By compressing and fusing flakes of graphene, a team of MIT engineers has produced one of the strongest, lightweight materials known. Their bold idea has resulted in a new 3-D material with five percent the density of steel and ten times the strength.
What is just as exciting and possibly more so, the strength of the new 3-D forms has more to do with the unique geometrical configuration than with the material itself. “You could either use the real graphene material or use the geometry we discovered with other materials, like polymers or metals,” said Markus Buehler, the team’s bold leader. “You can replace the material itself with anything.”
The MIT researchers claim the same geometry could be applied to large-scale structural materials. For example, builders could construct bridges using concrete made with this geometry. Buildings could be fabricated from lighter weight steel. In both cases, the resultant structures would have the necessary strength with a fraction of the weight and at a fraction of the cost.
The idea of graphene has intrigued and challenged scientists for almost 100 years. On paper, the concept made sense—create a “super material” by slicing a diamond into wafers just one atom thick. The result would be a two-dimensional, flexible carbon material with the physical properties of a sheet of crystal—the strongest material ever created on a per-weight basis with high electrical conductivity.
Diamond-slicing turned out to be difficult, but researchers recognized that atom-thin carbon was easy to make, in small fragments. It took until 2004 before a pair of researchers, Andre Geim and Konstantin Novoselov at the University of Manchester, figured out how to make graphene pieces large enough to be economically feasible. This discovery earned the pair of researchers a Nobel Prize in 2010.
In spite of much interest and a lot of hype, heretofore, researchers haven’t been able to do anything practical with the graphene fragments outside of their labs.
The hype is warranted, however. Successfully harnessing the promise of graphene is expected to “change the world” by providing high-strength, low-cost material for use in a wide variety of fields such as bioengineering, water filtration, infrastructure, and construction.
So back to MIT. The MIT research team led by Markus Buehler, head of MIT’s Department of Civil and Environmental Engineering (CEE) and the McAfee Professor of Engineering, were able to create 3-D graphene material by compressing small flakes of graphene using heat and pressure. The resultant material was strong, stable, and highly porous. After producing the material, the researchers used 3-D modeling to test its strength properties. One of the tests resulted in a material with five percent the density of steel, but ten times the strength.
Researchers have designed one of the strongest, lightest materials known. The bold impact on society? The door may at last be open for the practical development of the low cost, super materials of the future.
