Science

Aerographite claims title of World's Lightest Solid Material

Aerographite claims title of World's Lightest Solid Material
A microscope image of aerographite, which is now officially the world's lightest solid material (Image: Technical University of Hamburg)
A microscope image of aerographite, which is now officially the world's lightest solid material (Image: Technical University of Hamburg)
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A microscope image of aerographite, which is now officially the world's lightest solid material (Image: Technical University of Hamburg)
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A microscope image of aerographite, which is now officially the world's lightest solid material (Image: Technical University of Hamburg)

While they were each once hailed as the lightest solid material ever made, metallic microlattice and aerogel have now been moved back to second and third place (respectively), with aerographite taking the crown. Developed by a team from the Technical University of Hamburg and Germany’s University of Kiel, the material is composed of 99.99 percent air, along with a three-dimensional network of porous carbon nanotubes that were grown into each other.

Aerographite has a density of less than 0.2 milligrams per cubic centimeter, which allows it be compressed by a factor of 1,000, then subsequently spring back to its original state. Despite its extremely low density, it is black and optically-opaque in appearance. By contrast, the density of metallic microlattice sits at 0.9 mg per cubic centimeter.

The scientists discovered the sponge-like material when they were researching three-dimensionally cross-linked carbon structures. It is reportedly much more robust than the relatively fragile aerogel, being able to withstand at least 35 times as much mechanical force for its density. It is grown in a one-step process using zinc oxide templates, which allow blocks of the material to be created in various shapes, in sizes as large as several cubic centimeters.

Because it is electrically conductive and chemical-resistant, it could potentially find its way into devices such as batteries.

The development of aerographite was officially announced in a paper that was published yesterday, in the journal Advanced Materials.

Source: Technical University of Hamburg (German) via New Scientist

5 comments
5 comments
czark
If you filled that with hydrogen instead of air, it would be lighter than air. Sadly, I'll guess that the combination is still more expensive than helium. The Hindenburg question is - given that the flammable carbon and flammable hydrogen combination would prevent rapid exposure to oxygen, how safe would it be as a lifting solid?
christopher
Why hydrogen? Fill it with nothing (vacuum) instead - that's even lighter :-)
windykites
christopher, air pressure would collapse it. czark: the stuff is probably like a sponge, so would not hold hydrogen. It would interesting to know the surface area of a cube of this stuff. Could it be electro-plated with say, platinum? This could also be used in batteries.
ebrush870
Imagine if they were able to control the structure of the aerographite instead of just having it settle into random shapes. They could work it into a micro-lattice, for example, and then it would not only be much much lighter but also be structurally sound. A predictable structure is the key if this material is to get anywhere.
@christopher, windykites1: By the way, a micro-lattice structure like i mentioned would kill the sponge effect. This would partially enable christopher's idea to work. I've often thought of ways to have a structure to contain a buoyant vacuum like this but could never think of the right materials. Ooh, how about an egg shaped solid structure made of micro-lattice-aerographite, covered in a layer of plastic wrap (or other light airtight films not prone to tearing) and with a reinforced disk shape in the center of the egg (the weak-spot where pressure will be diverted to due to the egg shape). Just a thought.
On the example mentioned in the article towards it possibly being used in electrical applications, I predict an effect similar to touching steel wool to both poles of a battery.
Ofentse
I like the fact that it is chemically inert and it is electrically conductive which implies it has the potential to be applied in fuell cell technology as a membrane, because the thinner the membrane is the more efficient the cell is...but it may be need to be modified to avoid the fuel crossover.