Graphene, a honeycomb lattice composed of carbon atoms, is surprisingly resilient. It’s 300 times stronger than steel, one million times thinner than a single human hair and is an impressive conductor of heat and electricity.
In 2D, graphene molecule manipulation is no challenge—but 3D is a different story. In a bid to expand applications of this super-material, an international research team led by engineers from the University at Buffalo (UB) and the Harbin Institute of Technology in China has developed a stable three-dimensional form of graphene aerogel.Previous attempts to create this type of material used 3D printers and graphene mixed with a polymer or other thickening agent to maintain the structure.
However, removing the polymer through a thermal process damages the structure. The researchers built on this idea and used a modified 3D printer and frozen water to create lattice-shaped cubes and a three-dimensional truss with overhangs.
These stable 3D structures hold potential for commercial use in electronics, medical diagnostic devices and sensors. Below is a video demonstrating the researchers’ work:
"Graphene is notoriously difficult to manipulate, but the structures we built show that it's possible to control its shape in three-dimensional forms," said Chi Zhou, assistant professor of industrial and systems engineering at UB’s School of Engineering and Applied Sciences.
Sandwiched Graphene
The team’s research mixed the graphene oxide with water and printed the lattice framework on a surface of -25°C. In so doing, the graphene became the metaphorical baloney between layers of frozen ice. This “sandwich” created the necessary structural support for 3D graphene.
After a quick dip in liquid nitrogen to strengthen hydrogen bonds, the lattice was then placed in a freeze dryer to remove the ice. The end result was that the once-fragile 3D graphene aerogel became a strong, complex and sustainable material usable at room temperature.
"By keeping the graphene in a cold environment, we were able to ensure that it retained the shape we designed. This is an important step toward making graphene a commercially viable material," said Dong Lin, assistant professor of industrial and manufacturing systems engineering at Kansas State University.
So far, researchers have experimented with graphene only but plan to continue to investigate creating aerogel structures of various materials.
This breakthrough in 3D graphene could help improve computer speeds and battery power, as well as increase solar panel efficiency and many other applications.
For more information, read the team’s research paper here.