Developed Bulletproof Fabric Stronger And Thinner Than Kevlar

Kevlar has finally found a competitor. For decades it remained the gold standard in impact protection – from body armor to ar d vehicles – and is still widely used today. But now a new composite material has been developed that is stronger, stiffer and better at stopping bullets while being much thinner.

To withstand high-velocity impacts such as gunfire, the material must have resistance to breaking under load (high strength) and the ability to absorb large amounts of energy without breaking or losing protective properties (high toughness). Existing solutions, such as Kevlar made from aramid fibers, are limited by a very significant drawback. The stronger they try to make the threads, the fragile they turn out.

It is impossible to achieve high performance in both parameters. This is a classic compromise in materials science when trying to improve the overall performance of a material.

Steps to creating superfiber

The search for a solution took six years. The result is a combination of two materials: heterocyclic aramid (a high-strength fiber similar to Kevlar) and processed long carbon nanotubes (tl-SWNTs) – unusually stiff and light, with a thickness much less than a human hair.

The breakthrough, however, was not so much the correct combination of threads, but the way they were oriented. The developers ensured that the aramid fibers and carbon nanotubes were straight and parallel to each other. This is achieved by increasing the flexibility of the base aramid fiber followed by a multi-step stretching process to perfectly align the polymer chains and nanotubes.

This orientation is critical because it locks the components so tightly that they do not slide against each other upon impact. Thus, the material is able to absorb energy without breaking down.

Advantages over Kevlar

The new material was subjected to high-speed testing, including ballistic tests similar to body armor. The results can be found on the pages of the journal Matter.

The new product demonstrated dynamic strength significantly superior to existing fibers, and its energy absorption capacity than doubled the previous record, reaching 706.1 MJ m⁻³. When manufactured into fabric, this new superfiber showed superior anti-ballistic performance compared to current protective materials.

“Our study not only presents an effective strategy for creating aramid fibers with ultra-high dynamic strength and record toughness, but also offers new mechanistic insights,” the authors summarized in their paper.

In the long term, if this fiber finds application, it could make future defenses significantly lighter, thinner and safer.