New sun-reflecting fabric keeps the wearer cool by up to 8 degrees

Despite its dark-colored structure, this new-generation fabric—which reflects 87.6 percent of sunlight and emits body heat—provides effective cooling in hot weather without requiring electrical energy.

The cooling challenge of dark-colored fabrics

In hot weather, light-colored clothing is generally preferred because it reflects more sunlight. Most passive cooling fabrics developed to date have been produced in white, and achieving the same cooling effect in dark shades such as purple has proven quite difficult.

The advantage provided by the microscopic structure

To overcome this problem, researchers designed the fabric with a special structure on a microscopic scale. By using a purple-colored metal-organic material and zinc oxide particles within the fibers, they ensured that a large portion of solar energy is reflected back.

Heat transfer via infrared radiation

The fabric not only reflects sunlight but is also capable of releasing the heat it absorbs from the body outward in the form of infrared radiation. Measurements have determined that the fabric's heat emission rate in the mid-infrared region is at the 96.4 percent level.

Results of experiments conducted on skin surfaces

To examine the potential effects on the human body, experiments were conducted on a skin-like surface. Artificial skin covered with the new purple fabric managed to stay up to 8 degrees cooler during daylight hours compared to exposed skin.

Promising prospects for different color options

This study has demonstrated that cooling clothing will not be limited solely to white or light colors. Researchers anticipate that the same method could be applied to fabrics in various other colors in the future.