Technology developed by researchers at Ben-Gurion University of the Negev in partnership with Rice University in Houston, Texas is being commercialized by LIGC Application Ltd. to develop and manufacture products for filtration systems, including those that filter COVID-19 airborne particles.
LIGC is a company at the forefront of laser-induced graphene (LIG) commercialization. Hubei Forbon Technology Co. Ltd. (300387.SZ) in Wuhan, China provided $3 million in funding.
“For the past five years, our lab at BGU's Zuckerberg Institute for Water Research has focused on the development of LIG, specifically in antimicrobial filtration and environmental applications,” says Dr. Chris Arnusch. “We are excited to be commercializing our technology in a number of air filtration products for COVID-19 and other specialized filtration applications.”
LIGC Co-founder and Chief Executive Officer Yehuda Borenstein says, “In the absence of better filtration technology, the indoor spaces where we used to spend most of our ‘normal’ life—schools, stores and workplaces— due to COVID-19 present a real risk. This technology will provide cleaner and more breathable air with lower energy and maintenance costs and virtually silent sound levels.”
Active air filters made with LIG are designed to damage and destroy organic particles including bacteria, mold spores and viruses at the micron and sub-micron levels when passed through a microscopic network of porous graphene.
This cost-effective and scalable approach is produced using commercially available CO2 lasers to create a conductive graphene mesh. The graphene mesh heats, electrocutes and neutralizes organic particles and pathogens with revolutionary efficiency compared to active carbon filters, UV-C and fiber HEPA filters that are used widely in schools, offices, homes, ships, and other facilities. Aircraft are already equipped with HEPA filters that remove viruses and bacteria from the circulated cabin air, but at high energy and maintenance costs.
Since the LIGC filter uses low voltage electricity to eliminate bacteria and viruses, lower density filtration media can be used, resulting in significantly less energy consumption. In addition, LIGC active filters require lower maintenance than other filters and are safe for the operator during maintenance and replacement.
“To understand the technology, imagine the porous graphene is an electric fence that functions like a mosquito zapper at the submicron level,” Bornstein says. “When an airborne bacteria or virus touches the graphene surface, it is shocked at a low voltage and currents that are safe for use. While 2020 has highlighted the importance of protecting against airborne viruses, the post-pandemic world will likely show us how important it is to do so without increasing energy costs past the point of affordability.”
Two NETL projects have been named finalists in the prestigious 2020 R&D 100 Awards competition. C2G: NETL’s Low-Cost Coal-to-Graphene Manufacturing Process advanced in the Mechanical/Materials category and NETL’s IDAES PSE Computational Platform project was named a finalist in the Software/Services category.
The contest celebrates the top 100 ground-breaking technologies made in the past year. It will be a short wait for researchers on both NETL teams to learn if their projects will be named winners. The virtual award ceremony for the Mechanical/Materials category will be held Wednesday, Sept. 30, while Software/Services category winners will be announced the following day.
The coal-to-graphene project was submitted by NETL researchers Christopher Matranga, principal investigator, and team members Fan Shi, senior materials scientist, McMahan Gray, physical scientist, and Tuo Ji, research scientist.
Graphene is stronger than steel and possesses a higher electrical and thermal conductivity than copper. However, graphene has not been widely used in consumer products because of challenges and costs associated with producing large volumes of the material.
The NETL team developed a process to manufacture graphene from domestic coal feedstocks, which are substantially less expensive than graphite currently used. The Lab is partnering with industry and research universities to utilize its graphene for multiple purposes, including biosensing materials for detecting disease and materials for next-generation computer memory devices and microelectronics. NETL is evaluating the use of graphene as an additive to improve the strength and corrosion resistance of cement and concrete composites.
NETL’s Institute for the Design of Advanced Energy Systems (IDAES) seeks to be the foremost resource for the identification, synthesis, optimization and analysis of innovative advanced energy systems. Led by NETL’s Senior Fellow for Process Systems Engineering and Analysis, David Miller, IDAES is a collaboration with Sandia National Laboratories, Lawrence Berkeley National Laboratory, West Virginia University, Carnegie Mellon University and the University of Notre Dame. The IDAES Integrated Platform optimizes the design and operation of complex, interacting technologies and systems by providing rigorous modeling capabilities to increase efficiency, lower costs, increase revenue and improve sustainability.
