By Josh Perry, Editor
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Researchers from Virginia Tech University (Blacksburg, Va.) and Lawrence Livermore National Laboratory (Berkeley, Calif.) have developed a novel method for 3-D printing graphene objects at higher resolution that previously printed, which opens the door for graphene objects of all shapes and sizes.

Zoomed in graphene octet truss on strawberry blossom. (Virginia Tech University)

According to a report from Virginia Tech, graphene had previously only been made in 2-D sheets or basic structures. Now, graphene can be printed into a variety of shapes and sizes and designed to meet the specific needs of many applications, including thermal management.

Graphene aerogels have been created in the past, which gave scientists graphene shapes that retained some of the material’s mechanical properties, but this new technique enables the manufacture of graphene objects that can be optimized for strength, conductivity, and weight density.

“Previously, researchers could print graphene using an extrusion process, sort of like squeezing toothpaste, but that technique could only create simple objects that stacked on top of itself,” the article explained.

The researchers started with graphene oxide, which is a precursor to graphene, and crosslinked the sheets to form a porous hydrogel. The hydrogel was broken with ultrasound and light-sensitive acrylate polymers were added so that projection micro-stereolithography could build 3-D structures with graphene oxide trapped in the polymer chains.

The final step was to place the structure in a furnace burn off the polymers and fuse the object together, which left pure graphene aerogel.

“The key finding of this work…is that the researchers created graphene structures with a resolution an order of magnitude finer than ever printed,” the article continued. “The new technique allows [researchers] to print down to 10 microns in resolution, which approaches the size of actual graphene sheets.”

The research was recently published in Materials Horizon. The abstract stated:

“3D graphene foams exhibit immense degradation of mechanical properties. Micro-architecture can alleviate this problem, but no current technique meets the manufacturing requirements.

“Herein we developed a light-based 3D printing process to create hierarchical graphene structures with arbitrary complexity and order-of-magnitude finer features, showing enhanced mechanical properties at decreasing density.”