Billions of cubic meters of water are consumed each year. However, lots of the water resources such as rivers, lakes and groundwater are continuously contaminated by discharges of chemicals from industries and urban area. It’s an expensive and demanding process to remove all the increasingly present contaminants, pesticides, pharmaceuticals, perfluorinated compounds, heavy metals and pathogens. Graphil is a project that aims to create a market prototype for a new and improved way to purify water, using graphene.
Graphene enhanced filters for water purification (GRAPHIL) is one of eleven selected spearhead projects funded by The Graphene Flagship, Europe’s biggest initiative on graphene research, involving more than 140 universities and industries located in 21 countries. Chalmers is the coordinator of the Graphene Flagship.
The purpose of the spearhead projects which will start in April 2020, building on previous scientific work, is to take graphene-enabled prototypes to commercial applications. Planned to end in 2023, the project aims to produce a compact filter that can be connected directly onto a household sink or used as a portable water purifying device, to ensure all households have access to safe drinking water.
"This is a brand-new research line for Chalmers in the Graphene flagship, and it will be a strategic one. The purification of water is a key societal challenge for both rich and poor countries and will become more and more important in the next future. In Graphil, hopefully we will use our knowledge of graphene chemistry to produce a new generation of water purification system via interface engineering of graphene-polysulfone nanocomposites," says Vincenzo Palermo, professor at the Department of industrial and materials science.
Graphene enhanced filters outperforms other water purification techniques
Most of the water purification processes today are based on several different techniques. These are adsorption on granular activated carbon that removes organic contaminants, membrane filtration that removes for example, bacteria or large pollutants, and reverse osmosis. Reverse osmosis is the only technique today that can remove organic or inorganic emerging concern contaminants with high efficiency. Reverse osmosis has however high electrical and chemical costs both from the operation and the maintenance of the system.
Many existing contaminants present in Europe’s water sources, including pharmaceuticals, personal care products, pesticides and surfactants, are also resistant to conventional purification technologies. Consequently, the number of cases of contamination of ground and even drinking water is rapidly increasing throughout the world, and it is matter of great environmental concern due to their potential effect on the human health and ecosystem.
Graphil is instead proposing to use graphene related material polymer composites. Thanks to the unique properties of graphene, the composite material favours the absorption of organic molecules. Its properties also allow the material to bind ions and metals, thus reducing the number of inorganic contaminants in water. Furthermore, unlike typical reverse osmosis, granular activated carbon and microfiltration train systems, the graphene system will provide a much simpler set up for users.
Graphil will not just replace all the old techniques, but significantly out-perform them both in efficiency and cost. The filter works as a simple microfiltration membrane, and this simplicity requires lower operation pressures, amounting in reduced water loss and lower maintenance costs for end users.
Upscaling the technique for industrial use
Chalmers has, in collaboration with other partners of the Graphene Flagship, investigated during the last years the fundamental structure-property relationships of graphene related material and polysulfones composition in water purification. A filter has then been successfully developed and validated in an industrial environment by the National Research Council of Italy (CNR) and the water filtration supplier Medica.
Now the task is to integrate the results and prove that the production can be upscaled in a complete system for commercial use.
Prof. Vincenzo Palermo and Dr. Zhenyuan Xia from the department of Industrial and Materials Science, Chalmers will support Graphil with advanced facilities for chemical, structural and mechanical characterization and processing of graphene oriented-polymer composite on the Kg scale. Chalmers’ role in the project will be to perform chemical functionalization of the graphene oxide and of the polymer fibers used in the filters, to enhance their compatibility and their performance in capturing organic contaminants.
"We are very excited to begin this new activity in collaboration with partners from United Kingdom, France and Italy, and I hope that my previous ten years’ international working experience in Italy and Sweden will help us to better fulfil this project," says Zhenyuan Xia, researcher at the Department of industrial and materials science.
Graphil is a multidisciplinary project that consists of both academic and industry partners. The academic partners include Chalmers, the National Research Council of Italy (CNR) and the University of Manchester. The industrial partners are Icon Lifesaver, Medica SpA and Polymem S.A – all European industry leaders in the water purification sector. The aim is to have a working filter prototype that can be commercialized by the industry for household water treatment and portable water purification.
The Graphene Flagship is one of the largest research projects funded by the European Commission. With a budget of €1 billion over 10 years, it represents a new form of joint, coordinated research, forming Europe's biggest ever research initiative. The Flagship is tasked with bringing together academic and industrial researchers to take graphene from academic laboratories into European society, thus generating economic growth, new jobs and new opportunities.
The total budget of the spearhead project GRAPHIL will be 4.88 million EURO and it will start from April 2020 with a total period of 3 years.
