The fabric is made of specially engineered yarn coated with a conductive metal. Under hot, humid conditions, the strands of yarn become compact and change the way the fabric interacts with infrared radiation.
“This is the first technology that allows us to dynamically gate infrared radiation,” said the paper’s corresponding author Wang Yuhuang, a professor of chemistry and biochemistry at the University of Maryland.
Fibers are created with two kinds of synthetic materials: one absorbs water and the other repels it. Those fibers will warp when exposed to humidity, bringing the yarn strands closer and opening the pores in the fabric.
Then, the yarn distortion allows heat to escape and changes properties of the carbon nanotubes coating the strands to block infrared radiation. The reaction is almost instant, so before people realize they’re getting hot, the garment could already be cooling them down, according to the study.
On the other side, as a body cools down, the dynamic gating mechanism works in reverse to trap in heat. “This pioneering work provides an exciting new switchable characteristic for comfort-adjusting clothing,” said Ray Baughman, a professor of chemistry at the University of Texas who was not involved in the study.