Tag Archives: UK

Human Brain Project: update

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.

After reading the article, I looked up Henry Markram’s Wikipedia entry and found this,

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.[7][8]

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.[9]

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.

Blockchain made physical: BlocKit

Caption: Parts of BlocKit Credit: Irni Khairuddin

I’m always on the lookout for something that helps make blockchain and cryptocurrency more understandable. (For the uninitiated or anyone like me who needed to refresh their memories, I have links to good essays on the topic further down in this posting.)

A July 10, 2019 news item on ScienceDaily announces a new approach to understanding blockchain technology,

A kit made from everyday objects is bringing the blockchain into the physical world.

The ‘BlocKit’, which includes items such as plastic tubs, clay discs, padlocks, envelopes, sticky notes and battery-powered candles, is aimed to help people understand how digital blockchains work and can also be used by innovators designing new systems and services around blockchain.

A team of computer scientists from Lancaster University, the University of Edinburgh in the UK, and the Universiti Teknologi MARA, in Malaysia, created the prototype BlocKit because blockchain — the decentralised digital infrastructure that is used to organise the cryptocurrency Bitcoin and holds promise to revolutionise many other sectors from finance, supply-chain and healthcare — is so difficult for people to comprehend.

A July 10, 2019 Lancaster University press release (also on EurekAlert), which originated the news item, expands on the theme,

“Despite growing interest in its potential, the blockchain is so novel, disruptive and complex, it is hard for most people to understand how these systems work,” said Professor Corina Sas of Lancaster University’s School of Computing and Communications. “We have created a prototype kit consisting of physical objects that fulfil the roles of different parts of the blockchain. The kit really helps people visualise the different component parts of blockchain, and how they all interact.

“Having tangible physical objects, such as a transparent plastic box for a Bitcoin wallet, clay discs for Bitcoins, padlocks for passwords and candles representing miners’ computational power, makes thinking around processes and systems much easier to comprehend.”

The BlocKit consisted of physical items that represented 11 key aspects of blockchain infrastructure and it was used to explore key characteristics of blockchain, such as trust – an important challenge for Bitcoin users. The kit was evaluated as part of a study involving 15 experienced Bitcoin users.

“We received very positive feedback from the people who used the kit in our study and, interestingly, we found that the BlocKit can also be used by designers looking to develop new services based around blockchain – such as managing patients’ health records for example.”

I will be providing a link to and a citation for the paper but first, I’m excerpting a few bits,

We report on a workshop with 15 bitcoin experts, [emphasis mine] 12 males, 3 females, (mean age 29, range 21-39). All participants had at least 2 years of engaging in bitcoin transactions: 9 had between 2 and 3 years, 4 had between 4 and 5 years, 2had more than 6 years. All participants have at least graduate education, i.e., 6 BSc, 7 MScs, and 2 Ph.D. Participants were recruited through the mailing lists of two universities,and through a local Bitcoins meetup group. [p. 3]

A striking finding was the overwhelmingly positive experience supported by BlocKit. Findings show that 10 participants deeply enjoyed physically touching [emphasis mine] its objects and enacting their movement in space while talking about blockchain processes: “there is going to be other transactions from other people essentially, so let’s put a few bitcoins in that box. I love this stuff, this is amazing” [P12]. Participants suggested that BlocKit could be a valuable tool for learning about blockchain: “I think this all makes sense and would be fine to explain to the novices. It is cool, this is really an interesting kit”[P7]. Other participants suggested leveraging gamification principles for learning about blockchain: “It’s almost like you could turn this into some kind of cool game like a monopoly”[P5] [p. 5]

A significant finding is the value of the kit in supporting experts to materialize and reflect on their understanding of blockchain infrastructure and its inner working. We argue that through its materiality, the kit allows bringing the mental models into question, which in turn helps experts confirm their understandings, develop more nuanced understandings, or even revise some previously held, less accurate assumptions. [emphasis mine]

Even experts are still learning about bitcoin and blockchain according to this research sample. it’s also interesting to note that the workshop participants enjoyed the physicality. I don’t see too many mentions of it in my wanderings but I can’t help wondering if all this digitization is going to leave people starved for touch.

