A July 10, 2019 news item on ScienceDaily announces a more environmentally friendly way to produce graphene leading to more environmentally friendly devices such as computers,
In order to create new and more efficient computers, medical devices, and other advanced technologies, researchers are turning to nanomaterials: materials manipulated on the scale of atoms or molecules that exhibit unique properties.
Graphene — a flake of carbon as thin as a single later of atoms — is a revolutionary nanomaterial due to its ability to easily conduct electricity, as well as its extraordinary mechanical strength and flexibility. However, a major hurdle in adopting it for everyday applications is producing graphene at a large scale, while still retaining its amazing properties.
In a paper published in the journal ChemOpen, Anne S. Meyer, an associate professor of biology at the University of Rochester [New York state, US], and her colleagues at Delft University of Technology in the Netherlands, describe a way to overcome this barrier. The researchers outline their method to produce graphene materials using a novel technique: mixing oxidized graphite with bacteria. Their method is a more cost-efficient, time-saving, and environmentally friendly way of producing graphene materials versus those produced chemically, and could lead to the creation of innovative computer technologies and medical equipment.
Graphene is extracted from graphite, the material found in an ordinary pencil. At exactly one atom thick, graphene is the thinnest–yet strongest–two-dimensional material known to researchers. Scientists from the University of Manchester in the United Kingdom were awarded the 2010 Nobel Prize in Physics for their discovery of graphene; however, their method of using sticky tape to make graphene yielded only small amounts of the material.
“For real applications you need large amounts,” Meyer says. “Producing these bulk amounts is challenging and typically results in graphene that is thicker and less pure. This is where our work came in.”
In order to produce larger quantities of graphene materials, Meyer and her colleagues started with a vial of graphite. They exfoliated the graphite–shedding the layers of material–to produce graphene oxide (GO), which they then mixed with the bacteria Shewanella. They let the beaker of bacteria and precursor materials sit overnight, during which time the bacteria reduced the GO to a graphene material.
“Graphene oxide is easy to produce, but it is not very conductive due to all of the oxygen groups in it,” Meyer says. “The bacteria remove most of the oxygen groups, which turns it into a conductive material.”
While the bacterially-produced graphene material created in Meyer’s lab is conductive, it is also thinner and more stable than graphene produced chemically. It can additionally be stored for longer periods of time, making it well suited for a variety of applications, including field-effect transistor (FET) biosensors and conducting ink. FET biosensors are devices that detect biological molecules and could be used to perform, for example, real-time glucose monitoring for diabetics.
“When biological molecules bind to the device, they change the conductance of the surface, sending a signal that the molecule is present,” Meyer says. “To make a good FET biosensor you want a material that is highly conductive but can also be modified to bind to specific molecules.” Graphene oxide that has been reduced is an ideal material because it is lightweight and very conductive, but it typically retains a small number of oxygen groups that can be used to bind to the molecules of interest.
The bacterially produced graphene material could also be the basis for conductive inks, which could, in turn, be used to make faster and more efficient computer keyboards, circuit boards, or small wires such as those used to defrost car windshields. Using conductive inks is an “easier, more economical way to produce electrical circuits, compared to traditional techniques,” Meyer says. Conductive inks could also be used to produce electrical circuits on top of nontraditional materials like fabric or paper.
“Our bacterially produced graphene material will lead to far better suitability for product development,” Meyer says. “We were even able to develop a technique of ‘bacterial lithography’ to create graphene materials that were only conductive on one side, which can lead to the development of new, advanced nanocomposite materials.”
It’s been quite educational reading a June 24, 2019 news item on Nanowerk about deriving graphene from Eucalyptus bark (Note: Links have been removed),
Graphene is the thinnest and strongest material known to humans. It’s also flexible, transparent and conducts heat and electricity 10 times better than copper, making it ideal for anything from flexible nanoelectronics to better fuel cells.
The new approach by researchers from RMIT University (Australia) and the National Institute of Technology, Warangal (India), uses Eucalyptus bark extract and is cheaper and more sustainable than current synthesis methods (ACS Sustainable Chemistry & Engineering, “Novel and Highly Efficient Strategy for the Green Synthesis of Soluble Graphene by Aqueous Polyphenol Extracts of Eucalyptus Bark and Its Applications in High-Performance Supercapacitors”).
RMIT lead researcher, Distinguished Professor Suresh Bhargava, said the new method could reduce the cost of production from $USD100 per gram to a staggering $USD0.5 per gram.
“Eucalyptus bark extract has never been used to synthesise graphene sheets before and we are thrilled to find that it not only works, it’s in fact a superior method, both in terms of safety and overall cost,” said Bhargava.
“Our approach could bring down the cost of making graphene from around $USD100 per gram to just 50 cents, increasing it availability to industries globally and enabling the development of an array of vital new technologies.”
Graphene’s distinctive features make it a transformative material that could be used in the development of flexible electronics, more powerful computer chips and better solar panels, water filters and bio-sensors.
Professor Vishnu Shanker from the National Institute of Technology, Warangal, said the ‘green’ chemistry avoided the use of toxic reagents, potentially opening the door to the application of graphene not only for electronic devices but also biocompatible materials.
“Working collaboratively with RMIT’s Centre for Advanced Materials and Industrial Chemistry we’re harnessing the power of collective intelligence to make these discoveries,” he said.
A novel approach to graphene synthesis:
Chemical reduction is the most common method for synthesising graphene oxide as it allows for the production of graphene at a low cost in bulk quantities.
This method however relies on reducing agents that are dangerous to both people and the environment.
When tested in the application of a supercapacitor, the ‘green’ graphene produced using this method matched the quality and performance characteristics of traditionally-produced graphene without the toxic reagents.
Bhargava said the abundance of eucalyptus trees in Australia made it a cheap and accessible resource for producing graphene locally.
“Graphene is a remarkable material with great potential in many applications due to its chemical and physical properties and there’s a growing demand for economical and environmentally friendly large-scale production,” he said.
There seems to be much interest in bacteria as collaborators as opposed to the old ‘enemy that must be destoyed’ concept. The latest collaborative effort was announced in a January 19,2019 news item on Nanowerk,
More than one in 10 people in the world lack basic drinking water access, and by 2025, half of the world’s population will be living in water-stressed areas, which is why access to clean water is one of the National Academy of Engineering’s Grand Challenges. Engineers at Washington University in St. Louis [WUSTL] have designed a novel membrane technology that purifies water while preventing biofouling, or buildup of bacteria and other harmful microorganisms that reduce the flow of water.
