DailyTech - Researchers Looking to Carbon Nanotubes for New Body Armor

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Science Researchers Looking to Carbon Nanotubes for New Body Armor
Wolfgang Hansson (Blog) - November 6, 2007 4:19 PM

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70 comment(s) - last by feraltoad.. on Nov 12 at 3:51 AM

Carbon Nanotube Deflecting Projectile (Source: University of Sydney)

Researchers are studying carbon nanotubes for more effective replacement to Kevlar

Carbon nanotubes are one of the more promising materials conceived in the field of nanotechnology. These carbon nanotubes are the focus of many researchers from around the world for a wide variety of tasks and uses.

DailyTech has previously covered the use of carbon nanotube embedded paper used as a battery, carbon nanotube based thermal interface material for computer use and the use of carbon nanotubes in super capacitors.

Two researchers, Kausala Mylvaganam and L C Zhang, from the University of Sydney in Australia have released a study of carbon nanotubes for their ballistic resistance capacity (PDF). The researchers are looking at carbon nanotube sheets as an alternative to fibers like Kevlar.

The trait that makes carbon nanotubes so interesting for use in bulletproof vests is that the carbon nanotubes have excellent resistance to repeated ballistic impacts. In theory, that would mean that soldiers and police officers wouldn’t need to replace body armor after taking hits and multiple hits in prolonged firefights would be more survivable than with current generation body armor.

Unlike Kevlar fibers that deform and loose effectiveness after struck, the carbon nanotube vest can withstand repeated impacts to the same spot without allowing the bullet to penetrate. The researchers say that body armor 600nm in thickness constructed form six sheets of the 100nm thick carbon nanotube yarns could bounce off a bullet with muzzle energy of 320 J.

That would be enough strength to stop low powered bullets fired from some handguns, but high velocity bullets fired from assault rifles carry much more muzzle energy than the current carbon nanotube fibers can withstand.

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Knife vs Bullet

By Jjoshua2 on 11/6/2007 4:38:55 PM , Rating: 2

How could kevlar or carbon nanotubes stop a bullet and not stop a knife?

RE: Knife vs Bullet

By KristopherKubicki

(blog) on 11/6/2007 4:42:53 PM , Rating: 3

The sharp blade will actually separate the layers of CNTs, where as a bullet is blunt.

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RE: Knife vs Bullet

By Jjoshua2 on 11/6/2007 4:46:49 PM , Rating: 2

so if someone comes up with a needle-nose or some type of sharp pointed bullet, it will go right through kevlar and CNT?
BTW, I haven't ever figured out how to rate someone up or down.

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RE: Knife vs Bullet

By Aiserou on 11/6/2007 4:55:07 PM , Rating: 3

That's the jist behind the term "Armor Piercing Round". The sharp end of the projectile usually has to be hardened considerably to withstand the impact though.

As for the rating, you have to have a certain number of post, and I'm not sure, but I think a certain number of them have to be rated positively. Someone feel free to correct me on that though.

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RE: Knife vs Bullet

By ZimZum on 11/6/2007 6:08:04 PM , Rating: 6

"The slow blade penetrates the Shield"

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RE: Knife vs Bullet

By drakanious on 11/6/2007 8:30:47 PM , Rating: 2

Nice Dune reference.

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RE: Knife vs Bullet

By Calin on 11/7/2007 2:49:09 AM , Rating: 2

Also, the blunt nose will create a more devastating wound than a sharp nosed bullet would.
There is an mostly inverse proportion between "stopping power" (let's say biological damage) and penetration power for rounds having the same energy. While most pistol bullets concentrate on stopping power (final tissue damage and temporary deformations in tissue=pain), others concentrate on having bullets actually able to hurt someone behind a car's door.

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RE: Knife vs Bullet

By Visual on 11/7/2007 4:24:12 AM , Rating: 2

you can only give ratings in threads that you have not commented in.
i don't think your number of posts or their ratings are a factor at all.

