Tag: graphene

Cool graphene to solve chip burnout

The latest insight into the world of graphene has revealed the potential to stop laptops and other devices overheating, offering an end to burnt-out devices and scorched thighs.

As well as much vaunted possibilities for a future generation of non-silicon based chips, graphene has further applications for electronic devices.  An announcement last week highlighting the material’s piezoelectric properties, for example, demonstrated its flexability.  Indeed, one of the first applications we are likely to see with graphene is in flexible touchscreens.

Now, with a twist on the way the wonder material is usually constructed, a team of researchers from the US and China have shown how it can conduct heat to manage heat dissipation.

According to research led by the University of California, Riverside, by engineering graphene it’s possible to make much more use of the thermal conductivity found in its original state.

This could open up the material being used with a range of electronics, or even with photovoltaic cells, as long as the cost of the material can be kept down following the necessary tinkering.

This is because carbon materials – like the one-atom-thick graphene – are made up of two different isotopes, and by engineering the amount of each it is possible to greatly enhance heat conductivity.

While the applications for such engineered graphene are likely to be in thermal interface materials for chip packaging or transparent electrodes for PV cells, the researchers also reckon that it could help produce chips that work at lower processes.

As chips get smaller they generate more heat, and such a thermal conductor could be used to help silicon from overheating as chip designs get smaller and smaller, either as a heat-spreader or as interconnect wiring.

Graphene chip commercialisation gets 'nanowiggle' boost

Despite the relatively recent discovery of graphene it is being widely touted as revolutionising various industries due to its staggering properties.

Such is the potential that its two Manchester University discoverers were recently told that they would receive knighthoods, while a government fund has been set up to aid commercialisation.

Despite many eye-catching developments in labs across the world, many of the great claims about graphene are yet to be finalised.

One area where big things are expected of graphene is in the microchip industry.  Depending on where you ask, though, it seems that overthrowing silicon-based electronics is still quite far off.

However, scientists at the Rensselaer Polytechnic Institute think that their new graphene production method could help bring about commercialised electronic applications.

The benefits of doing so are potentially vast. Graphene has the possibility of push past the blocks to lower process chip designs that will be found in silicon at the 7nm process, and could open doors for spintronics devices based on spining electrons to store information.

Using a powerful supercomputer, the team at Rensselaer have been able to understand recently hypothesised forms of graphene nanoribbons, fantastically dubbed ‘nanowiggles’, which can be tuned and customised to specific tasks.

This is useful as it provides a basis of knowledge of how to work with the nanomaterials that could be instrumental in defect-free graphene nanostructures.  Up until now, this has caused many problems in developing graphene, creating a “near insurmountable barrier between innovation and the market” according to the team.

Graphene nanowiggles can be easily and quickly produced without defects.

The approach means a different way to create graphene structures.  In this case they are chemically formed atom by atom into bespoke nanoribbons, whereas usually graphene material design involves taking existing material and cutting into new structures.

The team says nanowiggles, named after their zigzag edges, can be easily manufactured and modified to display “exceptional conductive properties”.  The ability to customise the band gaps and magnetic properties of nanowiggles means that the conductivity can also be fine tuned depending on the intended application.

According to the team, the research should assist in designing new graphene based devices, potentially covering photovoltaics, semiconductors and spintronics.  Using the CCNI supercomputer at Rennsselaer for a helping hand, the time before calculations are complete can be cut to just a few months.

Scientists create graphene electronic mixer

Researchers at Sweden’s Chalmers University have walked away from their massage tables having pummelled out a CMOS compatible graphene based electronic mixer.

Electronic mixers combine multiple input signals into one or two composite outputs and while they had been successful at getting one to go at microwave frequencies they think it could be ready to scratch up to the terahertz range.

Jan Stake, professor of the research team, says that the performance of the mixer can be improved by further improving the circuit, and improving the on-off ratio and finding a really good DJ.

Stake is a big fan of G‐FET, who is not a DJ from Slut in Vasterbotten but a topology which pushes the mixer into higher frequencies.

This helps it to push the exceptional properties of graphene and paves the way for future technologies operating at high frequencies which only your dog can hear.

This will be jolly useful for security radar systems, radio astronomy and environmental monitoring or anywhere you might need a large array of highly sensitive, and compact mixers.

It all works because graphene can switch between hole and electron carriers thanks to its field effect. The mixer is built using only one transistor which makes it very small.