IDAES provides revolutionary new capabilities for Process Systems Engineering that exceed existing tools and approaches. The IDAES Modeling & Optimization Platform helps energy and process companies, technology developers, academic researchers and the U.S. Department of Energy to design, develop, scale-up and analyze new and potential technologies and processes to accelerate advances and apply them to address the nation’s energy needs.
Now in its 58th year, the 2020 R&D 100 Awards received entries from 19 countries and regions for the 2020 competition. This year, the judging panel grew to include nearly 50 industry professionals across the globe, including new judges from Australia, Nigeria and the United Kingdom.
The coronavirus pandemic created some difficulties. “The process of submitting to the awards program is a lengthy one, and with staffs working from home or facilities temporarily closed, we realize how challenging this was. We were delighted to see these scientists and engineers come through, and the number of nominations for this year was almost exactly the same as in 2019,” said Vice President, Editorial Director for R&D World Paul J. Heney, the organizer of the awards competition.
The U.S. Department of Energy’s National Energy Technology Laboratory develops and commercializes advanced technologies that provide reliable and affordable solutions to America’s energy challenges. NETL’s work supports DOE’s mission to advance the national, economic and energy security of the United States.
Edmonton International Airport has been chosen as the exclusive location to trial a new COVID-19 test that can produce results in seconds.
In partnership with GLC Medical (GLCM) Inc., a subsidiary of Graphene Leaders Canada (GLC) Inc., an Edmonton-based company, EIA will host clinical trials of this new technology that has the potential to have global implications for COVID-19 testing. This test is conducted with a handheld unit that takes a saliva sample from a person and is expected to tell if someone has COVID-19 in under 1-minute, compared to other tests with longer laboratory-based waiting periods for results.
This test promises many advantages from its ease of use to the elimination of the nasal swab to direct virus detection. This kind of test will help address the need for a 14-day quarantine period in Canada and potentially other international quarantine restrictions. By removing or reducing this barrier, it can help travellers feel safer in returning to travel.
GLC Medical (GLCM) Inc. is headquartered in the Edmonton Research Park and has garnered international attention for the development of this test, which is still undergoing clinical testing as part of the regulatory approval process with health authorities. As an airport, EIA understands working with governments and within a regulated structure. With secure and safe facilities and a consistent flow of passengers, it’s one reason an airport is an ideal place to start testing the trial phase of this new COVID-19 rapid test.
“We all want travel to get back to normal and a rapid COVID-19 test will accelerate this return while enhancing passenger confidence in the safety of our industry. While we have seen some growth in recent months, our passenger numbers during COVID-19 continue to remain low and a test like this is crucial to our future. All airlines, airports and the whole travel and hospitality sector are looking for this solution. If EIA can play a role in bringing new technology and science forward by partnering with experts like GLC that’s exactly what we’re going to do. This is an exciting opportunity for all of us.”
-Tom Ruth, CEO and President, Edmonton International Airport
“We are very excited to offer the world a graphene-enhanced rapid solution in COVID-19 virus detection. The opportunity to collaborate with EIA, a world-respected airport authority, to enable travel and to bring families back together is very rewarding for us. This graphene-enhanced rapid test demonstrates the power of graphene innovation to overcome the challenges of COVID-19. GLC is proud to be a part of EIA’s initiative in setting the global standard in safety and reliability for their travellers.”
-Donna Mandau, President & CEO, Graphene Leaders Canada (GLC) Inc. / GLC Medical (GLCM) Inc.
How the test works:
• The person being tested provides a saliva sample into the testing unit; • The graphene surface inside the testing unit is designed to bond to the spike protein in the virus; • This binding event changes the electronic characteristics of the graphene, and this measurable change is what is used to determine if a person is infected or not; • The device will show a red or green light in under 1-minute to indicate if a person is virus free or not; • The test is not required to be administered by a medical professional and with training can be administered by anyone, similar to how basic first aid training is done.
The next step is to bring this test and GLC to EIA and establish a safe and secure test site. Details about the testing and the process will be shared in the coming weeks. A start date has not been determined, but once it begins, the clinical trial will last several weeks over this fall. This trial phase will help GLC Medical secure regulatory approval and certification for its test from Health Canada and other regulatory bodies, including in the United States and other areas of the world.
As a not-for-profit corporation, EIA works to attract investment and jobs to the Edmonton Metro Region and support local innovation. Airports connect global communities and create opportunities for people and business. The partnership with GLC Medical has tremendous opportunities to impact many industries beyond just the travel industry. EIA is focused on safety and security as its number one core value and creating a safe passenger experience at the airport is a priority.