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RE: Knife vs Bullet

By imaheadcase on 11/7/2007 3:18:57 AM , Rating: 2

quote:
so if someone comes up with a needle-nose or some type of sharp pointed bullet, it will go right through kevlar and CNT?

Its already been invented, its called a "arrow". :D

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RE: Knife vs Bullet

By gradoman on 11/6/2007 4:43:25 PM , Rating: 2

That would be because all of the energy is focused on a such a small point.

Chainmail under vest, ftw.

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RE: Knife vs Bullet

By bodar on 11/6/2007 4:59:35 PM , Rating: 2

Chain mail will not stop a stab, it is only effective against slashing. It, like ballistic vests, were never able to protect against stabbing attacks. I have seen armor-grade steel chain stabbed through with a crappy Renn Faire sword. It was worn by a melon at the time, for a demonstration on medieval armor and weapons. Although I suppose it's possible the kevlar may slow the knife down enough to work.

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RE: Knife vs Bullet

By bodar on 11/6/2007 5:06:33 PM , Rating: 2

Also, I guess if the rings were welded, not butted, and were Titanium, not steel, you'd have a really good chance at least.

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RE: Knife vs Bullet

By KristopherKubicki

(blog) on 11/7/2007 12:38:18 AM , Rating: 3

Its been a while since I took a materials class, but I seem to recall Titanium being extremely difficult to weld.

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RE: Knife vs Bullet

By theapparition on 11/7/2007 9:36:59 AM , Rating: 2

You would be correct, it has to be done in an inert atmosphere, and requires specialized equipment.

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RE: Knife vs Bullet

By Martimus on 11/7/2007 9:33:25 AM , Rating: 2

Why would titanium work better than steel? Armor grade steel is harder than titanium, it is just heavier. As Kristopher said, titanium is nearly impossible to weld, although you could friction stir weld it easily enough. A bullet doesn't have much force behind it, it is just really small and travels at a very high rate of speed. A bayonet has a whole lot more force behind it.

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RE: Knife vs Bullet

By Captain Orgazmo on 11/6/2007 7:19:57 PM , Rating: 2

Some vests (typically for urban security guards or cops) have a titanium wire mesh/screen built in as a knife resistant layer. Also armour with plates/scales like Dragonskin are very good against knife attacks.

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RE: Knife vs Bullet

By Locke013 on 11/6/2007 4:55:02 PM , Rating: 5

It has a lot to do with the power behind the strike. A bullet has a lot of initial impact energy, but no follow up energy. Once a bullet's initial energy is absorbed, its gone. A Knife strike has the whole arm and muscle system behind it. Once a knife's initial energy is spent there is a whole lot of extra energy coming from the push of the person's muscles on the knife. Kevlar and vests designed to be bullet proof simply cannot withstand that extra force from a knife.

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RE: Knife vs Bullet

By feraltoad on 11/6/2007 7:14:58 PM , Rating: 3

Just to add more detail for fun: a bullet also deforms losing some of that energy like a crumple zone in a car, exspansion in tissue results in massive damage but in a vest helps slow it down since it is spreading energy across a larger area as well. A knife doesn't deform.

Interesting how it is against Geneva Convention to use hollow points (dumdum bullets) that cause severe tissue damage and death (I guess it would be the difference in "My arm, its been hit!" versus "My arm, its been f*cking blown off!", but it is the full metal jacketed bullets that are more effective in penatrating body armor. I have seen News agencies call them "cop killers", as if other bullets were designed to stun.

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RE: Knife vs Bullet

By rcc on 11/7/2007 5:28:08 PM , Rating: 2

quote:
but it is the full metal jacketed bullets that are more effective in penatrating body armor. I have seen News agencies call them "cop killers", as if other bullets were designed to stun.

Don't confuse the classic FMJ with an armor piercing round. Totally different animals. Your standard full metal jacket is a copper sheath on a lead bullet. It prevents leading in the barrel of guns (typically over 900fps), other than that, it has minimal impact on the expansion of the bullet.

