MIT Researchers Develop Fog Resistant, Self Cleaning Glass

Posted on April 27, 2012

MIT researchers have developed a glass they say is self-cleaning and resists fogging and glare. This type of glass could be useful in optical devices, gadget screens, car windshields and more. The image above is of a piece of glass that has one half with a normal flat surface, and the other with MIT's patterned nanotextured surface. It demonstrates the anti-fogging properties that the patterning provides. MIT also released this video that shows water droplets bouncing off the surface of its new glass like rubber balls. Take a look:

The surface pattern consists of an array of nanoscale cones that are five times as tall as their base width of 200 nanometers. It is based on a new fabrication approach the MIT team developed using coating and etching techniques adapted from the semiconductor industry. Fabrication begins by coating a glass surface with several thin layers, including a photoresist layer, which is then illuminated with a grid pattern and etched away; successive etchings produce the conical shapes.

The researchers say they drew their inspiration from nature, where textured surfaces ranging from lotus leaves to desert-beetle carapaces and moth eyes have developed in ways that often fulfill multiple purposes at once. Although the arrays of pointed nanocones on the surface appear fragile when viewed microscopically, the researchers say their calculations show they should be resistant to a wide range of forces, including impact by raindrops in a strong downpour, wind-driven pollen and grit and direct poking with a finger.

The research is described here in a research paper, publishing in ACS Nano. The paper was co-authored by mechanical engineering graduate students Kyoo-Chul Park and Hyungryul Choi, former postdoc Chih-Hao Chang SM �04, PhD �08 (now at North Carolina State University), chemical engineering professor Robert Cohen, and mechanical engineering professors Gareth McKinley and George Barbastathis.

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