A day that not only saw a solar eclipse, Friday, 20 March 2015, marked the start of a materials revolution: the opening of the National Graphene Institute (NGI). Since it opened its doors the NGI has played host to some of the world’s most famous faces and set the ball rolling in the advancement of graphene and other two-dimensional materials.
With its unique architectural design the NGI was designed to allow industry and academics to work side by side on new and exciting ideas.
Five years on we take a look at some of the highlights.
No sooner had the paint had dried, did we see the first graphene product: the launch of the graphene lightbulb. This demonstrated the practical uses of graphene and how it could be translated into everyday products.
In June, Manchester hosted the Graphene Flagship’s Graphene Week. The world’s largest graphene and related 2D materials conference. It also included the premiere of Graphene Suite, commissioned by Brighter Sound, the NGI’s composer in residence Sara Lowes collaborated with Professor Cinzia Casirgahi and fellow researchers to create a six-part piece which explored the relationship between science and music.
October saw President Xi Jinping of the People’s Republic of China visit the NGI. He saw the some of the latest developments in graphene applications and took at tour of the world-class facilities.
To conclude the year, the NGI was crowned Major Building Project of the Year at the annual British Construction Industry Awards. Designed by Jestico & Whiles, the NGI fought off strong competition from six other shortlisted schemes including the Weston Library at Oxford University, Five Pancras Square at Kings Cross and the Brooks Building at Manchester Metropolitan University.
The city of Manchester played host to the EuroScience Open Forum (ESOF) and held the title of European City of Science throughout 2016. To coincide with this, partnering with the Science and Industry Museum, the first graphene exhibition was launched: Wonder Materials: Graphene and beyond. Looking into the past, present and future, this turnkey exhibition brought graphene to life, taking visitors on an immersive journey inside laboratory clean rooms and stimulating learning environments. The exhibition then went tour to Hong Kong.
The Duke and Duchess of Cambridge visited the NGI in October. Amongst visiting graphene researchers and taking a tour of the impressive cleanrooms, The Duke and Duchess also celebrated the University’s Manchester Engineering Campus Development (MECD).
An ultralight high-performance mechanical watch made with graphene was unveiled in January thanks to a unique collaboration. The University of Manchester collaborated with watchmaking brand Richard Mille and McLaren F1 to create the world’s lightest mechanical chronograph by pairing leading graphene research with precision engineering.
April saw a scientific breakthrough when a team of researchers led by Professor Rahul Raveendran Nair, developed a graphene oxide membrane which was able to filter out common salts. Known as a ‘graphene sieve’ this demonstrated real-world potential of providing clean drinking water for millions of people who struggle to access adequate clean water sources. The team have gone on to turn whisky clear and produce membranes for oil separation.
Sprinting into 2018 the first graphene running shoes were launched. Collaborating with inov-8, the brand has been able to develop a graphene-enhanced rubber. Rubber outsoles were developed that in testing outlasted 1,000 miles and were scientifically proven to be 50% harder wearing.
A new national graphene characterisation service was launched, in partnership with the National Physical Laboratory. The service, allows companies to understand the properties of graphene and was established to accelerate the industrialisation of graphene in the UK – forging the missing link between graphene research and development, and its application in next generation products.
The summer also saw Newcastle host the Great Exhibition of the North. Once again we partnered with Brighter Sound to launch The Hexagon Experiment. Music, art and science collided in an explosive celebration of women’s creativity. The Hexagon Experiment featured live music, conversations and original commissions from some of the North’s most exciting musicians and scientists.
News of the ‘graphene sieve’ attracted global attention in 2017, which led to Lifesaver partnering with the NGI. The 18 month project focuses on developing graphene technology that can be used for enhanced water filtration, with the goal of creating a proprietary and patented, cutting-edge product capable of eliminating an even wider range of hazardous contaminants than currently removed by its existing high performance ultra-filtration process.
2019 also saw the first operational year of the Graphene Engineering Innovation Centre. Focusing on the rapid development and scale up of graphene and two dimensional materials. Together, the NGI and GEIC provide an unrivalled critical mass of graphene expertise and infrastructure. The two facilities reinforce Manchester's position as a globally leading knowledge-base in graphene research and commercialisation.
These are scary times, aren't they? First and foremost, my thoughts and prayers go out to anyone who is directly affected by the current global crisis caused by the SARS-CoV-2 coronavirus. It's an extremely serious issue that will require worldwide cooperation to overcome.
I have very clear and distinct memories of the previous SARS epidemic. In March 2003, while working at Rice University, I was helping to lead a group of ~50 science and engineering students on an overseas study trip to Hong Kong and Singapore with my former Rice colleague, Dr. Cheryl Matherly (who is now at Lehigh University). We were caught in the middle of the rapidly developing crisis and our travel itinerary had us departing Singapore for Hong Kong on the day the Singapore government warned its own citizens not to travel to Hong Kong!
