% in the wavelength range of 400–800 nm. The mechanism underlying optical properties was discussed. The hierarchical structure formed by maskless ECM is very suitable for mass production and large area fabrication.