Scientists from China’s Zhejiang University and Westlake University have created a jacket out of an experimental, reversible fabric that can both heat and cool the wearer. The multi-layered “Janus textile” consists of a base of expanded polytetrafluoroethylene (ePTFE) polymer fibers. When a garment made from the material is worn with the warming side facing outwards, zinc and copper nanoparticles on that side absorb solar energy and reduce the amount of body heat that escapes. When the wearer turns the garment inside-out, a porous coating of polymethyl methacrylate (PMMA) polymer on the cooling side reflects the sunlight and helps dissipate body heat.
In tests performed under natural sunlight, the heating side increased the temperature of underlying simulated skin by a total of 14 degrees Farhenheit more than black cotton. When the fabric was turned over, the cooling side reduced the skin temperature by 11 degrees more than white cotton. The cooling side had no effect when tested at night, although the warming side proved to be warmer than black cotton by 5 degrees.
According to the scientists, the textile is easy and inexpensive to manufacture, and it offers a breathability similar to that of cotton.
A paper on the study, which is being led by Zhejiang University’s Qiang Li and Westlake University’s Min Qiu, was published in the journal Nano Letters.
Sources: American Chemical Society and newatlas.com.