Materials

New 3D graphene is ten times as strong as steel

New 3D graphene is ten times a...
3D-printed gyroid models were used to test the strength and mechanical properties of a new lightweight material
3D-printed gyroid models were used to test the strength and mechanical properties of a new lightweight material
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3D-printed gyroid models were used to test the strength and mechanical properties of a new lightweight material
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3D-printed gyroid models were used to test the strength and mechanical properties of a new lightweight material
Simulation results of tensile and compression tests on 3-D graphene
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Simulation results of tensile and compression tests on 3-D graphene

It's incredibly strong and has unique electrical, thermal, optical, and chemical properties, but in some ways Graphene's two-dimensional structure makes it a bit like the laser was in the 1960s – a solution in search of a problem. To give graphene a new dimension, a team of MIT scientists have developed a sponge-like 3D version that has only five percent of the density of steel, yet is ten times as strong.

Graphene has long fascinated material scientists, but in its normal form it consists of two-dimensional flat sheets that are a mere atom thick, yet can theoretically stretch indefinitely in breadth and width. In order to make graphene a practical engineering material, it needs to be coaxed into a three dimensional form, but so far efforts to do so have been several orders of magnitude weaker than predicted.

Hoping for better chances of success, the MIT team concentrated less on the material itself and more on its geometrical configuration. To do this, they analyzed graphene's behavior down to the atomic level, then used the data to create a mathematical model to match the observations. From this, they were able to generate computer models that could imitate the loads in tensile and compression tests.

The team found that by compressing small flakes of graphene under heat and pressure, they could create strong, stable porous structures that were similar to coral and had an enormous surface area to volume ratio. According to the team, these shapes allow the two-dimensional graphene to form strong structures in the same way that sheets of paper can be folded and rolled into much stronger forms, including cylinder and corrugations, that can hold substantial loads.

Using this as a starting point, high resolution 3D-printed models were constructed out of plastic of various configurations – similar to the "nerf-like" porous structures called gyroids that graphene form naturally, though thousands of time larger. According to MIT, these shapes are so complex that printing is the only practical way to make them. These shapes were then tested for tensile strength and compression, and compared to the computer simulations.

Simulation results of tensile and compression tests on 3-D graphene
Simulation results of tensile and compression tests on 3-D graphene

The tests showed that graphene in a 3D form can achieve a density of five percent of steel, but with ten times the strength. However, the researchers found that much of this had more to do with the geometrical configuration than the material. When graphene was swapped out for polymers or metals, similar gains in strength were seen.

They also discovered that some hypothetical designs didn't work, including a 3D graphene structure that was lighter than air and could float like a helium balloon, but which the models showed would collapse under normal atmospheric pressure.

The team says that in addition to creating 3D graphene structures, the technology could be applied to other materials ranging from polymers to structural concrete and would not only produce structures that are stronger and lighter, but have better insulating properties. In addition, the porous structures could be used in filtration systems for water or chemical plants.

The research was published in Science Advances.

The video below discusses the 3D graphene project.

Source: MIT

One of the strongest lightweight materials known

8 comments
ChrisWalker
lmao! atoms are 3D structures in reality as spheres!
so is paper, it only seems thin to us, but atomically it is 3D in space as spherical structures!
Mzungu_Mkubwa
The article leads me to think that they have not actually achieved the fabrication of 3D graphene, just simulated it theoretically in a computer model, then printed blown-up plastic versions of these simulations to test physical properties. All that theory is wonderful fun to play with, but until it translates into producing real and usable materials that can be produced commercially and implemented to their best advantage for the benefit of mankind, where's the news?
ripshin
chris, two points. First, we don't KNOW that atoms are spherical objects. This is a description, a model, that seems to be consistent with observations, and thus is useful for scientists to use...but without directly observing atoms, we don't know this for sure. Secondly, everyone knows that there is no physically real 2-D material. A 2-D object is a theoretical construct only, in our spatial 3-D universe. BUT, it's convenient for scientists and engineers to use that term when describing something that's only 1 atom thick. The point is, yes, it's not 2-D in the strict theoretical sense, but the descriptor is useful for distinguishing objects/materials that are 1 atom thick (the thinnest conceivable thickness possible). It's like...marketing. Hope this clarifies this for you.
rip
Fretting Freddy the Ferret pressing the Fret
@ChrisWalker. Yes, everybody knows what you're trying to say. However, graphene has one dimension (its thickness) at its smallest unit of size. You can't get the thickness smaller than that (as opposed to paper), because it would stop being graphene and hence why it is considered 2 dimensional.
windykites
Porous (pause) for thought! I thought graphene came in nano tube form, which is 3-D.
Anyway, it looks like this article is merely about creating strong 3-D structures which could be 3-D printed in all sorts of different materials. Aerogel is still the lightest material then that can hold its own at atmospheric pressure. Foamed metal is another useful material.
Grunchy
Next step is to fabricate that nano-structure in bulk and test it. Aerogel has incredible heat-shedding properties, but (in typical form) you can crush it in your hand. I have an inkling that the 3d graphene nano-structure may have remarkable 'bulk' strength, but possibly won't have very good 'point' strength. So it may not stand up very well to loading scenarios such as high-energy impact. It might shatter or splinter, or who knows? in scenarios in which steel would exhibit ductile behavior. So it might not be an ideal drop-in replacement. Honestly who knows, carbon fibre performs spectacularly well with impact.
Techy-Teen
I have been following graphene for a while now. How can it be compared to a laser with a search for a purpose. We can make a material from a substance that is the seventh most abundant material on earth that is five percent the density of steel and ten times stronger. How is there not a use for it yet. Such a cool modern piece of science.
Martin Kemp
That 3D graphene is incredible. I wonder if that structure could be used as an energy absorption device for a vehicle's bumper bar in the case of an accident. Hmm.