It means that scientists can now think of the possibility of advanced sensor arrays for imaging at millimetre waves and even sub millimetre waves as G-FET technology progresses. Well, it beats going to the pictures.

The full text can be found here. 

Select Committee begins inquiry into research "valley of death"

The government has started a Select Committee inquiry into the “valley of death” that is thwarting scientific research from reaching commercial levels in the UK.

The Science and Technology Committee has opened up an inquiry into the “difficulty of translating research into commercial application”, with a lack of investment cited as a driving force.

Science Minister David Willetts recently discussed the situation in the UK. Research institutes have ideas that can’t proceed without a proof of concept that would enable a venture capitalist to get onboard with further development. This is widely referred to, as Willetts mentioned, as “the valley of death”.

The government has responded to this with its recent strategy for life sciences, which aims to help medical research push research into the product stage.  For many start ups this can be the killer blow.

TechEye was told that the inquiry will, however, be a wider look into the research commercialisation environment throughout the UK, taking in the full scope of science and tech research.

Indeed, the government is all too aware of the precarious position of moving into a manufacturing and knowledge-based growth economy during the economic depression without supporting research and development. 

This has led to the recently published Innovation and Research Strategy for Growth TechEye spoke to the Department for Business, Innovation and Skills which told us commercialisation is a main driver for the strategy.

Of course, as we found out at the time, the pledged amount to support research is arguably been a pittance compared to what’s needed for real change.  The laudable decision to support the development of graphene products, a prime example of the UK’s ability to innovate, may not be enough to stay at the forefront of international developments either.

Indeed, it seems that with the Select Committee inquiry following the “key recurring issue” of producing a final product there are still concerns over the UK leading on innovative products.

According to Campaign for Science and Engineering (CaSE) managing director Imran Khan, while there is great work done in the UK there is not always enough support for great ideas – despite the clear benefits.

“There is a slight tendency in the UK to be pessimistic about our commercialisation record – we’ve actually got some fantastic companies successfully bringing technologies to market, with new ones every week,” he told TechEye.

“For instance, the Technology Strategy Board works with companies to commercialise research, generating £7 return for the economy for every £1 invested, and there are really exciting companies working on everything from new drug delivery mechanisms to clean energy.”

Crucially, Khan says, the reason this is so important is “that we’re not fulfilling our potential.”

“By most measures we’ve got one of the most productive and high-quality research bases in the world,” Khan says, “and yet compared to our international competitors we have a much smaller high-tech sector.”

Khan says that less than one percent of the UK’s economy is spent on research and development – compared to over two percent for countries like the US and Germany.

“The reason it’s so important we fix that is we really need to rebalance our economy,” Khan believes. “It’s pretty obvious that the UK’s future is not in cheap labour or natural resources, and we’ve seen how foolish it is to just rely on the financial services sector – so we need to make the most of our advantage in science and engineering and turn that into economic growth.”

And if the money is there, the UK is the kind of country that can really succeed, according to Khan: “We’re one of only a few nations in the world that could genuinely become the high-tech leaders of the coming century, and it’d be a shame if we passed up the opportunity.

“The Government needs to be putting way more funding into organisations like the Technology Strategy Board, and encouraging an entrepreneurial culture amongst the UK’s young scientists and engineers while they’re still studying and researching.”

Everyone would be a winner, Khan thinks: “If we get it right, we’re not just going to put the UK economy on a sustainable and successful footing, but we’ll also get advances like better healthcare, cleaner energy, and faster communications along the way – it’s a win-win scenario.”

The Science and Technology Select Committee is now requesting written submission from anyone who wants to give some feedback on how to improve the transition from research to commercial applications.

IBM proves there is life after silicon

It’s a widely held belief that conventional silicon based circuitry will become unviable once manufacturing processes reach 7 nanometres.

Further than this, current silicon chips would be unable to function and the threshold is slowly approaching as chip designs edge closer to single digit processes.

This means that, in order to progress in line with Moore’s Law, someone’s got to find new ways to develop chips.  

IBM has been one of the firms at the forefront of developing one of the brightest hopes for the future chip, graphene.  Now, Big Blue has announced a series of prototype chips based on some of the most promising alternative designs.

A the IEEE International Electron Devices Meeting, IBM boffins lifted the lid on some of their attempts to produce a new breed of chips, which crucially are compatible with current CMOS production technology on 200mm wafers.

