Army scientists, engineers develop liquid body armor

Army News Service ^ | April 21, 2004 | Tonya Johnson

[O.C. - Old Cracker]

ABERDEEN PROVING GROUND, Md. (Army News Service, April 21, 2004) -- Liquid armor for Kevlar vests is one of the newest technologies being developed at the U.S. Army Research Laboratory to save Soldiers' lives.

This type of body armor is light and flexible, which allows soldiers to be more mobile and won’t hinder an individual from running or aiming his or her weapon.

The key component of liquid armor is a shear thickening fluid. STF is composed of hard particles suspended in a liquid. The liquid, polyethylene glycol, is non-toxic, and can withstand a wide range of temperatures. Hard, nano-particles of silica are the other components of STF. This combination of flowable and hard components results in a material with unusual properties.

“During normal handling, the STF is very deformable and flows like a liquid. However, once a bullet or frag hits the vest, it transitions to a rigid material, which prevents the projectile from penetrating the Soldier’s body,” said Dr. Eric Wetzel, a mechanical engineer from the Weapons and Materials Research Directorate who heads the project team.

To make liquid armor, STF is soaked into all layers of the Kevlar vest. The Kevlar fabric holds the STF in place, and also helps to stop the bullet. The saturated fabric can be soaked, draped, and sewn just like any other fabric.

Wetzel and his team have been working on this technology with Dr. Norman J. Wagner and his students from the University of Delaware for three years.

“The goal of the technology is to create a new material that is low cost and lightweight which offers equivalent or superior ballistic properties as compared to current Kevlar fabric, but has more flexibility and less thickness,” said Wetzel. “This technology has a lot of potential.”

Liquid armor is still undergoing laboratory tests, but Wetzel is enthusiastic about other applications that the technology might be applied to.

“The sky’s the limit,” said Wetzel. “We would first like to put this material in a soldier’s sleeves and pants, areas that aren’t protected by ballistic vests but need to remain flexible. We could also use this material for bomb blankets, to cover suspicious packages or unexploded ordnance. Liquid armor could even be applied to jump boots, so that they would stiffen during impact to support Soldiers' ankles.”

In addition to saving Soldiers' lives, Wetzel said liquid armor in Kevlar vests could help those who work in law enforcement.

“Prison guards and police officers could also benefit from this technology,” said Wetzel. “Liquid armor is much more stab resistant than conventional body armor. This capability is especially important for prison guards, who are most often attacked with handmade sharp weapons.”

For their work on liquid armor, Wetzel and his team were awarded the 2002 Paul A. Siple Award, the Army’s highest award for scientific achievement, at the Army Science Conference.

(Editor’s note: Tonya Johnson is a member of the Army Research Laboratory Public Affairs Office.)

[King Prout]

think segments and layers, non-continuous but contiguous (overlapping)

[Shaun_MD]

Ahhh I see now - like chain mail or mesh.

[King Prout]

addendum - the kinetic energy is transmittet laterally throughout the suspension, and is diffused as heat and noise. once energy levels drop below the critical threshhold, the suspension returns to the plastic state.

[King Prout]

closer to brigandine or scale, but sorta, yeah.

[coloradan]

No, the opposite of ketchup. Ketchup stays semi-gelled and won't pour, until you hit the bottle. This stuff stays liquid unless you hit it.

[Shaun_MD]

Like I said, I failed physics - lol

[crz]

I'd like to shoot someone like Saddam, with that under a High Voltage transmission line and see what would happen.

[The Grammarian]

Does anyone remember a few years back, when a Japanese Scientist invented a suit that made you near invisible?

You mean here?

[traumer]

Nothing new.... TERMINATOR II

[Shaun_MD]

Probably just turn him into a superhuman monster who can walk through walls, and who can irradiate you at will.
Probably make him immortal too.

[Flying Circus]

Nope. A shear-thickening fluid responds to the forces it encounters at the moment. At the moment a bullet or fragment hits it at high speed, the fluid cannot move out of its own way and acts like a solid. Once the energy has been absorbed, the fluid relaxes and flows like normal.

[King Prout]

if passing physics was what it took to put to practical use an oddity of materials-physics that many kids have played with in their youth... ;)

[Shaun_MD]

So the harder the impact, the more resistant the armor becomes...

[Who is John Galt?]

Liquid armor is much more stab resistant than conventional body armor.

An excellent 'point.' Conventional armor (minus ceramic inserts, of course ;>) apparently sucks when it comes to attacks using ice picks, sharpened screwdrivers, etc...

;>)

[chuckwalla]

eighteen year old single malt is body armor in any weather anywhere.

[Flying Circus]

Essentially. The harder you work to deform it, the more it resists the deformation.

[King Prout]

come here - neat practical physics with military applications, the basics of which you can play around with in the kitchen

[Ragtime Cowgirl]

The goal of the technology is to create a new material that is low cost and lightweight which offers equivalent or superior ballistic properties as compared to current Kevlar fabric, but has more flexibility and less thickness.."

“We would first like to put this material in a soldier’s sleeves and pants, areas that aren’t protected by ballistic vests but need to remain flexible. We could also use this material for bomb blankets, to cover suspicious packages or unexploded ordnance. Liquid armor could even be applied to jump boots, so that they would stiffen during impact to support Soldiers' ankles.”

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Ping for our troops, and for those who care about the welfare of our troops!

[budwiesest]

polyethylene glycol, is non-toxic, and can withstand a wide range of temperatures.

And if your Humvee overheats, you can squeeze some into the radiator.

[Shaun_MD]

This is what I love about Free Republic. You learn something new everyday. Where else could I learn about cornstarch, chainmail and high tech weaponry on a single page? (Even if I did fail physics......)