Lightweight and strong natural design, as found in balsa wood, has been replicated in the lab, and could improve vehicle fuel economy, in addition to other applications.
Hollow-core construction, the same natural design found in avian bones, also enables man-made flight and lighter and safer cars. Balsa wood, 95% of which comes from Ecuador, is lightweight, due to its low density, yet exceptionally strong. As long as it’s protected from the elements, it makes a good material for everything from model airplanes to surfboards to full-size airplanes. Even vehicle fuel economy could be improved by the application of such lightweight material. On the other hand, defects during growth can reduce its effectiveness, and we really don’t need to be cutting down any more Amazon Rainforest to get balsa, do we?
We’ve already done some exploring in lightweight composite materials, some of which are being used in wind turbine blades to keep them light and strong, airplane wings for better fuel economy, and even automobile frames. What if we could custom-design the materials themselves to be stronger, such as in 3D printing? On varying scales, 3D printing, following the lightweight designs we find in nature and improving on them, results in some pretty fantastic composite materials. CalTech has been experimenting with nanoscale 3D printing in practically any material. Theoretically, you could 3D nanoprint a steel car frame that is as strong as traditional frames, but at less than a tenth of the weight.
Harvard researchers, working on the macroscale, have developed a 3D printing process, the first of its kind to use carbon-fiber-impregnated epoxy resin.
The resulting honeycombed composite is “as stiff as wood, 10 to 20 times stiffer than commercial 3D-printed polymers, and twice as strong as the best printed polymer composites,” according to Harvard researchers. Scaled up to automobile supply levels, any weight reductions would have a huge impact on vehicle fuel economy, without sacrificing safety.
Image © Harvard