IBM scientists have, for the first time they claim, managed to create a graphene device that is CMOS compatible and able to function at up to 5 GHz while keeping stable at even 200 degrees. 

The design is a change to current attempts at graphene transistor structures.  According to the team, this involves developing an embedded gate structure that “enables high device yield on a 200mm wafer”, rather than trying to deposit gate dielectric on an inert graphene surface.

Another technology which IBM thinks could revolutionise chip engineering is Racetrack memory.  This combines the attributes of magnetic hard drives and solid state memory. The company has a prototype which exhibited both read and write functionality of “256 in-plane, magnetized horizontal racetracks”, which we’re sure is quite good.

If scientists are able to make the technology more reliable, after seven of years of development so far, then it could lead to a new form of computing which would allow masses of data to be accessed in a billionth of a second, the company claims.

Carbon nanotubes are often talked about as a future technology, and IBM researchers have developed what they claim is the first transistor with sub-10nm channel lengths.  According to IBM it’s “outperforming the best competing silicon-based devices at these length scales”.

Outside of Big Blue’s labs, another announcement today showed that there is indeed life after silicon.

Advances in the use of molybdenite-based chips at the Laboratory of Nanoscale Electronics and Structures (LANES) in Switzerland have given silicon a run for its money. 

The lab began looking at molybdenum disulfide (MoS2) earlier this year, and reckon that it offers advantages over silicon in terms of minituarisation, electricity consumption and mechanical flexibility.   In fact, they even think it’s better in some ways than attention-hogging graphene.

LANES says the material is a relatively abundant, naturally occurring mineral, and its semiconducting properties make it a bit nifty for using in transistors.

The main reason boffins are so excited about it is that it allows for reducing transistor size, enabling further miniaturisation – the holy grail for chip development.

It’s possible, claim the scientists, to construct layers of molybdenite that are just three atoms thicks, which the researchers say is at least three times smaller than feasible with silicon. Even at this point Molybdenite can conduct and should remain stable.

The chips could possibly be used in flexible electronics, one of the first applications that expected for graphene.

Which of the alternative materials could take the crown, if at all, is unclear – there’s still a long way to go before silicon reaches a dead end.



Graphene transistors communicate with living cells

It seems that nowadays graphene, which we are contractually obliged to refer to as a ‘wonder material’, is everywhere.  From applications in flexible touchscreens, a new wave of inkjet-printed ultrafast circuits or even a foam used to detect explosives, graphene could be set to revolutionise, well, everything.

Though we’re still awaiting the first applications of graphene to actually become commercially available – this is likely to be smartphone touchscreens, we are told – rarely a day goes by without new potential uses cropping up.

Now, researchers at the Technische Universitaet Muenchen have found a way to make the material even more pervasive.

This is because a team led by Dr Jose Garrido has been working on combining graphene with living cells.  Essentially this means that the material could, in the not-too-distant future, actually be making its way inside your brain.

This is not the first foray into electrical components in conjunction with biology. Many boffins are already working on getting chip and tissue to work together.  However, Garrido reckons that the use of graphene presents a much more viable method for achieving this goal than with silicon based circuitry.

Problems that have hampered silicon development include difficulty opereating in a wet  liquid environment, and being too ‘noisy’ to communicate with nerve cells. Furthermore, silicon is not very flexible, unlike graphene.  This means the researchers believe silicon development could in fact be a “dead end”.   

Graphene, on the other hand, is chemically stable, biologically inert, and can be fabricated relatively cheaply and easily.

Now Garrido’s team has developed, for the first time, a graphene-based transistor array that can be combined with living tissue, and crucially, pick up on electrical signals that are generated. 

This means a direct interface between microelectronic devices and nerve cells – essentially the holy grail of cyborg-style integration of technology into the human body.

This could lead to, for example, sensors inside a person’s brain, eye or ear to help compensate for damaged cells.  Unfortunately it seems that the researchers have not outlined any Deus Ex-style augmentation such as night vision or a bioluminesenct retina at this point.

The method involved using 16 graphene solution gated field effect transistors fabricated on copper foil.  Variations of the electrical and chemical environment around the FET gate could then be sensed and in turn converted in a variation of the transistor current.  

The team grew a layer of biological matter similar to heart muscle cells, and the team found that they could pick up easily the signals transmitted by the nerve cells, in a way that decades of silicon development has struggled to do.

