Abstract:
This article reviews and demonstrates recent research into wetting of structured hydrophobic surfaces. Here, ‘structured’ refers to features smaller than a typical water drop: sub-millimetric, microscopic, and nanoscale. Characterisation of wetting properties, including superhydrophobicity, is important for such surfaces, and drop impact has emerged as a near-standardised testing method for dynamic wetting. Wetting can be strongly influenced by designed structural elements with length scales comparable to a drop. Examples include ridges, fields of micropillar arrays, and surfaces designed to capture condensation. Fabrication of structured hydrophobic surfaces, especially superhydrophobics, is of broad interest for applications involving passive control of water drops.