Fortunately, everyone in our student group made it through that experience safely, and as unsettling as it was, the current situation is much much worse, with as yet unknown - but sure to be significant - social, economic and political ramifications that will most definitely impact future generations around the world.
I am currently based in Bangkok, Thailand, which is a global tourist destination. While we were fortunately to escape the first wave of of the SARS-CoV-2 virus that emanated from China, we're now faced with a second wave imported from Europe. We're not quite under total lockdown here, but things appear to be headed in that direction. It is clear to me form observation that the several governments in the region (Singapore, Hong Kong, and Taiwan, to be specific) are applying the lessons they learned from the previous SARS epidemic to help control the current pandemic. This give me hope, and the circumstances in general have given me plenty of time to think and reflect about what - if anything - I and my company, planarTECH, can do to improve this situation.
Graphene: The "Wonder Material"
I was lucky to fall into the world of graphene and 2D materials by accident through acquaintance with another former Rice University colleague, Dr. James Tour, and conversations I had with him 8 years ago. I will not spend a lot of time here talking about the specific properties of graphene as such information is widely available. The European Union's Graphene Flagship project, for example, has an excellent overview. The University of Manchester - where graphene was first isolated and where planarTECH's Chairman, Ray Gibbs, currently serves as the Director of Commercialization for the Graphene Engineering and Innovation Centre - also has a fantastic YouTube channel with many instructive videos about graphene and its properties.
With all of the amazing properties of graphene, the question is, can it offer any kind of solution to the current pandemic and global crisis?
Academic Work: Graphene's Antiviral Properties
The short answer to the question above is "possibly," but with some caveats. In particular, it would appear that graphene oxide (GO) may play a role in providing a solution.
I should say that I am not a doctor, an epidemiologist or someone with formal training in the biological sciences. I am an engineer by trade, and for the last 8 years, an entrepreneur in the field of graphene. However, since entering the graphene industry, I have grown accustomed to reading academic papers in order to understand the potential applications for graphene.
A paper published in 2015 by researchers at the Huazhong Agricultural University (ironically located in Wuhan, China, where the current pandemic originated) explored the antiviral properties of graphene oxide, and the authors of the paper concluded "that GO and rGO exhibit broad-spectrum antiviral activity toward both DNA virus (PRV) and RNA virus (PEDV) at a noncytotoxic concentration," and that "the broad-spectrum antiviral activity of GO and rGO may shed some light on novel virucide development." While encouraging, it should be noted that the researchers looked specifically at pseudorabies virus (PRV) and porcine epidemic diarrhea virus (PEDV), not the SARS-CoV-2 virus responsible for the current global pandemic.
Another paper published in 2017 by researchers at Southwest University in China looked at cyclodextrin functionalized graphene oxide and it's possible role in combatting respiratory syncytial virus (RSV), concluding that "the curcumin loaded functional GO was confirmed with highly efficient inhibition for RSV infection and great biocompatibility to the host cells." Likewise, a third paper published in 2019 by researchers at Sichuan Agricultural University in China demonstrated that "GO/HY [graphene oxide/hypericin] has antiviral activity against NDRV [novel duck reovirus] both in vitro and in vivo."
The conclusion we can draw from these works is that graphene oxide may offer a platform to fight a variety of viral infections (such as the SARS-CoV-2 coronavirus), possibly as some form of coating, though certainly more work needs to be done.
(Note that my good friends over at The Graphene Council had a recent and excellent blog post covering the same 3 articles in a little more detail. And kudos to them for shining light on the topic before me!)
Productization: From Lab to Market
If there's one thing I've learned from the past 8 years being involved with graphene commercialization (and the past 14 years working directly in the Asian supply chain) is that it is one matter to write an excellent academic paper as a proof-of-concept, but it is an entirely different matter to take work from an academic lab and turn it into a real product.
With respect to graphene in general, what we are seeing today is definite movement on the Gartner hype cycle from the Trough of Disillusionment to the Slope of Enlightenment. Real products using graphene are now on the market. One such example is the recent announcement of of a collaboration between UK-based Haydale Graphene Industries plc and Korea-based ICRAFT Co., Ltd. that results in the release of a graphene cosmetic face mask. And I am pleased to be able to say that - in connection with my previous responsibilities for Haydale's Asia-Pacific operations - I had some role (together with my colleague Yong-jae "James" Ji) in getting this product off the ground and into the marketplace.
