A team of researchers at the University of Cambridge, along with the Cambridge-based company Novalia, have produced new graphene-based inks which could lead to high-speed manufacturing of printed electronics. The method involves adding graphene and electrically conducting materials to water-based inks for printing. This is the first time graphene has been used for large-scale commercial printing at such high speeds.
It is a low-cost and high speed method for printing using a conventional roll-to-roll printing process that newspapers regularly use. This new method could lead to a decrease in printing expenses, better packaging and production of disposable sensors.
Dr. Tawfique Hasan of the Cambridge Graphene Centre (CGC) developed this new method.
“We are pleased to be the first to bring graphene inks close to real-world manufacturing. There are lots of companies that have produced graphene inks, but none of them has done it on a scale close to this. Being able to produce conductive inks that could effortlessly be used for printing at a commercial scale at a very high speed will open up all kinds of different applications for graphene and other similar materials,” Hasan said.
“This method will allow us to put electronic systems into entirely unexpected shapes. It’s an incredibly flexible enabling technology,” Chris Jones of Novalia added.
“Hasan’s method, developed at the University’s Nanoscience Centre, works by suspending tiny particles of graphene in a ‘carrier’ solvent mixture, which is added to conductive water-based ink formulations. The ratio of the ingredients can be adjusted to control the liquid’s properties, allowing the carrier solvent to be easily mixed into a conventional conductive water-based ink to significantly reduce the resistance. The same method works for materials other than graphene, including metallic, semiconducting and insulating nanoparticles,” according to Phys.org.
Currently, printed conductive patterns are manufactured with silver, which can cost $1,547.55 or more per kilogram. Graphene ink would be 25 times cheaper to manufacture. Also, silver is not recyclable while graphene can be easily recycled. “The new method uses cheap, non-toxic and environmentally friendly solvents that can be dried quickly at room temperature, reducing energy costs for ink curing. Once dry, the ‘electric ink’ is also waterproof and adheres to its substrate extremely well,” according to Phys.org.
The researchers hope to produce printed disposable biosensors, energy harvesters and RFID tags with this new method.
