The Best Australian Science Writing 2014 (23 page)

Since then, the surprises have kept coming, as graphene continues to show just how much it may be capable of. For starters, it's the world's thinnest material – with a sheet of graphene just an atom thick, it's a two-dimensional material. You'd need three million sheets to make a stack 1 millimetre high. It's very flexible, yet harder than diamond and 200 times stronger than steel; it is so strong, Columbia University researchers once calculated it would take an elephant balanced on a pencil to break through a layer of graphene as thick as plastic food wrap. It is practically transparent, so dense that not even the smallest gas atoms can penetrate it, and it conducts electricity and heat beautifully. While other commonly used materials such as silicon can match graphene in maybe one or two ways, what makes graphene so special is that it brings so many desirable qualities together in one package. In short, it seems to have it all.

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So what might this marvellous material give us? Some say transparent, super-thin computer and TV display screens that can be rolled up and put away. Slimmer, faster phones that recharge in seconds. Smaller, speedier computer chips. ‘It's beyond our comprehension of what is possible,' says Cathy Foley, chief of the CSIRO's Materials Science and Engineering Division. ‘There will be changes that will blow us away.' Graphene also has researchers fascinated with its potential for biomedical
tools, optics and plastics reinforcement (such as building lighter, hardier aircraft or satellites), as well as creating high-performing solar cells and electric vehicles, and next-generation filters for water purification and desalination. Defence industries are pursuing graphene-based ultra-sensitive gas and chemical sensors, while Bill Gates recently funded a University of Manchester project using graphene to make stronger, thinner condoms.

With such prizes on offer, scrutiny of graphene is intense. In 2004, the year Geim and Novoselov had their Eureka moment, fewer than 500 scientific papers on graphene were published. In 2012, there were almost 9000. Thousands of patents have been issued, and while few graphene-based devices are yet a reality, corporations such as Samsung are racing to control the market. The European Union last year committed €1 billion ($1.5 billion) to its multi-nation research efforts.

In such a busy crowd, Australia's researchers must find ways to stand out. ‘Our funding pool in Australia is much more limited,' says Dan Li, who leads a team of ten, ‘but that doesn't mean we can't do something unique'. A cheerful man with the rapid-fire speech of the very bright, Li is one of Australia's leading researchers in graphene, a field he entered after arriving in Australia on a fellowship from the US in 2006. ‘I wasn't that optimistic about graphene at first,' he admits. ‘A lot of promising materials never make it to market.'

While most researchers have focused on individual graphene sheets, Li is on a quest to use these sheets as molecular ‘bricks', assembling them in different ways to create new materials and devices infused with graphene's talents. He likens graphene to a world-beating athlete – extraordinary on its own and capable of as yet unimagined feats when teamed up with other materials. But as an engineer he knows that architecture is everything. ‘You could have the strongest bricks, but that doesn't necessarily mean
you'll end up with the strongest building – it depends on how all the components interact.'

Having already come up with a groundbreaking and deceptively simple technique which uses water and a series of chemical reactions to separate sheets of graphene and keep them from restacking, Li's team's latest success has been in the area of supercapacitors, specialised batteries already used in, for example, digital camera flashes, laptops and hybrid electric vehicles. Their flaw has always been their bulky size and regular need for recharging; using a graphene-based gel they invented at Monash, Li and his team have been able to produce supercapacitors in the lab that can store triple the amount of energy in a much smaller, and hence cheaper, package. ‘It's a kind of an impossible thing to do, but now we can do it,' says Li. Since publishing results in August 2013, they've been swamped with enquiries from around the world.

Li and his team are also working with Australian and Chinese researchers to use graphene in bone and tissue regeneration, harnessing its superconductivity to deliver electrical stimulation for cell growth. They've also patented a graphene-based foam which, by mimicking the natural structure of cork, is super elastic and lighter than air but able to support objects up to 50 000 times its own weight. Blended with other materials, such as plastics, it could vastly improve toughness and heat resistance. Li, who has received several fellowships for his work and is now looking to the private sector for commercialisation partners, has a preference for graphene projects with a social dividend. ‘I want to get something useful out there into the real world. I'm grateful to Australia for giving me these opportunities and I'd like to make sure Australia gets something in return.'

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University of Wollongong researchers also have high hopes. By placing two sheets of graphene – 25 000 times thinner than a human hair – on a biopolymer (a naturally produced molecule such as a protein), they hope to create a device to implant in the brains of people with epilepsy. The plan is that its graphene electrodes could detect an impending seizure and trigger the release of anti-seizure medication. Researchers last year also devised a way of using textile techniques to spin nano-fibres of graphene, designed to give super strength to materials used in bullet-proof vests and aircraft fuselages. They're working, too, in collaboration with Australian colleagues on applying graphene in nerve regeneration for damaged limbs.

Professor Gordon Wallace, executive research director of the Australian Research Council Centre of Excellence for Electromaterials Science, says while the scientific community is taking a wait-and-see approach, the excitement around graphene is more than hype. ‘The question is whether we, as scientists, technologists and engineers, can take its amazing properties from the nanomaterial world to the level of macroscopic devices,' he says. ‘And that's not graphene's challenge – it's ours.'

Graphene is not giving up all its secrets easily. Its amazing properties, for instance, mean that electrons surge through it at a constant speed of a million metres per second – yet it's not fully understood how they can be guided. Moving from the nanoscale to the commercial scale remains hugely complex. Making enough of it is still tricky. ‘We want to be able to press a button and have kilometres of the stuff come out,' says the CSIRO's Cathy Foley. At the moment, complex chemical and thermal processes are used to obtain graphene, but most take hours or days, involve toxic ingredients or only produce small amounts, not the mass quantities consumer products would need.

