Researchers at RMIT University’s Micro Nano Research Facility in Australia have developed a new, ultra-thin, self-modifying coating that responds to heat and cold to create smart windows. Working with colleagues at the University of Adelaide and supported by the Australian Research Council, the team said the breakthrough will help meet future energy needs and create temperature-responsive buildings.
“We are making it possible to manufacture smart windows that block heat during summer and retain heat inside when the weather cools,” lead investigator Associate Professor Madhu Bhaskaran said. “We lose most of our energy in buildings through windows. This makes maintaining buildings at a certain temperature a very wasteful and unavoidable process. Our technology will potentially cut the rising costs of air-conditioning and heating, as well as dramatically reduce the carbon footprint of buildings of all sizes. Solutions to our energy crisis do not come only from using renewables; smarter technology that eliminates energy waste is absolutely vital.”
New York’s Empire State Building reported energy savings of $2.4 million and cut carbon emissions by 4,000 metric tons after installing smart glass windows. This was using a less effective form of technology.
The self-regulating coating – a thousand times thinner than a human hair – is created using a material called vanadium dioxide. At 67 degrees Celsius, (152 degrees F) vanadium dioxide transforms from being an insulator into a metal, allowing the coating to turn into an optoelectronic material controlled by and sensitive to light. The coating stays transparent and clear to the human eye but goes opaque to infrared solar radiation, which humans cannot see and is what causes sun-induced heating.
The technology can also be used to control non-harmful radiation that can penetrate plastics and fabrics. This could be applied to medical imaging and security scans.