Liquid Armor

[A.Rahman]

Liquid Armor

Flexible full-body protection that could save our troops' lives and limbs is at the top of the list for many researchers and technology companies. One such product could soon make its way to Iraq. As this ScienCentral News video explains, the secret ingredient is a liquid that could turn lightweight material into full-body armor.

Full Liquid Jacket

The current war in Iraq is leaving behind a legacy of wounded soldiers. For every fatality there have been between seven or eight injured -- a number amounting to 18,356 as of June 11, 2006 (U.S. Department of Defense). That's a higher ratio of injured to dead than in any previous American war, a mixed blessing that can largely be attributed to advances in body armor and improved battlefield medical treatment.
A new "liquid armor" could be the solution for protecting the parts of the body that aren't currently covered by standard-issue ballistic vests – arms and legs, where many of these devastating and life-threatening injuries occur. Co-developed by two research teams – one led by Norman Wagner at the University of Delaware, and the other led by Eric Wetzel at the U.S. Army Research Lab in Aberdeen, MD – the liquid technology will soon lead to light, flexible full-body armor.

The liquid - called shear thickening fluid is actually a mixture of hard nanoparticles and nonevaporating liquid. It flows normally under low-energy conditions, but when agitated or hit with an impact it stiffens and behaves like a solid. This temporary stiffening occurs less than a millisecond after impact, and is caused by the nanoparticles forming tiny clusters inside the fluid. "The particles jam up forming a log jam structure that prevents things from penetrating through them," Wagner explains.
Wagner and Wetzel developed a way to specially treat ballistic fabrics, such as Kevlar, with the liquid, making them dramatically more resistant to puncture and much better at reducing blunt trauma.
"We integrate those materials with the fabric itself, imbibe it in a way, such that the shear thickening fluid is not at all evident, it's not a coating on the outside. It's actually intercalated directly into the material," says Wagner.
The stiffening of the liquid allows the energy of an impact to be distributed over a much larger surface area – so the force, rather than being focused on the area of a bullet head, is distributed over the area of the surrounding fabric. Ballistic tests have demonstrated that the treatment can actually prevent bullets from penetrating.
The treated Kevlar is even better at resisting puncture from sharp projectiles, such as knife stabs or shrapnel from roadside bombs. As Wagner explains, Kevlar was never designed to function against puncture.

Bullet proof vests and Kevlar are not very good against stab threats like puncture that you might see in correctional prison guards or from fragmentation threats on the battlefield," he says.
The treatment of the fabric prevents the fibers from spreading apart or "windowing," which keeps sharp objects from entering. That means that not only would materials treated with shear thickening fluids be better against conventional threats such as bullets, but would also resist puncture from shrapnel. The materials would also remain light – only 20 percent heavier after treatment - and flexible, which means they could be used for much-needed protection of the limbs.
"We can make thin layers of material for use on the arms and legs that remain flexible under normal motion, but become rigid and absorb energy when impacted by a ballistic threat or a knife," Wagner says.
U.S. manufacturer Armor Holdings recently licensed the technology and plans to release its first products by the end of the year.
Wagner says there could also be many civilian applications – like protecting people during car crashes, or making tires sturdier.
Some of Wagner's recent work was published in the May/June 2005 issue of the Journal of Rheology and was featured in the May 2006 issue of Scientific American. For a complete list of publications see Dr. Wagner's website. Some of the funding sources included IFPRI and the Army Research Laboratory CMT program through the Center for Composite Materials of the University of Delaware as well as the NASA Delaware Space Grant College and Fellowship Program.

 

[TexasJohn]

Slicker than $not on glass!!!! Sounds promising.

 

[A.Rahman]

yea, I will do anything to get rid of those bulky creamics plates under kelevar!

 

[Officer of Engineers]

Those cermanic plates absorb a hell of alot shock when cracked. Liquid, however, transfer shock alot more readily.