And they used bacteria to build such filtering membranes.
Srikanth Singamaneni, professor of mechanical engineering & materials science, and Young-Shin Jun, professor of energy, environmental & chemical engineering, and their teams blended their expertise to develop an ultrafiltration membrane using graphene oxide and bacterial nanocellulose that they found to be highly efficient, long-lasting and environmentally friendly. If their technique were to be scaled up to a large size, it could benefit many developing countries where clean water is scarce.
Biofouling accounts for nearly half of all membrane fouling and is highly challenging to eradicate completely. Singamaneni and Jun have been tackling this challenge together for nearly five years. They previously developed other membranes using gold nanostars, but wanted to design one that used less expensive materials.
Their new membrane begins with feeding Gluconacetobacter hansenii bacteria a sugary substance so that they form cellulose nanofibers when in water. The team then incorporated graphene oxide (GO) flakes into the bacterial nanocellulose while it was growing, essentially trapping GO in the membrane to make it stable and durable.
After GO is incorporated, the membrane is treated with base solution to kill Gluconacetobacter. During this process, the oxygen groups of GO are eliminated, making it reduced GO. When the team shone sunlight onto the membrane, the reduced GO flakes immediately generated heat, which is dissipated into the surrounding water and bacteria nanocellulose.
Ironically, the membrane created from bacteria also can kill bacteria. “If you want to purify water with microorganisms in it, the reduced graphene oxide in the membrane can absorb the sunlight, heat the membrane and kill the bacteria,” Singamaneni said.
Singamaneni and Jun and their team exposed the membrane to E. coli bacteria, then shone light on the membrane’s surface. After being irradiated with light for just 3 minutes, the E. coli bacteria died. The team determined that the membrane quickly heated to above the 70 degrees Celsius required to deteriorate the cell walls of E. coli bacteria.
While the bacteria are killed, the researchers had a pristine membrane with a high quality of nanocellulose fibers that was able to filter water twice as fast as commercially available ultrafiltration membranes under a high operating pressure.
When they did the same experiment on a membrane made from bacterial nanocellulose without the reduced GO, the E. coli bacteria stayed alive.
“This is like 3-D printing with microorganisms,” Jun said. “We can add whatever we like to the bacteria nanocellulose during its growth. We looked at it under different pH conditions similar to what we encounter in the environment, and these membranes are much more stable compared to membranes prepared by vacuum filtration or spin-coating of graphene oxide.”
While Singamaneni and Jun acknowledge that implementing this process in conventional reverse osmosis systems is taxing, they propose a spiral-wound module system, similar to a roll of towels. It could be equipped with LEDs or a type of nanogenerator that harnesses mechanical energy from the fluid flow to produce light and heat, which would reduce the overall cost.
The European Union’s Human Brain Project was announced in January 2013. It, along with the Graphene Flagship, had won a multi-year competition for the extraordinary sum of one million euros each to be paid out over a 10-year period. (My January 28, 2013 posting gives the details available at the time.)
At a little more than half-way through the project period, Ed Yong, in his July 22, 2019 article for The Atlantic, offers an update (of sorts),
Ten years ago, a neuroscientist said that within a decade he could simulate a human brain. Spoiler: It didn’t happen.
On July 22, 2009, the neuroscientist Henry Markram walked onstage at the TEDGlobal conference in Oxford, England, and told the audience that he was going to simulate the human brain, in all its staggering complexity, in a computer. His goals were lofty: “It’s perhaps to understand perception, to understand reality, and perhaps to even also understand physical reality.” His timeline was ambitious: “We can do it within 10 years, and if we do succeed, we will send to TED, in 10 years, a hologram to talk to you.” …
It’s been exactly 10 years. He did not succeed.
One could argue that the nature of pioneers is to reach far and talk big, and that it’s churlish to single out any one failed prediction when science is so full of them. (Science writers joke that breakthrough medicines and technologies always seem five to 10 years away, on a rolling window.) But Markram’s claims are worth revisiting for two reasons. First, the stakes were huge: In 2013, the European Commission awarded his initiative—the Human Brain Project (HBP)—a staggering 1 billion euro grant (worth about $1.42 billion at the time). Second, the HBP’s efforts, and the intense backlash to them, exposed important divides in how neuroscientists think about the brain and how it should be studied.
Markram’s goal wasn’t to create a simplified version of the brain, but a gloriously complex facsimile, down to the constituent neurons, the electrical activity coursing along them, and even the genes turning on and off within them. From the outset, the criticism to this approach was very widespread, and to many other neuroscientists, its bottom-up strategy seemed implausible to the point of absurdity. The brain’s intricacies—how neurons connect and cooperate, how memories form, how decisions are made—are more unknown than known, and couldn’t possibly be deciphered in enough detail within a mere decade. It is hard enough to map and model the 302 neurons of the roundworm C. elegans, let alone the 86 billion neurons within our skulls. “People thought it was unrealistic and not even reasonable as a goal,” says the neuroscientist Grace Lindsay, who is writing a book about modeling the brain. And what was the point? The HBP wasn’t trying to address any particular research question, or test a specific hypothesis about how the brain works. The simulation seemed like an end in itself—an overengineered answer to a nonexistent question, a tool in search of a use. …
Markram seems undeterred. In a recent paper, he and his colleague Xue Fan firmly situated brain simulations within not just neuroscience as a field, but the entire arc of Western philosophy and human civilization. And in an email statement, he told me, “Political resistance (non-scientific) to the project has indeed slowed us down considerably, but it has by no means stopped us nor will it.” He noted the 140 people still working on the Blue Brain Project, a recent set of positive reviews from five external reviewers, and its “exponentially increasing” ability to “build biologically accurate models of larger and larger brain regions.”
No time frame, this time, but there’s no shortage of other people ready to make extravagant claims about the future of neuroscience. In 2014, I attended TED’s main Vancouver conference and watched the opening talk, from the MIT Media Lab founder Nicholas Negroponte. In his closing words, he claimed that in 30 years, “we are going to ingest information. …
I’m happy to see the update. As I recall, there was murmuring almost immediately about the Human Brain Project (HBP). I never got details but it seemed that people were quite actively unhappy about the disbursements. Of course, this kind of uproar is not unusual when great sums of money are involved and the Graphene Flagship also had its rocky moments.
