The all incredible and strong Graphene has electrical, thermal, optical, and chemical properties unseen in any other material known to mankind. But Graphene has been used only in its two-dimensional structure up till now, leading to a limited number of applications. In comes the latest research by a team from MIT, which has given graphene a new dimension and has developed a sponge-like 3D version giving it only five percent of the density of steel, yet ten times its strength!
It is not the first attempt at making the two-dimensional, one atom thick graphene sheet into an industrially applicable material. But before this, all such attempts have resulted in creating a material that was weaker by several orders of magnitude than theoretically predicted.
How Did MIT Researchers Test 3D Graphene?
The MIT team managed to pull off the feat by concentrating less on the material itself and focusing on its geometrical configuration. The two-dimensional sheet, in theory, can be stretched in length and breadth to an infinite limit. Using this atomic-level behavior, the team created a mathematical model to match the observations and were able to generate models that could imitate the loads in tensile and compression tests.
Small flakes of graphene were compressed under heat and pressure, which resulted in ultra strong and stable porous structures similar to coral and having a massive surface area to volume ratio. The team concluded that these shapes allow the two-dimensional graphene to be turned into stronger structures much like the sheets of paper which can be folded and rolled into creating cylinders and corrugations capable of sustaining substantial loads.
This understanding led to the creation of high-resolution 3D-printed models out of similar configuration to the “nerf-like” naturally forming graphene structures called gyroids, although these were about a thousands of time larger. This is where the 3D printing comes in, as these shapes are so complex that no other manufacturing process can be applied to create them.
The subsequent compression and tensile tests on the 3D printed material confirmed that graphene in its 3D form, the material has a density of five percent of steel but ten times its strength. However, the real secret behind the strength lies in the geometrical configuration rather than the material itself. This was proven as when graphene was swapped for other polymers or metals, similarly strong materials were created.
The team hopes that this can be a start of applying the 3D graphene structure technology to a host of other purposes ranging from polymers to structural concrete, ushering in an era of materials that are not only stronger and lighter but also have better insulating properties. The porous structures can also be utilised in filtration systems for water or chemical plants.
The research was published in Science Advances.
The video below discusses the strength of a 3D graphene structure.