While the research is clearly a long way from real world applications, the team believes that it shows that key performance characteristics are feasible. 

According to Dr Garrido, there are some intriguing applications that being worked on right now.

“Our main goal is the development of grapheme for flexible brain implants,” he told TechEye. “Currently, we are considering two main applications in neuroprosthetics – cortical implants and retinal implants. Both applications will benefit from the flexible technology.”

Garrido tells us developments are in early stages, though working prototypes are expected within the timeframe of just a few years: “Currently, we are at the very beginning,” he said. “In particular, we have to transfer our current technology based on rigid substrates to a more suitable technology based on flexible substrates. We are part of an EU consortium where there are several partners, industrial and hospitals, interested in these applications, and we already have some experience with the technology needed for such applications.”

Fully characterised demonstration prototypes are expected in two to three years,Garrido tells us. After that, “preclinical studies will be necessary before we can expect approval from the FDA and European Medicines Agency.”

Garrido believes that graphene offers serious benefits over silicon-based devices: “The main advantages are chemical stability and biocompatibility of graphene films, facile integration with flexible technology, and the excellent performance of graphene sensors in terms of sensitivity.

“Our preliminary biocompatibility studies, using pure retinal ganglion cells from postnatal rats, has shown that graphene films exhibit similar performance than the standard glass substrates used for cell culture.

“The high carrier mobility in graphene results in devices with very high transconductance, i.e. ‘gate sensitivity’. In comparison to Si counterparts, the graphene FETs exhibit close two orders of magnitude increase in transconductance.

Garrido explains: “It’s not only the signal sensitivity which matters, also the noise level. Our graphene FETs show a noise level which is at the same level that ultra-low noise Si FETs. By improving the graphene growth and fabrication, we expect further lowering of the noise in these devices. We hope to be able to detect signals below one microvolt.

“One important remaining issue concerns long term stability under physiological conditions. It’s worth remembering that we’re talking about a material which is one atom thick. We only have tests performed in-vitro during less than 10 days. Still, we have to perform the long term tests.” 

Inkjet printers bang out graphene circuits

Another application of that wonder material graphene has emerged, adding to its growing list of strange and exciting potential uses, with a breakthrough in printed circuits.

According to work by Cambridge University, the possibilities of using graphene in printed circuits has received a significant boost with a new production method.

Printed circuits are nothing new, but the main problem that has held back cheaply produced thin film electronics, leading to flexible and transparent electronics, is that the processing power is far too slow.

This usually involves mixing in conducting polymers with inks that can be printed right onto substrates.  Compared to traditional chips they are miles behind producing computional speeds that consumers have grown accustomed to.

However, advances made by graphene expert Andrea Ferrari and colleagues at Cambridge have shown that the revolutionary properties of graphene could mean that printed circuitry could soon be viable.  Among the multitude of graphene applications currently researched in labs around the world, its use in next generation chips is strongly touted as it has the potential for extremely high speed processing.

The problem up until now is that it is difficult to get graphene to incorporate with droplets needed to function with an inkjet printer.

The results of the study, published on Arxiv, shows a method involving chipping flakes of graphene from a block of graphite with a chemical process, and filtering out any printer clogging bits.

Apparently the team has been able to knock out a number of circuits for thin film transistors, according to Technology Review, but the research appears to be in its infancy.

According to the team, the discovery will pave the way for “all-printed, flexible and transparent graphene devices on arbitrary substrates”.

TechEye spoke to Professor Andrea Ferrari, who told us that the developments with inkjet printing could lead to flexible and transparent electronics, smart textiles, games, toys and RF tags.

According to Ferrari, even though he and the team have just completed early stage research, the technology is already looking promising: “This is a first demonstration, but already at this stage, at the first attempt, our mobility is much bigger than the biggest reported to date for printed semiconductor electronics.

“This is just the beginning. We are in contact with potential industrial partners and we hope to have some prototypes ready in the near future.” 

UK government science spending claims blasted

The British government’s claims over science and engineering spending have attracted ire from the opposition and a leading science and engineering body over its continued cuts.

In a Commons debate, science Minister David Willets heralded a total of £793 million spent for science and research 2011-12.

Responding to a query from Conservative MP Jane Ellison over what capital expenditure has been made available, Willets pointed to initiatives such as “an additional £145 million in high performance computing”.

