As the world becomes hotter and hotter due to climate change, one of the continuing challenges that mankind will face is to survive the deteriorating high temperature. It is expected that the increase in temperature will bring more and more deadly heat waves, and even make the world certain The area is uninhabitable.

In the face of such severe heat, a new material developed by Chinese scientists may help the human body stay cool, thanks to a fabric that can reflect light and heat to a significant degree.

This emerging field of technology is called Personal Thermal Management (PTM), and in a new study, researchers say that their "super fabrics" can one day help the wearer resist excessive heat stress.

The team led by the first author Zeng Shaoning of Huazhong University of Science and Technology explained in a new paper: "This super fabric exhibits efficient radiant cooling performance and provides PTM with the necessary breathability and wearing comfort."

Above: Metafabric vest (right), blue is cooler than cotton (left).

In this case, the super fabric uses titanium oxide-polylactic acid composite nanoparticles laminated with a thin layer of polytetrafluoroethylene (PTFE), which is designed to strongly reflect light, including visible light (VIS) and mid-infrared (MIR) wavelengths and ultraviolet rays (UV) range.

Theoretically, by reflecting most of these wavelengths of light, the material should also reflect heat away before it has a chance to be absorbed.

The researchers wrote in their study: "Such a wide range of nanoparticles, when combined with PTFE nanobeads, can provide broad-spectrum scattering and reflectivity across the UV-VIS-NIR [Near Infrared] band."

In order to test the cooling potential of the super fabric under the sun, the researchers tried the material under clear sky conditions in Guangzhou, China, and measured the temperature of the fabric compared with other common materials on the panel.

Generated photo of white super fabric. (Zeng et al., Science, 2021)

"Under the peak solar irradiance between 11:00 and 15:00, the temperature of the super fabric is higher than that of cotton, spandex, chiffon, linen, and bare skin simulators," the researchers explained.

In another test closer to real-world conditions, a volunteer lay in direct sunlight for an hour while wearing a special vest. Half of the vest was made of super fabric and the other side was commercial cotton fabric. .

Above: After taking off the clothes, the skin under the super fabric (right) is much cooler than the skin under the cotton fabric (left).

The temperature difference between the two sides of the vest measured by an external thermal imager was 3.4°C, but the thermal sensor under the fabric showed that the difference under the vest was even more obvious-the half of the super fabric was about 4.8°C cooler than the half covered by the cotton.

In another experiment, the super fabric was covered on a car. The internal temperature of the car was about 30°C lower than that of a car without a cover, and about 27°C lower than that of a car with a commercial vehicle cover.

Although hypertextiles do show considerable prospects for cooling people and objects, it remains to be seen how the reflectivity will affect mobile individuals wearing the fabric as clothing, as the results reported here only involve stationary subjects and objects.

It is not yet clear how this material handles dyes and colors, which may affect its ability to reflect light, but future research and experiments are expected to solve these unknown problems.

On the bright side, the researchers stated that this material is compatible with commercial sewing techniques and exhibits mechanical properties comparable to commercial fabrics, including durability and water resistance.

The researcher told Science News that the team estimated that the low production cost of super fabrics might only increase the cost of typical garment manufacturing by about 10%.

If manufacturing partners join, the researchers hope that products made from this super fabric will be on the market within a year.

"These results show the great potential of commercial applications in various complex scenarios, such as smart textiles, sunshade products, logistics and transportation," the authors wrote in their paper.

"Through embroidery, cutting and sewing, the meta fabric can be integrated into various products in different scenes, such as clothing, tents, car covers, curtains and awnings."

The results of the study were published in the journal Science.