US engineers have recently shown using a miniature shooting range that graphene, a multilayered material with a 10 to 100 nm thickness, may be a top-class bullet-proof material, since it seems to absorb and disperse ten times more energy than steel or polyamide.
Graphene was patented in 2014 and it is an extremely thin carbon sheet, so thin that it only has 2 dimensions, but can hold weights 100 times heavier than steel. Graphene is also an excellent conductor for electricity and heat.
Experts also praise this material for being extremely strong and stiff due to it’s 2-D structure. Some researchers say that graphene is so strong that on a real scale it could hold the force of an elephant that is balancing on a pencil.
To this day, graphene hasn’t been tested for extreme conditions such as withstanding the speed of a bullet. Jae-Hwang Lee professor at the University of Massachusetts said his team was the first to test graphene under speed compared to real bullet speed. Professor Lee explained researchers couldn’t use traditional methods such as real firearms because graphene has such a microscopic scale, Instead the team used a laser to help a silica micro-bullet to accelerate towards a patch of graphene material.
The micro-bullet hit multiple graphene sheets at a supersonic speed (up to 2000m per hour) with the aid of the laser. Researchers were able to subtract the energy the bullet had after the impact from the energy released on impact and determined the energy absorbed.
A British scientist at the National Centre for Matter under Extreme Conditions said that the US researchers were able to demonstrate standard ballistics configuration’s utility on a microscopic scale, which was a very exciting experiment.
The graphene multilayered material was able to absorb about 0.90 MJ of ballistic energy per kilo and has cracks emerging across the impact area. Steel made materials are able to absorb only 0.08 MJ per kilo at the same bullet speed.
Professor Edwin Thomas, member of the US research team and Engineering Dean at Rice University said that graphene is as good as the amount of energy it absorbs, Dr Edwin Thomas added the whole trick was to get as many cracks on the impacted material as you can since many cracks are associated to an improved capacity of spreading the impact into more material, just like a tempered safety glass does. Safety glass is designed to spread the energy of impact and located it to any point.
Scientists compared graphene’s stiffness and strength to materials designed to stop bullets. Now, engineers’ main task is to make graphene on a scale that it can be used in mass production so graphene could be the next generation bulletproof material.