While this may seem like a trivial accomplishment given the context and seriousness of the current global pandemic, I offer this example as proof that graphene can be utilized in an everyday, cost-sensitive product, and it is not such a great conceptual leap to go from a cosmetic face mask to a protective face mask, which as we all know are in great demand these days (especially here in Asia). I would invite iCRAFT (or anyone else) to consider collaboration with planarTECH to develop such a product. (Above photo courtesy of Macau Photo Agency on Unsplash.)
Productization: Existing Products?
Very much related to this topic and very curious is a recent public announcement by LIGC Applications of its Guardian G-Volt face mask with a graphene-based filtration system. However, my understanding is that LIGC is not employing graphene specifically for it's potential antiviral properties but rather for its potential to enhance a filtration system, including (due to graphene's electrical conductivity) the ability to pass an electrical charge through the mask that "would repel any particles trapped in the graphene mask."
What I find very curious about this case is that subsequent to this announcement, LIGC's Indiegogo crowdfunding campaign, which was live, has now been placed under review, and the company's pitch video on YouTube has likewise been made private. I do not know what has happened here - perhaps is was perceived as poor timing? - but as a fellow entrepreneur who is conducting my own crowdfunding campaign, I wish LIGC the best of luck with its product development and ultimate launch. I definitely want to see more viable graphene products in the marketplace.
The Graphene Supply Chain: planarTECH's Role
One of the challenges the graphene industry faces overall is scalability. Very few graphene companies today (if any at all) can produce graphene at the scale, at the right cost, and with the consistent quality such that it can be used for truly high-volume applications. Over the past 8 years, I have met numerous customers, mostly in Asia, who want to use graphene in their products but cannot find a secure and stable supply that meets their expectations on specification, volume, and price.
At planarTECH we're interested in not only the end applications, but also in solving this problem of production scalability. While we have in the past mainly been focused on production systems for graphene and other 2D materials by Chemical Vapor Deposition (CVD), we also recently started offering continuous flow production systems for graphene oxide, which we believe can take graphene oxide production from lab-scale, high-cost (grams per week) to production-scale, low-cost (kilograms per hour). We're actively seeking partners to work with us on setting up production and exploration of the application space for graphene oxide, and we're currently conducting a crowdfunding campaign on Seedrs to help us expand our business and make graphene a commercial reality. As seen above, we think graphene oxide's antiviral properties can be exploited to make new and useful products.
I should clarify and caution that planarTECH is not in the position today to offer a graphene-based product that can immediately help alleviate current crisis and prevent widespread infection. Unfortunately, such a product is realistically 1-2 years away. But what we can offer is market expertise specific to graphene, production technologies, and experience in taking products from the idea phase to a reality in the marketplace.
Conclusion: Graphene is a Possible Solution
To conclude, I would like to reiterate a few broad points.
• Graphene (graphene oxide in particular) and coatings made from graphene would appear to have antiviral properties as reported in several published academic papers.
• Real commercial products exist that use graphene, but the industry as a whole still faces challenges around scalability, cost and quality.
• An immediate graphene-based solution to alleviate the effects of the global SARS-CoV-2 coronavirus pandemic is likely unrealistic, but could be possible in the future.
• planarTECH has a role in the supply chain and is seeking partners, as well as investors via its crowdfunding campaign, to expand its business and help end customers develop useful products.
Graphene Flagship researchers at the University of Rome Tor Vergata, the Italian Institute of Technology (IIT) and its spin-off, Graphene Flagship Associate Member BeDimensional, in cooperation with ENEA have successfully combined graphene with tandem perovskite-silicon solar cells to achieve efficiencies of up to 26.3%. Moreover, they envisioned a new manufacturing method that, thanks to the versatility of graphene, allows to reduce production costs and could lead to the production of large-area solar panels. Graphene-based tandem solar cells almost double the efficiency of pure silicon.
Laws of physics limit the maximum efficiency of silicon solar cells to 32%. For that reason, scientists have spent decades trying to come up with other alternatives, such as III-V and perovskites. However, the latter present several manufacturing challenges, and scaling up the production of solar panels is a key step towards success. With 'tandem cells', scientists had previously combined the advantages of both silicon and perovskites – however stability, efficiency and large-scale manufacturing still seemed like a far-fledged dream.
But then graphene came into play – and it could be a game changer. Graphene Flagship researchers identified its potential for energy harvesting, and in fact have dedicated two different industry-oriented 'Spearhead Projects' to dig into the possibilities of graphene-based solar cells. This new paper published in Joule – a reference journal in the field of energy research – is yet another proof that graphene and related layered materials will enable the commercialisation of more efficient and cost-effective large area solar panels.
Aldo di Carlo, lead author and researcher in Graphene Flagship partner University of Rome Tor Vergata, explains: "Our new approach to manufacture graphene-enabled tandem solar cells provides a double advantage. First, it can be applied to enhance all the different types of perovskite solar cells currently available, including those processed at high temperatures. But more importantly, we can incorporate our graphene using the widespread 'solution manufacturing methods', key to further deploy our technologies industrially and deliver large-surface, graphene-enabled solar panels."
