A group of researchers, led by Delia Milliron, a professor of chemical engineering at the University of Texas, have developed a new and innovative way to save energy resources. They have produced a new kind of electrochromic window glass which is able to change color when an electrical charge is applied. The glass blocks near-infrared light from the sun which produces heat in addition to blocking excessive visible light.

“Smart glass” is a concept which has existed in application for several decades. The term refers to glass which changes color to block visible sunlight. The cost of production has rendered the technology fairly obsolete, only appearing in expensive niche projects such as the new Boeing jetliner.

Delia’s team has developed a way to make smart glass which not only blocks visible light, but can also selectively block the heat producing components of sunlight. She believes they have developed a prototype that works well enough that Heliotrope Technologies, a startup Milliron helped to co-found, will be able to begin a commercialized manufacturing process which will be cheaper and have a higher yield than current smart glass production processes.  

The glass is composed of a framework of nanocrystals made of electrically conductive material in a glassy base material. The nanocrystals and the glass in which they are embedded have different but distinct electrical properties which change when an electrical charge is applied. The two materials work in tandem to control the passage of light. The nanocrystals can block 90% of near-infrared, heat producing light while the glassy material can transition between transparency and a neutral blue opacity which blocks 80% of visible light.

In “cool” mode, the electrochromic glass can be applied to help buildings save energy during the summer, and vehicles can use less fuel to support environmental controls. The glass is able to switch between modes in minutes—much faster than any commercially available smart glass. Buildings which applied Milliron’s glass would potentially save thousands of dollars a year on air conditioning.

It’s not hard to imagine the benefits of having glass that keeps you cooler on command. When can we expect to have access to this color changing technology? Jason Holt, president of Heliotrope Technologies, expects to bring their first products to market in 2017.