The EIA Ready program focuses not only on enhanced cleaning but also seeking out and adopting new innovations and technologies to help passengers feel comfortable in the airport and with travel overall. The recent announcement of EIA being accredited by Airports Council International (ACI) with the airport health certification is yet another example of how EIA is putting safety and security as a top priority in creating a safe airport.
Because of their unique physical, chemical, electrical and optical properties, two-dimensional (2D) materials have attracted tremendous attention in the past decades.
After revealing the realistic strength and stretchability of graphene, researchers from City University of Hong Kong (CityU) have carried forward the success by unveiling the high defect tolerance and elasticity of hexagonal boron nitride (h-BN), another 2D material known as “white graphene”.
This follow-up study (Cell Reports Physical Science, "Large Elastic Deformation and Defect Tolerance of Hexagonal Boron Nitride Monolayers”") will promote future development and applications of strain engineering, piezoelectronics and flexible electronics.
Since British scientists exfoliated single-atom-thick crystallites from bulk graphite in 2004 for the first time, research on 2D materials has undergone rapid advances. Novel 2D materials have been discovered, including hexagonal boron nitride (h-BN), the focus of this article, transition metal dichalcogenides (TMDs) such as MoS2, and black phosphorus (BP).
Those successfully isolated 2D materials have different band gaps (from 0 to 6 eV), and range from conductors, semiconductors to insulators1, which illustrates their potential in electronic device applications.
Sometimes referred as "white graphene", h-BN shares a similar structure with graphene. The theoretical estimates of its mechanical properties and its thermal stability are also comparable to those of graphene. Due to its ultra-wide band gap of ∼6 eV, h-BN can serve in optoelectronics or as a dielectric substrate for graphene or other 2D materials-based electronics.
More importantly, its band gap could be modified via the elastic strain engineering (ESE) approach in which the material band structure can be significantly tuned by lattice straining or distortion.
It is worth mentioning that h-BN can improve the performance of graphene devices. Similar to graphene’s atomic structure, monolayer h-BN has a small lattice mismatch and ultra-flat surface, which can significantly enhance graphene's carrier density. Carrier density represents the number of carriers that participates in conduction, which is one of the key factors contributing to electrical conductivity.
In addition, the ultra-wide band gap makes h-BN an ideal dielectric substrate for graphene and other 2D material-based electronics. Having no centre of symmetry, monolayer h-BN is predicted to exhibit induced piezoelectric potential under mechanical strains.
However, these fascinating properties and applications always require relatively large and uniform deformations. In fact, all materials need to have reliable mechanical properties before they can be used in practical devices.
That is why researchers have tried different approaches to explore the mechanical responses of graphene and other 2D materials under various conditions. Yet, most of the tests use the nanoindentation technique based on atomic force microscopy (AFM), in which the size of the indenter tip limits the testing area of the sample, and the strain is highly non-uniform.
Moreover, research that involves transferring samples of 2D materials onto a flexible substrate to introduce stretching has faced certain limitations. Due to the weak adhesion between 2D materials and substrate interface, it is very challenging to apply large strain on the samples of 2D materials. Hence tensile stretching of large pieces of freestanding monolayer h-BN and the effects of naturally occurring defects on its mechanical robustness remain largely unexplored.
Over the past three years, the research team led by Dr Lu Yang, Associate Professor of the Department of Mechanical Engineering (MNE) at CityU worked tirelessly with another team from Tsinghua University to develop the world’s very first quantitative in-situ tensile testing technique for free-standing 2D materials. Recently, they have expanded their research efforts from monolayer graphene to h-BN.
Using the 2D nanomechanical platform previously developed by the team, the researchers successfully performed quantitative tensile straining on freestanding monolayer h-BN for the first time (see Figure 1). The experiment showed that its fully recoverable elasticity was up to 6.2% and the corresponding 2D Young's modulus was about 200 N/m.
Another focus of the research was to explore the effects of h-BN’s naturally occurring defects on structural integrity and mechanical robustness. The team discovered that, monolayer h-BN containing voids of ~100 nm can be even strained up to 5.8% (see Movie/GIF). The atomistic and continuum simulations showed that compared to the imperfections introduced during sample preparation, the elastic limit of h-BN is virtually immune to naturally occurring atomistic defects (such as grain boundaries and vacancies). Those sub-micrometre voids are not detrimental, only reducing the elastic limit of h-BN from ~6.2% to ~5.8%, which demonstrates its high defect tolerance.
