US Air Force Academy cadet turns goo into bullet-stopping armor

US Air Force Academy cadet turns goo into bullet-stopping armor
Air Force Academy Cadet 1st Class Hayley Weir created a goo-like substance that can stop bullets
Air Force Academy Cadet 1st Class Hayley Weir created a goo-like substance that can stop bullets
View 1 Image
Air Force Academy Cadet 1st Class Hayley Weir created a goo-like substance that can stop bullets
Air Force Academy Cadet 1st Class Hayley Weir created a goo-like substance that can stop bullets

A US Air Force Academy cadet demonstrated that school lessons aren't just about retreading old ground, by turning a classroom exercise into a new ballistic armor made out of goo. In 2014, Cadet 1st Class Hayley Weir's assignment to combine epoxy, Kevlar and carbon fiber into an anti-ballistic substance inspired her to develop the task into a new type of flexible bullet stopper.

Composite armors aren't new and Weir's assignment was a standard one, but she wasn't satisfied with the result, which could stop a bullet but was hard and brittle. Following the suggestion of an Academy chemical adviser, she swapped out the epoxy with a shear thickening liquid.

Again, this wasn't new. Shear thickening liquids are made of nanoparticles suspended in a polymer that looks like a plastic goo and is as flexible as a defrosted freezer gel pack under normal conditions. But if they're struck hard enough, their properties change radically and they become extremely hard and viscous.

If you want a cheap analogy to this, take a ball of Silly Putty and play with it. Molded by fingers, it's soft, saggy, and will even ooze under its own weight if left alone. But yank it or hit with a hammer and it snaps or even shatters like glass. Such fluids are already used in motorcycle leathers and military personnel armor, but Weir had stumbled on something new.

Teaming up with military and strategic studies professor Ryan Burke, Weir started developing her idea for a Kevlar, composite goo armor. When the two looked at the existing research, however, they found that no one had produced anything similar to Weir's combination.

In 2016, Weir and Burke conducted tests with the new armor as they tried to develop a mix of the three elements that was most effective. They also attempted to figure out how to layer them for the best stopping power. By December, they were ready for test shots.

What they found was that not only had they come up with a bullet stopper, but one that was more effective the larger and faster the round. A 9-mm round pierced most of the layers only to be stopped by the Kevlar fiber backing, but a .40 Smith & Wesson only got to the third Kevlar layer, and a high velocity .44 Magnum round didn't get past the first.

"The greater the force, the greater the hardening or thickening effect," says Burke.

Weir, who is graduating from the Academy, will continue her research at Clemson University in South Carolina as she and Burke work to perfect the technology. They see it as having a wide range of applications, including as personal and vehicle armor, protective tent material against bullets and shrapnel, and as quick-deploying barricades to protect civilians in mass shooting incidents.

Source: US Air Force

Joseph Smathers
Every caliber of ammo has great variation between velocity and weight. The base caliber does define exactly how large of a diameter the fired bullet has, but 9mm, .40S&W, and .44 Magnum have a great variation in weight and muzzle velocity. So it can't be said that just because one of each were fired at samples means that larger and faster has any bearing - you have absolutely no idea or reason to believe the larger calibers were going faster.
That said, stopping all three of those pistol calibers has long been a behavior of ballistic armor, even and especially just plain kevlar vests. If this new approach is to have any relevance whatsoever, it needs to be able to stop the equivalent of 5.56 NATO (and it's Russian and Chinese counterparts). Otherwise, it doesn't do anything new or interesting.
You go girl. Seriously amazing science. I wonder if it would work against objects in space (to protect a spacecraft).
Reminds of me of Dune!
The Holtzman Shield from Frank Herbert's Dune made the use of projectile weapons and thrown blades (which were too fast) partly obsolete. The only effective combat method was the deft use and careful precision of a handheld dagger.
Time to go to H.P. White Ballistics Lab or Hardwire Armor in Maryland and do some real testing. Our troops need this.
What happens to the force? I assume the idea behind bullet suppression is to dissipate the force - so if you make area it hits hard - does this mean the bullet is stopped but the force is transferred or is it dissipated?
JA Larson
If you look at a standard ballistic table:
9mm ranges roughly from 975-1155 fps and 310-340 ft-lbs.
.40 S&W is 800-1175 fps and 360-500 ft.-lbs.
.44 Mag is 1150-550 fps and 800-1,000 ft-lbs.
Therefore it is reasonable to say that the .44 mag is typically faster and more powerful than the other 2 calibers.
The issue with body armor is not only what caliber bullet it stops, but also the armor's cost, weight, and heat load.
The other consideration is how the armor handles multiple hits.
Ideally the research gives the designer options to create protection zones to minimize weight/heat load and optimize risk.
The good old subsonic 1911 45 caliber sidearm may make a comeback.
Further testing & development is of course needed however body armor is not the only important application. Airplane luggage & cargo containers that are both lighter and more explosion resistant would be a great innovation. Also accessory secondary armor for vehicles, aircraft, & ships is worth looking at. I wish her well.
Douglas Bennett Rogers
It isn't clear what this really does. Soft steel or aluminum work hardens under deformation. This will resist penetration by hard, low speed, sharp objects. It will focus the energy of supersonic projectiles, forming molten jets, and allowing deep penetration. Resin composites defocus the energy, blowing a large hole, and dissipating the energy in a short distance. A glass matrix composite on the surface will disrupt the round and further defocus the energy. This new product appears to allow a deformable material that can be used for clothing but will act like a rigid composite when hit by a supersonic projectile.
Right on, Hayley. I hope you do develop a better protection for your fellow servicepeople. People thinking to tell an Air Force scientist (working on bulletproofing) about ammo specs is just a bit arrogant. And who said the 1911 .45 piston ever went away, huh? Half a dozen manufacturers make copies of it.