Polar bears could inspire the next generation of winterwear, according to a new study. An experimental sweater made from polar bear fur-inspired fibers was found to have exceptional thermal insulation – despite being five times thinner than a traditional puffer jacket.
Chinese scientists – inspired by the structure of polar bear fur – created a knittable aerogel fiber with amazing thermal and mechanical properties. They say the fibers are washable, dyeable, durable, and well-suited to be used in advanced textiles.
“Aerogels are an ideal material for thermal insulation. They demonstrate high porosity and extremely low thermal conductivity,” said Mingrui Wu, a master’s student at Zhejiang University.
However, the research team explained that the application of aerogels in insulating fibers for textiles has been limited because of their fragility and poor processability. Not only do they lack the strength and stretchability needed to weave or knit them into practical textiles, but current aerogel fibers are not machine washable and quickly lose their thermal insulation capability in wet or humid environments.
But many animals that live in extremely cold environments have evolved specialized furs that keep them warm and dry. For example, polar bear hair is comprised of a porous core enclosed within a dense shell structure. As a result, the hairs provide outstanding thermal insulation while maintaining strength and flexibility.
Mimicking the core-shell structure of polar bear hair, the Chinese researchers used a freeze-spinning approach to create a strong polymeric aerogel fiber. They then encapsulated it with a thin, stretchable rubber layer.
Wu said the resulting encapsulated aerogel fiber (EAF) achieves excellent thermal insulation performance while also being mechanically robust, making it suitable for knitting or weaving. Despite the fiber’s high internal porosity, the Chinese study – published in the journal Science – showed that the fiber is stretchable up to 1,000 percent strain – a significant improvement compared to traditional aerogel fibers, which only achieve around two percent strain.
“The fiber maintained its thermal insulation properties with minimal impact even after 10,000 repeated stretching cycles at 100 percent strain,” said Wu.
The researchers also showed that the EAF is both washable and dyeable. As a proof-of-concept, the Chinese team wove a thin sweater made from the fibers, which, despite being roughly just a fifth as thick as a down jacket, provided comparable insulating performance.
Produced in association with SWNS Talker