As for Yong’s contribution, I’m glad he’s debunking some of the hype and glory associated with the current drive to colonize the human brain and other efforts (e.g. genetics) which they often claim are the ‘future of medicine’.
To be fair. Yong is focused on the brain simulation aspect of the HBP (and Markram’s efforts in the Blue Brain Project) but there are other HBP efforts, as well, even if brain simulation seems to be the HBP’s main interest.
In 2013, the European Union funded the Human Brain Project, led by Markram, to the tune of $1.3 billion. Markram claimed that the project would create a simulation of the entire human brain on a supercomputer within a decade, revolutionising the treatment of Alzheimer’s disease and other brain disorders. Less than two years into it, the project was recognised to be mismanaged and its claims overblown, and Markram was asked to step down.
On 8 October 2015, the Blue Brain Project published the first digital reconstruction and simulation of the micro-circuitry of a neonatal rat somatosensory cortex.
I also looked up the Human Brain Project and, talking about their other efforts, was reminded that they have a neuromorphic computing platform, SpiNNaker (mentioned here in a January 24, 2019 posting; scroll down about 50% of the way). For anyone unfamiliar with the term, neuromorphic computing/engineering is what scientists call the effort to replicate the human brain’s ability to synthesize and process information in computing processors.
In fact, there was some discussion in 2013 that the Human Brain Project and the Graphene Flagship would have some crossover projects, e.g., trying to make computers more closely resemble human brains in terms of energy use and processing power.
The Human Brain Project’s (HBP) Silicon Brains webpage notes this about their neuromorphic computing platform,
Neuromorphic computing implements aspects of biological neural networks as analogue or digital copies on electronic circuits. The goal of this approach is twofold: Offering a tool for neuroscience to understand the dynamic processes of learning and development in the brain and applying brain inspiration to generic cognitive computing. Key advantages of neuromorphic computing compared to traditional approaches are energy efficiency, execution speed, robustness against local failures and the ability to learn.
Neuromorphic Computing in the HBP
In the HBP the neuromorphic computing Subproject carries out two major activities: Constructing two large-scale, unique neuromorphic machines and prototyping the next generation neuromorphic chips.
The large-scale neuromorphic machines are based on two complementary principles. The many-core SpiNNaker machine located in Manchester [emphasis mine] (UK) connects 1 million ARM processors with a packet-based network optimized for the exchange of neural action potentials (spikes). The BrainScaleS physical model machine located in Heidelberg (Germany) implements analogue electronic models of 4 Million neurons and 1 Billion synapses on 20 silicon wafers. Both machines are integrated into the HBP collaboratory and offer full software support for their configuration, operation and data analysis.
The most prominent feature of the neuromorphic machines is their execution speed. The SpiNNaker system runs at real-time, BrainScaleS is implemented as an accelerated system and operates at 10,000 times real-time. Simulations at conventional supercomputers typical run factors of 1000 slower than biology and cannot access the vastly different timescales involved in learning and development ranging from milliseconds to years.
Recent research in neuroscience and computing has indicated that learning and development are a key aspect for neuroscience and real world applications of cognitive computing. HBP is the only project worldwide addressing this need with dedicated novel hardware architectures.
I’ve highlighted Manchester because that’s a very important city where graphene is concerned. The UK’s National Graphene Institute is housed at the University of Manchester where graphene was first isolated in 2004 by two scientists, Andre Geim and Konstantin (Kostya) Novoselov. (For their effort, they were awarded the Nobel Prize for physics in 2010.)
Getting back to the HBP (and the Graphene Flagship for that matter), the funding should be drying up sometime around 2023 and I wonder if it will be possible to assess the impact.
I have two relatively recent news bits about nanomaterials, the second being entirely focused on graphene.
A July 9, 2019 news item on Nanowerk announces a means of finding out what hazards may be associated with 300 different nanomaterials (Note: A Link has been removed),
A new search tool for nanomaterials has been published on the European Union Observatory for Nanomaterials (EUON) website. It will enable regulators to form a better view of available data and give consumers access to chemicals safety information.
The tool combines data submitted by companies in their REACH registrations [Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) ], data collected about nanomaterials used as ingredients in cosmetic products under the Cosmetics Regulation and data from the public national nanomaterial inventories of Belgium and France.
The EUON’s search brings data from these sources together in one place, allowing users to easily search for nanomaterials that are currently on the EU market. The results are linked to ECHA’s [European Chemicals Agency] database of chemicals registered in the EU and, for the first time, summarised information about the substances, their properties as well as detailed safety and characterisation data can be easily found.
While there are over 300 nanomaterials on the EU market, 37 are currently covered by an existing registration under REACH. The information requirements for REACH were revised last year with explicit obligations for nanomaterials manufactured in or imported to the EU. The new requirements enter into force in January 2020 and will result in more publicly available information.
The EUON aims to increase the transparency of information available to the public on the safety and markets of nanomaterials in the EU. A key aim of the observatory is to create a one-stop shop for information, where EU citizens and stakeholders including NGOs, industry, and regulators can all easily find accessible and relevant safety information on nanomaterials on the EU market.
There was a bit of a scandal about fake graphene in the Fall of 2018 (my May 28, 2019 posting gives details). Dexter Johnson provides additional insight and information about the launch of a new graphene verification programme and news of a slightly older graphene verification programme in his July 9, 2019 article for the Nanoclast blog on the IEEE (Institute of Electrical and Electronics Engineers) website (Note: Links have been removed),
Last year , the graphene community was rocked by a series of critical articles that appeared in some high-profile journals. First there was an Advanced Material’s article with the rather innocuously title: “The Worldwide Graphene Flake Production”. It was perhaps the follow-up article that appeared in the journal Nature that really shook things up with its incendiary title: “The war on fake graphene”.
In these two articles it was revealed that material that had been claimed to be high-quality (and high-priced) graphene was little more than graphite powder. Boosted by their appearance in high-impact journals, these articles threatened the foundations of the graphene marketplace.
But while these articles triggered a lot of hand wringing among the buyers and sellers of graphene, it’s not clear that their impact extended much beyond the supply chain of graphene. Whether or not graphene has aggregated back to being graphite is one question. An even bigger one is whether or not consumers are actually being sold a better product on the basis that it incorporates graphene.
Dexter details some of the issues from the consumer’s perspective (Note: Links have been removed),
Consumer products featuring graphene today include everything from headphones to light bulbs. Consequently, there is already confusion among buyers about the tangible benefits graphene is supposed to provide. And of course the situation becomes even worse if the graphene sold to make products may not even be graphene: how are consumers supposed to determine whether graphene infuses their products with anything other than a buzzword?
