Scientists have copied the structure of bone to create a strong yet light synthetic material.
Making something strong but light is a holy grail of engineering and technical development. Technical foams have gone some of the way to achieving this, yet do not have the strength comparable with bulk materials such as steel.
The natural world has solved many mechanical problems through adaption and evolution, although it can take millions of years to get it right.
Not wanting to wait this long, researchers in Germany have looked at how bones achieve a winning combination of strength and low weight.
Bone is composed of tiny particles that work like nanosized building blocks that organise themselves into a minute framework. This structure leaves small gaps between the particles, making the material light.
Using 3D laser printing, Jens Bauer and his team, publishing in the Proceedings of the National Academy of Sciences journal, have been able to replicate bone microarchitecture in ceramics and create synthetic materials which, for their weight, are stronger than any natural or man-made materials.
Surprisingly, the smaller something is, the stronger it is. You may be able to snap a credit card in half once, but try to break the remaining half and it will be much harder. Because the internal framework - or microarchitecture - of the bone is so small, it is much harder to crush.
The team tried many different patterns for their framework. Taking further inspiration from natural mechanics, the honeycomb pattern was found to provide the strongest structure, with a performance equivalent to high-strength steels.
However it will be a while yet before we see these new materials in use, as Jens Bauer explained "it is in the experimental stage ... the little cubes you see in the paper, it takes one hour to make one of those [to] produce a sample an inch by an inch would take weeks or years" he added, due to the small size "some first applications could be cushions for microelectronical devices or for filtration in microfluidics".
It is not necessarily new to incorporate air into a structure. Your basic foam is essentially air + polystyrene. Some of the lightest materials are Aerogel, aerographite. and metallic microlattice.
As one of our most common building materials, iron is strong, but also very dense.
As has been done for many years in building aircraft wings. Several light aircraft use a GRP shell over styrofoam to give a more continuous contour than you can get with conventional ribs, and simple model planes use self-skinned polyurethane which is virtually crashproof.