As summer ends and winter arrives, people from Maine to Alaska begin to activate their radiators, furnaces, or electric heaters in preparation for the intense cold. Many households in the United States and around the world still rely on fire and gas-based equipment to control heat, and when the power goes out due to snowstorms or poor connectivity, many people have to resort to wearing layers of clothing and enduring the cold.
However, the solution to our temperature problems may finally be here! Researchers at the University of Texas at Austin have found a way to potentially rid our homes of loud radiators and other energy-guzzling heating devices. The solution lies with promising nanocrystal technology. University of Texas at Austin Professor Delia Milliron first published a paper on the topic of nanocrystals in 2013, and her research produced encouraging results suggesting the potential use of nanocrystals to regulate heat in confined spaces. Her technology has been dubbed “smart windows.”
Professor Milliron received her bachelor’s degree in Chemistry and Materials Science and Engineering from Princeton University in 1999 and her Ph.D. in Physical Chemistry from UC Berkeley in 2004. She worked at the IBM T. J. Watson Research Center for four years and then worked at Lawrence Berkeley National Laboratory until 2014.
The concept of “smart glass” or “smart windows” has been around for decades but had not previously been used due to the high cost of producing the glass. However, Professor Milliron and her team have recently developed a more economically viable method to make the glass more accessible to the public. The technology works by embedding a solution of electrically conductive nanocrystals into a glassy material, which is then cut into small squares to resemble the windows we have in our homes and offices. Then, the nanocrystal-embedded glass is subjected to various voltages. Different values of voltage across the glass result in a different response from the “smart window.” When the voltage is set to a certain value, the nanocrystals become charged and can block infrared rays of light from passing through the window. Infrared light transmits heat, so in effect, the charged window is preventing heat from outside the home from entering. When the voltage is reduced, the nanocrystals become discharged, and allow the infrared light to pass through, potentially in larger amounts than currently permitted with regular glass windows. This setting would heat up the inside of your home, thus harnessing the power of the sun to keep you warm and toasty during the winter, and cool during the summer.
“Smart windows” also serve a dual purpose. In addition to blocking or transmitting heat, the windows can block or transmit visible light. Have you ever tried to watch TV, but realized that it is too bright outside to see the screen? Running a certain current through the windows can block or allow different frequencies, or all frequencies, of visible light. So, if you wanted your room to be lit in all green, you could just apply a certain voltage across the window, and lo and behold, your room would be awash in green light.
The potential of this technology is limitless. Instead of having separate AC and heating units taking up space and power in your home, you could have these devices all combined into a couple of panes of “smart glass.” Energy use would be a lot more efficient; you could regulate, with precision, the amount of heat or light in a certain room. Unlike current heating and cooling units, which require a continuous source of electricity, a voltage can be applied for a short period of time across the window to charge the crystals. After that, the electricity source can be turned off, and the windows will still block out whatever frequency of light you desire. Especially in climates with extreme high and low temperatures, energy conservation would be enormous. Large businesses especially will be able to save millions of dollars on climate control, and people will be able to afford insulation systems for their homes while maintaining a low electricity bill. This will also reduce the load on the electrical grid, which is vital in the face of a growing population.
In 2015, Professor Milliron and her team determined that the “smart window” is now ready for commercial use. Professor Milliron’s startup, Heliotrope Technologies, has begun to experiment with the most efficient way to manufacture the individual panes of Smart Glass. The company has already developed a method to give the glass a blue color, which is more pleasing to the eye and can be adapted for other uses with ease. Expect to see “smart windows” coming to a store near you sometime in 2017.