A team of University of Colorado engineers has developed a metamaterial that has the ability to cool objects even under direct sunlight with zero energy and water consumption.
Officials on the Boulder campus say the metamaterial — an engineered material with properties not found in nature — can be used as an air conditioning system, and supplementary cooling material for thermoelectric plants, according to a news release.
The material, which is slightly thicker than aluminum foil, cools objects beneath it by reflecting sunlight back into space while also allowing the object to shed its own heat through a process called passive radiative cooling.
To make the material, researchers embedded visibly-scattering but infrared-radiant glass microspheres into a polymer film and then added a thin, silver coating underneath in order to achieve maximum spectral reflectance.
It can be manufactured in rolls, which makes it economical.
"We feel that this low-cost manufacturing process will be transformative for real-world applications of this radiative cooling technology," said CU professor Xiaobo Yin, who is co-director of research on the project.
Researchers say that the material can also be used to improve the efficiency and life span of solar panels. Panels can overheat in direct sunlight, which hampers their ability to convert solar rays into electricity.
Yin — along with Gang Tan, an associate professor in the University of Wyoming, and Ronggui Yang, a professor of mechanical engineering at CU — received a $3 million grant in 2015 to conduct their research. They are currently seeking a patent on their invention.