In an era when both environmental comfort and sustainability are key concerns in architecture, the tendency to cover buildings entirely in glass is among the most criticized and controversial traits of contemporary architecture, as all-glass buildings often guzzle energy thanks to their demanding cooling and heating requirements. Over the years, a number of fixes for this problem have been attempted, including smart glass solutions that allow users to modify the transparency of the window. The problem with this solution, however, is that smart glass is unable to block infrared (heat) transmission without ruining the very thing that makes glass attractive in the first place: its transparency to visible light.
That conundrum may soon be a thing of the past, though. As reported by Phys.org, a team of researchers at the Cockrell School of Engineering at The University of Texas at Austin have developed a new smart window technology that allows users to selectively control the transmission of light and heat to suit their requirements.
Led by chemical engineering professor Delia Milliron, the team from the Cockrell School of Engineering have created a new nanocomposite material which changes its properties with the application of a very small voltage - just as with regular smartglass. However, by using doped titania nanocrystals, their material can block near-infrared and visible light independently with small changes in the voltage applied.
This development means that windows could be transparent to visible light while blocking up to 90% of infrared rays, keeping buildings cool on hot sunny days, or transparent to both to encourage solar heating on a cooler day. The material even has what the research team call a "warm" mode, which allows solar heating while reducing visible light transmission - useful, they say, for blocking the glare reflected off of snow without eliminating the solar gain required on a cold winter's day. Furthermore, these changes can be enacted in just a few minutes.
"These two advancements show that sophisticated dynamic control of sunlight is possible," explained Milliron to Phys.org. "We believe our deliberately crafted nanocrystal-based materials could meet the performance and cost targets needed to progress toward commercialization of smart windows."