"Based on our experimental platform, we managed to investigate the mechanical properties of another important 2D material. For the first time, we demonstrated the high stiffness and large uniform elastic deformation of monolayer h-BN. The encouraging results not only contribute to the development of h-BN applications in strain engineering, piezoelectronics and flexible electronics, but also propose a new way to improve the performance of 2D composites and devices. They also provide a powerful tool to explore the mechanical properties of other 2D materials," Dr Lu said.
This Article was authored by The University of Manchester
Chemical engineer Aranza Carmona Orbezo hails from Mexico City, so she knows about the importance of reliable water supply for a large population. For the last four years, she’s been working on her PhD at Manchester’s Department of Chemistry, using graphene in capacitor systems to desalinate sea water for human consumption. She tells us about her research, the challenges that 2020 has posed and her vision for future technology.
So what brought you from Mexico to Manchester? I did my undergrad and Master’s in chemical engineering and my Master’s was focused a little bit on nanomaterials. So the first time that I heard about graphene, I fell in love with it.
I knew from the moment that I read that amazing paper [Geim/Novoselov et al on the isolation of graphene] that I wanted to work on something related to graphene. And of course, there’s no better place to work with graphene than in Manchester.
I started to do some research into the things that I could do and I found Professor Robert Dryfe on the Graphene@Manchester website and that he specialised in working with energy storage and the electrochemical performance of graphene.
That’s a topic that I’ve always been very passionate about: the idea that we can used these very technical electrochemistry concepts and use them in a final application, because the world that we’re living in really needs these types of things.
I got in touch with Prof Dryfe and then during Graphene Week, which took place in Manchester in 2015, I had the amazing opportunity to visit and have a meeting with him, and fall even more in love with the University.
Tell us a bit about your research… Water supply and scarcity is going to be a huge problem that faces humanity in the next 10 to 15 years. Sometimes for people in Britain, it’s not that obvious – they say “c’mon, water scarcity? It rains here all the time” – but London, for example, is one of the 12 cities across the world that are going to have big water scarcity issues in that timeframe.
Mexico City has had water supply problems for the last 20 years, and it’s getting worse by the minute, so it’s really important to find solutions now.
So my main research is using energy storage systems – capacitors and supercapacitors – to desalinate sea water and make it available for human consumption.
We try to understand the fundamentals – to really understand how it works – and then incorporate graphene or other 2D materials in the system to improve its performance. We know that graphene has great electrical conductivity, so it can be used within this system.
The technical name for what I’m working on is ‘capacitive deionisation’ and though it isn’t being reproduced at scale yet, it can definitely be scaled up. The idea is to find these better materials and better technologies to be able to compete with a process like reverse osmosis, which is the main process used currently to desalinate water.
One of our key advantages is that deionisation brings a lower overall cost for desalination because energy usage is reduced. As the system uses capacitors, you can recover some of that energy.
How has the Covid crisis affected your work and your life in Manchester? It was difficult for my research because [at the time of lockdown] I needed only three more weeks to finish my entire experimental work for my PhD. It was so frustrating because I was so close but then so far!
In the end it was 15 weeks until I was able to get back in the lab. But on the positive side it gave me a really good opportunity to focus on thesis writing – just me and my computer – and it really helped me with the final document.
I decided to stay in Manchester rather than go home to Mexico as things were a little bit more complicated over there, and I had the chance to explore the city in a really quiet state – in the hour that we were allowed to go out and walk – and just to go and breathe and try to relax and understand the crazy situation.
And it also gave me time for a sense of closure on my PhD – I can’t quite believe that I’m finishing my PhD I the middle of a pandemic – but it gave me a chance reflect on all of the things that I have learned during these past four years.
In a more ideal world, how do you like to spend your spare time? I love walking around the city itself but also getting out and walking around the Peak District, which is so beautiful and relaxing. And also the traditional stuff, going to the movies, seeing my friends, going to the pub.
I also like doing scientific outreach – going to events to talk about research and show young people how they can get involved with science. I’ve been involved previously in [pub-based outreach initiative] Pint of Science as media and promotions officer and I’m also a spokesperson for women in STEM.
What do you see as the future of graphene research in your area? In the short term, I think we’re going to see a lot more of graphene being included in energy storage devices. There’s a lot of work going on in supercapacitors and batteries, so I think we’re going to see that working in a really short time.