Francesco Bonaccorso, co-author, co-founder of Graphene Flagship spin-off BeDimensional, says: "This innovative approach proposed in the context of the Graphene Flagship is the first step toward the development of tandem solar cells delivering an efficiency higher than the limit of single junction silicon devices. Layered materials will be pivotal in reaching this target.".
Emmanuel Kymakis, Graphene Flagship Energy Generation Work Package Leader, says: "There are some compatibility issues that have to be tackled before the full exploitation of the perovskite-Si tandem PVs concept. This pioneering work demonstrates that the integration of GRMs inks with on-demand morphology and tuneable optoelectronic properties in a tandem structure, can lead to high-throughput industrial manufacturing. Graphene and related materials improve the performance, stability and scalability of these devices.
The stacked silicon-perovskite configuration will act as the foundation of the new Graphene Flagship Spearhead Project GRAPES, in which a pilot line fabrication of graphene-based perovskite-silicon tandem solar cells will take place, paving the way towards breaking the 30% efficiency barrier and a significant decrease on the Levelized Cost of Energy."
Andrea C. Ferrari, Science and Technology Officer of the Graphene Flagship and Chair of its Management Panel, adds: "The application of graphene and related materials to solar energy generation was recognized as a strategic priority since the start of the Graphene Flagship. The first graphene-based solar farm is being set up this year. These new results underpin our effort for the following 3 years to produce panels defining the state of the art. This also shows how the work of the Graphene Flagship strongly aligns with the UN's Sustainable Development Goals."
Frontier IP, a specialist in commercialising university intellectual property, today announces that portfolio company Cambridge Raman Imaging Limited has been awarded €140,000 by the European Union's Graphene Flagship to accelerate development of its innovative graphene-enabled scanning Raman microscope.
The Company, a spin out from the University of Cambridge and the Politecnico di Milano in Italy, was incorporated in March 2018 to develop and commercialise the joint work of both universities to create graphene-based ultra-fast lasers. Frontier IP owns 33.3 per cent of the Company.
Cambridge Raman Imaging is initially developing a Raman-imaging scanning microscope to diagnose and track tumors, and for other detection applications.
The technology uses graphene to modulate ultra-short pulses of light that can be synchronised in time and are much lower cost than conventional systems.
The Company's scanning microscope will target real-time digital images of fresh tissue samples to detect and show the extent of tumours, their response to drug treatments and to allow surgeons to see if a cancer has been completely removed.
Existing histopathology technologies mean samples taken from a patient must be stained and sent to a laboratory for analysis, including during operations. Cambridge Raman Imaging's lasers will be compact enough to use in an operating theatre, speeding up progress. The global market size for tumour analysis and tracking has been estimated to be £9 billion a year, according to Grandview Research.
Potential future applications include endoscopic examination, scanning body fluids for pathogens or tumour cells, and imaging semiconductors or proteins.
The Graphene Flagship is one of the largest research initiatives ever funded by the EU, tasked with bringing together academic and industrial researchers to take graphene from academia and into society.
Paul Mantle, Cambridge Raman Imaging director, said: "This technology has the potential to revolutionise patient care by giving the clinician accurate information on tumour type and response to treatment."
Neil Crabb, chief executive officer of Frontier IP Group, said: "Cambridge Raman Imaging is our first spin out to develop a graphene-based technology. Although the first applications are in healthcare, we believe there could be broader applications in other industries. We're delighted the EU Graphene Flagship recognises the potential of the technology with the grant award to accelerate its development "
The Aachen Graphene & 2D Materials Center has won two projects on basic research and innovation on graphene in the last FLAG-ERA Joint Transnational Call.
FLAG-ERA is a network of national and regional funding organizations in Europe that supports the two first FET Flagship projects of the European Commission: the Graphene Flagship and the Human Brain Project. On November 2018, FLAG-ERA announced its third Joint Transnational Call (FLAG-ERA JTC 2019), with an initial budget of 20 M€. This type of call presents a number of peculiarities. First, it funds only topics where synergies with the two Flagships are expected. Second, it funds only projects that involve partners form three or more different countries participating to the FLAG-ERA net. Third, while all projects are evaluated “centrally” by an independent evaluation panel, those recommended for funding are funded by the individual funding agencies − meaning that each partner of the project is funded by its national funding agency.
“It might seem a complicated way of financing research”, says Prof. Max Lemme from the chair of Electronic Devices at RWTH Aachen University, “but graphene is a topic that profits enormously from this kind of transnational collaborations.” Lemme is partner of the project 2D-NEMS, together with Prof. Christoph Stampfer − also at RWTH − and with colleagues from the Royal Institute of Technology in Sweden and from Graphenea Semiconductor in Spain.