Getting back to blockchain, here’s the link and citation I promised,

BlocKit: A Physical Kit for Materializing and Designing for Blockchain Infrastructure by Irni Eliana Khairuddin, Corina Sas, and Chris Speed.presented at Designing Interactive Systems (DIS) 2019
ACM International Conference Series [downloaded from https://eprints.lancs.ac.uk/id/eprint/132467/1/Design_Kit_DIS_28.pdf]

This paper is open access, as for BlocKit, it exists only as a prototype according to the July 10, 2019 Lancaster University press release.

Introductory essays for blockchain and cryptocurrency

Here are two of my favourites. First, there’s this February 6, 2018 essay (part ii of a series) by Tim Schneider on artnet.com explaining it all by using the art world and art market as examples,

… the fraught relationship between art and value lies at the molten core of several pieces made using blockchain technology. Part one of this series addressed how, in theory, the blockchain strengthens the markets for new media by introducing the concept of digital scarcity. This innovation means that works as simple as an “original” JPG or GIF could be made as rare as Francis Bacon paintings. (This fact leads to a host of business implications that will be covered in Part III.

However, a handful of forward-looking artists is using the blockchain to do more than reset the market’s perception of supply and demand. The technology, their work proves, is more than new software—it’s also a new medium.

The description of how artists using blockchain as a medium provides some of the best descriptions of cryptocurrency and blockchain that I’ve been able to find.

The other essay, a January 5, 2018 article for Slate.com by Joshua Oliver, provides some detail I haven’t seen anywhere else (Note: A link has been removed),

Already, blockchain has been hailed as likely to revolutionize … well … everything. Banks, health care, voting, supply chains, fantasy football, Airbnb, coffee: Nothing is beyond the hypothetical reach of blockchain as a revolutionary force. These predictions are easy to sell because blockchain is still little-understood. If you don’t quite know what blockchain is, it’s easier to imagine that it is whatever you want it to be. But before we can begin to search for the real potential amid the mass of blockchain conjecture and hype, we need to clear up what exactly we mean when we say blockchain.

One cause of confusion is the phrase the blockchain, which makes it sound like blockchain is one specific thing. In reality, the word blockchain is commonly used to describe two broad types of computer systems. [emphases mine] Both use similar underlying protocols, but they have other important differences. Bitcoin represents one approach to using blockchain, one wedded to principles of radical decentralization. The second approach—pioneered by more business-minded players—puts blockchain to use without adopting bitcoin’s revolutionary, decentralized governance. Both of these designs are short-handed as blockchains, so it’s easy to miss the crucial differences. Without grasping these differences, it’s hard to understand where we are today in the development of this promising technology, which blockchain ventures are worth your attention, and what might happen next.

That’s all I’ve got for now.

Science inspired by superheroes, Ant-Man and the Wasp

It’s interesting to see scientists take science fiction and use it as inspiration; something which I think happens more often than we know. After all, when someone asks where you got an idea, it can be difficult to track down the thought process that started it all.

Scientists at Virginia Tech (Virginia Polytechnic Institute and State University) are looking for a new source of inspiration after offering a close examination of how insect-size superheroes, Ant-Man and the Wasp might breathe. From a December 11, 2018 news item on phys.org (Note: A link has been removed),

Max Mikel-Stites and Anne Staples were searching for a sequel.

This summer, Staples, an associate professor in the Department of Biomedical Engineering and Mechanics in the College of Engineering, and graduate student Mikel-Stites published a paper in the inaugural issue of the Journal of Superhero Science titled, “Ant-Man and the Wasp: Microscale Respiration and Microfluidic Technology.”

Now, they needed a new hero.

The two were working with a team of graduate students, brainstorming who could be the superhero subject for their next scientific inquiry. Superman? Batgirl? Aquaman?

Mikel-Stites lobbied for an investigation of Dazzler’s sonoluminescent powers. Staples was curious how Mera, The Princes sof Atlantis, used her hydrokinetic powers.

It turns out, comic books are a great inspiration for scientific discovery.

This month, Mikel-Stites is presenting the findings of their paper at the American Physical Society’s Division of Fluid Dynamics meeting.

