Ten times stronger than steel but still light. Researchers blend flakes of graphene for new super tough material
A team of scientists at MIT has created a potentially breakthrough piece of material using flakes of graphene.
They claim the new material can be 10 times stronger than steel, but is much lighter, adding that the design is one of the strongest, lightest materials known to man.
The new sponge-like material has a density of just 5 percent, and utilises porous, 3D forms of graphene.
Graphene is already known to be one of the strongest of all known materials in its two-dimensional form, but until now researchers have struggled translating that two-dimensional strength into useful three-dimensional materials.
However the MIT scientists now think they have cracked it, as their research found that the crucial aspect of the new 3D forms has more to do with their unusual geometrical configuration than with the material itself.
The MIT engineers successfully designed the new 3-D material with five percent the density of steel and ten times the strength, making it one of the strongest lightweight materials available, which could possibly be used in cars, aeroplanes and buildings.
The findings are reported in the journal Science Advances, in a paper by Markus Buehler, the head of MIT’s Department of Civil and Environmental Engineering (CEE) and the McAfee Professor of Engineering; Zhao Qin, a CEE research scientist; Gang Seob Jung, a graduate student; and recent graduate Min Jeong Kang Meng.
A video of the new material can be found here.
The MIT team was able to compress small flakes of graphene using a combination of heat and pressure to produce a strong, stable structure, with the form resembling that of some corals.
“Once we created these 3-D structures, we wanted to see what’s the limit – what’s the strongest possible material we can produce,” said Zhao Qin. The team then created a variety of 3D models and then subjected them to various tests. In computational simulations, which mimic the loading conditions in the tensile and compression tests performed in a tensile loading machine, “one of our samples has 5 percent the density of steel, but 10 times the strength,” Qin said.
The researchers point out that paper for example has very little strength, but when it is made into certain shapes (i.e. a tube), it is much stronger and can support substantial weight. Similarly, the geometric arrangement of the graphene flakes after treatment naturally forms a very strong configuration.
“You could either use the real graphene material or use the geometry we discovered with other materials, like polymers or metals,” Buehler said, in order to gain similar advantages of strength combined with advantages in cost, processing methods, or other material properties (such as transparency or electrical conductivity).
“You can replace the material itself with anything,” Buehler said. “The geometry is the dominant factor. It’s something that has the potential to transfer to many things.”
“This is an inspiring study on the mechanics of 3D graphene assembly,” said Huajian Gao, a professor of engineering at Brown University, who was not involved in this work. “The combination of computational modelling with 3D-printing-based experiments used in this paper is a powerful new approach in engineering research.
Key applications could include fast electronic and optical devices, flexible electronics, functional lightweight components and advanced batteries.
The British government has also thrown its weight behind the material. It first invested £50m into the technology back in October 2011, which was followed by an additional £21.5 million investment for some of the leading universities in the UK, in order to develop commercial uses for graphene.
The British investment came amid fears that the UK may be struggling to keep up in the race to exploit graphene, as patent publications surge in the US and particularly in Asia.
However the UK seems to be responding quickly, and the university of Cambridge has already established a Graphene Research Centre in the ‘Silicon Fen’ area, in order to streamline manufacturing of the useful material and help turn it into flexible, wearable and transparent electronics.