New sweater inspired by polar bear fur provides a thinner, warmer alternative to down jackets

Polar bears
(Image credit: Johnny Johnson / Getty Images)

Could super-warm, super-thin  fake polar bear sweaters be all the rage on the slopes in a few years? Welcome to the dawn of 'faux'-lar bear knitwear.

Scientists at Zhejiang University in China have created a sweater knitted from a new synthetic fiber that mimics polar bear fur, and which is thinner but warmer than traditional down jackets. They published their findings yesterday in the journal Science.

The fiber – technically an ultralight aerogel coated with polyurethane – is washable, durable and can protect wearers from the cold at a fraction of the thickness needed for conventional sweaters or down jackets.

The scientists were inspired by the pelts of animals that live in extreme cold environments, such as the Arctic and the Antarctic. A polar bear’s fur, for example, is made of a porous core enclosed within a dense shell structure, providing outstanding thermal insulation while maintaining strength and flexibility.

The research team at Zhejiang University recreated the core-shell structure of polar bear fur, creating a strong polymeric aerogel fiber called EAF with pores within a thin, stretchable rubber layer made from thermoplastic polyurethane, which is often used in sports clothing and equipment.

The resulting fiber was not only super-warm, but also flexible enough that it could be used for knitting or weaving. It can also be washed and dyed. 

They then knitted a jumper that was a fifth as thick as the average down jacket, but provided pretty much the same degree of insulation (actually, in a controlled test, the polar bear-inspired jumper was a teeny tiny bit warmer).

But don’t go ordering your faux-lar bear knitwear off Amazon just yet. The scientists warn that manufacturing the fiber currently takes far too long to make it commercially viable at the moment. But it’s something they’re working on.