Researchers at Iowa State University find new ways to use graphene.
Graphene is known as a “wonder material”, reported Printed Electronics World, and its properties are being used to conduct “electricity and heat” as it is “strong and stable”, and is likened to a “honeycomb” structure but made of carbon and “an atom thick”.
Recently, researchers at ISU in Jonathan Claussen’s lab have used inkjet printers to “print multi-layer graphene circuits and electrodes”, which then made them wonder about using the technology for “wearable […] low cost electronics” and Suprem Das, the university’s postdoctoral research associate in mechanical engineering, asked “Could we make graphene at scales large enough for glucose sensors?”
Problems with the “existing technology” meant that “high temperatures or chemicals could degrade flexible or disposable printing surfaces”, and that’s when Das and Claussen thought about using lasers to treat graphene. Claussen, an “Iowa State assistant professor of mechanical engineering and an Ames Laboratory associate”, worked with Gary Cheng, “an associate professor at Purdue University’s School of Industrial Engineering” to test the idea, which worked.
By treating “inkjet-printed, multi-layer graphene electric circuits and electrodes” with a “pulsed-laser process”, the electrical conductivity improved “without damaging paper, polymers or other fragile printing surfaces”.
Claussen said that “this creates a way to commercialise and scale-up the manufacturing of graphene”, and a patent for the technology has been filed for, Claussen adding: “The breakthrough of this project is transforming the inkjet-printed graphene into a conductive material capable of being used in new applications. Those applications could include sensors with biological applications, energy storage systems, electrical conducting components and even paper-based electronics.”
Das said that this is possible because “the laser works with a rapid pulse of high-energy photons that do not destroy the graphene or the substrate. They heat locally. They bombard locally. They process locally”. This means that the process of using lasers also enables it to “change the shape and structure of the printed graphene from a flat surface to one with raised, 3D nanostructures”.
This will make the circuits “useful for chemical and biological sensors” and Claussen’s nanoengineers think that this could take graphene to “commercial applications”. A quote from the research paper said: “This work paves the way for not only paper-based electronics with graphene circuits, it enables the creation of low-cost and disposable graphene-based electrochemical electrodes for myriad applications including sensors, biosensors, fuel cells and (medical) devices.”