Inside Graphene City, Birthplace of a Wonder Material
What can you actually do with the carbon-based 'miracle material'?
Image: University of Manchester
On a workbench illuminated by slats of low winter sun sits a small glass jar containing a dark grey powdery substance. It doesn't look much—like ground-up pencil lead—but this is the first time I've actually seen a form of graphene.
Back in 2010, graphene sprung into the public eye when two UK-based scientists won the Nobel Prize for their work on the two-dimensional material.
It was hailed as a wonder material: stronger than steel yet many times lighter, more conductive than copper, more flexible than rubber. The British government bet big on graphene in the following years, pledging £50 million funding for research and development in 2011. There was talk of a new industrial revolution. "We're going to get Britain making things again," said George Osborne, chancellor of the Exchequer.
Four years later, and graphene is still making headlines. But despite the hype, questions abound over how it could actually be used. When will we see the material making its way into everyday products? What can you actually do with graphene?
Or as James Baker, business director of the new National Graphene Institute, put it to me: "How do you make graphene not a white elephant?"
The NGI, largely funded by that investment, opens for business this March. It's part of Manchester University, where the Nobel Prize-winning scientists Andre Geim and Konstantin Novoselov first isolated graphene in 2003. The idea of the institute is to bring researchers and industry together to work on potential applications for the material.
From there springs a vision of "Graphene City," Manchester's answer to Silicon Valley—which it's easy to forget was originally inspired by a material too.
Graphene is basically a very thin sheet of carbon: a layer of carbon atoms arranged in a hexagonal pattern often compared to honeycomb or chicken wire. As it's just one atom thick, it's known as a 2D material.
You can actually make graphene quite easily at home. All you need is some graphite (the stuff you get in pencils) and sticky tape. Keep peeling the tape off the graphite, and you'll gradually pull layers off it; eventually you'll end up with some single-atom-thick flakes. This is, in fact, how Geim and Novoselov first "made" graphene.
"Obviously it's not that simple, because it's easy to make it; it's harder to know that you've made it," chemist Robert Dryfe, who works on graphene applications in electrochemistry, told me. "You need some good microscopes and things like that."
Describing the properties of graphene produces a list of beguiling superlatives: It's surprisingly strong yet incredibly light, it's pretty much as thin as you can can get, and it conducts heat and electricity extraordinarily well. A defect-free layer is also impermeable to all atoms and molecules.
That combination of attributes means there are potential applications in all kinds of sectors, from electronics to aerospace, packaging to medicine, even paint.
In a way, that makes the transition from the lab to an actual application more difficult. Where do you start? "Part of the challenge of graphene is which of those [potential applications] are real?" Baker said. "Which of those does graphene really offer a discriminator compared to conventional materials? And more importantly, how do you then make that happen?"
During our conversation, he dropped several examples of the long-term hypothetical products that get people so excited about graphene.
Take your smartphone. Graphene could make it smaller, lighter, and a whole lot bendier than an iPhone 6. Thanks to advances with graphene in battery tech, it could hold its charge for longer but recharge much quicker. "The phone of the future will be a very small screen you can fold up in your pocket," Baker said. "You can wear it as a watch, you can stitch it into your clothing, you can recharge it in seconds."
Scale up that battery idea, apply it to vehicles, and "you could have a car that when it gets to the traffic lights, there might be a charging plate, and it recharges its battery as it's waiting at the junction," he explained.
These kind of transformative and everyday products aren't available yet and may never be; Baker reckons it'll be five to ten years before we start seeing graphene in the car and aerospace industries. But the material is already starting to trickle into consumer goods. Sports brand Head incorporates graphene into some of its tennis racquets, used by both Andy Murray and Novak Djokovic in the recent final of the Australian Open. Head claims its Graphene XT line is up to 20 percent lighter than a conventional racquet but has the "equivalent swing weight" when you hit the ball.
Meanwhile, a Manchester University spin-out company is set to launch a graphene LED light bulb that includes a small amount of graphene to make it slightly more efficient, which Baker says will be available in hardware stores in the next six to 12 months. And the Nobel scientists are already walking around with two different models of "graphene" phones, made in China by smartphone company AWIT Inc and Shanghai startup Powerbooster Technologies. "It's still quite niche, it's a bit gimmicky if you like, but you can buy a phone with graphene in it," said Baker.
There are over 200 researchers working on graphene and other 2D materials at Manchester today. Rob Dryfe specialises in the potential of graphene in batteries and supercapacitors. According to him, there are three main problems with the lithium-ion batteries you get in your phone or laptop that graphene could help with: They take a long time to charge, they don't last as long as you might like, and their performance drops off over time.
