Researchers at the University of Waterloo have unlocked the potential of graphene in areas as diverse as vehicles, consumer electronics and environmental cleanup with an eco-friendly ink for 3D-printing.
Graphene is well known for its strength, electrical conductivity and thermal properties, but it is typically produced in a powder form that can be difficult to work with, therefore limiting its uses.
Waterloo researchers tackled that problem by creating the world's first all-graphene ink by engineering graphene nanosheets that can disperse in water while still maintaining conductivity.
A 3D printer uses the graphene ink to make a UW logo (University of Waterloo)
In addition to extreme versatility, the new ink is environmentally friendly because it is additive-free and, unlike alternatives, does not require any chemical solvents for printing.
"Shaping graphitic materials into complex geometries for advanced applications has long been a critical challenge that has limited their widespread adoption," said Dr. Milad Kamkar, a professor in the Department of Chemical Engineering at Waterloo. "With our proposed methods, we can 3D-print graphene into any shape."
As a water-based, functional ink, graphene can be used with 3D printers to make sensors for smartwatches and fitness bands, or glucose monitoring for people with diabetes.
Other potential applications include 3D-printed parts to make vehicles lighter, reducing fuel consumption while also improving durability, and filters to purify and even desalinate water.
Chemical Engineering PhD student Shakiba Samsami loading the graphene ink into the 3D printer. (University of Waterloo)
Graphene ink could also be used in batteries, printed electronics and environmental remediation, such as cleaning up oil spills in oceans with porous, super-absorbent structures, and capturing carbon dioxide in the atmosphere to help minimize climate change.
To devise these inks, the research team - which included members from the University of Calgary, the University of British Columbia and Aalto University in Finland - developed a two-step electrochemical process that is well-suited to mass-manufacturing.
A specially designed step called intercalation, which involves the insertion of a molecule into layered graphite, allows for continuous production of the graphene nanosheets in water.
"Our modern technological advancements have come at the cost of new environmental challenges," said Kamkar, who is also director of the Multiscale Materials Design Lab at Waterloo.
"To survive and address these challenges, we must develop new materials that are more effective than those currently available. This can only be achieved by controlling and fine-tuning material properties across multiple scales, from the molecular and nano levels to the macro scale."
The researchers' next steps will involve exploring advanced applications for environmental remediation and carbon dioxide capture technology.
The study, Additive-free graphene-based inks for 3D printing functional conductive aerogels, appeared in Journal of Materials Chemistry A.
