Polar bears have a thick pelt that keeps them warm in the arctic environment even when temperatures average -40°F during the winter months. Scientists at China’s Zhejiang University College of Chemical and Biological Engineering studied the microstructure and thermal insulation qualities of the polar bear’s coat and have developed a fiber that mimics it. The hair of these arctic animals consists of a sponge-like network of hollows at the core that seals in air. When air is static, heat convection cannot take place, reducing the loss of heat and making it a super insulator.
The research team developed a freeze-spinning technique to continuously fabricate a silk fibroin solution into a fiber with an aligned porous microstructure. The biomimetic fibers can be woven into a textile that has remarkable thermal insulation, is breathable and wearable, and offers a promising material for personal thermal management.
In addition to passively insulating heat loss, the textile could be a wearable heater when doped with electro-heating materials such as carbon nanotubes. The treatment would promote a fast thermal response and uniform heating while maintaining a soft and porous quality for comfort.
Ultimately, the research team plans to develop additional materials with properties inspired by nature, and has developed a portable blanket that can be heated to more than 50°F in seconds. For more information,
visit www.zju.edu.cn.