Graphene is a true wonder material. A technological innovation from the University of Manchester that won the Nobel Prize in Physics in 2010, it has been used to develop water filtration devices, tough and flexible digital touchscreens, and advanced night vision contact lenses. Unfortunately, graphene is currently very expensive to manufacture; however, researchers at the University of Glasgow have just announced that they have found a way to produce it at a dramatically reduced cost. Their findings are published in the journal Scientific Reports.
Graphene has incredible properties: it’s only one carbon atom thick, it’s 200 times stronger than steel and conducts heat and electricity better than many other metals. This unique combination means it could revolutionize several fields of nanotechnology, from prosthetics that allow artificial skin to “feel” to making microscopic drug delivery systems.
Bringing these incredible proof-of-concepts to a commercial market, however, is difficult if making the graphene itself is so expensive. Now, a team of researchers led by Dr. Ravinder Dahiya have modified the process often used to produce graphene – and in the process, they’ve made it 100 times cheaper.
Gaseous, reactive substances (such as methane) are allowed to interact with a substrate, another reactive layer, in order to produce graphene. This process is known as chemical vapor deposition (CVD).
For the new process, the team used a copper substrate, one that is commercially available for £0.65 ($1) per square meter. Normally, the copper substrate used in traditional, graphene-producing CVD costs £75 ($115) for the same area; this also tends to require additional preparation before it can be used as a substrate, further adding to the cost of use.
In both cases, the use of a smooth copper substrate produces near-perfect, incredibly thin layers of graphene. However, by using the cheaper variant, this team have managed to produce graphene with far-improved electrical conductivity and optical properties – which incidentally formed in the shape of snowflakes.
Image credit: Snowflake graphene. The scale here is in micrometers: one micrometer is roughly a ten-thousandth of an inch. Polat et al./Scientific Reports
As it turns out, the cheaper copper – the type found in commonplace lithium-ion batteries – is in fact far smoother than the traditional, expensive type. Although only viewable under a powerful microscope, the researchers discovered than the expensive copper sheets contain deep trenches and cracks that cause any graphene films to form on them to have deformities and imperfections.
“Our process produces high-quality graphene at low cost, taking us one step closer to creating affordable new electronic devices with a wide range of applications, from the smart cities of the future to mobile healthcare,” said Dr. Dahiya in a statement.
“Much of my own research is in the field of synthetic skin. Graphene could help provide an ultraflexible, conductive surface which could provide people with prosthetics capable of providing sensation in a way that is impossible for even the most advanced prosthetics today.”
2
