Shutterstock | Inozemtsev Konstantin
As part of our coverage of the ESOF conference taking place in our home city of Manchester we were lucky enough to attend a panel discussion on the potential impact 2D materials are going to have on our everyday lives, technology and society as a whole.
Graphene, the most popularly mentioned (and first discovered 2D) material has seen a lot of positive press since its discovery in Manchester in 2004. With the huge list of superlatives that are rehearsed almost every time it is mentioned (world’s strongest, world’s stretchiest, world’s most conductive... etc.) it’s almost impossible to not imagine the huge potential this material has to change our lives.
To discuss the plausibility of this, and to look forwards into the two-dimensional future, ESOF gathered a multidisciplinary team including Dr. Michael De Volder, lecturer of nanoengineering at Cambridge University, Kirill Bolotin, a professor of the electronic properties of 2D materials, and Wolfgang Templ, a semiconductor specialist at Nokia working on developing new communications networks.
The panel discussed the boundaries between fantasy and reality in the 2D materials space. Many promises have been made concerning graphene, but how many of these are achievable using currently existing technology, and how many are the speculative dreams of hopeful scientists?
Carbon nanotubes, first discovered in the 1990's, were the first isolated 2D material. They can be considered as analogous to a sheet of graphene rolled into a tube. Shutterstock | Dimarion
What is Holding us Back?
To begin, we heard about the different applications that graphene and carbon nanotubes (graphene’s older brother) could be used for in the future.
Electronics appear to be the holy grail of graphene research. Unfortunately, the promises of superconducting wires, ultrafast processing chips for computers, advanced batteries and super-efficient power generation are not going to become a reality any time soon. There are two big obstacles that are preventing these discoveries;
- Graphene needs to be completely pure and defect free to have the extremely high conductivity that would make these systems possible. Unfortunately, at the time of writing no process has been developed that allows the bulk manufacturing of pure graphene at an economical price.
- Computer chips need to have a band gap to function (it is the band gap that allows chips to either be 1, on, or 0, off). Introducing a band gap to graphene reduces its conductivity. Researchers are currently trying to develop a method that retains the high conductivity of graphene whilst allowing it to function as a semiconductor.
Graphene, like metals, has a band gap of zero meaning electrons can flow freely, like in a circuit. However this makes it impossible to 'switch off' pure graphene which is nessecary in electronic circuits such as computer chips and processors
What is Graphene Being Used For?
That’s not to say graphene isn’t going to make any impact in the near future. The graphene composites space is booming, with new technologies and materials being introduced regularly.
Particular focus was drawn towards electrical composites, where the addition of small amounts of graphene or CNTs resulted in a significant increase in a materials conductivity. These composites could be used for a range of applications, from electronics to sportswear, where they conduct heat away from the body.
Mechanical composites are also gaining a lot of attention. Sportswear (again) is a big benefiter of this technology with graphene doped fibres being used in ski suits to reduce drag, and graphene composite tennis rackets which are stronger, and more flexible, than their predecessors.
Other clothing was also mentioned; we were particularly impressed by a graphene woven suit that was light to wear but had the capacity to stop a bullet in its tracks.
With its ability to increase the strength of a material whilst remaining light it is no surprise that graphene is expected to be used widely in the automotive and aeronautical spaces. This technology is already in the prototyping stage.
This was demonstrated with the BAC mono sports car, which hads graphene composite panels, reducing the weight of the car whilst increasing its strength, the graphene composite is 20% lighter than carbon fiber and 200 times stronger than steel. Haydale and UCLan have also collaborated on the construction of the World’s first graphene composite drone.
The BAC Mono uses a graphene composite to reduce it's weight and increase its strength. BAC Mono
What do Carbon Nanotubes and Geckos Have in Common?
Dr. Michael De Volder, of Cambridge University, spoke on novel ways of using graphene and CNTs. He stressed that the organisation of 2D materials on the nanoscale can be used to create even more astounding properties.
This is already used by mother nature; for example, the organisation of nanofibers on the feet of geckos increases the surface area of their feet by such a high degree that it allows them to walk upside down, even on the slipperiest of surfaces.
This uniform organisation of CNTs is being exploited in the production of anisotropic conductive adhesives; in laymans terms this means adhesives such as tape which will conduct electricity, but only in one direction.
These are important components of handheld electronics and are expected to make a big impact in the display space, with super strong, electrically conducting wall mounts expected to become commonplace.
The organisation of nanotubes on gecko's feet is responsible for their ability to strongly grip smooth surfaces and has served as the inspiration for anisotropic conductive adhesives. Shutterstock | sarayuth3390
It’s Not All About Carbon...
Dr. Kirill Bolotin made sure to draw our attention away from graphene to look at the other 2D materials, which may not get quite as much attention as graphene, but have the potential to make just as big a difference.
The materials mentioned varied in their mechanical and electronic properties, ranging from hexagonal boron nitride, an insulator, to black phosphorus, a small bandgap semiconductor. Together, all of the 2D materials that have been isolated over the past 10 years can cover the entire range of the electromagnetic spectrum.
This is expected to have a huge impact on the communications space, with the possibility of these materials being integrated into existing technology, to make them more effective and to aid with their miniaturisation.
Wonder Materials of the Future
There is always going to be some disappointment when the hype is built up so much around a material such as graphene.
Whilst we’re still years away from the super products the newspapers have been promising us it’s evident that 2D materials are going to start appearing in our transport, tools and telephones sooner than we think.
Whilst this might not be as spectacular as the atom-thin water scrubbing membranes or the ultra-clean hydrogen fuel cells we have been hoping for, 2D materials are still going to impact our lives in new and wonderful ways sooner than we think.
This piece is part of our coverage of ESOF 2016, for more information on the conference and the talks we attended please see our overview article.
We're also in the process of conducting interviews with leading scientists from the conference. Watch this space!