Professor Chunlei Guo has developed a technique that uses lasers to render materials hydrophobic, illustrated in this image of a water droplet bouncing off a treated sample. Credit: J. Adam Fenster / University of Rochester

Scientists at the University of Rochester in the USA have treated metals so that they keep dry even when splashed with water.

Chunlei Guo, professor of optics at the University of Rochester in the USA explains that these ‘super-hydrophobic’ (water-hating) materials are useful, for example, for preventing ice from forming on aircraft wings, or to keep surfaces clean and dry and free of bacteria (germs).

Most current hydrophobic materials rely on chemical coatings, but these can rub off. Professor Guo used lasers to make tiny patterns on the surface of the metals. The patterns make the metals repel water.

As water bounces off the super-hydrophobic surfaces, it also collects dust particles and takes them along for the ride. To test this self-cleaning property, Professor Guo and his team took ordinary dust from a vacuum cleaner and dumped it onto the treated surface. Roughly half of the dust particles were removed with just three drops of water. It took only a dozen drops to leave the surface spotless. Better yet, it remains completely dry.