The goal of the project is to explore the potential of heterostructures formed by graphene and other two-dimensional materials for realizing ultra small and ultra sensitive sensors, such as accelerometers. “We want to understand which combination of 2D-materials works better for a certain type of sensors and why”, says Lemme. “And, most importantly, we want to realize prototypes that are not only good for high-impact publications, but that can be of real interest for industry.”
Christoph Stampfer, head of II Institute of Physics A, is also involved in the FLAG-ERA project TATTOOS, together with colleagues from UC Louvain in Belgium and CNRS in Paris. TATTOOS is a more exploratory project, dedicated to some of the most fascinating properties of bilayer graphene.
As the name says, bilayer graphene is a material formed by two layers of graphene. One of the big scientific surprises of 2018 was that for certain “magic angles” between the two layers the system can exhibit superconductivity or other exotic properties. “In TATTOOS we’ll use a technique developed by our CNRS colleague, which should allow to rotate dynamically the angle between the layers with the tip of an atomic force microscope.”, explains Stampfer. “It’s a crazy idea! Typically, changing the angle requires making a new sample. If they hadn’t already demonstrated this approach on a similar system, I would not believe it can work. I’m really excited to see what new physics we can explore in this way.”
Lemme and Stampfer are both members of the Aachen Graphene and 2D Materials Center. “The fact that the Center is participating in two of the nine projects funded in the sub-call “Graphene – Basic Research and Innovation”, is a good example of the relevance of the research done here in Aachen”, says Stampfer, who is also the spokesperson of the Center.
Researchers at Graphene Flagship partner the Cambridge Graphene Centre, University of Cambridge, have developed a new type of resistive memory that can be scaled down beyond current limitations. They also collaborated with colleagues at Soochow University to discuss the state-of-the-art technology and evaluate the future of resistive memories based on graphene and related materials (GRMs). Furthermore, Graphene Flagship partners at CNRS, France, and CSIC and ICREA, Spain, along with SAC member Luigi Colombo, analysed the properties and device structures required for practical GRM-based memory devices to reach their potential.
Data storage in computers comes in two distinct flavours: volatile and non-volatile memory, and both are essential in modern electronic devices. Volatile memory is used in random access memory (RAM) and computer processors to store temporary data, whereas non-volatile memory is used in hard drives and flash drives for long-term data storage.
Over the past 25 years, this technology has advanced tremendously – with Moore's Law predicting a near-doubling in the number of transistors on a microchip every two years, while the cost of computers roughly halves. For most of the past few decades, this has resulted in exponential growth in computer storage space and a corresponding reduction in size. But Moore's Law is dying, and we are rapidly approaching the physical limits of data storage. One of the reasons for this is that when the size of memory devices approaches the nanometer scale, leakage currents in capacitors lead to severe data losses.
By integrating a layer of graphene into resistive RAM devices made with tetrahedral amorphous carbon, Graphene Flagship scientists have now developed a new type of memory that can be scaled down beyond previous size limitations. The new memory devices could lead to better-performing computers and personal electronics with much larger storage capacities. In the devices, tetrahedral amorphous carbon, which has high electrical resistance, is sandwiched between two electrodes. When an electric field is applied between the electrodes, a conductive path forms in the carbon layer, connecting the two electrodes and forming a low resistance state. The high- and low-resistance states can be used to encode data in the form of binary 1s and 0s.
In their paper, published in the journal 2D Materials, Graphene Flagship partner University of Cambridge showed that by adding a graphene layer between an amorphous carbon layer and one of the electrodes, they can significantly improve the performance of the memory and suppress the leakage current that leads to data loss. "Leakage currents become more dominant as device sizes get smaller, and it's important that the two memory states – the high- and low-resistance states, or the ones and zeroes – are not too close together," explains Anna Ott from the Cambridge Graphene Centre. "Adding a graphene layer improves this ratio by an order of magnitude and suppresses the leakage current, showing that amorphous carbon-based memories are suitable for achieving the smallest possible memory size."
In their Advanced Electronic Materials paper, the Graphene Flagship researchers conclude that the main challenges facing scientists developing new, state-of-the-art resistive RAM devices, are creating durable devices that can run for over 109 switching cycles and achieving data retention times of over 10 years. The researchers find that augmenting resistive RAM with GRMs results in highly stable devices with very promising performance. They show that GRMs are already fit for some non-volatile memory requirements, and that they can be a promising alternative to currently used technologies.
