The fabrics may serve as the sunscreen, and also enable the shell temperature of human bodies lower around 5°C. It is excellently wearable and compatible with the overall textile industry, suitable for the large-scale promotion, preparation and industrialized application. Related achievements were released on the American magazine Science.

In recent years, in order to help people cope with outdoor extreme climate conditions, the thermal management fabrics of the human body based on the radiation refrigeration technology has been widely studied, which is to adjust the heat of human bodies through clothing, so as to improve comfort and achieve the effect of "self-cooling".

Previously, the team of Professor Tao Guangming cooperated with other scientific research and industrial units, and developed an optical metamaterial fabrics of morphology hierarchy, which may realize passive cooling and make the temperature of the cooled object 2 - 10°C lower than the surrounding environment.

Based on the radiation refrigeration principle and the design idea of morphology hierarchy, the research team designed and manufactured a kind of metamaterial fabrics, conducted hierarchy in different spaces and different dimensions according to the spatial structure of fabrics, fiber structure and inner nanostructure of fiber, and formed a macroscopically orderly and microscopically random morphology hierarchy system. According to the structural design, it may divide the optical spectrum from the solar radiation band to the intermediate infrared band into three sections, and deliver it to responses of different levels in the metamaterial fabrics. And finally, it may realize the accurate adjustment of broadband spectrum of ultraviolet, visible - near-infrared and middle-infrared band, thus effectively avoiding the spectrum crosstalk of different bands and optimizing the spectral response efficiency.

Research shows that compared with commercial fabrics, such as cotton, spandex, chiffon and fiber with the same color and the same thickness, metamaterial fabrics may obviously "realize self-cooling".

"When such material is made into clothing and worn on the body, it is just like putting a mirror on the back, with a plug-in air conditioning", said Tao Guangming, "mirror" does not mean that the clothing directly reflects the sunshine like the mirror surface; instead, through specific configuration and design of metamaterial fabrics, it is just like creating a nano maze. After sunshine shines in, it keeps being reflected and turned off, and finally reflected, so as to realize the light reflex with the maximum limit, and block the input of heat.

"Air conditioning" does not mean to install the refrigeration equipment into the clothing; instead, it is to make use of the absolute minimum temperature cold source with the universe background, and strengthen the heat exchange between the human body and the external cool space through the transparent window of the atmosphere(8-13μm), so as to maximize the radiation loss of the human body, and achieve the effect of cooling.

Source: Functional Textiles