New fabric lowers human body temperature through passive cooling
One of the challenges that humans will face in the midst of the warming caused by climate change is the survival of the species during increasing warming; The expected increase in temperatures will result in more deadly heat waves or make some areas of the world uninhabitable. Chinese scientists have developed to tackle the extreme heat a new material that can help keep the human body much cooler, through the fabric of this material, which reflects light and heat to an amazing extent, this field is known as the birth of technology of thermal autonomy.
In a new study, researchers note that their pioneering fabric known as "metaveric" will enable the wearer to overcome severe heat exhaustion.
"We found Metaveric to be highly efficient in radiative cooling performance, in addition to providing the necessary air permeability and comfort," explains Shauning Zheng, director of the research team who wrote the paper at Huazhong University of Science and Technology.
Metaveric consists of a mixture of polytetrafluoroethylene, a mixture of polytetrafluoroethylene, with titanium dioxide nanoparticles coated with a thin film of polytetrafluoroethylene, and is specially designed to reflect a great deal of light, including visible light and even wavelengths in the mid-infrared and ultraviolet spectrum.
In theory, with so much light being reflected across those different wavelengths, heat must be reflected away before it can be absorbed.
“Such a large distribution of nanoparticles when mixed with polytetrafluoroethylene nanoparticles leads to a broad spectrum of scattering and reflection across the three bands mentioned above,” the researchers said. These are ultraviolet, visible and infrared rays.
The researchers conducted experiments with metapheric under clear skies in Guangzhou, China, to test the coolness of metapheric under sunlight, and measured the temperature of the fabric compared to other common materials.
The researchers explain: “Under the peak solar irradiation between 11 am and 3 pm, the temperature of the metapheric was colder by 5.0°, 6.8°, 7.0°, 5.8° and even 10.2°C than cotton, spandex, chiffon, linen and simulation systems human skin, respectively.
In another more realistic test, the volunteer lay in a special jacket in direct sunlight for an hour; The jacket was half made of metapheric and the other half of commercial cotton.
An outdoor thermal camera measured a temperature difference of 3.4 degrees Celsius between the sides of the jacket, while thermal sensors underneath the fabric showed that the difference under the leading fabric was more pronounced, with the fabric being cooler than the cotton-covered part, about 4.8 degrees Celsius lower.
In another experiment, in which the Metaveric covered a car, the temperature inside the car dropped to about 30 degrees Celsius compared to the temperature of the open car, and to 27 degrees Celsius lower than the temperature of the car covered with a commercial car cover.
Metaveric promises to cool people and things alike, but its reflexive efficacy when worn by people in motion is still being investigated. As the experiences were of fixed people and things.
It is not yet known how the material will interact with dyes and colors, it may affect the material's ability to reflect light, but perhaps future research can explain what will happen to the fabric when dyeing.
On the positive side, the researchers point out that metaveric is susceptible to common weaving methods, as well as having mechanical properties similar to commercial fabrics such as endurance and water resistance, and can also be incorporated into various products and for various purposes; Such as fabrics, tents, car covers, curtains and awnings through various garment manufacturing processes including sewing, embroidery and cutting.
The authors note that: “Price estimation of the productivity of metapheric is cheap; Perhaps the increase will amount to only 10% of the costs of the usual textile industry.”
The researchers hope to join manufacturing partners; Metaveric products will be available within a year at the most.
"The results demonstrate huge potential for commercial applications in several complex scenarios such as smart textiles, sunshades and logistics," the researchers said.