The wonder team’s paper looked at how Ant-Man and the Wasp breathe when they shrink down to insect-size and Staples’ lab studied how fluids flow in nature. Insects naturally move fluids and gases efficiently at tiny scales. If engineers can learn how insects breathe, they can use the knowledge to invent new microfluidic technologies.

A November 2018 Virginia Tech news release (also on EurekAlert but published on December 11, 2018) by Nancy Dudek describes the ‘Ant-Man and Wasp respiratory project’ before revealing the inspiration for the team’s new project,

“Before the 2018 ‘Ant-Man and the Wasp’ movie, my lab was already wondering about insect-scale respiration,” said Staples. “I wanted to get people to appreciate different breathing mechanisms.”

For most of Mikel-Stites’ life, he had been nit-picking at the “science” in science-fiction movies.

“I couldn’t watch ‘Armageddon’ once they got up to space station Mir and there was artificial gravity. Things like that have always bothered me. But for ‘Ant-Man and the Wasp’ it was worse,” he said.

Staples and Mikel-Stites decided to join forces to research Ant-Man’s microscale respiration.

Mikel-Stites was stung by what he dubbed “the altitude problem or death-zone dilemma.” For Ant-Man and the Wasp to shrink down to insect size and still breathe, they would have to overcome an atmospheric density similar to the top of Mt. Everest. Their tiny bodies would also require higher metabolisms. For their survival, the Marvel comic universe had to give Ant-Man and the Wasp superhero technologies.

“I thought it would be fun to find a solution for how this small-scale respiration would work,”said Mikel-Stites.”I started digging through Ant-Man’s history. I looped through scenes in the 2015 movie where we could address the physics. Then I did the same thing with trailers from the 2018 movie. I used that to make a list of problems and a list of solutions.”

Ant-Man and the Wasp solve the altitude problem with their superhero suits. In their publication, Mikel-Stites and Staples write that the masks in Ant-Man and the Wasp’s suits contain “a combination of an air pump, a compressor, and a molecular filter including Pym particle technology,” that allows them to breathe while they are insect-sized.

“This publication showed how different physics phenomena can dominate at different size scales, how well-suited organisms are for their particular size, and what happens when you start altering that,” said Mikel-Stites. “It also shows that Hollywood doesn’t always get it right when it comes to science!”

Their manuscript was accepted by the Journal of Superhero Science before the release of the sequel, “Ant-Man and the Wasp.” Mikel-Stites was concerned the blockbuster might include new technologies or change Ant-Man’s canon. If the Marvel comic universe changed between the 2015 ‘Ant-Man’ movie and the sequel, their hypotheses would be debunked and they would be forced to retract their paper.

“I went to the 2018 movie before the manuscript came out in preprint so that if the movie contradicted us we could catch it. But the 2018 movie actually supported everything we had said, which was really nice,” said Mikel-Stites. Most moviegoers simply watched the special effects and left the theater entertained. But Mikel-Stitesleft the movie with confirmation of the paper’s hypotheses.

The Staples lab members are not the only ones interested in tiny technologies. From lab-on-a-chip microfluidic devices to nanoparticles that deliver drugs directly to cells, consumers will ultimately benefit from this small scientific field that delivers big results.

“In both the movies and science, shrinking is a common theme and has been for the last 50-60 years. This idea is something that we all like to think about. Given enough time, we can reach the point where science can take it from the realms of magic into something that we actually have an explanation for,” Mikel-Stites said.

In fact, the Staples lab group has already done just that.

While Mikel-Stites is presenting his superhero science at the APS meeting, his colleague Krishnashis Chatterjee, who recently completed his Ph.D. in engineering mechanics will be presenting his research on fabricating and testing four different insect-inspired micro-fluidic devices.

From fiction to function, the Staples lab likes to have fun along the way.

“I think that it is really important to connect with people and be engaged in science with topics they already know about. With this superhero science paper I wanted to support this mission,” Staples said.

And who did the lab mates choose for their next superhero science subject? The Princess of Atlantis, Mera. They hope they can publish another superhero science paper that really makes waves.

Here’s a link to and a citation for the paper,

Ant-Man and The Wasp: Microscale Respiration and Microfluidic Technology by Anne Staples and Maxwell Mikel-Stites. Superhero Science and Technology (SST) Vol 1 No 1 (2018): https://doi.org/10.24413/sst.2018.1.2474 July 2018 ISSN 2588-7637

This paper is open access.