 

[A.Rahman]

Those cermanic plates absorb a hell of alot shock when cracked. Liquid, however, transfer shock alot more readily.

Also I heard they get more internal injuries, which is worse then bullet wound.

 

[Muradk]

Quote:
Originally Posted by Officer of Engineers
Those cermanic plates absorb a hell of alot shock when cracked. Liquid, however, transfer shock alot more readily.

Also I heard they get more internal injuries, which is worse then bullet wound.

Ballistic tests have demonstrated that the treatment can actually prevent bullets from penetrating. you are right it will create more damage and more internal injuries

 

[Ahassan]

doesnt sound good..................

 

[Shabz Nist]

Any Update on this?!?!? It looks very promising....

 

[bubble123]

lol its a 5 year old thread man.

 

[gagaga]

yeah~~~~~~

 

[Zabaniyah]

Here is a fairly recent article:

Will liquid body armor becoming a reality?
March 25, 2011

The theory is sound but the implementation a little — okay, a lot — more difficult
The promise of “liquid body armor” incorporating shear-thickening fluid (STF) has been on the horizon for at least seven years, ever since the technology was first developed at the University of Delaware. Now, BAE Systems says we may see the first models in use within two years.

Liquid body armor is liquid only in that a thick fluid is used in combination with conventional Kevlar fabric. The liquid is actually a suspension of ethylene or polyethylene glycol and very fine silica particles. Alcohol is added to make the solution less viscous, and then it’s poured between layers of Kevlar. The alcohol evaporates, leaving the suspension behind.

To explain the way the technology works, imagine that you stack iron cannonballs as a barrier in the street. If you drive your car into the barrier at high speed, the car will be destroyed. But if you nudge the pile with the car, moving slowly, you can probably dislodge the pile and move through it. STF works similarly. If something compresses the fluid compartment slowly, the silica particles move out of the way. When something like a fast-moving projectile compresses the fluid compartment rapidly, the silica particles bind against each other and form a rigid barrier.

Viscosity of Applesauce
In a beaker, STF has the apparent viscosity of applesauce. You can stir it slowly, but if you try to move anything through the fluid quickly, it will seize up and hold the stirrer rigid for a moment before it returns to its viscous state. This mechanism is sufficient to rob any fast-moving projectile of its kinetic energy and stop it cold.

Penetration tests have shown that four layers of Kevlar impregnated with STF have more resistance to projectiles than ten layers without STF, and are considerably more flexible than the ten layer thickness. The downside is weight. Four layers of Kevlar and STF weigh two percent more than ten layers of Kevlar alone, although it’s only half as thick and slightly more flexible than four layers of dry Kevlar.

Uncomfortable and Stinky
There is no indication that the STF degrades the Kevlar over time, but wearing a protective garment like this might not be very comfortable, especially in warm climates. To keep the STF inside the Kevlar, any carrier is going to have to be impervious to the STF, and that may make it effectively sweat-proof, too. Body armor has never been comfortable when it’s hot, but most models allow for some “wicking” or other moisture transport to keep the wearer relatively dry of perspiration. Wearing one of these garments might be very uncomfortable, not to mention stinky.

STF-layered armor may be the first practical solution to a problem that has plagued the military as long as there have been soldiers: injuries to extremities. As many as 80 percent of combat injuries are to extremities, where there is typically no more protection beyond that of the uniform sleeve or trouser leg. It may now be possible to outfit combat troops with protective gear that is light and flexible enough to move in, while offering protection from wounds to arms and legs.

Will we see this in the public safety market? BAE Systems — the large holding company that has Safariland among its subsidiaries — has licensed the technology from the University of Delaware and has been working on development for several years. The latest report is that they hope to have a product ready for deployment within two years.

Source: Body Armor News : Will liquid body armor becoming a reality?: Bullet Proof Vests : Body Armor Manufacturer

Also check out this:
Bullet-proof custard: British soldiers could be wearing revolutionary new liquid body armour within two years | Mail Online