Water repellent surface produced using a femtosecond laser

For the first time a multifunctional metal surface has been created that is super-hydrophobic, self-cleaning and extremely absorbent.

Researchers at the University of Rochester (US) have applied both micro- and nanotextures to a surface using a femtosecond laser. The texture consists of a matrix of hills and valleys with a width of 50 micrometers and a depth of 75 micrometers. This results in air being trapped inside the matrix so that water droplets are unable to attach themselves to the surface. Falling droplets appear to spring back onto an air cushion, resulting in the surface remaining dry. The technology was successfully applied to platinum, titanium and copper in the laboratory.

Applications could be found in self-cleaning components - the rolling water droplets carry off unattached particles - and also in energy efficient components thanks to the very low levels of frictional resistance.