This new ultra light textile with high insulation is inspired by polar bears

Scientists at Zhejiang University in China have created a revolutionary fiber that could transform the textile industry. The team, led by associate professor Gao Weiwei and professor Bai Hao, looked to nature to draw inspiration from to overcome the limitations of aerogel. And what better animal to draw inspiration from to overcome the limitations of the world’s lightest solid material known for its thermal insulation than the polar bear? Traditional aerogel, although used extensively in the aerospace industry, has found little use in other areas, partly due to its fragility and difficult processing.

Besides the lack of strength and stretchability needed to weave or knit them into practical textiles, current aerogel fibers are not machine washable and quickly lose their thermal insulation capability in wet or humid environments. Many animals have, however, evolved to have specialized furs that keep them warm and dry from living in extremely cold environments for years. The research team designed an encapsulated (EAF) with a core-shell structure, akin to polar bear hair, which significantly enhances its performance and durability.

Unlocking nature’s secrets for advanced fibers. Polar bears have hair with a unique core-shell structure that served as the blueprint for the researchers’ innovation. The porous core enclosed within a dense shell provides exceptional thermal insulation while maintaining strength and flexibility, characteristics essential to keep the fur warm and dry in extremely cold environments.

Mimicking this structure, the team developed a strong polymeric aerogel fiber with lamellar pores and encased it within a thin, stretchable rubber layer. This allows the EAF to be bent and twisted, overcoming the brittleness associated with traditional silica aerogel. “Despite its high internal porosity of over 90 percent, our fiber is stretchable up to 1,000 per cent strain, significantly outperforming traditional aerogel fibers, which stand about 2 per cent strain,” said Professor Bai, speaking to .

From sweaters to spacesuits. The practical applications of the EAF are wide-ranging. The researchers demonstrated the feasibility of using EAF by weaving a jumper with thermal insulation comparable to a traditional down jacket but only one-fifth as thick.

In an experiment conducted in a -20 degree celsius environment, the EAF material showcased its superior insulation capabilities, outperforming down, wool, and cotton in maintaining surface temperatures. Moreover, the EAF fiber is washable and dyeable, making it suitable for everyday use in textiles. This presents a significant advancement over traditional silica aerogel, which loses its thermal insulation properties in wet or humid environments.

The researchers emphasized that EAF retains its properties even after 10,000 stretching cycles, indicating its potential for multifunctional use beyond thermal textiles. While there is immense potential for use in civilian applications, Professor Zhang Xuetong of the Suzhou Institute of Nano-tech and Nano-bionics highlighted challenges in mass production. “Challenges exist regarding how to develop fast spinning technology and resolve the continuous fabrication that is necessary for mass production,” he said, noting its potential use “in areas such as military uniforms and space suits in extremely cold environments.

” The findings of the team were published in the journal . Aerogels have been considered as an ideal material for thermal insulation. Unfortunately, their application in textiles is greatly limited by their fragility and poor processability.

We overcame these issues by encapsulating the aerogel fiber with a stretchable layer, mimicking the core-shell structure of polar bear hair. Despite its high internal porosity over 90%, our fiber is stretchable up to 1000% strain, which is greatly improved compared with that of traditional aerogel fibers (~2% strain). In addition to its washability and dyeability, our fiber is mechanically robust, retaining its stable thermal insulation property after 10,000 stretching cycles (100% strain).

A sweater knitted with our fiber was only one-fifth as thick as down, with similar performance. Our strategy for this fiber provides rich possibilities for developing multifunctional aerogel fibers and textiles. .