Another source of confusion arises because when graphene is incorporated into a product it is effectively a different animal from graphene in isolation. There is ample scientific evidence that graphene when included in a material matrix, like a polymer or even paper, can impart new properties to the materials. “You can transfer some very useful properties of graphene into other materials by adding graphene, but just because the resultant material contains graphene it does not mean it will behave like free-standing graphene, explains Tom Eldridge, of UK-based Fullerex, a consultancy that provides companies with information on how to include graphene in a material matrix
The rest of Dexter’s posting goes on to mention two new graphene verification progammes (producer and product) available through The Graphene Council. As for what the council is, there’s this from council’s About webpage,
The Graphene Council was founded in 2013 with a mission to serve the global community of graphene professionals. Today, The Graphene Council is the largest community in the world for graphene researchers, academics, producers, developers, investors, nanotechnologists, regulatory agencies, research institutes, material science specialists and even the general public. We reach more than 50,000 people with an interest in this amazing material.
Interestingly the council’s offices are located in the US state of North Carolina. (I would have guessed that its headquarters would be in the UK, given the ‘ownership’ the UK has been attempting to establish over graphene Let me clarify, by ownership I mean the Brits want to be recognized as dominant or preeminent in graphene research and commercialization.)
The council’s first verified graphene producer is a company based in the UK as can be seen in an April 1, 2019 posting by council director Terrance Barkan on the council’s blog,
The Graphene Council is pleased to announce that Versarien plc is the first graphene company in the world to successfully complete the Verified Graphene Producer™ program, an independent, third party verification system that involves a physical inspection of the production facilities, a review of the entire production process, a random sample of product material and rigorous characterization and testing by a first class, international materials laboratory.
The Verified Graphene Producer™ program is an important step to bring transparency and clarity to a rapidly changing and opaque market for graphene materials, providing graphene customers with a level of confidence that has not existed before.
“We are pleased to have worked with the National Physical Laboratory (NPL) in the UK, regarded as one of the absolute top facilities for metrology and graphene characterization in the world.
They have provided outstanding analytical expertise for the materials testing portion of the program including Raman Spectroscopy, XPS, AFM and SEM testing services.” stated Terrance Barkan CAE, Executive Director of The Graphene Council.
Andrew Pollard, Science Area Leader of the Surface Technology Group, National Physical Laboratory, said: “In order to develop real-world products that can benefit from the ‘wonder material’, graphene, we first need to fully understand its properties, reliably and reproducibly.
“Whilst international measurement standards are currently being developed, it is critical that material characterisation is performed to the highest possible level.
As the UK’s National Measurement Institute (NMI) with a focus on developing the metrology of graphene and related 2D materials, we aim to be an independent third party in the testing of graphene material for companies and associations around the world, such as The Graphene Council.”
Neill Ricketts, CEO of Versarien said: “We are delighted that Versarien is the first graphene producer in the world to successfully complete the Graphene Council’s Verified Graphene Producer™ programme.”
“This is a huge validation of our technology and will enable our partners and potential customers to have confidence that the graphene we produce meets globally accepted standards.”
“There are many companies that claim to be graphene producers, but to enjoy the benefits that this material can deliver requires high quality, consistent product to be supplied. The Verified Producer programme is designed to verify that our production facilities, processes and tested material meet the stringent requirements laid down by The Graphene Council.”
“I am proud that Versarien has been independently acclaimed as a Verified Graphene Producer™ and look forward to making further progress with our collaboration partners and numerous other parties that we are in discussions with.”
James Baker CEng FIET, the CEO of Graphene@Manchester (which includes coordinating the efforts of the National Graphene Institute and the Graphene Engineering and Innovation Centre [GEIC]) stated: “We applaud The Graphene Council for promoting independent third party verification for graphene producers that is supported by world class metrology and characterization services.”
“This is an important contribution to the commercialization of graphene as an industrial material and are proud to have The Graphene Council as an Affiliate Member of the Graphene Engineering and Innovation Centre (GEIC) here in Manchester ”.
Successful commercialization of graphene materials requires not only the ability to produce graphene to a declared specification but to be able to do so at a commercial scale. It is nearly impossible for a graphene customer to verify the type of material they are receiving without going through an expensive and time consuming process of having sample materials fully characterized by a laboratory that has the equipment and expertise to test graphene.
The Verified Graphene Producer™ program developed by The Graphene Councilprovides a level of independent inspection and verification that is not available anywhere else.
As for the “Verified Graphene Product” programme mentioned in Dexter’s article (it’s not included in the excerpts here), I can’t find any sign of it ion the council’s website.
Light-harvesting devices—I like that better than solar cells or the like but I think that the term serves as a category rather than a name/label for a specific device. Enough musing. A December 17, 2018 news item on Nanowerk describes the latest about graphene and light-harvesting devices (Note: A link has been removed,
An international research team, co-led by a physicist at the University of California, Riverside, has discovered a new mechanism for ultra-efficient charge and energy flow in graphene, opening up opportunities for developing new types of light-harvesting devices.
The researchers fabricated pristine graphene — graphene with no impurities — into different geometric shapes, connecting narrow ribbons and crosses to wide open rectangular regions. They found that when light illuminated constricted areas, such as the region where a narrow ribbon connected two wide regions, they detected a large light-induced current, or photocurrent.
The finding that pristine graphene can very efficiently convert light into electricity could lead to the development of efficient and ultrafast photodetectors — and potentially more efficient solar panels.
Graphene, a 1-atom thick sheet of carbon atoms arranged in a hexagonal lattice, has many desirable material properties, such as high current-carrying capacity and thermal conductivity. In principle, graphene can absorb light at any frequency, making it ideal material for infrared and other types of photodetection, with wide applications in bio-sensing, imaging, and night vision.
In most solar energy harvesting devices, a photocurrent arises only in the presence of a junction between two dissimilar materials, such as “p-n” junctions, the boundary between two types of semiconductor materials. The electrical current is generated in the junction region and moves through the distinct regions of the two materials.
“But in graphene, everything changes,” said Nathaniel Gabor, an associate professor of physics at UCR, who co-led the research project. “We found that photocurrents may arise in pristine graphene under a special condition in which the entire sheet of graphene is completely free of excess electronic charge. Generating the photocurrent requires no special junctions and can instead be controlled, surprisingly, by simply cutting and shaping the graphene sheet into unusual configurations, from ladder-like linear arrays of contacts, to narrowly constricted rectangles, to tapered and terraced edges.”
