Everyone knows that bathroom mirrors fog up during a hot shower. To evaporate the mist for its privileged guests, some top-end hotels put heating coils behind the mirrors.
But humid conditions can cloud-up eyeglasses or camera lenses by the same mechanism, and there has heretofore been no way to fix the problem short of a smudge-producing wipe.
And the same problem can become dangerous when a car’s windshield is affected, especially for those who don’t understand that the AC needs to be on in order to solve that problem.
When warm, humid air contacts a relatively cold glass surface, water vapor will condense on the glass. The condensate consists of billions of water droplets that diffract light.
Various sprays and chemical alterations have largely failed to solve the annoyance, but now a Chinese team may have figured it out once and for all.
Junhui He and colleagues from Beijing’s Chinese Academy of Sciences have created an anti-mist coating made of nanoparticles that can be applied to windshields at a cost of a few cents per item.
He’s team recognized that certain nanoparticles, applied just so, effectively break the surface tension of the water droplets when they try to form. The result is a transparent film of water that does not scatter light.
After experimenting with various shapes and chemicals, He’s team determined that oxygen-treated, silicone-covered polystyrene spheres shaped like raspberries were most effective in this regard.
The team plans to commercialize the process immediately.