In terms of the application for desalination, I think that’s going to be more medium to long-term because there are a lot of things that we still need to understand. Graphene works in really interesting ways, some of which we weren’t expecting – in the systems that we have, and there are questions that still need to be answered.
Fortunately there are a lot of groups, here in Manchester and around the world, working on it and trying to find solutions, so hopefully we will be able to see graphene being used in these capacitive desalination systems before too long.
In terms of water desalination in general – with membranes, for example – since I arrived in 2016, there have already been some great breakthroughs with graphene in reverse osmosis systems, so I think we will see them, at least at the scale for home use, quite soon.
Even wider, one of the things I love about graphene is that there’s no limit for its applications. The only limit is our own imaginations. In the long term, graphene will be that material that will change the world and all of the investment that we’ve seen over the last few years will be paid back many, many times. The sky’s the limit!
And what about your own future? I would love to continue my career in academia or in industry, as long as I am involved in science and working in breakthroughs in science that allow me to deliver applications for a final user experience.
So right now I’m thinking about whether to do a post-doc or shift a little bit towards trying to get seed money for a start-up. Thinking further forward, I’d love to still be working in applied research and work with governments and other organisations to expand what we’re doing in science to solve the big problems facing our society – so-called ‘scientific diplomacy’. That’s my long-term goal for the future.
SCIENTIFIC ACHIEVEMENT At the Advanced Light Source (ALS), researchers visualized flat band structures associated with exotic electronic phases in stacked graphene layers offset from each other by a “magic angle.”
SIGNIFICANCE AND IMPACT The work corroborates theoretical predictions and discusses a new flexible testbed to study correlation effects that are leading to topological phases and superconductivity.
Graphene with a twist Graphene consists of a single sheet of carbon atoms that form a hexagonal lattice resembling chicken wire. One of the many fascinating properties of graphene is its extremely high electron mobility. The charge carriers in the system act as if they are massless—a condition signified by linear (cone-shaped) electronic band structures.
When two graphene layers are stacked on top of each other, the electronic bands are modified through interlayer coupling and orbital mixing, resulting in parabolic band structures. It’s also possible to tune the material’s behavior by introducing a small twist angle between the two layers. Due to the mismatch between the offset hexagonal lattices, the twist produces a moiré-patterned superlattice that can also affect electronic properties, depending on the twist angle.
Magic-angle moiré It has been theorized that, at a twist angle of about 1° (the “magic angle”), twisted bilayer graphene (tBLG) will exhibit flattened electronic bands near the charge-neutrality point (where upper and lower bands meet). An implication of this flat band structure is a high density of states, which has been known to provide a platform for emergent electronic phases involving strong (correlated) electron interactions. For example, magic-angle tBLG can host both strongly correlated insulating and superconducting states that can be controlled by doping the material with charge carriers using an applied gate voltage.
In general, magic-angle tBLG has been shown to exhibit a rich phase diagram at low temperature, making it a promising, relatively simple system for the study of exotic phenomena such as unconventional superconductivity, topological phases, and orbital magnetism. Although the implications of flat band dispersions have been widely reported, flat bands in tBLG had never before been directly visualized experimentally.
MAESTRO resolves the flat bands In this work, the researchers used nanofocused angle-resolved photoemission spectroscopy (nanoARPES) at ALS Beamline 7.0.2 (MAESTRO) to probe tBLG samples for evidence of the flat bands, which are difficult to resolve using other methods. Moreover, the high spatial resolution of the nanoARPES beamline is crucial in light of the micron-sized effective sample area, along with the inhomogeneity and local variations in the twist angle that are known to occur in fabricated tBLG samples. Following the nanoARPES experiment, the magic-angle twist of the sample was verified by measuring the periodicity of the moiré superlattice as imaged by scanning impedance microwave microscopy (sMIM).
Toward a future “twistronics” The measurements demonstrated the existence of the predicted flat bands in magic-angle tBLG near the charge-neutrality point at room temperature. In particular, the results provided direct evidence that the localized electronic states associated with the moiré geometry are responsible for the observed exotic behaviors. Future efforts will involve detailed nanoARPES studies of other flat band structures induced by moiré superlattices in related van der Waals heterostructure systems, including observations of electronic behavior at different doping levels induced by in situ electrostatic gating. Overall, the direct visualization enabled by the nanoARPES capability at MAESTRO should help researchers gain a more quantitative understanding of moiré-based physics, or “twistronics,” in magic-angle tBLG and other materials.