Pristine graphene is completely charge neutral, meaning there is no excess electronic charge in the material. When wired into a device, however, an electronic charge can be introduced by applying a voltage to a nearby metal. This voltage can induce positive charge, negative charge, or perfectly balance negative and positive charges so the graphene sheet is perfectly charge neutral.
“The light-harvesting device we fabricated is only as thick as a single atom,” Gabor said. “We could use it to engineer devices that are semi-transparent. These could be embedded in unusual environments, such as windows, or they could be combined with other more conventional light-harvesting devices to harvest excess energy that is usually not absorbed. Depending on how the edges are cut to shape, the device can give extraordinarily different signals.”
The research team reports this first observation of an entirely new physical mechanism — a photocurrent generated in charge-neutral graphene with no need for p-n junctions — in Nature Nanotechnology today [Dec. 17, 2018].
Previous work by the Gabor lab showed a photocurrent in graphene results from highly excited “hot” charge carriers. When light hits graphene, high-energy electrons relax to form a population of many relatively cooler electrons, Gabor explained, which are subsequently collected as current. Even though graphene is not a semiconductor, this light-induced hot electron population can be used to generate very large currents.
“All of this behavior is due to graphene’s unique electronic structure,” he said. “In this ‘wonder material,’ light energy is efficiently converted into electronic energy, which can subsequently be transported within the material over remarkably long distances.”
He explained that, about a decade ago, pristine graphene was predicted to exhibit very unusual electronic behavior: electrons should behave like a liquid, allowing energy to be transferred through the electronic medium rather than by moving charges around physically. “But despite this prediction, no photocurrent measurements had been done on pristine graphene devices — until now,” he said.
The new work on pristine graphene shows electronic energy travels great distances in the absence of excess electronic charge.
The research team has found evidence that the new mechanism results in a greatly enhanced photoresponse in the infrared regime with an ultrafast operation speed. “We plan to further study this effect in a broad range of infrared and other frequencies, and measure its response speed,” said first author Qiong Ma, a postdoctoral associate in physics at the Massachusetts Institute of Technology, or MIT.
The researchers have provided an image illustrating their work,
Here’s a link to and a citation for the paper,
Giant intrinsic photoresponse in pristine graphene by Qiong Ma, Chun Hung Lui, Justin C. W. Song, Yuxuan Lin, Jian Feng Kong, Yuan Cao, Thao H. Dinh, Nityan L. Nair, Wenjing Fang, Kenji Watanabe, Takashi Taniguchi, Su-Yang Xu, Jing Kong, Tomás Palacios, Nuh Gedik, Nathaniel M. Gabor, & Pablo Jarillo-Herrero. Nature Nanotechnology (2018) Published 17 December 2018 DOI: https://doi.org/10.1038/s41565-018-0323-8
A company from Ontario (Canada) has signed a memorandum of unterstanding (MOU) for graphene research with the University of British Columbia (Canada, Okanagan Campus). From a June 20, 2019 news item on Azonano,
ZEN Graphene Solutions has announced the signing of a memorandum of understanding (“MOU”) with the University of British Columbia (UBC), Okanagan Campus, School of Engineering, where ZEN will contribute a minimum of $300,000 over three years in support of graphene research and application development.
The main initial objectives defined in the MOU are:
(a) To formalize a collaborative research program utilizing expertise and capabilities from both ZEN and UBC and, where applicable, utilizing additional support and resources from government agencies such as the Natural Sciences and Engineering Research Council (NSERC), Mitacs and the National Research Council Industrial Research Assistance Program (NRC-IRAP); and,
(b) To structure an initial three-year research program with a committed minimum contribution by ZEN of $100,000 per year in support of UBC-based research projects.
ZEN has already supplied samples of its graphene and graphene oxide to UBC where it has undergone preliminary testing in the following applications: In multiple battery technologies; As an additive in cement-based composites; As an additive to aluminum and aluminum alloys; and, As a diesel and jet fuel additive.
“UBC has become a strong partner for ZEN over the last year bringing top quality researchers from multiple fields and connecting us with potential industrial partners. We wish to recognize the excellent research contributions made to date by Prof. Lukas Bichler and his team, and we look forward to formalizing our relationship with this agreement,” commented Dr. Francis Dubé.
“The three-year project, slated to begin this summer, challenges UBC engineering researchers to develop the next generation of stronger and lighter composite materials. The partnership with ZEN Graphene will allow for a transformational approach to composite materials development utilizing the unique properties of the Albany Graphite product. This will result in new composite materials with performance characteristics long beyond the reach of engineers and scientists using traditional material processing techniques. Linking to R&D activities at UBC will in turn enable ZEN to develop the Albany Graphite Deposit and get its graphene product to market more rapidly with a clear focus on high-impact real-world applications,” commented Dr. Bichler, associate professor of engineering at UBC’s Okanagan campus and research supervisor. Click here for video
About ZEN Graphene Solutions Ltd
ZEN Graphene Solutions Ltd. is an emerging graphene technology company with a focus on development of the unique Albany Graphite Project. This precursor graphene material provides the company with a competitive advantage in the potential graphene market as independent labs in Japan, UK, Israel, USA and Canada have demonstrated that ZEN’s Albany Graphite/Naturally PureTM easily converts (exfoliates) to graphene, using a variety of simple mechanical and chemical methods.
For further information: Francis Dubé, Chief Executive Officer Tel: +1 (289) 821-2820 Email: firstname.lastname@example.org
To find out more on ZEN Graphene Solutions Ltd., please visit our website at www.ZENGraphene.com. A copy of this news release and all material documents in respect of the Company may be obtained on ZEN’s SEDAR profile at www.sedar.ca
Forward Looking Statements
This news release includes certain “forward-looking statements”, which often, but not always, can be identified by the use of words such as “potential”, “believes”, “anticipates”, “expects”, “estimates”, “may”, “could”, “would”, “will”, or “plan”. These statements are based on information currently available to ZEN and ZEN provides no assurance that actual results will meet management’s expectations. Although the Company believes that the expectations reflected in these forward-looking statements are reasonable, undue reliance should not be placed on them because the Company can give no assurance that they will prove to be correct. Since forward-looking statements address future events and conditions, by their very nature they involve inherent risks and uncertainties. Although ZEN believes that the assumptions and factors used in preparing the forward-looking information in this news release are reasonable, undue reliance should not be placed on such information, which only applies as of the date of this news release, and no assurance can be given that such events will occur in the disclosed time frames or at all. ZEN disclaims any intention or obligation to update or revise any forward-looking information, whether as a result of new information, future events or otherwise, other than as required by law. Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release. The Company’s full disclosure can be found at https://zengraphene.com/disclaimer/
Zenyatta’s Albany Graphite Project hosts a large and unique deposit of highly crystalline graphite. Independent labs in Japan, UK, Israel, USA and Canada have demonstrated that Zenyatta’s Albany Graphite/Naturally PureTM easily converts (exfoliates) to graphene, using a variety of simple mechanical and chemical methods. The deposit is located in Northern Ontario, just 30km north of the Trans-Canada Highway, near the communities of Constance Lake First Nation and Hearst. Important nearby infrastructure includes hydro-power, natural gas pipeline, a rail line 50 km away, and an all-weather road just 10 km from the deposit.
