The wettability of a surface—whether drops of water or another liquid bead up or spread out when they come into contact with it—is a crucial factor in a wide variety of commercial and industrial applications, such as how efficiently boilers and condensers work in power plants or how heat pipes funnel heat away in industrial processes. This characteristic has long been seen as a fixed property of a given pair of liquid and solid materials, but now MIT researchers have developed a way of making even the most unlikely pairings of materials take on a desired level of wettability.