Insulating fabric inspired by a camel’s hump could protect firefighters from extreme heat as well as allow their sweat to pass through it.
There are a wide variety of heat-resistant fabrics used for firefighter’s uniforms, but they almost all trap moisture within the fabric, leaving firefighters to get soaked in sweat as they labour in the heat.
at Soochow University in China and his colleagues have developed an insulating fabric that uses pockets of aerogel, in which the liquid component of a gel is replaced with gas. It is sandwiched between two layers of heat resistant plastic polymer. This is said to mimic the fat stores in a camel’s hump.
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The aerogel pockets are produced using ultrasonic welding, where sound is used to melt the two layers of plastic together at various points. This process also creates micropores in the fabric that can wick away moisture. “We created many pore structures, like the camel’s sweat glands, that can guide liquid from inside to outside, helping you when you get sweaty,” says Fang.
When the researchers exposed the fabric to temperatures of about 80°C (176°F) for about 20 minutes, they found that a thermostatic plate covered by it stayed around 20°C cooler than one covered by conventional firefighter uniform fabric. And when it was exposed to a 1000°C flame for 10 seconds, the camel-hump fabric also suffered far less burning and damage.
The material also trapped around 13 per cent less moisture than the next-best firefighter uniform plastic.
The parts used are cheap, such as the silica-based aerogel, and the ultrasonic welding process is straightforward and widely used, says Fang, so the material should be easy to produce on a larger scale.
While using aerogel embedded in fabric is an interesting idea, the material would need to undergo standardised tests common to EU and US safety standards, such as using a thermal mannequin at higher heat levels, before it could be used in real-world scenarios, says at the University of Bolton, UK.
“This biomimicking 3D fabric is interesting,” he says, “but how it performs under more commonly used thermal test methods would be useful and how it relates to current moisture and heat transfer research and practice also needs to be considered.”
Advanced Functional Materials