For more information on Zenyatta Ventures Ltd., please visit our website at www.zenyatta.ca. A copy of this press release and all material documents with respect of the Company are available on Zenyatta’s SEDAR profile at www.sedar.ca.
CAUTIONARY STATEMENT: Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release. This news release may contain forward looking information and Zenyatta cautions readers that forward-looking information is based on certain assumptions and risk factors that could cause actual results to differ materially from the expectations of Zenyatta included in this news release. This news release includes certain “forward-looking statements”, which often, but not always, can be identified by the use of words such as “potential”, “believes”, “anticipates”, “expects”, “estimates”, “may”, “could”, “would”, “will”, or “plan”. These statements are based on information currently available to Zenyatta and Zenyatta provides no assurance that actual results will meet management’s expectations. Forward-looking statements include estimates and statements with respect to Zenyatta’s future plans, objectives or goals, to the effect that Zenyatta or management expects a stated condition or result to occur, including the expected uses for graphite or graphene in the future, and the future uses of the graphite from Zenyatta’s Albany deposit. Since forward-looking statements are based on assumptions and address future events and conditions, by their very nature they involve inherent risks and uncertainties. Actual results relating to, among other things, results of metallurgical processing, ongoing exploration, project development, reclamation and capital costs of Zenyatta’s mineral properties, and Zenyatta’s financial condition and prospects, could differ materially from those currently anticipated in such statements for many reasons such as, but are not limited to: failure to convert estimated mineral resources to reserves; the preliminary nature of metallurgical test results; the inability to identify target markets and satisfy the product criteria for such markets; the inability to complete a prefeasibility study; the inability to enter into offtake agreements with qualified purchasers; delays in obtaining or failures to obtain required governmental, environmental or other project approvals; political risks; uncertainties relating to the availability and costs of financing needed in the future; changes in equity markets, inflation, changes in exchange rates; fluctuations in commodity prices; delays in the development of projects; capital and operating costs varying significantly from estimates and the other risks involved in the mineral exploration and development industry; and those risks set out in Zenyatta’s public documents filed on SEDAR. This list is not exhaustive of the factors that may affect any of Zenyatta’s forward-looking statements. These and other factors should be considered carefully and readers should not place undue reliance on Zenyatta’s forward-looking statements. Although Zenyatta believes that the assumptions and factors used in preparing the forward-looking information in this news release are reasonable, undue reliance should not be placed on such information, which only applies as of the date of this news release, and no assurance can be given that such events will occur in the disclosed time frames or at all. Zenyatta disclaims any intention or obligation to update or revise any forward-looking information, whether as a result of new information, future events or otherwise, other than as required by law.
Looking at the June 10, 2019 news release, it seems that they’ve split the company in two with Zenyatta being the corporate name for the mining interests and ZEN Graphene for applications.
Oddly, UBC has not issued its own news release with this happy announcement.
Here’s one of the more recent efforts to create fibres that are electronic and capable of being woven into a smart textile. (Details about a previous effort can be found at the end of this post.) Now for this one, from a Dec. 3, 2018 news item on ScienceDaily,
The quest to create affordable, durable and mass-produced ‘smart textiles’ has been given fresh impetus through the use of the wonder material Graphene.
An international team of scientists, led by Professor Monica Craciun from the University of Exeter Engineering department, has pioneered a new technique to create fully electronic fibres that can be incorporated into the production of everyday clothing.
Currently, wearable electronics are achieved by essentially gluing devices to fabrics, which can mean they are too rigid and susceptible to malfunctioning.
The new research instead integrates the electronic devices into the fabric of the material, by coating electronic fibres with light-weight, durable components that will allow images to be shown directly on the fabric.
The research team believe that the discovery could revolutionise the creation of wearable electronic devices for use in a range of every day applications, as well as health monitoring, such as heart rates and blood pressure, and medical diagnostics.
The international collaborative research, which includes experts from the Centre for Graphene Science at the University of Exeter, the Universities of Aveiro and Lisbon in Portugal, and CenTexBel in Belgium, is published in the scientific journal Flexible Electronics.
Professor Craciun, co-author of the research said: “For truly wearable electronic devices to be achieved, it is vital that the components are able to be incorporated within the material, and not simply added to it.
Dr Elias Torres Alonso, Research Scientist at Graphenea and former PhD student in Professor Craciun’s team at Exeter added “This new research opens up the gateway for smart textiles to play a pivotal role in so many fields in the not-too-distant future. By weaving the graphene fibres into the fabric, we have created a new technique to all the full integration of electronics into textiles. The only limits from now are really within our own imagination.”
At just one atom thick, graphene is the thinnest substance capable of conducting electricity. It is very flexible and is one of the strongest known materials. The race has been on for scientists and engineers to adapt graphene for the use in wearable electronic devices in recent years.
This new research used existing polypropylene fibres – typically used in a host of commercial applications in the textile industry – to attach the new, graphene-based electronic fibres to create touch-sensor and light-emitting devices.
The new technique means that the fabrics can incorporate truly wearable displays without the need for electrodes, wires of additional materials.
Professor Saverio Russo, co-author and from the University of Exeter Physics department, added: “The incorporation of electronic devices on fabrics is something that scientists have tried to produce for a number of years, and is a truly game-changing advancement for modern technology.”
Dr Ana Neves, co-author and also from Exeter’s Engineering department added “The key to this new technique is that the textile fibres are flexible, comfortable and light, while being durable enough to cope with the demands of modern life.”
