Fabric that regulates heat

Washington, Feb. 10: Scientists created a fabric that can automatically regulate the amount of heat that passes through it, helping a person stay cool or warm depending on the weather conditions.

When conditions are warm and moist, such as those near a sweating body, the fabric allows heat to pass through. When conditions become cooler and drier, the fabric reduces the heat that escapes, researchers said.

This is first textile shown to be able to regulate heat exchange with the environment, according to the study published in the journal Science. Under hot, humid conditions, the strands of yarn compact and activate the coating, which changes the way the fabric interacts with infrared radiation. They refer to the action as “gating” of infrared radiation, which acts as a tunable blind to transmit or block heat.

The base yarn for this new textile is created with fibres made of two different synthetic materials. The strands are coated with carbon nanotubes, a special class of lightweight, carbonbased, conductive metal. Since materials in the fibres both resist and absorb water, the fibres warp when exposed to humidity such as that surrounding a sweating body. That distortion brings the strands of yarn closer together, which opens the pores in the fabric. This has a small cooling effect because it allows heat to escape.