One of the main problems with protective equipment, be it for astronauts, firefighters, or soldiers, is that materials strong enough to protect against ballistic threats typically can’t protect against extreme temperatures and vice versa.
As a result, most of today's protective gear is made of multiple layers of different materials, which makes it incredibly heavy — to the point that it severely limits the wearer's mobility.
In order to tackle this problem, Harvard University researchers, in collaboration with the U.S. Army and West Point, have developed a lightweight, multifunctional nanofiber material that can protect wearers from both extreme temperatures and ballistic threats, such as bullets and shrapnel.
Kevlar and Twaron
Kevlar and Twaron are two commercially available products that are used extensively in protective gear. They can both provide either ballistic or thermal protection, depending on how they are manufactured.
Woven Kevlar's highly aligned crystalline structure, for example, means that it is used in protective bulletproof vests. Porous Kevlar aerogels, meanwhile, have been shown to be highly protective against heat.
“Our idea was to use this Kevlar polymer to combine the woven, ordered structure of fibers with the porosity of aerogels to make long, continuous fibers with porous spacing in between,” Gonzalez said in a Harvard press release. “In this system, the long fibers could resist a mechanical impact while the pores would limit heat diffusion.”
The team from Harvard, led by senior author, Kit Parker, the Tarr Family Professor of Bioengineering and Applied Physics at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and a lieutenant colonel in the United States Army Reserve, used immersion Rotary Jet-Spinning (iRJS), a technique developed by Parker’s Disease Biophysics Group, to manufacture their fibers.
Pushing the boundaries
“While there are improvements that could be made, we have pushed the boundaries of what’s possible and started moving the field towards this kind of multifunctional material,” said Gonzalez.
The ultimate goal was to design a multifunctional material that would be able to protect people working in extreme environments, such as astronauts or soldiers.
“We’ve shown that you can develop highly protective textiles for people that work in harm’s way,” said Parker. “Our challenge now is to evolve the scientific advances to innovative products for my brothers and sisters in arms.”
Harvard’s Office of Technology Development has filed a patent application for the technology and has started seeking commercialization opportunities for the nanofiber. The team's research is published in the journal Matter.