Mark Megahan
Wouldn’t it be great to have a heat regulator built right into your clothing? You would be amazed how many of our modern devices are based on ideas of classic science fiction. Andre Norton predicted the idea with astonishing accuracy back before 1958, when her timeless classic “The Time Traders” was published. Wearable air conditioning will hit the market sooner, rather than later. The new “wearable variable-emittance device,” or WeaVE, researchers say, “could be used to make next-generation smart thermal management fabrics.”
Heat resistant clothing
In the classic tale, the protagonist gets hold of “a skin-tight suit made of an iridescent dark-blue fabric that covers all but his head and his hands.” He liberated it from the life boat of an alien ship, crash landed on Earth. It saves his life when the rightful owners start trying to hunt him down. In arctic temperatures, he was toasty and warm.
Later, when he had to escape by walking through a fire, he didn’t even notice the heat. Anyone who works outside in places like Phoenix, Arizona, where temperatures have been well over 110 for the past month, could really use one of those.
The University of Chicago, North Carolina State University and Duke University all teamed together to come up with a “thermoregulating textile” which can move heat either in or out. It “keeps its wearers comfortable with a minimal amount of energy input thanks to a conductive polymer that can be modified to adjust how much infrared radiation it sheds.”
With these smart thermal management fabrics you can be perfectly comfortable anywhere you happen to be, from the ski slope to the desert and everywhere in between. One of those button batteries can power the logic circuits needed for you to select what feels best for you.
The idea is based on nature. Many animals “are good at manipulating infrared radiation to heat themselves up and cool themselves down.” Like Saharan silver ants. They dissipate excess energy “thanks to triangular hairs on their bodies that reflect differing amounts of near-IR rays depending on the position of the Sun.”
Humans happen to be tuned to be especially sensitive to “IR radiation with a wavelength of 10 microns.” On our own, “our skin is not capable of controlling this wavelength range in real time to help us regulate body temperature.”
Flip the switch between states
The only thing that takes any power at all is the switch to flip between states. As a “device” WeaVE requires three components. An “active layer made of a conducting polymer called polyaniline; metallized nylon; and a semi-solid electrolyte.”
When a tiny voltage is applied “the active material switches between a transmissive dielectric state and a lossy metallic state” to move or block heat. In other words “by switching between them, the amount of thermal radiation the fabric puts out can be adjusted to make it either heat-emitting (cooling) or heat-shielding (heating).”
“The textile can thus keep the wearer comfortable by adjusting how much body heat is retained and how much is radiated away,” explains Chicago’s Po-Chun Hsu, who led the development team together with Jie Yin of NC State. Just like in the book “the user would feel the same skin temperature regardless of the external temperature.” The best thing about it is the tiny amount of power needed compared with traditional methods of heating and cooling.
This type of thermoregulation, the experts say, is “adaptive.” That means “that it relies on modulating the material’s heat-transfer coefficient, and it uses far less energy than ‘active‘ technologies” As a result, “the energy required” to maintain comfort “is virtually zero.”
The thing which makes it most like Andre Norton’s detailed prediction is the fabric itself. She must have had her crystal ball tuned in good that day. “A further advantage is that the metallized nylon in the fabric is cut in a kirigami-style pattern, which allows it to stretch and move with the user’s body while fully preserving the connections and configuration of the electrochemical cell.”
Just put it on and ignore heat or cold no matter how extreme. Then hope nobody builds in the tracking device which lets the Galactic Police home in on it.