In the Advanced Materials publication, the Graphene Flagship researchers state that for these technologies to be realized, scientists must focus on two main areas of progress: high-speed and high-capacity non-volatile memories and low-cost, flexible and transparent storage devices for wearable electronics. "You normally need one to two decades of intense research before an exciting proof-of-concept like this can turn into a game-changing technology and hit the market," comments Samorì from Graphene Flagship Partner University of Strasbourg. He emphasizes that this is feasible, but sustainable and continuous funding support will be needed before it can become a reality.
Indeed, Ott explains that graphene-enabled memory devices compare well to state-of-the-art: in terms of speed, they are faster than traditional flash memories, comparable to the dynamic RAM common in today's computer components, and slower than static RAM, which Ott says is expected. "Carbon-based resistive RAM provides much better scaling possibilities compared to static and dynamic RAM and flash memories. We can also add oxygen to get oxygen-amorphous carbon, which improves the endurance – how many times the device can be switched between the two resistance states – to be comparable to flash memories," she continues.
Daniel Neumaier, leader of the Graphene Flagship's Electronic Devices Work Package, comments: "These papers are highly valuable for scientists trying to create smaller and smaller resistive RAM technology. Data loss due to leakage currents is one of the main problems in nanoscale-sized memory devices, and the work demonstrates that incorporating tetrahedral amorphous carbon reduces this problem."
Further collaborations could lead to graphene-integrated memories hitting the market. However, the integration of GRMs into memory manufacturing processes may be a challenge. "This will be one of the main issues to overcome in order to bring graphene from laboratories to factories," concludes Ott.
Andrea C. Ferrari, Science and Technology Officer of the Graphene Flagship and Chair of its Management Panel, adds: "These publications show that graphene and related materials are finding their way into new applications of resistive memories. These are at the centre of an ever-increasing research effort and, yet again, the Graphene Flagship and its collaborators are at the forefront of not just novel research, but also of the outlining of future directions."
The Graphene Flagship is looking for a new partner that brings in specific industrial and technology transfer competences or capabilities that complement the present consortium of the Spearhead Project GRAPES.
We are seeking an industrial partner with the following expertise and capabilities:
· A world-leader in renewable power generation.
·A proven track record in manufacturing and assembly of photovoltaic (PV) panels and operation of solar parks.
·A fully automated pilot silicon PV line in order to transfer the tandem process developed within SH5 Grapes to its line and demonstrates industrial S2S manufacturing.
·Operational solar parks in different European geographical locations.
·The Company must have:
1. Fully automated pilot line for the production of Si high efficiency solar cells (>20%) with a throughput>150 MW/year.
2. Manufacturing Execution System and Statistical Process Control for real-time out of control detection to costs and performances optimization.
3. Owner/Operator of solar parks for on-site outdoor testing of tandem PV panels in multiple sites across Europe.
The newly selected partner will be incorporated in the Core 3 Project under the Horizon 2020 phase of the Graphene Flagship, which will run during 1 April 2020 - 31 March 2023. The new partners will be requested to sign the relevant agreement with the European Commission.
Graphene-based heterostructures of the van der Waals class could be used to design ultra-compact and low-energy electronic devices and magnetic memories. This is what a paper published in the latest issue of the Nature Materials journal suggests. The results have shown that it is possible to perform an efficient and tunable spin-charge conversion in these structures and, for the first time, even at room temperature.
The work has been led by ICREA Prof. Sergio O. Valenzuela, head of the ICN2 Physics and Engineering of Nanodevices Group. The first authors are L. Antonio Benítez and Williams Savero Torres, of the same group. Members of the ICN2 Theoretical and Computational Nanoscience Group, as its head, ICREA Prof. Stephan Roche, also signed the paper. This study has been developed within the framework of the Graphene Flagship, a broad European Project in which researchers of the Catalan Institute of Nanoscience and Nanotechnology (ICN2) play a leadership role. The results complement recent researches carried out within this same initiative, such as the one published in 2019 in NanoLetters by scientists from the University of Groningen (RUG).
The electronics that use spin - a property of electrons - to store, manipulate and transfer information, called spintronics, are driving important markets, such as those of motion sensors and information storage technologies. However, the development of efficient and versatile spin-based technologies requires high-quality materials that allow long-distance spin transfer, as well as methods to generate and manipulate spin currents, i.e. electron movements with their spin oriented in a given direction.
The spin currents are usually produced and detected using ferromagnetic materials. As an alternative, spin-orbit interactions allow the generation and control of spin currents exclusively through electric fields, providing a much more versatile tool for the implementation of large-scale spin devices.
Graphene is a unique material for long distance spin transport. The present work demonstrates that this transport can be manipulated in graphene by proximity effects. To induce these effects, transition metal dichalcogenides have been used, which are two-dimensional materials as graphene. Researchers have demonstrated a good efficiency of spin-charge interconversion at room temperature, which is comparable to the best performance of traditional materials.
