Materials // Aerographite – Lightest Material in the World © Based on Material by KU / TUHH, Germany

Scientists of Kiel University (KU) and Hamburg University of Technology (TUHH) in Germany present in Advanced Materials Aerographite, a net- work of porous carbon tubes that is three-dimen- sionally interwoven at nano and micro level – the lightest material in the world. It weights only 0.2 milligrams per cubic centimetre, and is therefore 75 times lighter than Styrofoam.

Despite of its low weight Aerographite is highly resilient. While lightweight materials normally withstand compression but not tension, Aerographite features both: an excellent compression and tension load. It is able to be compressed up to 95 percent and be pulled back to its original form without any damage, says professor Rainer Adelung of Kiel University.

"Up to a certain point the Aerographite will become even more solid and therefore stronger than before," he points out. Other materials become weaker and less stable when exposed to such stress. "Also, the newly constructed material absorbs light rays almost completely. One could say it creates the blackest black,” acknowledges Hamburg’s Professor Karl Schulte.

"Think of the Aerographite as an ivy-web, which winds itself around a tree. And than take away the tree", Adelung describes the construction process. The "tree" is a so-called sacrificial template, a means to an end. The Kiel-team, consisting of Arnim Schuchardt, Rainer Adelung, Yogendra Mishra and Sören Kaps, used a zinc oxide in powder form. By heating this up to 900° Celsius (1,652° F), it was transformed into a crystalline form. 

Image: Small crumb being big: the newly constructed material absorbs light rays, such as this green laser pointer, almost completely. © Stefanie Maack / CAU