Scientists develop first fabric to automatically cool or insulate depending on conditions

February 7, 2019, University of Maryland
This new fabric being developed by University of Maryland scientists YuHuang Wang and Ouyang Min is the first textile to automatically change properties to trap or release heat depending on conditions. Credit: Faye Levine, University of Maryland

Despite decades of innovation in fabrics with high-tech thermal properties that keep marathon runners cool or alpine hikers warm, there has never been a material that changes its insulating properties in response to the environment. Until now.

University of Maryland researchers have created a that can automatically regulate the amount of heat that passes through it. When conditions are warm and moist, such as those near a sweating body, the fabric allows (heat) to pass through. When conditions become cooler and drier, the fabric reduces the heat that escapes. The development was reported in the February 8, 2019 issue of the journal Science.

The researchers created the fabric from specially engineered yarn coated with a conductive metal. Under hot, , the strands of yarn compact and activate the coating, which changes the way the fabric interacts with infrared . They refer to the action as "gating" of infrared radiation, which acts as a tunable blind to transmit or block heat.

"This is the first technology that allows us to dynamically gate infrared radiation," said YuHuang Wang, a professor of chemistry and biochemistry at UMD and one of the paper's corresponding authors who directed the studies.

The base yarn for this new textile is created with fibers made of two different synthetic materials—one absorbs water and the other repels it. The strands are coated with carbon nanotubes, a special class of lightweight, carbon-based, conductive metal. Because materials in the fibers both resist and absorb water, the fibers warp when exposed to humidity such as that surrounding a sweating body. That distortion brings the strands of yarn closer together, which does two things. First, it opens the pores in the fabric. This has a small cooling effect because it allows heat to escape. Second, and most importantly, it modifies the electromagnetic coupling between the carbon nanotubes in the coating.

University of Maryland Chemistry and Biochemistry Professor YuHuang Wang (left) and Physics Professor Min Ouyang hold a swatch of their new fabric that can automatically adjust its insulating properties to warm or cool a human body. Credit: Faye Levine, University of Maryland
"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 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."

Depending on the tuning, the fabric either blocks infrared radiation or allows it to pass through. The reaction is almost instant, so before people realize they're getting hot, the garment could already be cooling them down. On the flip side, as a body cools down, the dynamic gating mechanism works in reverse to trap in heat.

"The human body is a perfect radiator. It gives off heat quickly," said Min Ouyang, a professor of physics at UMD and the paper's other corresponding author. "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."

According to the Science paper, this is first textile shown to be able to regulate exchange with the environment.

Response of an IR-gating textile revealing the meta-fibers in action. Credit: M. Li, S. Deng, Y.H. Wang, University of Maryland
"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."

More work is needed before the fabric can be commercialized, but according to the researchers, materials used for the base fiber are readily available and the carbon coating can be easily added during standard dying process.

"I think it's very exciting to be able to apply this gating phenomenon to the development of a textile that has the ability to improve the functionality of clothing and other fabrics," Ouyang said.

Explore further: Clothing fabric keeps you cool in the heat

More information: X.A. Zhang el al., "Dynamic gating of infrared radiation in a textile," Science (2019). science.sciencemag.org/cgi/doi … 1126/science.aau1217

Related Stories

Clothing fabric keeps you cool in the heat

November 16, 2017

(Phys.org)—Researchers have designed a thermal regulation textile that has a 55% greater cooling effect than cotton, which translates to cooler skin temperatures when wearing clothes made of the new fabric. The material ...

Materials chemists tap body heat to power 'smart garments'

January 22, 2019

Many wearable biosensors, data transmitters and similar tech advances for personalized health monitoring have now been "creatively miniaturized," says materials chemist Trisha Andrew at the University of Massachusetts Amherst, ...

A bullet-proof heating pad

October 31, 2018

Sometimes nothing feels better on stiff, aching joints than a little heat. But many heating pads and wraps are rigid and provide uneven warmth, especially when the person is moving around. Researchers have now made a wearable ...

Recommended for you

Light-based production of drug-discovery molecules

February 18, 2019

Photoelectrochemical (PEC) cells are widely studied for the conversion of solar energy into chemical fuels. They use photocathodes and photoanodes to "split" water into hydrogen and oxygen respectively. PEC cells can work ...

Solid-state catalysis: Fluctuations clear the way

February 18, 2019

The use of efficient catalytic agents is what makes many technical procedures feasible in the first place. Indeed, synthesis of more than 80 percent of the products generated in the chemical industry requires the input of ...

Sound waves let quantum systems 'talk' to one another

February 18, 2019

Researchers at the University of Chicago and Argonne National Laboratory have invented an innovative way for different types of quantum technology to "talk" to each other using sound. The study, published Feb. 11 in Nature ...

3 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

Osiris1
3 / 5 (2) Feb 07, 2019
Ultimate birth control and infection control....use it to make condoms. They won't break, they won't bake if you get in too 'hot' a place, and if you put a lab on a chip design into them using flexible electronics, they could detect STD's and cool you oofff really quick, kill virii and allow one a quick pull out of situations.
johnhew
4 / 5 (4) Feb 07, 2019
But you need safety glasses to wear this stuff
EnricM
not rated yet Feb 11, 2019
Heck, I need this NOW! I hate having to carry extra clothes during a long run when the weather is variable.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.