Graphene is still the strongest material on Earth, even when patched together according to a new studied published in the journal Science.
Graphene is made up from rings of carbon atoms, joined together in sheets, similar to graphite found in pencils. These sheets in graphene are just one-atom thick. Over small areas, these sheets can be nearly-perfect, forming the strongest material known.
There was debate about whether graphene would still exhibit its remarkable strength when pieced together like a quilt. According to this new study, graphene does still retain most of its strength even when patched together.
"Large-area sheets required for applications must contain many small grains connected at grain boundaries, and it was unclear how strong those grain boundaries were... and we're excited to say that graphene is back and stronger than ever," James Hone, professor of mechanical engineering and lead researcher of the study, said.
Hone and researchers from Columbia Engineering grew graphene using the process of chemical vapor deposition (CVD), which is the same method commonly used by researchers who claimed the boundaries between grains were weak. During this process, sheets of graphene a few feet across are grown on copper under heat. A chemical agent is then used to remove the graphene from the copper, and it was this chemical agent that was causing the weaknesses in the boundaries. What Hone's study shows is that the weaknesses seen in earlier studies was not inherent in the material. The team developed a new transfer method that does not harm these bonds, allowing the material to retain its remarkable strength.
"[I]t would take an elephant, balanced on a pencil, to break through a sheet of graphene the thickness of Saran Wrap," Hone and his colleagues wrote in 2008.
Part of the reason graphene is damaged so easily during post-production handling appears to be because the material is only one atom thick. A break that would only represent the slightest surface damage to most materials rip clear through a sheet of graphene.
New camera chip technology made from graphene that eliminates the need for a flash has just been announced. Future applications of graphene could include creating flexible computer monitors, flexible robots, or even an elevator to space.
