LONDON – Researchers from the University of Cambridge have reported the ink-jet printing of graphene circuits, thereby demonstrating the suitability of graphene inks for flexible and transparent electronics. The simple use of a graphene-based ink and modified but standard ink-jet printers could bring closer the possibility of flexible, low-cost wearable computing devices, the researchers said.
The ink-jet printing of semiconducting polymer materials is well known for the large-area production of transistors, displays, photovoltaic devices, organic light emitting diodes (OLEDs). However, the electron mobilities of these materials are still much lower than standard silicon technology. The use of metal oxides and carbon nanotubes has been proposed to improve this but it usually comes at the cost of complexity in terms of adding stabilizer processes. By contrast graphene is a 2-D form of carbon in a single molecular layer that is the world's strongest and most conductive material.
The research team, led by Andrea Ferrari, made the ink by removing microscopic flakes from a block of graphite and suspending them in N-methylpyrrolidone (NMP). The use of NMP minimizes the "coffee mug ring" effect that occurs when some solvents evaporate. The team was able to print structures down to 90 -micron line widths and 90-nm thickness and below. The liquid-phase exfoliation (LFE)graphene-ink is described as a low-cost way to print thin-film transistors for flexible and transparent electronics.
The work was reported in the arXiv publication on condensed matter materials science.
Wow! Printing 90nm and below using a modified standard inkjet printer. That should get them the Nobel Prize. Surely there must be an error of several orders of magnitude in this? Even 90um width is still impressive.
Combine this with home 3D printers and one day some percentage of the manufacturing infrastructure could be replaced. Throw in Arduino and other open-source designs and things really get interesting.
I agree that the technology has a way to go, but that said, it has been a long time since I such a potential game changing technology as Graphene. Only time will tell if it fulfills its promises.
Cool stuff thought.
@PeterClark: timely article... the Printed Electronics conference starts at Santa Clara tomorrow. I was privy to a news brief by Dr. Cathleen Thiele of IDTechEx who says Vorbeck Materials Inc. will have their patented Graphene-based electronic ink will appear in major retail stores sometime in late 2011 (we are there almost!). I will keep you posted most likely with an article on EE Times (if you are going to attend, please let me know, we can meet F2F!).
Dr. MP Divakar
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