Transistors based on carbon rather than silicon could potentially boost computers' speed and cut their power consumption more than a thousandfold -- think of a mobile phone that holds its charge for months -- but the set of tools needed to build working carbon circuits has remained incomplete until now.
A team of chemists and physicists at the University of California, Berkeley, has finally created the last tool in the toolbox, a metallic wire made entirely of carbon, setting the stage for a ramp-up in research to build carbon-based transistors and, ultimately, computers.
"Staying within the same material, within the realm of carbon-based materials, is what brings this technology together now," said Felix Fischer, UC Berkeley professor of chemistry, noting that the ability to make all circuit elements from the same material makes fabrication easier. "That has been one of the key things that has been missing in the big picture of an all-carbon-based integrated circuit architecture."
Metal wires -- like the metallic channels used to connect transistors in a computer chip -- carry electricity from device to device and interconnect the semiconducting elements within transistors, the building blocks of computers.
The UC Berkeley group has been working for several years on how to make semiconductors and insulators from graphene nanoribbons, which are narrow, one-dimensional strips of atom-thick graphene, a structure composed entirely of carbon atoms arranged in an interconnected hexagonal pattern resembling chicken wire.
The new carbon-based metal is also a graphene nanoribbon, but designed with an eye toward conducting electrons between semiconducting nanoribbons in all-carbon transistors. The metallic nanoribbons were built by assembling them from smaller identical building blocks: a bottom-up approach, said Fischer's colleague, Michael Crommie, a UC Berkeley professor of physics. Each building block contributes an electron that can flow freely along the nanoribbon.
While other carbon-based materials -- like extended 2D sheets of graphene and carbon nanotubes -- can be metallic, they have their problems. Reshaping a 2D sheet of graphene into nanometer scale strips, for example, spontaneously turns them into semiconductors, or even insulators. Carbon nanotubes, which are excellent conductors, cannot be prepared with the same precision and reproducibility in large quantities as nanoribbons.
"Nanoribbons allow us to chemically access a wide range of structures using bottom-up fabrication, something not yet possible with nanotubes," Crommie said. "This has allowed us to basically stitch electrons together to create a metallic nanoribbon, something not done before. This is one of the grand challenges in the area of graphene nanoribbon technology and why we are so excited about it."
Metallic graphene nanoribbons -- which feature a wide, partially-filled electronic band characteristic of metals -- should be comparable in conductance to 2D graphene itself.
"We think that the metallic wires are really a breakthrough; it is the first time that we can intentionally create an ultra-narrow metallic conductor -- a good, intrinsic conductor -- out of carbon-based materials, without the need for external doping," Fischer added.
Crommie, Fischer and their colleagues at UC Berkeley and Lawrence Berkeley National Laboratory (Berkeley Lab) will publish their findings in the Sept. 25 issue of the journal Science.
Tweaking the topology
Silicon-based integrated circuits have powered computers for decades with ever increasing speed and performance, per Moore's Law, but they are reaching their speed limit -- that is, how fast they can switch between zeros and ones. It's also becoming harder to reduce power consumption; computers already use a substantial fraction of the world's energy production. Carbon-based computers could potentially switch many times times faster than silicon computers and use only fractions of the power, Fischer said.
Graphene, which is pure carbon, is a leading contender for these next-generation, carbon-based computers. Narrow strips of graphene are primarily semiconductors, however, and the challenge has been to make them also work as insulators and metals -- opposite extremes, totally nonconducting and fully conducting, respectively -- so as to construct transistors and processors entirely from carbon.
Several years ago, Fischer and Crommie teamed up with theoretical materials scientist Steven Louie, a UC Berkeley professor of physics, to discover new ways of connecting small lengths of nanoribbon to reliably create the full gamut of conducting properties.
Two years ago, the team demonstrated that by connecting short segments of nanoribbon in the right way, electrons in each segment could be arranged to create a new topological state -- a special quantum wave function -- leading to tunable semiconducting properties.
In the new work, they use a similar technique to stitch together short segments of nanoribbons to create a conducting metal wire tens of nanometers long and barely a nanometer wide.
The nanoribbons were created chemically and imaged on very flat surfaces using a scanning tunneling microscope. Simple heat was used to induce the molecules to chemically react and join together in just the right way. Fischer compares the assembly of daisy-chained building blocks to a set of Legos, but Legos designed to fit at the atomic scale.
