The age of graphene
It’s strong, it’s flexible, and it’s here. After a long time cooking in the labs, the first graphene-based products are beginning to trickle out into the world of smartphones, wearables, batteries, virtual reality, sports equipment, super-capacitors and supercars.
It’s a material that some believe has been coerced from abandoned space ships, left on earth by distant races years ago. While that’s a little unlikely, the power of this super thin, strong, conductive and all-round amazing material is deserving of such a conspiracy.
It’s been over 60 years coming as scientists and manufacturers alike have struggled to harness the power of this awesome material – but it’s closing in on revolutionising so many things we’re using day to day.
What if you could charge your phone in five minutes? That’s the thinking behind the Zap & Go charger, the first graphene supercapacitor charger, which uses tech that could eventually replace lithium-ion batteries in phones.
“It charges fully in five minutes,” says Quentin Lemarie at the Oxford-based Zapgocharger, which is fresh from a surge of crowdfunding on IndieGoGo.
Benefiting from graphene-enhanced electronics, the working prototypes of this portable charger – which is about the same size as an iPhone 6 – contain a 750mAh battery, which is about half the capacity of an iPhone battery.
“You can charge half of your phone in five minutes,” says Lemarie. “Our eventual aim it to replace the batteries in phones, and to do that we need to make it smaller and thinner. We’re not far off.”
Graphene could allow cars to gather, and store, the energy they produce as they move – thereby saving precious fuel. KERS (short for Kinetic Energy Recovery System) was all the rage in the ultra-secretive sport of Formula 1 a few years ago.
Now called ERS, these power units use graphene supercapacitors, and pretty soon so will freight. Saving a staggering 15-25% on fuel consumption, patented nanoporous carbide-derived carbon, better known as ‘curved graphene’, is being used by Skeleton Technologies and Adgero to produce a hybrid system for road freight vehicles where a bank of high-power car batteries – called SkelCaps – work alongside an electrically-driven axle and automatically control the energy recovery.
Spanish car manufacturer Spania also uses graphene electrodes in a 12-volt starter battery of its Spano supercar, which means its starts-up more quickly as well as being cheaper, smaller and longer lasting.
More speed, more grip, stronger and puncture-resistant tires. That’s the reason why Vittoria Industries is putting graphene into its top of the range Corsa tires. However, graphene is also going into Vittoria’s carbon wheels.
“We are using are graphene-nanoplatlets in the resin, which we impregnate into the carbon fibre,” says Giulio Cesareo, CEO of Directa Plus, which supplies the graphene.
“The objective was to improve mechanical properties and thermal conductivity, and we were able to get mechanical improvements close to two digits.” The end product is lighter, stronger, and more flexible, with that extra thermal conductivity meaning better stiffness and grip.
Graphene paint has also been used to add strength to tennis racquets – such as the Head Graphene XT Radical series– though that one is as much about marketing as science.
Soon, the Fitbit, Jawbone, Misfit and other fitness ‘wristables’ are soon going to look clunky – and dumb. Graphene promises not only much thinner (even paper-thin) wrist bands, but they’ll have integrated graphene light sensors and circuitry that bring extra functionality just by using light.
“By shining light on the skin you can find a lot of interesting things about the body,” says Stijn Goossens, Postdoctoral research engineer, Nano-optoelectronics, Institute of Photonic Sciences (ICFO) in Barcelona. “The colours of light absorbed by the skin tells you about heart rate and blood oxygen.”
That’s great for general fitness metrics, but it’s also really useful for, say, premature babies; blood that is low in oxygen is blue-purple, while oxygen-rich blood is bright red.
More useful windows
Graphene’s transparent appearance and super low-power meansnames it can be used in some unexpected places. Since it’s got super-low power consumption and it’s highly sensitive, the tech could be used in inert materials such as windows.
“The light sensors can be embedded in anything, so you could think about putting it in windows or other places where there’s no power, such as packaging,” says Goossens at the ICFO.
“In a window in a building it could detect whether it’s night or day for your curtains to open or close automatically.” It’s also the first step along the way to windows managing to harvest energy during the day and illuminating during the night – while still being transparent.
However, a more short-term killer app is probably as a hands-free system in a car. “You would need four sensors to detect a directionality, so in a car window it could detect motion sensing – you could change the track on a CD just by waving your hand,” says Goossens.
The advantage over existing tech is that graphene can be completely transparent – the entire window could be full of sensors.
Graphene can also be used to make super-thin, super-sensitive image sensors that can detect invisible infra-red light. That means night vision goggles working on graphene-based CMOS sensors that could cost as little as £10 instead of £20,000 once graphene sensors are mass-produced (augmented reality headsets with night vision, anyone?) and spectral applications to differentiate between different organic materials.
“We will also be able to put graphene spectrometers in your phone, so you can see if a mango in a supermarket is ripe, or whether the tyres on your car are worn, or whether a wood product is real wood,” says Goossens at the ICFO. It could also detect harmful chemicals in food.
How close is this? Graphene spectrometers in phones could take as little as two years, but only if there was a lot of targeted investment by one of the big phone/component manufacturers.
Speeding up swimmers
Launched last month at at ISPO Munich by Italian sportswear brand Colmar
“It helps transfer heat from the hot zone to colder zones one, keeping the wearer comfortable.”
G+ – being used here for the first time – also reduces friction with air and water, so could be useful for increasing agility for general sports, as well as for increasing speed, perhaps for swimmers.
Making water safe
Water, soil and air purification is also possible with graphene. One of these products – Grafysorber from Directa Plus – is super-absorbent, and ideal for oil spills.
“One gram of Grafysorber is able to absorb up to 90 grams of oil,” says Rizzi. The mobile Grafysorber Decontamination Unit contains a plasma machine to produce the wonder material on-site, which is even able to return contaminated water to safe levels for drinking.
“Normally you have to use biological or chemical process to treat contaminated water, but Grafysorber is completely chemical-free,” adds Rizzi.
Love the glove
It’s not often said, but virtual reality isn’t not very convincing. It needs movement sensors to become so, and what better than a pair of super-responsive gloves that are sensitive to tiny changes in motion and temperature?
“Graphene flakes printed in very thin layers are very sensitive to strain,” says Dr Darryl Cotton, Senior Researcher, Nanotechnology, Nokia Research Center, Cambridge. “We’ve also put reduced graphene oxide into a temperature sensor.”
The end result is a glove that, for now, sets off surface-mounted LEDs, but they’re so thin and flexible that they could be used to make virtual reality environments responsive to tiny movements in fingers.
Printed electronics are they next big thing, and graphene is at the forefront. Costing just a few pennies each are paper wristbands or tickets, which have graphene ink printed onto them. In a recent demo, the proximity of a graphene RFID tag to a reader caused a picture to be taken of the wearer or holder.
“This could be used in closed environments such as airports for monitoring passengers boarding a high security flight, or on the London Underground to track which entrances and exits passengers take just by tracking their ticket,” says Dr Thanasis Georgiou, VP, Graphene Security Ltd., Photon Science Institute, University of Manchester.
“Products in supermarkets could have [graphene-based] RFID technology on them so you could know in real-time where products are.”
As well as making shop-lifting much harder, and perhaps even getting rid of the checkout altogether, a connected Internet of Things-like system would be able to see instantly when stocks are running low of specific products.