A fascinating article on the substance Graphene, or diamene. The idea that a material only 2 atoms thick could provide extremely lightweight protection is pretty thought-provoking. Anyone who has worn body armor knows the discomforts involved. Kevlar does NOT breathe. Still, better hot than shot. Ballistic rifle plates, both steel and ceramic, are stiff and heavy. I’m really interested to see what comes of this.
Nuclear Body Armor?
On a side note, the headline perpetuates a misconception about diamonds and hardness. Diamonds are resistant to having their surface scratched, not from breakage or shipping. They are actually so hard that they are quite brittle. Think about hardening and tempering steel. That is what most people misunderstand: The difference between hardness and toughness. Hardness is resistance to scratching and is measured on the Moh’s scale. Toughness is resistance to breakage and is measured as inch-pound-force per cubic inch. When you lubricate a stiff lock with graphite or use your #2 pencil for notes, the material you are using is tougher than that diamond in your girl’s ring. But it shears and slides easily against itself and even breaks into a thin line of carbon on paper.
What makes graphite ‘slick’ is its extreme resistance to surface deformation, which allows individual atoms to shear easily into platelets 1 atom thick which slide over each other. Sure, it’s all carbon, but diamonds form in a cubic crystal system and graphite forms in a hexagonal system. Cubic crystals are just that: Cubes. Would you try to use a bunch of children’s alphabet building blocks under a safe to move it? Nope, cubes would increase the friction coefficient, not reduce it. But graphite forms in the hexagonal system where the atomic bonds are ‘flat’ and 1 atom thick. The article says Graphene is honeycomb-shaped. Hexagonal. Imagine a bunch of stop signs (yeah, they are octagonal, but go with the imagery) made of a super thin, super slick material so that they slide over each other and the edges are so thin and sharp they don’t jam against each other. Now make this thousands of times smaller than your eye can see and you have an understanding of why graphite can be a lubricant. But the fascinating factor that makes graphite ‘hard’ is the incredible nuclear forces that hold that little 6-atom molecule together. You can’t break that nuclear force that bonds it together. And where the big breakthrough comes is the discovery that stacking one layer of Graphene on top of another takes advantage of the nuclear forces that hold those hexagonal graphite molecules together.
So the body armor of the future is going to be based on nuclear physics. Of course the reason Kevlar threads are stronger than steel is tied up with its molecular structure at a nuclear level, but so what? A new material is always more interesting to talk about, and calling it nuclear makes it sound dangerous and sexy, so we’re going with the new nuclear paradigm. OK, OK, I’m done. The geeky deputy will shut up.