Flexible Graphene Turns Hard as Diamonds When Struck by a Bullet
Physicists at the City University of New York have developed a material called diamene, which could become a new class of armor for people, vehicles, and spacecraft.
How's this for a science fiction premise: Scientists develop an ultralight material thinner than aluminum foil that morphs instantly into diamond hardness when struck by a bullet or other projectile.
As you may have intuited, this isn't science fiction at all. In new research published this week, physicists say they have developed a lightweight, flexible material that instantly becomes harder than diamonds upon any significant impact. The material could potentially be used to create an entirely new class of protective coatings and armor for people, vehicles, and even spacecraft.
Published Dec. 18 in the journal Nature Nanotechnology,the research from the City University of New York describes a new process for creating diamene — flexible, layered sheets of graphene that become hard as diamonds and virtually impenetrable upon impact. This work was funded by the Basic Energy Sciences Office of the US Department of Energy
Graphene is form of elemental carbon composed of a single sheet of carbon atoms in a honeycomb pattern. The CUNY technique essentially combines two layers of flexible graphene, each one atom in thickness. When the adjoining layers are deformed by outside pressure, they snap together to form a new structure with different physical properties.
"This is the thinnest film with the stiffness and hardness of diamond ever created," lead researcher Elisa Riedo, of the Advanced Science Research Center at the Graduate Center, CUNY, said in a statement.
The technique was originally established using computer simulations and later confirmed with laboratory tests, Riedo told Seeker. The transformation into diamond-hardness takes place instantly and only manifests around the point of contact. As such, body armor coated with the material would remain flexible even as it deflects the ballistic energy of individual bullets or projectiles.
Interestingly, the lab experiments and computer models show that this graphite-diamond transition does not occur for more than two layers or for a single graphene layer. The magic number is two. (When two layers of graphene are combined, the material is considered graphite.)
"Previously, when we tested graphite or a single atomic layer of graphene, we would apply pressure and feel a very soft film,” Riedo said in a statement issued with the new research. “But when the graphite film was exactly two-layers thick, all of a sudden, we realized that the material under pressure was becoming extremely hard and as stiff, or stiffer, than bulk diamond."
Riedo cautioned that practical applications of the technique are still a good ways off. Further research is needed to explore methods for stabilizing the process and predicting how the graphite-to-diamond phase transition behaves under different conditions. Even in a best-case scenario, Riedo said, it's impossible to estimate how long these processes will take.
“It's difficult to say, honestly,” she said. “We will need investors.”
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