Three engineers from the University of Massachusetts Amherst have invented a fabric that concludes the 80-year quest to make a synthetic textile inspired by polar bear fur. The results, recently published in the journal Applied materials and ACS interfacesare already being developed into commercially available products.

Polar bears live in some of the harshest conditions on the planet, ignoring arctic temperatures as low as -50 Fahrenheit. While bears have many adaptations that allow them to thrive when temperatures drop, since the 1940s scientists have focused on one in particular: their fur. How, the scientific community has wondered, does a polar bear’s fur keep them warm?

Generally, we think the way to stay warm is to insulate ourselves from the elements. But there is another way: one of the major discoveries of the last decades is that many polar animals actively use sunlight to maintain their temperature, and polar bear fur is a well-known example.

Scientists have known for decades that part of the bears’ secret is their white fur. You would think that black fur would absorb heat better, but it turns out that polar bear fur is extremely good at transmitting solar radiation to bear skin.

“But fur is only half the equation,” says the paper’s lead author, Trisha L. Andrew, associate professor of chemistry and adjunct chemical engineering at UMass Amherst. “The other half is the black skin of polar bears.”

As Andrew explains, polar bear fur is essentially a natural fiber optic, conducting sunlight to the bear’s skin, which absorbs the light, heating the bear. But fur is also exceptionally good at keeping the now-warmed-up skin from radiating all that hard-earned warmth. When the sun shines, it’s like having a thick blanket that heats up and then traps that heat close to your skin.

What Andrew and his team did was design a two-ply fabric where the top layer is made up of yarns that, like polar bear fur, conduct visible light to the bottom layer, which is made of nylon and covered with a dark material called PEDOT. PEDOT, like the skin of polar bears, heats efficiently.

So effectively, in fact, that a jacket made of such material is 30% lighter than the same cotton jacket while still keeping you comfortable in temperatures 10 degrees Celsius cooler than the cotton jacket does. could withstand, as long as the sun is shining or a room is well lit.

“Space heating consumes huge amounts of energy that comes mostly from fossil fuels,” says Wesley Viola, the paper’s lead author, who has completed his doctorate. in chemical engineering at UMass and is now at Andrew’s startup, Soliyarn, LLC.

“While our textile really shines like outerwear on sunny days, the light and heat trapping structure works efficiently enough to imagine using existing indoor lighting to directly heat the body. By concentrating energy resources on the “personal climate” around the body, this approach could be much more sustainable than the status quo.