Fogged glasses are a real nuisance – made worse by masks and the cold weather. Researchers have now developed a kind of heater to ensure a clear view.

Fogged glasses could soon be a thing of the past – that’s what researchers at the Swiss Federal Institute of Technology (ETH) Zurich promise. A wafer-thin coating of gold has made it possible to develop a kind of heater for lenses that generates enough heat when exposed to sunlight to keep the lenses free of fogging. According to the researchers, the technology is also suitable for car windows or other surfaces that can impair visibility in unfavorable conditions.

Up to eight degrees Celsius

To apply the gold layer, the researchers use established technology that is already used in industry. In a clean room in a vacuum, the smallest amounts of gold are vapour-deposited onto the respective surface. The coating is then able to absorb the sun’s infrared radiation and thus heat up by up to eight degrees Celsius. This is to prevent humidity from condensing on the surface.

According to the researchers, the effect is comparable to heating a rear window in a car, but does not consume any electricity and is therefore not only more efficient, but also more universally applicable.

“Scinexx” writes that direct sunlight is not absolutely necessary. The effect also works with dense cloud cover and even indoors.

The result now presented is the result of several years of research and shows the thinnest and most inconspicuous coating to date. The gold layer is said to be completely transparent and flexible.

Favorable costs, variable use

Although the coating consists of real gold particles, so little material is required when vaporizing surfaces that the material costs are “nevertheless low”, according to the ETH. The entire layer, which consists of two layers of titanium dioxide in addition to gold, is twelve times thinner than gold leaf. The Blattgoldschl├Ągerei Eytzinger specifies the thickness of gold leaf as 0.000125 millimeters.

The ETH Zurich technology is currently patent pending. Meanwhile, the researchers are checking whether the coating can also be used for buildings, mirrors or optical sensors. Concerns that a room could heat up noticeably due to treated glass are already dispelled by those responsible: Because the gold only absorbs infrared rays, only the pane heats up and less radiation gets into the room, which means that it stays even cooler than with conventional ones windows.