First Fabric to Automatically Regulate Temperature

In a study published in Science, researchers at the University of Maryland (UMD) have developed fabric that changes its insulating properties in response to the environment.

The material created regulates the amount of heat automatically as it passes through. "This is the first technology that allows us to dynamically gate infrared radiation," explains YuHuang Wang, a professor of chemistry and biochemistry and the study’s corresponding author. If conditions are warm and moist, the fabric allows infrared radiation (heat) to pass through. If conditions become cooler and drier, fabric reduces escaping heat.

"The human body is a perfect radiator. It gives off heat quickly," says Min Ouyang, professor of physics at UMD. "For all of history, the only way to regulate the radiator has been to take clothes off or put clothes on. But this fabric is a true bidirectional regulator."

The fabric was created from engineered yarn that is coated with conductive metal. Under hot conditions, strands of yarn compact and activate the coating changing the way the fabric interacts with infrared radiation—making it a tunable blind that transmits or blocks heat.

"You can think of this coupling effect like the bending of a radio antenna to change the wavelength or frequency it resonates with," Wang said. "It's a very simplified way to think of it, but imagine bringing two antennae to close together to regulate the kind of electromagnetic wave they pick up. When the fibers are brought closer together, the radiation they interact with changes. In clothing, that means the fabric interacts with the heat radiating from the human body."

This was the first study to show a textile’s capability of regulating heat exchange with the environment.

"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. "Textiles were known that increase porosity in response to sweat or increasing temperature, as well as textiles that transmit the infrared radiation associated with body temperatures. However, no one before had found a way to switch both the porosity and infrared transparency of a textile so as to provide increased comfort in response to environmental conditions."