Yeah this is all very good; until, of course graphene bullets are made, then ...

Sounds promising, but......what about a double tap ie two rounds in quick sucession next to each other? (Usual method of firing). and of course there are many different calibres with different kinetic powers. A 30-06 round normally travels at 2800-3000 feet per second but if it is steel tipped you are in a whole new ball game to a .45acp at 745fps. It would be fantastic if the vest was self healing and reverted.

The interesting question is why it only works with two sheets? Could multiply layers of the two ply sheets be layered with a non diamene between to further strength.

Diamonds crack very easily. Hardness is for abrasives, not impact resistance.

I'm going to file this one with all the other graphene articles under "Not In My Lifetime".
Do you think the word "graphene" will be used by future generations the same way we use "snake-oil"?

It should be affordable and available to everyone .

So it hardens, then what, more damage from the remnants?

You are correct, Bob. Hardness does NOT equate to toughness or strength. Tungsten carbide is very hard, but fractures quite easily under impacts, so even materials that it may cut through on my lathe can dull the bits if they are uneven, like say splines on an axle shaft. Or hard spots (inclusions) in cheaply made steels. As to HKMK23's comments, that energy has to go some place, so just stopping penetration is only a part of the equation to consider. 2K Ft Lbs of energy going into your body is going to shake things up a bit here and there. Take multiple hits, and you'll be taking an extra long dirt nap too! Randy

I wonder how much kinetic energy it takes from the bullet to form the diamond structure. Unless it absorbs a substantial portion, then you'll have a diamond tipped bullet entering your body.

How about we use this for space craft to protect against micro meteorites?