“People who are skiing or hiking in colder weather usually wear layers so they can adjust how much heat their clothing is trapping as their body heats up. But by strategically placing patches of a material that can let out heat when a person is sweating, one could imagine making a one-piece-fits-all textile,” said researcher Po-Chun Hsu.
Physics, not electronics
The scientists turned to physics, not electronics, to open those vents. They used a combination of nylon that reacts to moisture with a layer of heat-trapping silver. When the bottom layer of nylon gets wet, it wants to expand like a sheet being pulled by the sides. But because it’s attached to the silver on top, it can’t stretch in those directions. This results in the material curling up, allowing the nylon to expand while forcing the silver to shrink.
It expands the thermal comfort zone by 30%
The researchers tested a patch of this material about the size of a hand with vents a few millimetres long. Compared to your typical polyester and spandex, the material is about 16% warmer when dry with the flaps closed and 14% cooler when humid with the flaps open. This means that the new material expands the thermal comfort zone by 30%. Plus, this approach is much more practical compared to something like armpit zippers that are commonly used nowadays.
“We want the sweating parts of the body to be vented, which is not necessarily the underarms. Our chest and back need more venting but the effort to unzip these areas, if zippers are even available, is almost the same as simply taking off the clothing,” said Po-Chun Hsu.
Further research is now focused on making the vents as small as possible and adding a top nanocomposite layer that could make the material any colour while keeping its thermal attributes.
“I expect that if we can find the right laser cutting method to create very small flaps and attach the patch to clothing, we can create this effect without looking like we’re wearing a costume. With enough work, this kind of material could look very similar to what we’re wearing today,” said Po-Chun Hsu.
This kind of technology would be amazing for cold weather rides when you have to keep putting layers on and off. Will you give this new material a try when it comes to market?