Carbon nanotubes could be a Kevlar killer

A firm named Nanocomp Technologies is being funded by the Pentagon to develop lightweight vehicle and body armor. CNN reports:

In April, Lashmore had a mechanical multicaliber gun shoot bullets at different versions of his sheet, each less than a fifth of an inch thick, at a speed of 1,400 feet per second. Four sheets were breached, but three showed no damage. Lashmore and his 35 employees were ecstatic.

“We didn’t expect it to work at all,” he admits.

According to Nanocomp’s website.

our spun conductive yarns exhibit breaking strengths up to 3 GPa expressed or in other terms: 1.5 Nt/Tex or 450,000 psi and with fracture toughness that is higher than aramids (such as Kevlar® or Twaron®). Our CNT sheets have breaking strengths, without binders, that range from 500 MPa to 1.2 GPa depending upon tube orientation. Aluminum breaks at 500 MPa, carbon steel breaks around 1 GPa.

Extremely Lightweight – Less than half the weight of aluminum

Not being an engineer or physicist, I really don’t know what to make of their claims. Feel free to chime if you understand this stuff.

Many thanks to Mark for emailing me the link.

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • Clodboy

    Diamonds, though just a crystal lattice of carbon atoms, are the hardest known naturally occuring substance; carbon nanotubes promise to combine this kind of hardness with the tensile strength and conductivity of steel, and the high flexibility and low weight of plastics.

    The neat thing is that just like with diamonds, carbon atoms will readily assemble into these tubular structures given the right conditions – the problem is that to utilize their full potential, the tubes have to be of parallel orientation and sufficient length (i.e. milimeter-sized, which may not seem like much until you consider their diameter is around 1 nanometer, i.e. a millionth of its length), which requires considerable finetuning of the method.

    But given the advances made in nanotube production in the last few years, there is little doubt that they will find widespread acceptance in the decades to come.

  • Vitor

    If carbon nanotubes deliver their potential, it will cause a turmoil in the armies around the world, since any caliber that is not a .30 with a tugsten sabot would be very innefective against such body armor.

  • Mu

    While carbon nanotubes itself are very strong, materials made from them have been rather disappointing. The values reported of this material are still half what you can get for high strength conventional carbon fiber, Toray T1000 reports 6.4 GPa. The one thing they might have going for them is better impact tolerance, since it’s a yarn it might have more “give” than the rather brittle carbon fibers.
    As for the rifle round stopping material, that will have a LONG way to go. You still need the impact plate to dull the tip or it will cut through any fabric like butter. The fiber is only good if you get to load it in tension by spreading the load.

  • Mr.Tolliver

    I wouldn’t say carbon nanotubes (CN’s) would kill Kevlar. I’m guessing here, since I have yet to see a patent about this, that those sheets are made up of fibers heavily reinforced with milli/micrometer CN fibers. We have yet to see continuous CNs making up bulk matter. Still even just by throwing in CNs in the processing of normal fibers would still increase their tensile strength, toughness, and etc. Its nice to see at least a greater introduction of CNs in the marketplace.

  • jdun1911

    Aren’t they replacing Kevlar with polyethylene fiber? Kevlar isn’t the best soft body armor to use in hot or rainy weather.

  • R.A.W.

    Carbon nanotubes (fullerenes) do indeed have extremely high theoretical strength, but making them long enough has heretofore been a problem, as has getting them to stay in any sort of composite matrix (they’re rather slippery). They’re also pricey to produce in any significant bulk, and they’ve shown some worrying incompatibility with living cells.

    On the other hand, they have some very interesting electrical properties and are of course very small. I suspect that they will become common in electronics before they become common in structural components.

    But we shall see; perhaps nanocomp is on to something.

  • Michael

    CNTs have tremendous possibility for armor applications, pretty much anywhere that kevlar is now utilized. But, as R.A.W has pointed out, volume production of CNTs remains a problem, but it has been advancing quite rapidly. The cost of such an item is primarily dependent on the tolerances, wether it requires CNTs of consistent thickness and of what individual length. I have been out of the nano-research field for a couple years now, but I find it interesting that in the article Antoinette says that in 4 years he’ll be producing it at $10 for 35 grams (or $.30/gram). Wikipedia says that in 2007 the price for SWCNTs was $100/gram. So, he has a significant way to go still, if he hopes to make that price. I would assume that his price is a simple extrapolation of the improvements in process over the past 5 years– i.e. assuming that we can repeat that progress. Four years is a long time in business, but not always in science. That timeline is long enough that I seriously doubt that he honestly knows how to make them that cheap. But the performance claims are real.

  • Clodboy

    jdun: AFAIK, the US Armed Forces and various law enforcement agencies have been trying to phase out Kevlar in favor of Zylon, although that too seems to be falling out of favor now that it has been discovered to degrade fairly quickly over time.

    So yes, High Modulus Polyethylene (“Dyneema”) is probably the way to go for the time being.

    • very interesting guys.

  • Mu

    To give you an idea on today’s pricing, I just ordered a kg of “low grade” MWNT for $3.5k. This is still a factor of 10 above the guy’s target price. Unless he’s not really using nanotubes but nanofibers, those can be had for 1k/kg. But those are hard to get untangled at reasonable length.