May 21, 2013
Graphene Ink Could Lead To Bendable Electronics
Lee Rannals for redOrbit.com - Your Universe Online
The team's graphene-based ink is highly conductive and tolerant to bending, which could eventually pave the way for bendable tablet computers or electronic newspapers.
“Graphene has a unique combination of properties that is ideal for next-generation electronics, including high electrical conductivity, mechanical flexibility, and chemical stability,” said Mark Hersam, professor of materials science and engineering at Northwestern´s McCormick School of Engineering and Applied Science. “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.”
The new method for mass-producing graphene can be carried out at room temperature using ethanol and ethyl cellulose to exfoliate graphite. This process minimizes residues and results in a powder with a high concentration of nanometer-sized graphene flakes.
The team demonstrated printing ink in multiple layers, each 14 nanometers thick, in order to create precise patterns. The ink's conductivity remained unchanged, suggesting that it could be used to create foldable electronic devices.
Inkjet printing with graphene has remained a challenge because it is difficult to harvest a sufficient amount of graphene without compromising its electronic properties. The team's method surpasses some of these challenges, opening up the door to a future with bendable smartphones.
Graphene was discovered in 2004, and scientists believe the material holds plenty of promise in the future. Scientists discovered the material by peeling off carbon layers from graphite using ordinary scotch tape. It is the world's thinnest, strongest and most conductive material. Scientists could eventually use the material for applications like computer chips, broadband connections and drug delivery.
Researchers from the University of Manchester and National University of Singapore wrote in the journal Science about how graphene could lead to photovoltaic structures that could be placed on the outer walls of buildings to absorb sunlight. The team said they found that graphene could also help environmental conditions like temperature and brightness by directing energy to change the transparency and reflectivity of individual fixtures and windows.
“Such photoactive heterostructures add yet new possibilities, and pave the road for new types of experiments,” said Professor Kostya Novoselov of the University of Manchester. “As we create more and more complex heterostructures, so the functionalities of the devices will become richer, entering the realm of multifunctional devices.”