"They are all precisely engineered so that there is only one way they can fit together. It's as if you take a bag of Legos, and you shake it, and out comes a fully assembled car," he said. "That is the magic of controlling the self-assembly with chemistry."
Once assembled, the new nanoribbon's electronic state was a metal -- just as Louie predicted -- with each segment contributing a single conducting electron.
The final breakthrough can be attributed to a minute change in the nanoribbon structure.
"Using chemistry, we created a tiny change, a change in just one chemical bond per about every 100 atoms, but which increased the metallicity of the nanoribbon by a factor of 20, and that is important, from a practical point of view, to make this a good metal," Crommie said.
The two researchers are working with electrical engineers at UC Berkeley to assemble their toolbox of semiconducting, insulating and metallic graphene nanoribbons into working transistors.
"I believe this technology will revolutionize how we build integrated circuits in the future," Fischer said. "It should take us a big step up from the best performance that can be expected from silicon right now. We now have a path to access faster switching speeds at much lower power consumption. That is what is driving the push toward a carbon-based electronics semiconductor industry in the future."
Applied Graphene Materials, the producer of speciality graphene additives, is delighted to announce that INFINITY WAX, a leading innovator in car care products, will launch the ground-breaking QDX Graphene Detailing Spray during Q4 2020. Detailing sprays are used to elevate shine and enable car owners to wipe away dirt in a far more straightforward manner.
The detailing spray polish that will be available to global retailers is the result of an extensive product development and rigorous third-party testing programme which has produced a formulation and system that delivers industry-leading performance.
When launched, the product which is enhanced with AGM's market-leading Genable® graphene dispersions will be available to car owners of all types representing yet another significant milestone achieved by the Company.
Adrian Potts, Chief Executive Officer of AGM, said:
“We have seen growing interest from the Car Care sector for graphene nanoplatelet dispersions to take product innovation to a new and exciting performance level. The QDX Graphene Detailing product is a great step forward for Infinity Wax and a major milestone in this space for AGM. It further validates the ease-of-use and outstanding utility of the graphene nanoplatelet dispersions we offer. Selecting the correct form of dispersion as the optimum delivery system for nanoplatelet materials is key to successful product formulating. Integration of our products into a new sector further demonstrates that well-dispersed graphene materials can be introduced into existing formulated systems to create new, higher performance products that build on the remarkable attributes of our graphene nanoplatelets. I am particularly excited to see this innovation come to market with Infinity Wax as our lead customer in this space and look forward to seeing volumes grow as the product is adopted by the public."
Mike Cipriani, Infinity Wax company Founder, commented:
“The team at Infinity Wax is excited to launch the first graphene-enhanced product in our retail range, QDX Graphene. It builds on the success of our existing range of detailing sprays and with the Genable® graphene dispersions supplied by AGM we can take the performance of the products to the next level. It is a highly powerful spray product with industry-leading performance that is incredibly easy to use. We would like to thank all at AGM for their invaluable support and assistance during this project and look forward to building Genable® into other product formulations.”
Electrochemistry is playing an increasingly important role:Whether it is fuel cells, electrolysis or chemical energy storage, chemical reactions controlled by electric current are used. The decisive factor in all these applications is that the reactions are as fast and efficient as possible.
An important step forward has now been taken by a team from TU Wien (Vienna) and DESY in Hamburg: They showed that a special material made of lanthanum, strontium, iron and oxygen can be switched back and forth between two different states: In one state the material is catalytically extremely active, in the other less so. The reason for this is the behavior of tiny iron nanoparticles on the surface, which has now been demonstrated in experiments at the German Electron Synchrotron DESY in Hamburg. This finding should now make it possible to develop even better catalysts. The result has been published in the journal "Nature Communications".
Electrical voltage causes oxygen ions to migrate "We have been using perovskites for our electrochemical experiments for years," says Prof. Alexander Opitz from the Institute of Chemical Technologies and Analytics. "Perovskites are a very diverse class of materials, some of them are excellent catalysts." The surface of the perovskites can help to bring certain reactants into contact with each other – or to separate them again. "Above all, perovskites have the advantage that they are permeable to oxygen ions. Therefore, they can conduct electric current, and we are taking advantage of this," explains Alexander Opitz.