One group of CSIRO researchers thinks they've solved that conundrum, in part thanks to a bad cold. In 2011, PhD student
Donghan Seo was at home in Sydney nursing a cold with lemon and honey tea and reading the Bible. When he came to ‘Exodus', which talks of ‘a land flowing with milk and honey', he had his own epiphany. ‘I suddenly thought, why wouldn't honey work in making graphene? I had a strong religious feeling that it would work, and from a scientific point of view it made sense.' The next day, he took some honey to the lab, where he subjected less than a gram to plasma testing, pelting it with highly charged ions to purify it down to its basic carbon structure. The CSIRO Plasma Nanoscience team he's part of can now create a 1 centimetre × 1 centimetre sheet of graphene in nine minutes – ‘while I go and get a coffee,' he says. The team claims they have already used honey-derived graphene in a gas sensor and butter-derived graphene in a battery. ‘We know it works in the lab,' Seo says.

In the meantime, Australia has graphite deposits, and several companies keen to begin mining. Adelaide-based Archer Exploration Ltd hopes to fire up its new mine on South Australia's remote Eyre Peninsula within two years. With world graphite prices rising, high-quality deposits ‘are ripe for development,' says Archer's managing director Gerard Anderson. Back at the University of Wollongong, Gordon Wallace says he'd love to use local graphite. It's one way, he says, in which Australia has the chance to help shape the era of graphene.

‘But the window of opportunity for that is not going to be there forever,' he says. ‘We need to get that alignment of the mining opportunities with the technical expertise, from graphite to graphene to graphene-based devices, as quickly as possible. We won't be the only people thinking of doing that – but we have to be nimble enough to be the first.'

The CAVE artists

Here be dragons

Pitch fever

Trent Dalton

He was born before the first pitch drop, at 13 minutes past four on the morning of 12 January 1935. He knows precisely what time he was born because time is precious to him. Three seconds to wipe his nose with his hanky and place it back in his right pocket. Six seconds for his black leather shoes to shuffle across a tiled floor from the entry of the University of Queensland's physics building to a bench seat outside lecture theatre 222, which accommodates almost 200 science students engrossed in a unit called ‘Earth 1000'. One second to brush his snow-white hair across his scalp, from left to right. Half a second to clear his throat. Two hours and 13 minutes to tell the story of the world's longest running laboratory science experiment, the Pitch Drop Experiment.

Professor John Mainstone, retired head of the UQ physics school, leans towards a glass display cabinet outside the lecture theatre. Inside it, on a shelf, sits a glass dome encasing a funnel of hard, black, tar pitch, a substance so dense and brittle that it would shatter under a swift hammer blow. Yet this pitch – solid to the naked eye – has been moving heartbreakingly slowly through the funnel over the course of 86 years, producing only eight monumental drops that have fallen at increasing intervals:
seven years, eight years, nine years, 12 years. The last drop fell on 28 November 2000. And the kicker – the scientific anomaly the experiment's creator, the late UQ physics head Thomas Parnell, never could have predicted – is that nobody has ever seen a drop fall.

Mainstone's eyes fix on a globule of pitch with a stem stretching 4 centimetres from the bottom of the funnel, at once falling and solid. This is the ninth drop. It hangs like a tonsil, like a fig, like a bell refusing to toll. Suspended in time. Pregnant. Perfectly pendent. Mainstone inspects this drop five times a day. He is the custodian. He has dedicated 52 of his 78 years on Earth to waiting for a single, majestic splashdown – an event he estimates will unfold in the space of one-tenth of a second.

Twice he has come agonisingly close, on drops seven and eight in 1988 and 2000, but physics conspired with calamity and the gods of science laughed in his puzzled face. Now he watches the ninth drop like a sentinel, protects it, cherishes it, stares at it through the cabinet glass the way new mums stare through nursery windows. And the world stares with him. Fixed beside the glass dome is a Logitech video camera with a Carl Zeiss lens streaming live footage of the pending ninth drop to internet audiences across the globe.

Between 17 February 2012 and 17 February 2013 the University of Queensland's School of Mathematics and Physics pitch drop live streaming page welcomed 361 876 unique viewers. ‘The pitch drop junkies,' Mainstone says. More than a quarter of a million people around the planet tuning in, all desperate to be the first to see a drop fall. Some stare for minutes, some for hours, faces still, mouths agape, lost in time and space, consumed by the hypnotic anticipation of the drop. The still and stubborn drop questions their notions of time, challenges the way they lead their lives, dares them to attend to more pressing matters in the 24 hours they've been allotted by the universe each passing day.

Each morning Mainstone opens his emails to respond to questions and theories sent to him by South American pitch drop enthusiasts, Inuits with predictions on the ninth drop's time of splashdown, Dutchmen giving suggestions on camera angles. He's been interviewed by journalists from
The New Yorker
, featured in Russian news spots and the Polish edition of
National Geographic
. On 14 February 2013, Mainstone gave an interview on America's National Public Radio network announcing his belief that the ninth pitch drop could fall this year, and, indeed, any second now. Giddy with excitement, some 14 958 global viewers – 10 372 Americans alone – promptly clicked onto the pitch drop page, a wave of interest so big it temporarily crashed the UQ School of Mathematics and Physics website.

In the foyer of lecture theatre 222, Mainstone laughs, stroking his chin thoughtfully, as he often does, looking at a black-and-white photo in the display cabinet of his predecessor Parnell, pinned next to the world's longest running lab experiment's Guinness World Records certificate. Beside the funnel of pitch is a square clock, showing Eastern Standard Time, its little hand making its eternal journey around the clock face.