Innovative coating prevents fogging

Researchers at the Swiss Federal Institute of Technology in Zurich (ETH) have developed a coating that works entirely without electricity, the ETH reported in a press release. Just a few nanometers thick, the coating is made of gold nanoparticles embedded in non-conductive titanium oxide. “Our coating absorbs the infrared component of sunlight along with a small part of the visible sunlight and converts the light into heat,” explained Christopher Walker, a doctoral student in ETH Professor Dimos Poulikakos’s group and lead author of the study. By heating the surface by around three or four degrees, it prevents the glasses or lens from fogging up in the event of a sudden drop in temperature or increase in humidity.

Until now, dark surfaces have been used to absorb light and convert it into heat, explained Efstratios Mitridis, another doctoral student in the research group. “We’ve created a transparent surface that has the same effect.” Tests have shown that the coating developed by the ETH researchers performs better than normal anti-fog agents. These agents make condensation form an even thin film of liquid over the surface rather than separate droplets.

The ETH scientists are now planning to bring their new method to market in collaboration with a partner from industry. “We’re looking to refine our already robust coating to ensure it lasts for years, and we want to take the technology from lab scale to industry scale,” says Christopher Walker.