An armor piecing, or cop killer, round (watch Lethal Weapon much?) is either teflon coated, or made with a steel or tungsten core.

Actually, hollow points and dum dums are different animals as well. A hollow point is just that, and it facilitates expansion of the the bullet on impact. A "dum dum" is scored in some fashion, usually an X or +, and is designed to fragment on impact. Depending on the movies you watch, a hollow point is the one you see them filling with mercury and various other unpleasant things to compound the damage or effects of a hit.

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RE: Knife vs Bullet

By feraltoad on 11/12/2007 3:51:15 AM , Rating: 2

Oops not the Geneva Convention!!!!

It was the Hague Peace Conferences of 1899 & 1907. Sorry. :(

Plus out Military snipers use jacketed hollow points so it doesn't even seem to stand.

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RE: Knife vs Bullet

By murphyslabrat on 11/7/2007 12:21:08 AM , Rating: 2

OK, you putting 600 joules of kinetic energy behind a knife, and some handguns have a muzzle velocity closer to 800 joules.

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RE: Knife vs Bullet

By ElFenix on 11/6/2007 5:09:30 PM , Rating: 2

the same way kevlar will stop a bullet yet you can cut it with a pair of kindergarten safety scissors.

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RE: Knife vs Bullet

By scrapsma54 on 11/6/2007 5:54:15 PM , Rating: 3

There are pockets for titanium plates behind the armor so knife penetration is not that bad unless the knife wielder knows where the plate seams are located. However the attacker would have to be a skilled blade user to even accomplish such. And combat training teaches us how to counter knife attacks.

As for sharp ended bullets thats what armor piercing rounds are. They are massive bullets that most Chain guns and sniper rifles carry. They are massive and their tips are designed to withstand High heat (air friction) and travel faster than the speed of sound for long range capacity so the bullet can maintain its point. This will slice through body armor and penetrate the titanium plates in an instant.

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RE: Knife vs Bullet

By Redfoot on 11/6/2007 8:38:02 PM , Rating: 4

Pretty much any modern rifle round is supersonic, including the mighty .22 long rifle. A proper projectile will not deform from "air friction". As far as the shape of the bullet producing the penetrating effects, that is largely incorrect, as I would challenge you to find me a .556 or 7.62 round in common use that has an open hollowpoint.

The construction of the outer and inner cores and materials used differentiate marksman rounds vs. standard ammunition. Titanium, ceramic, and metal matrix plates will stop most rounds, including sniper, to 7.62X51 NATO to 7.62X54 (think Dragunov). Start getting into .338 Lapua and some of the new .400 rounds, and we have an issue.

Chain Guns are generally 20mm or larger, and found on vehicles. They better be able to penetrate body armor, or your contractor sucks.

I would seriously like to see your "counter knife technique".

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RE: Knife vs Bullet

By Calin on 11/7/2007 3:34:08 AM , Rating: 2

At larger than 20 mm, one can use shells (exploding) instead of bullets. While the fragments might not be able to penetrate kevlar armor, they can hit anywhere not protected - limbs, face...
By the way, the AK-47 round has a muzzle velocity of 715 m/s (more than twice the speed of sound)

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RE: Knife vs Bullet

By masher2

(blog) on 11/7/2007 4:35:54 AM , Rating: 2

quote:
"As far as the shape of the bullet producing the penetrating effects, that is largely incorrect, as I would challenge you to find me a .556 or 7.62 round in common use that has an open hollowpoint."

You won't often find a 5.56 or 7.62 hollowpoint because those are standard military rounds, and hollowpoint rounds are banned in warfare by the Hague convention.

That said, the shape of a bullet *does* have some effect on its penetration power. A small effect, but some. A hollow-point round's lesser penetration is governed more by expansion than its open tip, and an armor-piercing round's penetration influenced more by hardening than the sharp point...but the shape is still a factor.

