By Peter Weiss
Nanotechnologists have created a remarkably effective liquid-repelling surface that can also become, at the flick of a switch, a welcome mat for liquids. The ability to go from dry to wet and back on command makes the surface potentially useful for manipulating solutions in microchip chemical laboratories and many other devices, the material’s developers say.
The new surface is made from ordinary silicon. Its liquid-shunning property emerges when the scientists etch the wafer to create an array of pillars only hundreds of nanometers in diameter and then apply a thin, Teflonlike coating, report physicist Tom N. Krupenkin and his colleagues of Lucent Technologies’ Bell Labs in Murray Hill, N.J.