When an electrical voltage is applied to the perovskite, oxygen ions are released from their place within the crystal and start to migrate through the material. If the voltage exceeds a certain value, this leads to iron atoms in the perovskite migrating as well. They move to the surface and form tiny particles there, with a diameter of only a few nanometers. Essentially, these nanoparticles are excellent catalysts.
"The interesting thing is that if one reverses the electric voltage, the catalytic activity decreases again. And so far the reason for this was unclear," says Alexander Opitz. "Some people suspected that the iron atoms would simply migrate back into the crystal, but that's not true. When the effect takes place, the iron atoms do not have to leave their place on the material surface at all.”
Analysis with X-rays at DESY The research team at TU Wien collaborated with a team at the Electron Synchrotron in Hamburg (DESY) to precisely analyze the structure of the nanoparticles with X-rays while the chemical processes take place. It turned out that the nanoparticles change back and forth between two different states - depending on the voltage applied: "We can switch the iron particles between a metallic and an oxidic state," says Alexander Opitz. The applied voltage determines whether the oxygen ions in the material are pumped towards the iron nanoparticles or away from them. This allows to control how much oxygen is contained in the nanoparticles, and depending on the amount of oxygen, the nanoparticles can form two different structures - an oxygen-rich one, with low catalytic activity, and an oxygen-poor, i.e. metallic one, which is catalytically very active.
"This is a very important finding for us," says Alexander Opitz. "If the switching between the two states were caused by the iron atoms of the nanoparticle diffusing back into the crystal, very high temperatures would be needed to make this process run efficiently. Now that we understand that the activity change is not related to the diffusion of iron atoms but to the change between two different crystal structures, we also know that comparatively low temperatures can be sufficient. This makes this type of catalyst even more interesting because it can potentially be used to accelerate technologically relevant reactions.
From hydrogen to energy storage This catalytic mechanism is now to be further investigated, also for materials with slightly different compositions. It could increase the efficiency of many applications. "This is particularly interesting for chemical reactions that are important in the energy sector," says Alexander Opitz. "For example, when it comes to the production of hydrogen or synthesis gas, or to energy storage by producing fuel with electric current."
ZEN Graphene Solutions is pleased to report that after 5 months of optimization, it has developed a novel graphene-based virucidal ink with 99% effectiveness against COVID-19. Highlights:
• ZEN’s Virucidal ink is 99% effective against the COVID-19 virus • ZEN’s Virucidal ink was still 99% effective a minimum of 35 days after application to N95 mask material • ZEN is now developing plans to expedite commercialization of this product, pending regulatory approval. • ZEN has filed a provisional patent for this graphene-based virucidal product • ZEN invites PPE companies to reach out for potential partnerships to bring this new technology to market: Antiviralink@ZENGraphene.com • ZEN is beginning antibacterial and antifungal tests utilizing its proprietary ink formulation
The company has received results from the latest round of testing of its proprietary, virucidal graphene-based ink formulation at Western University’s ImPaKT facility Biosafety Level 3 laboratory. Two graphene-based ink samples at different concentrations were applied to N95 mask filtration media and then exposed to the SARS-CoV-2 virus that causes COVID-19 and tested for antiviral properties in accordance with ISO 18184:2019. Very significant virucidal activity was recorded and reported, achieving 99% inactivation of the virus for both samples in 3 separate tests each and verified through a second round of testing. Of significance, the antiviral effect of the second round of testing was on material that was prepared 35 days earlier demonstrating the ongoing virucidal activity of ZEN’s proprietary ink. For those interested in seeing the report, please contact the company directly.
The research and development of this antiviral ink formulation was conducted entirely by ZEN’s research team at its Guelph, Ontario facility using a graphene product that was produced from its Albany PureTM Graphite.
ZEN is now developing plans to bring this novel virucidal ink to commercial production including working with regulatory authorities and government agencies to fast track this product to Canadian and global markets to help the fight against the Coronavirus pandemic. ZEN is expanding the testing of this graphene-based ink formulation to include pathogenic bacteria and fungi and will report on these tests as soon as the results are available.
CEO Dr. Francis Dube commented, “These recent results have dramatically exceeded our expectations with our ink achieving 99% virucidal activity against the SARS-CoV-2 virus 35 days after production of the samples. I am very proud of our Research and Development team for their exceptional work in developing this novel formulation. We are excited about the role our ink can play in the fight against this global pandemic and are moving quickly to mobilize our resources to bring this product to market.”