One-step method for fabrication of bioinspired hierarchical superhydrophobic surface with robust stability

Abstract Functional surfaces provided by nature, especially some typical examples, such as lotus leaf, legs of water spiders, and shells of beetles, which inspire the study of biomimetic superhydrophobic surfaces. These natural surfaces exhibit fantastic wetting behavior with spatially, micro-nano hierarchical structures. Inspired by this, a one-step, facile electrodeposition process was developed for the fabrication of superhydrophobic surface on aluminum alloy. A Danxia-landform-like morphology surface is obtained by electrodeposition, with micro-nano-binary scale structure and low surface energy coating. The surface with convex microscale pillars and fractals in nanoscale, which are the key points of superhydrophobicity. Also, wettability is controlled by changing the anodization voltages, and roughness of the surface increased with a higher voltage. Due to the spatially, hierarchical morphology, the as-prepared surface possessed robust mechanically stability, for the nano coating layer located in ‘concave valleys’ is well protect. Experiments results verified that the prepared superhydrophobic surface have good performances of mechanical durability, as well as corrosion resistance. Thus, such a fabrication method would flourish approaches of water-repellence surface on aluminum alloy engineering materials.