By Donna Lu
We’re used to piling on the layers to warm ourselves up, but what about wearing clothes to cool us down? A temperature sensitive fabric adjusts to how hot, cold or sweaty the wearer is to help them reach the perfect temperature.
The textile is made from heat-sensitive yarn with fibres that expand or contract in response to heat and humidity. When the yarn is hot or wet, it collapses into a tight bundle, effectively opening gaps in the cloth to enable heat loss. The opposite effect occurs when the textile is cold or dry: the fibres expand, reducing gaps to prevent heat escaping.
This acts as a heat regulating-switch, which automatically turns on or off depending on your level of thermal discomfort, says YuHuang Wang at the University of Maryland.
One of the ways the human body absorbs and loses heat is by infrared radiation. At room temperature, around 40 per cent of heat transfer happens this way.
Most fabrics trap infrared radiation to keep us warm, but can’t vary by how much they do so. This is also true of moisture-wicking fabrics that are often used by people when they exercise to help regulate their temperature. Wang’s team’s fabric can vary the amount of infrared radiated by 35 per cent as the humidity of the underlying skin changes.
It can be knitted, dyed and washed like other sportswear fabrics. Wang hopes that in the near future his team can partner with a manufacturer to produce clothing using the fabric.
Journal reference: Science, DOI: 10.1126/science.aau1217
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