Scientists have created a self-heating fabric that can protect against even the harshest cold.

New smart fabric converts light into heat. It can increase temperature by more than 30 °With just 10 minutes of sun exposure, reports Live Science.

The new material can be used in clothing designed for very low temperatures.

Specialized nanoparticles absorb sunlight and convert it into heat. They are embedded in the new fabric. At the same time, heat-sensitive dyes incorporated into the fibers change color reversibly. This allows visual monitoring of temperature fluctuations.

Maintaining body temperature

For years, scientists have been developing fabrics that help maintain a comfortable body temperature in cold conditions. Such fabrics could be used in mine rescue equipment and even in clothes for pets. But existing designs typically rely on expensive components—metal nanomaterials or bulky, battery-powered heating elements.

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To get around these problems, chemical engineer Yuning Li and his team at the University of Waterloo in Canada turned to photothermal polymers, which are plastic-like materials that convert light into heat.

Nanoparticles of two polymers, polyaniline and polydopamine, are embedded in a matrix of thermoplastic polyurethane fibers. This material is widely used to make waterproof and sportswear. Yuning Li's team added various temperature-sensitive (thermochromic) dyes to the mixture. The result was a series of fibers that changed color as the material's temperature increased.

Using these fibers, the developers knitted a tiny pullover for a teddy bear to test the properties of the smart material. The red sweater reached an impressive +53,5 ºC after just 10 minutes in the sun. As the temperature increased, the molecules of the red dye changed their chemical structure and turned white.

"The embedded nanoparticles absorb sunlight very efficiently across a range of wavelengths," Li explained. "When sunlight hits these nanoparticles, they absorb energy and release it as heat through a process called photothermal conversion."

According to the study, the smart fabric has a soft and elastic texture. It allows the material to stretch five times its original size and maintain its color-changing and temperature-changing properties even after 25 washes.

"We prioritized durability. The fabric will be able to withstand repeated use and environmental impacts while maintaining its innovative properties," Lee noted.

His team is working to prepare the material for commercial production, with further testing needed before it can be widely distributed.

"The next steps of this research are aimed at reducing production costs, scaling up the manufacturing process and ensuring the safety of the fibers during long-term skin contact," concluded chemical engineer Yuning Li.