Cheaper smart windows invented at UBC

March 19, 2018

University of British Columbia chemistry researchers have developed a simple, cost-effective technique for making smart windows that could lead the way for wide-scale adoption of this energy-saving technology.
Smart windows conserve building energy by switching from clear to tinted, controlling heat and light from the sun.
“Conventional windows waste a third of all energy used to heat, ventilate and air condition buildings,” said Curtis Berlinguette, a professor of chemistry, chemical and biological engineering and the Stewart Blusson Quantum Matter Institute at UBC. “Smart window technologies offer the opportunity to reduce these energy losses but the main challenge is finding ways to make these windows less expensive.”
Wei Cheng, who led this project as part of his postdoctoral work at UBC, found a new way to make glass materials that change colour in response to electricity. Cheng’s method deposits a liquid solution containing a metal ion onto glass and then uses ultraviolet light to transform it into a film that coats the glass. The film is completely transparent but becomes blue when electricity passes through, ultimately creating the active component of a smart window.
Smart windows currently cost about $500 to $1,000-per-square-metre to make, much higher than the $30 to $200-per-square-metre cost of a conventional glass window. This new method means that windows can be manufactured without high temperatures or the sophisticated vacuum equipment currently used to make such devices—thereby reducing the cost.
 “A commercial window needs to last many years, and we need to prove our windows can do the same,” said Cheng, who also noted they were experimenting with more neutral tints so the windows would go grey instead of blue.