The breakthrough is the result of a new low-temperature process for coating the smart material on plastic, which makes it easier and cheaper to apply than traditional coatings that are made directly on the glass itself.
The engineers, led by Delia Milliron, an associate professor in the McKetta Department of Chemical Engineering, demonstrated how a flexible electrochromic device—that can emit a small electric charge (about 4 volts)—can lighten or darken the material and control the transmission of heat-producing, near-infrared radiation.
The research team is an international collaboration, including scientists at the European Synchrotron Radiation Facility and CNRS in France, and Ikerbasque in Spain. Researchers at UT Austin's College of Natural Sciences provided key theoretical work.
The newly developed low-temperature process results in a material with a unique nanostructure, doubling the efficiency of the coloration process when compared with a coating produced by a conventional high-temperature process.
The material permits switching between clear and tinted more quickly, while using less power.
The researchers credit the new smart window’s capabilities to their ability to engineer amorphous materials, those whose atoms lack any long-range organization—as would be found in a crystal—in order to improve their performance.
"There's relatively little insight into amorphous materials and how their properties are impacted by local structure," said Milliron. "But, we were able to characterize with enough specificity what the local arrangement of the atoms is, so that it sheds light on the differences in properties in a rational way."
According to Milliron, the advancement achieved here could inspire other work on these kinds of amorphous materials for applications like supercapacitors that store and release electrical energy quickly.
The researchers now plan to develop a flexible material using the low-temperature process that meets or exceeds the best performance of electrochromic materials made by conventional high-temperature processing.