Fog-Resistant, Self-Cleaning Glass Developed at MIT
April 30, 2012

Fog-Resistant, Self-Cleaning Glass Developed at MIT

Researchers at the Massachusetts Institute of Technology (MIT) have reportedly developed a way to make glass free of glare and reflections, resistant to fog, and essentially self-cleaning, the university announced in a press release last Thursday.

According to the MIT News Office, the technology is a new surface temperature that can be applied to glass, essentially eliminating reflections and making it so that water droplets bounce right off the surface, not unlike rubber balls. This new type of glass is based on surface nanotextures that produce an array of conical features, is self-cleaning and resists fogging and glare, the researchers said.

A paper detailing their discovery, which was written by mechanical engineering graduate students Kyoo-Chul Park and Hyungryul Choi, former post-doctoral student Chih-Hao Chang, chemical engineering professor Robert Cohen, and mechanical engineering professors Gareth McKinley and George Barbastathis, has been published in the journal ACS Nano.

The pattern used to create the surface is made up of nanoscale cones with a base width of 200 nanometers, Geekosystem's James Plafke wrote last week. He added that it is created by coating the glass with thin layers, including one that is photoresistant. It is then overlaid with a grid, which serves as a guide for the etching that follows, producing the conical shapes.

This surface, PCMag reporter Damon Poeter wrote, uses its ability to clean water in order to essentially be self-cleaning. As the water droplets bounce off of the surface, he pointed out, they take foreign particles with them. The scientists believe that this enhanced glass could be used for touch-screen devices, including tablets and smartphones, Poeter also said.

Another possible use for the covering, Engadget's James Trew said, is as a covering for solar panels, which lose their efficiency over time due to residual build up on the surface.

Furthermore, Poeter wrote, "The team is also considering developing the glass for microscopes and cameras that are used in humid environments, as well as for televisions and even building windows," and Plafke quipped, "Personally, I´d like a shower mirror that is actually anti-fog like they always claim to be but never are."

There is one major obstacle to those applications, however: price.

"The only stumbling block is that the glass costs a lot to produce. But the researchers may have figured out a way to bring down manufacturing costs," PCMag said. "Park and Choi told MIT News that 'in the future glass or transparent polymer films might be manufactured with such surface features simply by passing them through a pair of textured rollers while still partially molten,' adding a minimal extra cost to the overall cost of making regular glass."


Image Caption: Through a process involving thin layers of material deposited on a surface and then selectively etched away, the MIT team produced a surface covered with tiny cones, each five times taller than their width. This pattern prevents reflections, while at the same time repelling water from the surface. Image: Hyungryul Choi and Kyoo-Chul Park