The Department for Business, Innovation and Skills informed TechEye that the new figure of £793 million capital expenditure accounts for; £548 million capital allocations for science; £100 million capital spending on science as announced in the Budget 2011; and the high performance computing spending announced at the Party Conference.

This also includes recent announcements for £50 million funding for graphene research.

Despite Willetts’ claims that capital spending on science and research is “comparable” with figures for spending under the previous administration, he has been attacked by the shadow science minister.

Labour MP Chi Onwurah said that recent claims that “all long-term economic growth was linked to innovation”, businesses are being “denied the innovation support they need”.

Citing cuts of “12 percent” to the Campaign for Science and Engineering (CaSE), she asked the opposition minister “If innovation is the engine of growth, why is the Secretary of State doing so much to damage it?”

CaSE’s director, Imran Khan, also feels that, despite some high profile announcements, the government is still not doing enough to support its claims to bring about a shift in economic focus for innovation and development.

Khan told TechEye that the government needs to get serious about its support of science and innovation if it wants to use it to boost the ailing economy.

“We have to look at the big picture,” Khan told us. “While the government has announced capital funding for projects recently, which CaSE backs, the landscape is ultimately one of cuts.”

Khan continued: “If we want to base a rebalanced economy on innovation as government rhetoric has indicated then the only way to achieve this is to back the sector to support more discoveries. Vast amounts have been spent backing the bankers, but by 2014 there will be less funding available than there is now for the science sector.

“If the government wants to support future development then more spending is needed.”

Scientists create carbon nanotube mechanical system

Materials Today reports on a new way to use carbon nanotubes to manufacture mechanical components, which can then be used in micro-machines.

The problem so far has been in reducing the size of mechanical systems. Other corners of the scientific community have managed to miniaturise components to the nanoscale level, but shrinking mechanical systems has proved difficult.

A scientist, Manuel Belmonte, has implanted carbon nanotubes in silicon nitride, a ceramic. Using this technique he and his team have increased electrical doncutivity by 13 orders of magnitude.

They then used an existing technique, electrical discharge machining (or EDM), to create a microgear with relatively little trouble.

EDM usually means a target material has to be electrically conductive, giving rise to problems with using the technique on ceramic materials. It uses, says Elsevier, a spark of electricity to get rid of unwanted materials – with the remaining material creating complex shapes.

According to Belmonte, the breakthrough should lead to the manufacturing of intricate 3D components. In turn advanced ceramics could become a viable option along with other insulating materials. 

The full, in-depth article is available here

UK graphene fund is a stepping stone to EU project

The government announced a £50 million investment into graphene development.

Chancellor George Osborne outlined plans to create a Graphene Global Research and Technology Hub to commercialise the wonder-material, as part of a wider £200 million investment into science.

Garphene is already sparking experiments into many potential uses, with plenty labs across the world vying to create the first commercialised products from the atom-thick material, first created at the University of Manchester.

Companies such as Nokia and Samsung have been keen to stay at the forefront of its potential commercial use, with applications ranging from flexible touchscreens to transistors or superfast internet.

Speaking at the Conservative conference in Manchester, Osborne promised a national research programme to take graphene from the “British laboratory to the British factory floor”.

And with the government promising to get the UK producing again, its leading stance in graphene development could provide many potential jobs and other business boosts to the economy.

A plan for support that will push the current research into commercialised production is being looked at by the Engineering and Physical Sciences Research Council (EPSRC) alongside the Technology Strategy Board (TSB): “The Research Hub will certainly allow us to explore deeper into the vast applied potential of graphene, but also will lead to many new exciting results, continuing the scientific excellence in the UK.”

The scientific communitiy has applauded the move to invest in graphene, and is a sign of initial science and engineering funding that has the potential to reap financial benefits for the economy.

One leading graphene expert, Prof Andrea C Ferarri at the University of Cambridge, tells TechEye that he welcomes the increase in funding, but pointed out that this is really a preliminary step.

He believes that it is a good starting point, but the main aim at the moment is to secure funding from the EU Graphene Flagship project which has €1 billion available, with individual groups able to apply for up to €100 million.

“£50 million enough to start getting additional investment from the private sector, but it is not necessarily enough for developing commercially,” Ferarri told us. “The aim of the funding is to bring graphene to market, not just research. It is not as much as some other countries are putting into graphene, but certainly keeps the UK at the forefront of development.

“It gives a clear signal that the UK is backing graphene, and shows that it is really serious about it.

“But this investment  is a step towards getting the flagship funding.”