Researchers at the University of Cambridge, in England, in collaboration with Novalia, a Cambridge-based technology company, have developed a low-cost, high speed new method for printing graphene inks. This method allows graphene and other electrically conducting materials to be added to conventional water-based inks and printed using typical commercial equipment.
Roll-to-roll printing of graphene ink for inexpensive printed electronics, intelligent packaging, and disposable sensors.
Image credit: Dr. Tawfique Hasan
How the new method works
The study of graphene, a network of carbon atoms just one atom thick, has led researchers to the development of a new method for printing electronics using graphene based inks. According to a Cambridge University's press release, the method, which was developed at the University's Nanoscience Center by Dr. Tawfique Hasan of the Cambridge Graphene Center (CGC), works by suspending tiny particles of graphene in a carrier solvent mixture, which is added to conductive water-based ink formulations.
“The advantage of our ink systems for electronics is higher conductivity than traditional carbon inks,” Hasan told EBN. “Most applications that require a carbon ink and silver overprint combination can now be replaced with our graphene ink, leading to environmentally friendly electronics and sensors.” The required low temperature makes a large percentage of certain printed electronics component completely biodegradable resulting in a cheaper production.
The ratio of the ingredients can be adjusted to control the liquids 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 with other materials including metallic, semiconducting, and insulating nanoparticles.
“The advantage of our inks for sensing applications comes from higher conductivity and large surface area of graphene flakes. In addition to cheaper production costs, these lead to better sensor sensitivity,” Hasan said. According to the researcher, the nature of graphene's two-dimensional structure will potentially allow them to modify their surface chemistry to detect a range of molecules. “We can also print our inks onto paper and biodegradable plastics,” Hasan said.
Inexpensive printed electronics & other commercial applications
Thanks to the new method, it will be possible for the first time to use graphene on a large-scale commercial printing press at high speed.
Cheap, printable sensors could be used to track parcels, or luggage, or products across a production and supply chain. The potential of flexible, transparent printed electronics is infinite with applications not only in the electronics industry but also in healthcare, and retail.
Graphite, roll of Scotch tape, and graphene transistor donated to the Nobel Museum in Stockholm, Sweden by Andre Geim and Konstantin Novoselov from the University of Manchester, England after being awarded the Nobel Prize in Physics 2010 for their discovery of graphene in 2004. The physicists used regular Scotch tape for separating thin flakes of carbon from a piece of graphite.
Image source: Susan Fourtané
Commercial applications for the new graphene based inks include inexpensive printed electronics, intelligent packaging, and disposable sensors. Dr. Tawfique Hasan told EBN that intelligent packaging and disposable sensors are probably going to be the most attractive applications that will directly affect the retail and healthcare industries. “In intelligent packaging, we envision applications in interactive packaging solution to convey certain information to the users,” Hasan added.
Other short to medium term applications include printed, disposable biosensors, energy harvesters, and RFID tags. “For disposable sensors we are targeting applications in biomedical as well as gas sensors for air quality monitoring in closed environments,” Hasan said Hasan also considers cheap and biodegradable printed sensors that could be directly printed onto perishable food product packaging.
The use of graphene in electronics has been demonstrated in lab prototypes around the world, but not yet realized in a commercial scale. Now, for the first time, graphene inks come close to real-world manufacturing using a graphene formulation that uses cheap, non-toxic, environmentally friendly solvents, and is recyclable.