Fabric Heats Up and Cools Down its Wearer

Textile engineers have developed a fabric woven out of ultra-fine nano-threads made in part of phase-change materials and other advanced substances that combine to produce a fabric that can respond to changing temperatures to heat up and cool down its wearer depending on need. The material that can store and release large amounts of heat when the material changes phase from liquid to solid. Combining the threads with electrothermal and photothermal coatings that enhance the effect, they have in essence developed a fabric that can both quickly cool the wearer down and warm them up as conditions change.

Such fabrics often make use of phase-change materials (PCMs) that can store and later release large amounts of heat when the material changes phase (or state of matter, for example, from solid to liquid). One such material is paraffin, which can in principle be incorporated into a textile material in different ways. When the temperature of the environment around the paraffin reaches its melting point, its physical state changes from solid to liquid, which involves an absorption of heat. Then heat is released when the temperature reaches paraffin’s freezing point.


The problem here has been that the manufacturing methods for phase-change micro-capsules are complex and very costly,” said Hideaki Morikawa, corresponding author of the paper and an advanced textiles engineer with the Institute for Fiber Engineering at Shinshu University. “Worse still, this option offers insufficient flexibility for any realistically wearable application.”

So the researchers turned to an option called coaxial electrospinning. Electrospinning is a method of manufacturing extremely fine fibers with diameters on the order of nanometers. When a polymer solution contained in a bulk reservoir, typically a syringe tipped with a needle, is connected to a high-voltage power source, electric charge accumulates on the surface of the liquid.

A paper describing the manufacturing technique appeared in the American Chemical Society journal ACSNano.