This could be a game-changer for both marathon runners and Alpine adventurers: Scientists have developed a fabric that changes its insulating properties in response to the environment.

Researchers from the University of Maryland (UMD) have created a material 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 infrared radiation (heat) to pass through. When conditions become cooler and drier, the fabric reduces the heat that escapes.

The research is described in the Feb. 8, 2019 issue of the journal Science.

The fabric was created from specially engineered yarn that expand or contract in response to heat and humidity. Under hot and humid conditions, when the yarn is hot or wet, it collapses into a tight bundle, effectively opening gaps in the cloth to expel heat.

The opposite effect occurs in cool conditions, when the textile is cold or dry: the fibers expand, reducing gaps to prevent heat from escaping.

This acts as a heat regulating-switch, which automatically turns on or off depending on your level of thermal discomfort, said YuHuang Wang, a UMD professor of chemistry and biochemistry and one of the paper’s corresponding authors.

 

The yarn that makes up this auto-regulating fabric can be woven, washed, and dyed much like other performance fabrics.

 

Many fabrics already trap infrared radiation to keep us warm, but can’t vary by how much they do so. The same goes for moisture-wicking fabrics that are often used by people when they exercise to help regulate their temperature. The UMD team’s fabric can vary the amount of infrared radiated by 35 per cent as the humidity of the underlying skin changes.

The new fabric is also said to work almost instantly, so that even before someone realizes they are getting hot, their garment immediately starts cooling them down.

The yarn that makes up this auto-regulating fabric can be woven, washed, and dyed much like other performance fabrics.

“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.”

Scientists have knitted the fabric into a piece of material almost five square feet in size. It is set to be tested by a clothing company and could be available in two years. Materials used for the base fiber are readily available and the carbon coating can be easily added during standard dyeing process, according to the researchers.