Your glasses can change from transparent to translucent and back, so why can’t your windows? Smart glass has been around a while, but it’s very expensive, hence why it’s only been used in super-expensive cars, like the Ferrari 575M Superamerica; the electrochromic roof had five levels of tint owners could cycle through with the addition or removal of electric charge.
While most smart glass blocks ultraviolet light (the visible kind that leads to sunburns), it still lets in heat-producing near-infrared rays. University of Texas at Austin professor Delia Milliron and her team at the McKetta Department of Chemical Engineering have developed a material that can control both. The electrochromic materials can block 90 percent of near-infrared rays and 80 percent of the sun’s visible light. It can transition from “dark mode,” blocking both types of light (the equivalent of closing your blinds), to “cool mode,” blocking only near-infrared heat, in two minutes. And if you want a normal window, you can let in both types of light. The team has a proof-of-concept of a “warm” mode that lets in heat but blocks light, so you could block the sun’s glare but keep the warmth on winter days.
Milliron has launched a startup called Heliotrope Technologies to start making a commercial product. The process involves two solutions, which they’ll deposit on glass films. They apply one layer by depositing the solution and spinning it around at high speed to dry it; they then heat it up to 400 degrees Celsius, then spin the other layer on and heat it again. It’s a quicker and less-energy-intensive system than traditional manufacturing, according to MIT Technology Review.
“We believe our new architected nanocomposite could be seen as a model material, establishing the ideal design for a dual-band electrochromic material,” Milliron said in a statement. “This material could be ideal for application as a smart electrochromic window for buildings.” Heliotrope hopes to have a commercial product by 2017.