These advances are the result of a joint effort by experimental and theoretical researchers, who worked side by side in the framework of the Graphene Flagship. The outcomes of this study are of great relevance for the communities of spintronics and two-dimensional materials, as they provide relevant information on the fundamental physics of the phenomena involved and open the door to new applications
Graphene is a unique material with great potential for the long-distance transportation of spin information. However, spin-to-charge interconversion (SCI) in graphene and graphene-based heterostructures to date could not be performed at room temperature. But now, researchers at Graphene Flagship partners ICN2 and Universitat Autònoma de Barcelona, Spain, and the University of Groningen, the Netherlands, have achieved efficient room temperature SCI in graphene-based structures, and devised a way to make this process tuneable using an external electric field. The findings, published in Nature Materials and Nano Letters, could allow scientists to use layered heterostructures for ultra-compact, low-power consumption magnetic memory devices.
Spintronics is a branch of electronics which uses electrons' spin to store, manipulate and transfer information. Spintronics could benefit many emerging markets, like motion sensing and next-generation memory devices. Developing efficient and versatile spin-based technologies requires both high-quality materials for long-distance spin transfer, and suitable engineering methods to generate and manipulate spin currents, to ensure electrons move in a controlled way with their spins oriented along a given direction.
Generally, spin currents are generated and detected using ferromagnetic contacts. But as an alternative, spin-orbit interactions could enable spin currents to be controlled entirely by an electric field, resulting in a far more versatile tool to be implemented in large-scale spin devices. Now, Graphene Flagship researchers ICREA Prof. Sergio O. Valenzuela, ICREA Prof. Stephan Roche, and colleagues have exploited the unique spin properties of graphene to transport spin information across long distances in large-scale SCI electronics. Additionally, by interfacing graphene with transition metal dichalcogenides (TMDs), another family of layered materials with strong spin-orbit coupling, they were able to precisely control spin transport in these devices. "Thanks to this research, the Graphene Flagship's Spintronics Work Package has made a major step towards the engineering of SCI in quantum devices, with genuine potential for spintronics applications," explains Roche.
By fabricating a high-quality device and using very sensitive detection techniques to evaluate the spin Hall and inverse spin Galvanic effects – focusing in particular on spin precession and non-local measurements – they demonstrated experimentally that the SCI in graphene–TMD heterostructures is in good agreement with theoretical models. Furthermore, using these techniques, Graphene Flagship researchers not only demonstrated the spin-related character of the signals, but also tailored the efficiency of their SCI and sign using electrostatic gating. This important feature directly showcases their ability to manipulate spin information in the heterostructures with an electric field, and this could soon lead to new applications in magnetic memory devices. Most notably, they found that the room temperature SCI efficiencies were just as high as the best results using other materials.
"We're very excited to report the first unambiguous evidence of large and tuneable SCI in van der Waals heterostructures at room temperature," comments Valenzuela, from Graphene Flagship partner ICN2. "This is a significant step forward towards the long sought-after goal of electrostatic control of spin information," he continues. Additionally, Prof. Bart van Wees, from Graphene Flagship partner the University of Groningen, elaborates: "It is difficult to imagine how complex it is to fabricate spin devices combining various types of magnetic and non-magnetic materials, graphene, boron nitride, and strong spin-orbit coupling materials such as TMDs. Thanks to this work, the Spintronics Work Package has developed a unique expertise in realizing operational spin devices which really show the full potential of layered materials."
Kevin Garello, Graphene Flagship Work Package Leader for Spintronics, comments: "Devices involving the spin–orbit torque phenomenon, such as the spin Hall effect and the spin Galvanic effect, are great candidates for future spintronics applications as they require low power input and are capable of ultra-fast performance. It is great to see that spin-orbit torques can be electrically manipulated and improved by the smart engineering of layered materials, which has now been unequivocally confirmed independently by two experimental teams in Work Package Spintronics. This opens the door for new and exciting perspectives and strategies to manipulate spin information and further advance applications in spintronics based on layered materials."
The success of these studies is the result of the joint effort between experimental and theoretical researchers working closely together in the EU-funded Graphene Flagship framework. The results provide valuable insights for the spintronics and layered materials communities, and the researchers hope that their findings will enable scientists to explore new theoretical models and further experiments in the future.
Andrea C. Ferrari, Science and Technology Officer of the Graphene Flagship and Chair of its Management Panel, adds: "The Graphene Flagship has invested in spintronics research since the very beginning. The great potential of graphene and related materials in this area has been showcased by world-leading work done in the Flagship. These results indicate that we are getting close to the point where the fundamental work can be translated into useful applications, as foreseen in our science and technology and innovation roadmaps."