In 2015, an international team of scientists, including Professor Craciun, Professor Russo and Dr Ana Neves from the University of Exeter, have pioneered a new technique to embed transparent, flexible graphene electrodes into fibres commonly associated with the textile industry.
I have an earlier post about an effort to weave electronics into textiles for soldiers, from an April 5, 2012 posting,
I gather that today’s soldier (aka, warfighter) is carrying as many batteries as weapons. Apparently, the average soldier carries a couple of kilos worth of batteries and cables to keep their various pieces of equipment operational. The UK’s Centre for Defence Enterprise (part of the Ministry of Defence) has announced that this situation is about to change as a consequence of a recently funded research project with a company called Intelligent Textiles. From Bob Yirka’s April 3, 2012 news item for physorg.com,
To get rid of the cables, a company called Intelligent Textiles has come up with a type of yarn that can conduct electricity, which can be woven directly into the fabric of the uniform. And because they allow the uniform itself to become one large conductive unit, the need for multiple batteries can be eliminated as well.
I dug down to find more information about this UK initiative and the Intelligent Textiles company but the trail seems to end in 2015. Still, I did find a Canadian connection (for those who don’t know I’m a Canuck) and more about Intelligent Textile’s work with the British military in this Sept. 21, 2015 article by Barry Collins for alphr.com (Note: Links have been removed),
A two-person firm operating from a small workshop in Staines-upon-Thames, Intelligent Textiles has recently landed a multimillion-pound deal with the US Department of Defense, and is working with the Ministry of Defence (MoD) to bring its potentially life-saving technology to British soldiers. Not bad for a company that only a few years ago was selling novelty cushions.
Intelligent Textiles was born in 2002, almost by accident. Asha Peta Thompson, an arts student at Central Saint Martins, had been using textiles to teach children with special needs. That work led to a research grant from Brunel University, where she was part of a team tasked with creating a “talking jacket” for the disabled. The garment was designed to help cerebral palsy sufferers to communicate, by pressing a button on the jacket to say “my name is Peter”, for example, instead of having a Stephen Hawking-like communicator in front of them.
Another member of that Brunel team was engineering lecturer Dr Stan Swallow, who was providing the electronics expertise for the project. Pretty soon, the pair realised the prototype waistcoat they were working on wasn’t going to work: it was cumbersome, stuffed with wires, and difficult to manufacture. “That’s when we had the idea that we could weave tiny mechanical switches into the surface of the fabric,” said Thompson.
The conductive weave had several advantages over packing electronics into garments. “It reduces the amount of cables,” said Thompson. “It can be worn and it’s also washable, so it’s more durable. It doesn’t break; it can be worn next to the skin; it’s soft. It has all the qualities of a piece of fabric, so it’s a way of repackaging the electronics in a way that’s more user-friendly and more comfortable.” The key to Intelligent Textiles’ product isn’t so much the nature of the raw materials used, but the way they’re woven together. “All our patents are in how we weave the fabric,” Thompson explained. “We weave two conductive yarns to make a tiny mechanical switch that is perfectly separated or perfectly connected. We can weave an electronic circuit board into the fabric itself.”
Intelligent Textiles’ big break into the military market came when they met a British textiles firm that was supplying camouflage gear to the Canadian armed forces. [emphasis mine] The firm was attending an exhibition in Canada and invited the Intelligent Textiles duo to join them. “We showed a heated glove and an iPod controller,” said Thompson. “The Canadians said ‘that’s really fantastic, but all we need is power. Do you think you could weave a piece of fabric that distributes power?’ We said, ‘we’re already doing it’.”Before long it wasn’t only power that the Canadians wanted transmitted through the fabric, but data.
“The problem a soldier faces at the moment is that he’s carrying 60 AA batteries [to power all the equipment he carries],” said Thompson. “He doesn’t know what state of charge those batteries are at, and they’re incredibly heavy. He also has wires and cables running around the system. He has snag hazards – when he’s going into a firefight, he can get caught on door handles and branches, so cables are a real no-no.”
The Canadians invited the pair to speak at a NATO conference, where they were approached by military brass with more familiar accents. “It was there that we were spotted by the British MoD, who said ‘wow, this is a British technology but you’re being funded by Canada’,” said Thompson. That led to £235,000 of funding from the Centre for Defence Enterprise (CDE) – the money they needed to develop a fabric wiring system that runs all the way through the soldier’s vest, helmet and backpack.
There are more details about the 2015 state of affairs, textiles-wise, in a March 11, 2015 article by Richard Trenholm for CNET.com (Note: A link has been removed),
Speaking at the Wearable Technology Show here, Swallow describes IT [Intelligent Textiles]L as a textile company that “pretends to be a military company…it’s funny how you slip into these domains.”
One domain where this high-tech fabric has seen frontline action is in the Canadian military’s IAV Stryker armoured personnel carrier. ITL developed a full QWERTY keyboard in a single piece of fabric for use in the Stryker, replacing a traditional hardware keyboard that involved 100 components. Multiple components allow for repair, but ITL knits in redundancy so the fabric can “degrade gracefully”. The keyboard works the same as the traditional hardware, with the bonus that it’s less likely to fall on a soldier’s head, and with just one glaring downside: troops can no longer use it as a step for getting in and out of the vehicle.
An armoured car with knitted controls is one thing, but where the technology comes into its own is when used about the person. ITL has worked on vests like the JTAC, a system “for the guys who call down airstrikes” and need “extra computing oomph.” Then there’s SWIPES, a part of the US military’s Nett Warrior system — which uses a chest-mounted Samsung Galaxy Note 2 smartphone — and British military company BAE’s Broadsword system.
ITL is currently working on Spirit, a “truly wearable system” for the US Army and United States Marine Corps. It’s designed to be modular, scalable, intuitive and invisible.
While this isn’t an ITL product, this video about Broadsword technology from BAE does give you some idea of what wearable technology for soldiers is like,
Uploaded on Jul 8, 2014
Broadsword™ delivers groundbreaking technology to the 21st Century warfighter through interconnecting components that inductively transfer power and data via The Spine™, a revolutionary e-textile that can be inserted into any garment. This next-generation soldier system offers enhanced situational awareness when used with the BAE Systems’ Q-Warrior® see-through display.
If anyone should have the latest news about Intelligent Textile’s efforts, please do share in the comments section.
I do have one other posting about textiles and the military, which is dated May 9, 2012, but while it does reference US efforts it is not directly related to weaving electronics into solder’s (warfighter’s) gear.
