Ever wanted a bendable tablet computer or a foldable electronic magazine? These devices may not be far off, according to graphene research from Northwestern University.
Specifically, the researchers developed a graphene-based ink that is tolerant to bending. They then used the ink to inkjet-print graphene patterns that can be used for electrodes. The patterns are 250 times more conductive than similar previous attempts. This could open a whole new world of consumer electronics.
"Graphene has a unique combination of properties that is ideal for next-generation electronics, including high electrical conductivity, mechanical flexibility, and chemical stability," Mark Hersam, professor of materials science and engineering at Northwestern's McCormick School of Engineering and Applied Science, said. "By formulating an inkjet-printable ink based on graphene, we now have an inexpensive and scalable path for exploiting these properties in real-world technologies."
Graphene is the world's strongest, thinnest and most conductive material. However, inkjet printing with graphene has been a challenge because of the difficulty of obtaining enough graphene without a loss of electronic properties. In order to get around this challenge, the researchers mass-produced graphene at room temperature by using ethyl cellulose and ethanol to exfoliate graphite. This process reduced residue and produced a powder with a high concentration of nanoscale graphene flakes. To create precise patterns, the team printed the ink in multiple layers, each 14 nanometers thick. Since the ink's conductivity did not change, the scientists deduced that it could be used to make foldable electronics.
A number of graphene developments have taken place this year, including the first graphene earphones, graphene aerogel and research indicating that graphene could be used as solar paint.
The research regarding the inkjet-printed graphene was published April 8 in the Journal of Physical Chemistry Letters.
