Register for an account

X

Enter your name and email address below.

Your email address is used to log in and will not be shared or sold. Read our privacy policy.

X

Website access code

Enter your access code into the form field below.

If you are a Zinio, Nook, Kindle, Apple, or Google Play subscriber, you can enter your website access code to gain subscriber access. Your website access code is located in the upper right corner of the Table of Contents page of your digital edition.

Technology

Glass That Keeps Its Cool

Scientists at the University College London have developed “intelligent glass,” which selectively reflects the infrared on hot days.

Newsletter

Sign up for our email newsletter for the latest science news

Ordinary windows are dumb: They let in the sun’s warming infrared rays whether it is sweltering or freezing outside. So Ivan Parkin and Troy Manning at University College London have developed “intelligent glass,” which selectively reflects the infrared on hot days. Skyscrapers that incorporate this smart material could save millions of dollars a year in air-conditioning costs, the researchers estimate, while cars with smart-glass windows could remain relatively cool even in blinding sun.

The secret is a superthin coating of vanadium dioxide molecules doped with tungsten, Parkin says. At low temperatures, vanadium dioxide is transparent to infrared. At higher temperatures, the bonding between the molecules changes and the material becomes reflective, like a metal. A dose of tungsten determines where the switch occurs; a 2 percent mix makes it happen roughly at a comfortable room temperature. Parkin and Manning are talking to commercial glassmakers about applying the coating process to industrial-scale manufacturing. Another hurdle is the coating’s yellow-brown tone, unappealing to builders because it looks dirty; adding other ingredients could neutralize the color. Within five years, Parkin estimates, intelligent-glass windows could be on the market, costing perhaps 20 percent more than the ordinary kind.

    2 Free Articles Left

    Want it all? Get unlimited access when you subscribe.

    Subscribe

    Already a subscriber? Register or Log In

    Want unlimited access?

    Subscribe today and save 75%

    Subscribe

    Already a subscriber? Register or Log In