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RE: Knife vs Bullet

By Misty Dingos on 11/7/2007 7:52:06 AM , Rating: 2

I use a 5.56 69 grain open hollow point bullet. They come from some fly by night outfit called Sierra. You might have heard of them. I use them because they are ballisticly a near ideal round for my rifle. I think you are being somewhat disingenuous to argue that open point bullets are not commonly available in what are nominally rifle calibers.

And to further muddy the waters. There is legal ammunition for snipers to use in war that are open points. It was the subject of great consternation in the US Army. And a supply NCO and contratot should be in prison because of it. Not because they ordered it but because they stopped the shippment.

http://www.military.com/opinion/0,15202,87045,00.h...

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RE: Knife vs Bullet

By scrapsma54 on 11/7/2007 9:02:49 AM , Rating: 2

Please excuse that extra word "us". I just saw that.

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RE: Knife vs Bullet

By FNG on 11/6/2007 11:02:06 PM , Rating: 2

I thought kevlar melted slightly around a hot projectile? Thus teflon coated bullets slide right through because the kevlar can't adhere.

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RE: Knife vs Bullet

By Redfoot on 11/6/2007 11:12:04 PM , Rating: 3

I have not seen any burns from rifle or pistol projectiles on the body armor of my patients. IED's are another thing.

Teflon coated bullets are a myth. You can google "Fail Safe" or "Black Talon". While not teflon coated, they were treated with a menacing looking black lubricant coat that offered mildly improved ballistics in the form of supposedly reducing the friction between barrel and bullet.

However, you are onto something. There was a body armor manufacturer that had an issue using composites in the fact that the material became superheated on impact, causing burns to the victim in addition to the nasty impact from the projectile. The name escapes me, but it was a real threat.

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But...

By gradoman on 11/6/2007 4:26:35 PM , Rating: 2

How well does it do against stabbing weapons, eh?

RE: But...

By GhandiInstinct on 11/6/07, Rating: -1

RE: But...

By KristopherKubicki

(blog) on 11/6/2007 4:35:02 PM , Rating: 4

Actually, this is a real concern in England. Kevlar does not stop knives.

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RE: But...

By Lord 666 on 11/6/07, Rating: 0

RE: But...

By BitJunkie on 11/6/07, Rating: 0

RE: But...

By feraltoad on 11/6/2007 7:19:51 PM , Rating: 5

Actually, now that I have achieved my main life goal of procreating with my sibling I have a lot of free time to focus on technology breakthroughs in a van down by the river.

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RE: But...

By daftrok on 11/6/2007 4:57:30 PM , Rating: 2

Chainmail is most effective.

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RE: But...

By WilsuN on 11/6/2007 4:59:59 PM , Rating: 3

chainmail is too heavy, right? (I don't know, not really into armors...)

Bullet dodging skills for the win.

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RE: But...

By joemoedee on 11/6/2007 5:37:45 PM , Rating: 2

quote:
Bullet dodging skills for the win.

Unfortunately whereas Staples has the Easy Button, no one has yet to create the "Bullet Time" button...

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RE: But...

By HaZaRd2K6 on 11/6/2007 7:24:28 PM , Rating: 2

I'm sure Max Payne had one of those...

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RE: But...

By daftrok on 11/6/2007 9:37:41 PM , Rating: 5

Yeah, he calls it Meth.

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All That Carbon

By drank12quartsstrohsbeer on 11/6/2007 4:37:49 PM , Rating: 2

So now we are going to exploit carbon for armor. What happens when the world runs out of carbon? Has anyone thought about what this will do to poor mother earth?

All that greed.... it's Bush's fault!

RE: All That Carbon

By KristopherKubicki

(blog) on 11/6/2007 4:43:26 PM , Rating: 2

Soylent Carbon :)

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RE: All That Carbon

By Master Kenobi

(blog) on 11/6/07, Rating: -1

RE: All That Carbon

By BladeVenom on 11/6/2007 4:47:52 PM , Rating: 3

Hydrogen is the most abundant element in the universe.

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RE: All That Carbon

By maverick85wd on 11/6/2007 4:49:44 PM , Rating: 2

I thought that was Hydrogen

with Magnesium being the most abundant in mass

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RE: All That Carbon

By Hase0 on 11/7/2007 2:40:06 PM , Rating: 1

You do know what a joke is right?

