3D-printed graphene could create strong, light parts for planes and cars

A “breakthrough” technique for 3D-printing graphene at high resolutions could lead to stronger and lighter parts for aerospace, automotive and other sectors, its creators have claimed.

Engineers from Virginia Tech and Lawrence Livermore National Laboratory in California developed the technique, which converts the 2D ‘wonder material’ into complex 3D shapes.

“This new design and manufacturing freedom will lead to optimisation of strength, conductivity and weight density,” said assistant professor Xiaoyu "Rayne" Zheng at Virginia Tech.

Previously, researchers could print graphene using an extrusion process like squeezing toothpaste, but that technique only created simple objects.

"With that technique, there's very limited structures you can create because there's no support and the resolution is quite limited, so you can't get freeform factors,” Zheng said. "What we did was to get these graphene layers to be architected into any shape that you want with high resolution."

To create these complex structures, lead author Ryan Hensleigh started with graphene oxide, a precursor to graphene, crosslinking the sheets to form a porous hydrogel. He then used ultrasound to break the hydrogel and added light-sensitive acrylate polymers.

Using projection micro-stereolithography, he created the desired solid 3D structure with the graphene oxide trapped in long, rigid chains of acrylate polymer. Finally, he placed the 3D structures in a furnace to burn off the polymers and fuse the object together, leaving behind a pure and lightweight graphene aerogel.

"It's a significant breakthrough compared to what's been done," Hensleigh said. "We can access pretty much any desired structure you want."

The process reportedly offers printing resolution of 10 microns, 10 times better than previous methods.

"We've been able to show you can make a complex, three-dimensional architecture of graphene while still preserving some of its intrinsic prime properties," Zheng said. "Usually when you try to 3D-print graphene or scale up, you lose most of the lucrative mechanical properties found in its single-sheet form."

Zheng has received grants to study nanoscale materials and scale them up to lightweight and functional materials for applications in aerospace, cars and batteries.

The research was published in Materials Horizons.

Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.