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No-Fog Glass

September 22, 2005

Fogged-up eyeglasses and windshields can be nuisances. Science reporter Bob Hirshon reports on an innovation that could rid us of these annoyances for good.


Glass that doesn’t fog. I’m Bob Hirshon and this is Science Update.

Fog appears on windshields and eyeglasses when warm water vapor condenses into tiny water droplets on the cool glass. The droplets act like prisms, scattering light as it passes through the glass and making it hard to see.

Now materials scientist Michael Rubner of MIT and his colleagues have discovered a way to make glass that doesn’t fog—using nanotechnology. They layer a glass surface with invisible glass nanoparticles. Water that condenses on this surface gets wicked into the tiny spaces between the particles.

When these tiny drops of water hit it, they immediately spread across the surface, and they create a film of water across the surface that is nice and transparent.

Rubner says the anti-fog glass is also anti-reflective, which would make it useful for greenhouses and solar-cell panels.

I’m Bob Hirshon, for AAAS, the science society.