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RE: All That Carbon

By AvidDailyTechie on 11/6/2007 7:05:20 PM , Rating: 3

quote:
What happens when the world runs out of carbon?

this either wins the award for most absurd comment of the year or is a bad joke

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RE: All That Carbon

By Ringold on 11/6/2007 7:09:14 PM , Rating: 2

I know you're kidding.. but at least you have an idea why whenever an environmentalist says "That's not sustainable", I shake my head.

Breathing is not sustainable.

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RE: All That Carbon

By Scrogneugneu on 11/6/2007 9:56:19 PM , Rating: 2

It is because of trees.

It's not if we cut them all down. Hence, they're unhappy when we cut them down.

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RE: All That Carbon

By murphyslabrat on 11/7/2007 12:48:20 AM , Rating: 4

Actually, approximately 70% of the oxygen reclamation cycle is performed by algaes and other colony/single-celled organisms. Trees have a relatively small role.

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What's the latest on Carbon Nanotube toxicity?

By NicePants42 on 11/6/2007 4:37:43 PM , Rating: 2

From some of the (admittedly older) reports I've read, I'm under the impression that more studies are needed to determine the toxicity of carbon nanotubes to human tissues. Seems like strapping on a carbon nanotube vest and getting shot up would be a good way to get yourself exposed to a (un)healthy dose - but I'll be the first to admit that I'm not up to speed in this area.

RE: What's the latest on Carbon Nanotube toxicity?

By Jjoshua2 on 11/6/2007 4:41:05 PM , Rating: 2

I think if I'm getting shot (and hit!) I might have other things to think about than if carbon is going to possibly give me cancer twenty years later.

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RE: What's the latest on Carbon Nanotube toxicity?

By Aiserou on 11/6/2007 4:49:55 PM , Rating: 2

While true, you spend a lot of time wearing a vest while not being shot at. Especially if your in the military and get stuck on guard duty for a month at a time (speaking from experience).

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RE: What's the latest on Carbon Nanotube toxicity?

By Jjoshua2 on 11/6/2007 4:53:29 PM , Rating: 2

Valid point, but I figured you would be wearing camo or a shirt at least underneath it, so it would not have much skin contact. I thought the only possible hazard was if it got under your skin, but I don't know much about carbon toxicity. Glad you served the country!

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RE: What's the latest on Carbon Nanotube toxicity?

By ElFenix on 11/6/2007 5:07:41 PM , Rating: 2

hmmm... hot lead poisoning or carbon nanotubes? i'm really at an impasse here.

and why would someone necessarily be exposed to the nanotubes? the whole point is that they don't break when fired upon (well, ok, they're probably much lighter than kevlar as well). if the tube-fibers don't break, how does one get exposed?

there was an article in the houston chronicle the other day about using carbon nanotubes to treat cancer. the nanotubes are injected into cancer cells. then the patient is exposed to radio waves, the nanotubes heat up, destroying the cancer cell but leaving neighboring cells unharmed. the remnants of the cell and the nanotubes then pass from the body. given that the study is correct, i don't see any danger from nanotube body armor.

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RE: What's the latest on Carbon Nanotube toxicity?

By RogueSpear on 11/6/2007 7:01:25 PM , Rating: 2

quote:
hmmm... hot lead poisoning or carbon nanotubes? i'm really at an impasse here.

It's usually someone who doesn't have to have to wear body armor or worry about getting shot that makes such snide remarks. Believe it or not some people are worried about occupational hazards that may not manifest into a problem until you're thinking about retiring. Read a little about motorcycle patrols and radar guns to see what I'm talking about.

And just how would you know if none of the tubes break from the impact of a high velocity round? While scientific knowledge about carbon nanotubes is probably pretty extensive, I still think that there is quite a bit left to be discovered.