Peter Bøggild over at DTU [Technical University of Denmark] just published an interesting opinion piece in Nature titled “The war on fake graphene”.
The piece refers to a paper published in Advanced Materials (“The Worldwide Graphene Flake Production”) that studied graphene purchased from 60 producers around the world.
The study’s [“The Worldwide Graphene Flake Production”] findings show unequivocally “that the quality of the graphene produced in the world today is rather poor, not optimal for most applications, and most companies are producing graphite microplatelets. This is possibly the main reason for the slow development of graphene applications, which usually require a customized solution in terms of graphene properties.”
A conclusion that sounds even more damming is that “our extensive studies of graphene production worldwide indicate that there is almost no high quality graphene, as defined by ISO [International Organization for Standardization], in the market yet.”
The team also points out that a large number of the samples on the market labelled as graphene are actually graphene oxide and reduced graphene oxide. Furthermore, carbon content analysis shows that in many cases there is substantial contamination of the samples and a large number of companies produce material a with low carbon content. Contamination has many possible sources but most likely, it arises from the chemicals used in the processes.
Graphite is composed of layers of carbon atoms just a single atom in thickness, known as graphene sheets, to which it owes many of its remarkable properties. When the thickness of graphite flakes is reduced to just a few graphene layers, some of the material’s technologically most important characteristics are greatly enhanced — such as the total surface area per gram, and the mechanical flexibility of the individual flakes. In other words, graphene is more than just thin graphite. Unfortunately, it seems that many graphene producers either do not know or do not care about this. …
Imagine a world in which antibiotics could be sold by anybody, and were not subject to quality standards and regulations. Many people would be afraid to use them because of the potential side effects, or because they had no faith that they would work, with potentially fatal consequences. For emerging nanomaterials such as graphene, a lack of standards is creating a situation that, although not deadly, is similarly unacceptable.
It seems that the high-profile scientific discoveries, technical breakthroughs and heavy investment in graphene have created a Wild West for business opportunists: the study shows that some producers are labelling black powders that mostly contain cheap graphite as graphene, and selling them for top dollar. The problem is exacerbated because the entry barrier to becoming a graphene provider is exceptionally low — anyone can buy bulk graphite, grind it to powder and make a website to sell it on.
Nevertheless, the work [“The Worldwide Graphene Flake Production”] is a timely and ambitious example of the rigorous mindset needed to make rapid progress, not just in graphene research, but in work on any nanomaterial entering the market. To put it bluntly, there can be no quality without quality control.
Here are links to and citations for the study providing the basis for both Berger’s Spotlight article and Bøggild’s opinion piece,
The Worldwide Graphene Flake Production by Alan P. Kauling, Andressa T. Seefeldt, Diego P. Pisoni, Roshini C. Pradeep, Ricardo Bentini, Ricardo V. B. Oliveira, Konstantin S. Novoselov [emphasis mine], Antonio H. Castro Neto. Advanced Materials Volume 30, Issue 44 November 2, 2018 1803784 https://doi.org/10.1002/adma.201803784
The study which includes Konstantin Novoselov, a Nobel prize winner for his and Andre Geim’s work at the University of Manchester where they first isolated graphene, is behind a paywall.
When two atomically thin two-dimensional layers are stacked on top of each other and one layer is made to rotate against the second layer, they begin to produce patterns — the familiar moiré patterns — that neither layer can generate on its own and that facilitate the passage of light and electrons, allowing for materials that exhibit unusual phenomena. For example, when two graphene layers are overlaid and the angle between them is 1.1 degrees, the material becomes a superconductor.
“It’s a bit like driving past a vineyard and looking out the window at the vineyard rows. Every now and then, you see no rows because you’re looking directly along a row,” said Nathaniel Gabor, an associate professor in the Department of Physics and Astronomy at the University of California, Riverside. “This is akin to what happens when two atomic layers are stacked on top of each other. At certain angles of twist, everything is energetically allowed. It adds up just right to allow for interesting possibilities of energy transfer.”
This is the future of new materials being synthesized by twisting and stacking atomically thin layers, and is still in the “alchemy” stage, Gabor added. To bring it all under one roof, he and physicist Justin C. W. Song of Nanyang Technological University, Singapore, have proposed this field of research be called “electron quantum metamaterials” and have just published a perspective article in Nature Nanotechnology.
“We highlight the potential of engineering synthetic periodic arrays with feature sizes below the wavelength of an electron. Such engineering allows the electrons to be manipulated in unusual ways, resulting in a new range of synthetic quantum metamaterials with unconventional responses,” Gabor said.
Metamaterials are a class of material engineered to produce properties that do not occur naturally. Examples include optical cloaking devices and super-lenses akin to the Fresnel lens that lighthouses use. Nature, too, has adopted such techniques – for example, in the unique coloring of butterfly wings – to manipulate photons as they move through nanoscale structures.
“Unlike photons that scarcely interact with each other, however, electrons in subwavelength structured metamaterials are charged, and they strongly interact,” Gabor said. “The result is an enormous variety of emergent phenomena and radically new classes of interacting quantum metamaterials.”
Gabor and Song were invited by Nature Nanotechnology to write a review paper. But the pair chose to delve deeper and lay out the fundamental physics that may explain much of the research in electron quantum metamaterials. They wrote a perspective paper instead that envisions the current status of the field and discusses its future.
“Researchers, including in our own labs, were exploring a variety of metamaterials but no one had given the field even a name,” said Gabor, who directs the Quantum Materials Optoelectronics lab at UCR. “That was our intent in writing the perspective. We are the first to codify the underlying physics. In a way, we are expressing the periodic table of this new and exciting field. It has been a herculean task to codify all the work that has been done so far and to present a unifying picture. The ideas and experiments have matured, and the literature shows there has been rapid progress in creating quantum materials for electrons. It was time to rein it all in under one umbrella and offer a road map to researchers for categorizing future work.”
In the perspective, Gabor and Song collect early examples in electron metamaterials and distil emerging design strategies for electronic control from them. They write that one of the most promising aspects of the new field occurs when electrons in subwavelength-structure samples interact to exhibit unexpected emergent behavior.
“The behavior of superconductivity in twisted bilayer graphene that emerged was a surprise,” Gabor said. “It shows, remarkably, how electron interactions and subwavelength features could be made to work together in quantum metamaterials to produce radically new phenomena. It is examples like this that paint an exciting future for electronic metamaterials. Thus far, we have only set the stage for a lot of new work to come.”