Researchers have engineered a new fabric from synthetic yarn with a carbon nanotube coating that is activated by temperature and humidity, releasing heat in warm humid conditions and trapping heat when conditions are cool and dry.
The base yarn for this new textile is created with fibers made of two different synthetic materials -- one absorbs water and the other repels it. The strands are coated with carbon nanotubes, a special class of lightweight, carbon-based, conductive metal. Because materials in the fibers both resist and absorb water, the fibers warp when exposed to humidity such as that surrounding a sweating body. That distortion brings the strands of yarn closer together, which does two things. First, it opens the pores in the fabric. This has a small cooling effect because it allows heat to escape. Second, and most importantly, it modifies the electromagnetic coupling between the carbon nanotubes in the coating.
Image Credit: Faye Levine, University of Maryland