Interfacial materials with special wettability. This issue of MRS Bulletin highlights state-of-the-art biomimetic and bioinspired materials with special wettability properties, and some of their potential applications in high/low temperature environments. The cover shows water droplet formation during condensation on smooth and nanostructured copper tubes with varying wettability characteristics. (Top to bottom): A thin liquid fi lm on a smooth hydrophilic copper tube, discrete droplets on a smooth hydrophobic copper tube, Wenzel droplets on a superhydrophobic nanostructured copper oxide tube, jumping Cassie droplets on a superhydrophobic nanostructured copper oxide tube, and highly mobile droplets on an oil infused nanostructured copper oxide (slippery liquid-infused porous surface or SLIPS) tube. The background shows a high magnification view of the copper oxide nanostructure. Image courtesy of Evelyn Wang, Nenad Miljkovic, and Jeremy Angier. See the technical theme that begins on page 366.