"The next question is: As well as improving those, can we make any of those devices work on the vehicle scale?" Dryfe said. "And the third thing going beyond the vehicle scale is: Can we use these storage mechanisms on the grid scale?"
At the moment, lithium-ion batteries aren't as good as gas. Dryfe explained that a battery's energy density—the energy stored per unit of mass—is at least a factor of ten lower than that of petrol. Tesla's electric cars use lithium-ion batteries, but a lot of companies are put off by the need to have very heavy battery packs that still won't last as long as a tank of fuel.
On the grid scale, a way to store more energy could be a boon for renewables like solar and wind power. You'd still need huge batteries, but if they could store energy to be extracted over a longer period of time, that would make these energy sources more reliable.
So how can graphene help? Usually, one electrode in a lithium-ion battery is made of graphite—the "mother" of graphene. When you charge the battery, you force lithium ions into the graphite where the energy is stored. "It's suggested that you can store more lithium and therefore more energy if you have graphene instead of graphite," said Dryfe.
Another potential advantage of graphene is that it could be used with ions other than lithium. "So graphene makes the sodium-ion battery viable," Dryfe said. Sodium is much more abundant than lithium—it's in seawater—which could make it cheaper and easier to source. This is all still in the research stage, but Dryfe said he would be surprised if batteries containing graphene in some form aren't available in the next three to four years.
In his lab, post-doc Mark Bissett showed me a prototype the researchers are currently testing. It was about the size of a watch battery and made of a composite of graphene and some other 2D materials. "I couldn't say exactly what because it's not in the public domain yet, but using graphene and other materials we're seeing some interesting behaviours," said Dryfe.
They're also trying to explore different ways of actually making graphene in the first place. This is a major technical challenge, as there's still no great way of making graphene in the right form and in large quantities. There's only so much you can do with sticky tape.
One way to do it is to make graphene oxide and then exfoliate it into its individual sheets. "It's oxidised graphene in the same way that vinegar is oxidised wine," said Dryfe. But just as you can't turn vinegar back to wine, you can't turn graphene oxide perfectly back into graphene.
Another method Dryfe is pursuing takes us back to the idea of lithium-ion batteries. Lithium is one of the smallest ions, and fits between the graphene layers; he's trying to use a bigger ion that could act as a wedge or an atomic-scale axe and break up the graphite into its graphene sheets.
He'll be scaling up that production method with a project at the National Graphene Institute when it opens its doors.
The NGI is a short walk from the existing chemistry and physics departments; its shiny facade mirrors the winter sky behind construction barriers. The exterior walls are decorated with a honeycomb pattern in reference to graphene's lattice of carbon atoms, and when the light hits it right, the different-sized hexagons spell out a formula included in Geim and Novoselov's breakthrough paper. I'm told that Novoselov added a "joke" into the equation on the panels, but no one knows what it is—or if you need a Nobel Prize in physics to find it funny. Geim and Novoselov were unavailable for comment.
Riyaaz Patel, a senior project manager at building consultancy firm EC Harris, showed me round the building in hard hat and safety boots. One of the institute's main features is found in the basement, almost all of which is taken up by a huge, white clean room with strict specifications to keep stray particles in the air to an absolute minimum. A set of corridors allow maintenance to get to the facilities without actually entering the room, and there's even a "clean lift" that travels up to a smaller clean room on the floor above.
The rest of the building contains lab spaces and meeting rooms, with a third floor space providing 20 different gases to experiment with. Patel told me it was placed there to separate it from the rest of the building in case anything blows up. There are also a couple of metal "rooms in a room" that cancel out any magnetic effects that could impact test results.
The whole ground floor is unusable; it's taken up with the ducts, cables, fans, and lighting needed to service the clean room, accessible by steel walkways. Across the building, the services are separated from the labs with a space between the walls—so any vibration doesn't cross over and threaten the most delicate experiments.
It's hoped that the institute's dedicated space, equipment, and research talent will attract industry to bring their ideas and problems (and their markets and funding) to develop graphene into something useable.
Over in the physics department, researcher Rahul Nair showed me an early version of something entirely different to Dryfe's battery: a graphene oxide membrane.
Nair's work focuses on one of the less headline-grabbing properties of graphene: its impermeability. Graphene oxide, which is graphene "decorated" with groups of oxygen, shares only some of this quality. "Graphene oxide is highly permeable to water, but it is impermeable to all gas," Nair explained. That means you could potentially use it as a kind of selective filter known as a molecular sieve.
A major application here could be water filtration, and particularly desalination: A membrane with small enough pores could filter the sodium chloride right out of seawater.
