Scientists have come up with a solution to one of the most common problems that glasses wearers face. Researchers at the Zurich Federal Institute of Technology (ETH) have developed anti-fog coatingeven if you are wearing a mask. The coating based on gold nanoparticles can also be used on car windshields or camera lenses.
Nano coating absorbs solar radiation and heats the surface, preventing condensation that fog up glasses. This is possible thanks to thin layer consisting of tiny particles of gold evenly distributed. The cape is coated on both sides with titanium oxide, an electrically insulating material that acts as a shield to prevent wear.
Both increase the efficiency of surface heating, which can increase up to eight degrees Celsius. Sandwich leads to transparent and flexible coating with a thickness of only 10 nanometers. The researchers note that due to its properties, it is more efficient, as it absorbs infrared light more selectively.
The photo-induced heating effect provides superior sustained defogging (4x better) and removal (3x better) than uncoated samples, as well as impressive overall indoor and outdoor performance, even in cloudy conditions.
The proposal by the ETH team of scientists is different from traditional methods, which use molecules that attract water to distribute condensate. Gold based plating passively heats the surface of your glasses due to sunlight. It is curious that this advantage also becomes its main disadvantage, since it works only during the day.
Anti-fog glasses, but only during the day
The new anti-fog coating is the fruit of many years of work on passively heated coatings. Three years ago, ETH scientists announced a gold-based coating with the same properties. The difference of this version is that the current work it is noticeably thinner – twelve times thinner than ordinary gold leaf – and flexible, therefore can be applied to curved surfaces such as glasses.
Normally dark surfaces absorb light and convert it to heat, but we created a transparent surface that gives the same effect.
Efstratios Mitridis, ETH researcher
Because sunlight is their source of energy, researchers are working on alternatives to make it run smoothly at night. One of them is to insert a small battery into the frame of the glasses. This would exploit the conductive property of gold by emitting small discharges that would serve to heat the surface.
Likewise, those responsible for the study explore other materials with similar properties. Although the amount of gold used in the reservoir is minimal and does not represent a significant cost, the demand for this precious metal in many industries makes it necessary to look for alternatives. The idea is that implementation cost is so low that it can be mass-produced.
Dimos Poulikakos and Thomas Schucius, ETH professors who lead the research team, noted that nanocoating uses traditional production methods. Their goal now is to further refine the product to ensure it lasts while also working with a partner that can produce it at an industrial level.
If they do, they will solve one of the problems that eyeglass wearers face, one that even soaps or anti-fog sprays can’t solve.
Source: Hiper Textual