Anyway as someone who does wear a vest for work, beyond the concerns of toxicity I'm curious if there would be any increased benefits regarding comfort - flexibility, threat level rating to weight ratio, and the ability of the material to breathe. Hot, humid, and in the 90's is uncomfortable enough with just a cotton t-shirt and a wool/cotton/poly blend uniform shirt. Throw in a Kevlar vest and you have the perfect recipe for some serious skin irritation. Something that would allow for a bit more air circulation would be quite welcome indeed. And no, the special t-shirts that some companies sell claiming to allow for more air flow and to draw away perspiration do not work.

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RE: What's the latest on Carbon Nanotube toxicity?

By jtemplin on 11/7/2007 9:09:54 AM , Rating: 2

While nanomaterials hold the promise of being able to achieve marvelous feats of materials and medical engineering, we must concern ourselves with the latent health risks these exotic materials present. This post I wrote back in the beginning of October is pretty messy, but it has the fact you are looking for. Let me know what you think

http://www.dailytech.com/article.aspx?newsid=9130&...

Click parent if you want to see what I was specifically responding to (if you didnt know already : ) )

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hey

By meepstone on 11/6/2007 5:28:38 PM , Rating: 2

Has anyone heard of Dragonskin body armor??? It stops assault weapon bullets.

RE: hey

By PrimarchLion on 11/6/2007 5:56:01 PM , Rating: 2

And knives.

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RE: hey

By SavagePotato on 11/6/2007 6:09:51 PM , Rating: 2

And grenades.

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RE: hey

By BladeVenom on 11/6/2007 6:39:09 PM , Rating: 3

But can it stop a bear? http://www.youtube.com/watch?v=Q3CzYw5-qdA

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RE: hey

By SavagePotato on 11/6/2007 9:12:39 PM , Rating: 2

Theres a better way to stop a bear. Avoid the large furry growling thing that looks like it might eat you.

Take one of these with you when in the wilderness.

http://www.marlinfirearms.com/firearms/bigbore/444...

Just live with the sore shoulder for the next week.

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RE: hey

By Captain Orgazmo on 11/6/2007 7:38:04 PM , Rating: 3

Dragon Skin demonstration from Discovery Channel's "Future Weapons":

http://www.youtube.com/watch?v=KS0pSwdQfbY

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Had to say it....

By Gnoad on 11/6/2007 4:48:30 PM , Rating: 2

Can we say "Maximum armor"?

RE: Had to say it....

By Fenixgoon on 11/6/2007 6:08:42 PM , Rating: 2

that's exactly what I thought of too.

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This was

By BruceLeet on 11/7/2007 12:36:00 AM , Rating: 2

Crytek's idea obviously, the nanosuit :P

RE: This was

By jtemplin on 11/7/2007 9:11:33 AM , Rating: 2

When I saw the diagram of the wall of nanotubes deflecting with the bullet's impact, I was immediately reminded of the opening FMV sequence in the Crysis demo where it zooms in on the bullets striking the suit and basically deforming the suit material somewhat and totally vaporizing the bullet. : )

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Spider Goats

By Etern205 on 11/6/2007 7:51:06 PM , Rating: 2

This was actually talked about on the Science Channel
or was it the Science Channel? Oh well at least it was pretty cool

quote:
Spider-Goats
In an unlikely coupling, genetic engineers have now bred goats that have spider silk genes inside them. By doing this, they can harvest the silk proteins from the goat's milk (silky milk, anyone?). The silk gene was just one of 70,000 that make up the DNA blueprint for building a normal goat. In adult female goats, the silk gene is activated only while the animal is producing milk. One goat can produce about 7g of silk per day.

Spiders in space and surgery
Called 'biosteel', the silk is lighter, yet tougher than Kevlar, and nearly as elastic as nylon. It could be used in medical supplies, space equipment and bullet-proof vests.

So there's a new superhero in town. Swinging from skyscraper to skyscraper, fighting crime as it shoots jets of silk from its udders, it's … Spider-Goat!

http://www.bbc.co.uk/science/hottopics/superheroes...