Credit: Image courtesy of Charles Black, Antonio Checco, and Atikur Rahman
(Top left) Arrays of tapered-cone and (bottom left) cylindrical nanostructures that create superhydrophobic or water-repellant surfaces. Air pockets between the structures give rise to the hydrophobic properties. (Right) High-speed photographs of a falling water droplet on a nanostructured surface (top) before, (middle) during, and (bottom) after impact.