Nair's membranes aren't at that point yet, but he's working on it. The membranes are not just one layer of graphene oxide, but thousands (which means you can actually see them). By modifying the material with other functional groups of atoms, he hopes to reduce the space between each layer to less than the current one nanometre. "If we can reduce this below one nanometre, then we will be able to achieve this cut-off for water filtration," he said.
Post-doc researcher Yang Su showed me a graphene membrane in action. He placed the small, yellowish circle, supported by a white polymer substrate, into a metal pressure cell. He poured water containing a neon orange dye into this, and applied gas to push it through. We waited 15 or 20 minutes, Su stepping up the pressure to try to speed up the experiment so he could make his next meeting. Just as we were scheduling to come back and see the results later, the first droplet appeared on the end of the pressure cell's tap. It was crystal clear; every trace of the dye had been filtered out.
It was an impressive experiment to watch, but we might not see graphene used in water filtration soon. Developing graphene applications isn't just about technological prowess; it's a business problem too.
Nair explained that there's not necessarily a market for graphene membranes in standard reverse osmosis water filtration plants, which might not want to go to the expense of replacing their existing membranes. "The problem is cost," explained Nair. "They may not be very keen to replace their existing technology with a new technology, which is high risk again." Where it could prove more popular is in new processes that don't yet have much infrastructure built, like forward osmosis.
The business outlook is different for another of Nair's applications: a graphene coating that, instead of letting water through, keeps it out. Su showed me a brick that had been half painted with a graphene oxide coating, a smooth black layer on the jagged surface. He dropped a small amount of water on both sides of the brick: on the raw surface, it started to get absorbed almost instantly, but on the painted side it sat on the surface in a bubble.
Here, there's a clear market. "Many people are actually really looking for a barrier coating," said Nair—especially given requirements for protective and anti-corrosion coatings in industries like shipbuilding and nuclear applications. "So now the challenge is just scaling it up and making sure that it behaves exactly the same as [at a] smaller scale."
Scaling up is the key to the next chapter of graphene's story, both scientifically and commercially. While the scientists are working to find ways of effectively producing greater quantities of graphene, and of testing the properties of larger amounts of the material, the business team at NGI are pushing to generate more interest and investment.
Business director Baker explains the problem in terms of "technology readiness level" or TRL, a nine-point scale that estimates the maturity of a technology. One on the scale is the initial idea; nine is a finished product. Graphene, he says, is currently around two or three. "Academics normally do one, two, three," he said. "And I won't say it then gets boring, but their motivation tends to be new discovery."
The problem is, that's still pretty early for a business to be really interested in today's relatively risk-averse climate. Baker said you get what they call a "valley of death" around TRL levels three to six.
The UK has been criticized for running behind in the patent race when it comes to graphene; the US and China have filed many more. Baker admitted that a crowded patent field could have the detrimental effect of deterring companies from getting involved, but is confident that fewer, well-substantiated patents will trump the more "scattergun" approach to patenting in some countries, and that there is still plenty fertile ground for discovery.
And Manchester isn't stopping with the National Graphene Institute. Before the NGI has even opened, another centre is being planned. Baker proudly showed me a small model of the £60 million Graphene Engineering Innovation Centre or GEIC, affectionately pronounced "geek."
This will also be partly funded by the government, with £30 million coming from Abu Dhabi-based renewable energy company Masdar. It's designed more like a factory than the NGI's lab and office spaces: While the NGI will deal with small amounts of graphene, the GEIC will scale up to kilograms and tons. Then, according to the Manchester group's vision: Graphene City. They've already trademarked the name.
The payoff for companies that do invest in graphene is not yet certain, and with the amount of hype around the "wonder material" it's easy to get carried away.
Baker admits there's a chance graphene could fail to deliver on its promises—"but I think it's quite low." Another scenario could see graphene make an incremental difference. Incorporated into a composite material, for instance, it could make something one, five, or 20 percent lighter. That sounds small, but Baker, who comes from an aerospace background, gave the example of an A380 aircraft, where a few percent weight saving could translate to tons.
But where things get exciting is if graphene is able to go beyond gradual improvements and make the most of multiple properties. As well as making an aircraft stronger and lighter, Baker points to its conductivity. Planes usually have a layer of copper mesh to disperse heat from lightning strikes around the body should it get hit—but what if graphene could negate the need for that? Going one step further, what if it could use this heat-transfer property to replace a de-icing system? Or to change the heat signature of a stealthy military plane?
"So all of a sudden you have this multifunctional effect that now means I can change the way I design and make aircraft," said Baker.
"If you have that what I call 'disruptive' effect, graphene can now have a huge impact."
This story is part of The Building Blocks of Everything, a series of science and technology stories on the theme of materials. Check out more here: http://motherboard.tv/building-blocks-of-everythin...