And, just because the idea of a superhero science journal tickles my fancy, here’s a little more from the journal’s About webpage,

Serial title
Superhero Science and Technolog

Focus and Scope
Superhero Science and Technology (SST) is multi-disciplinary journal that considers new research in the fields of science, technology, engineering and ethics motivated and presented using the superhero genre.

The superhero genre has become one of the most popular in modern cinema. Since the 2000 film X-Men, numerous superhero-themed films based on characters from Marvel Comics and DC Comics have been released. Films such as The Avengers, Iron Man 3, Avengers: Age of Ultron and Captain America: Civil War have all earned in excess of $1 billion dollars at the box office, thus demonstrating their relevance in modern society and popular culture.

Of particular interest for Superhero Science and Technology are articles that motivate new research by using the platform of superheroes, supervillains, their superpowers, superhero/supervillain exploits in Hollywood blockbuster films or superhero/supervillain adventures from comic books. Articles should be written in a manner so that they are accessible to both the academic community and the interested non-scientist i.e. general public, given the popularity of the superhero genre.

Dissemination of content using this approach provides a potential for the researcher to communicate their work to a larger audience, thus increasing their visibility and outreach within and outside of the academic domain.

The scope of the journal includes but is not limited to:
Genetic editing approaches;
Innovations in the field of robotics;
New and advanced materials;
Additive Manufacturing i.e. 3D printing, for both bio and non-bio applications;
Advancements in bio-chemical processing;
Biomimicry technologies;
Space physics, astrophysical and cosmological research;
Developments in propulsion systems;
Responsible innovation;
Ethical issues pertaining to technologies and their use for human enhancement or augmentation.

Open Access Policy
SST is licensed under a Creative Commons Attribution 4.0 International (CC BY 4.0) licence. You are free to use the work, but you have to attribute (refer to) the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work). The easiest way to refer to an article is to use the HOWTO CITE tool that you’ll find alongside each article in the right sidebar.

I also looked up the editorial team, from the journal’s Editorial Team webpage,

Editor-in-Chief
Dr. Barry W. Fitzgerald, TU Delft, the Netherlands
Editorial Board
Prof. Wim Briels, University of Twente, the Netherlands
Dr. Ian Clancy, University of Limerick, Ireland
Dr. Neil Clancy, University College London, UK
Dr. Tom Hunt, University of Kent, UK
Ass. Prof. Johan Padding, TU Delft, the Netherlands
Ass. Prof. Aimee van Wynsberghe, TU Delft, the Netherlands
Prof. Ilja Voets, TU Eindhoven, the Netherlands


For anyone unfamiliar with the abbreviation, TU stands for University of Technology or Technische Universiteit in Dutch.

An artificial synapse tuned by light, a ferromagnetic memristor, and a transparent, flexible artificial synapse

Down the memristor rabbit hole one more time.* I started out with news about two new papers and inadvertently found two more. In a bid to keep this posting to a manageable size, I’m stopping at four.

UK

In a June 19, 2019 Nanowerk Spotlight article, Dr. Neil Kemp discusses memristors and some of his latest work (Note: A link has been removed),

Memristor (or memory resistors) devices are non-volatile electronic memory devices that were first theorized by Leon Chua in the 1970’s. However, it was some thirty years later that the first practical device was fabricated. This was in 2008 when a group led by Stanley Williams at HP Research Labs realized that switching of the resistance between a conducting and less conducting state in metal-oxide thin-film devices was showing Leon Chua’s memristor behaviour.

The high interest in memristor devices also stems from the fact that these devices emulate the memory and learning properties of biological synapses. i.e. the electrical resistance value of the device is dependent on the history of the current flowing through it.

There is a huge effort underway to use memristor devices in neuromorphic computing applications and it is now reasonable to imagine the development of a new generation of artificial intelligent devices with very low power consumption (non-volatile), ultra-fast performance and high-density integration.

These discoveries come at an important juncture in microelectronics, since there is increasing disparity between computational needs of Big Data, Artificial Intelligence (A.I.) and the Internet of Things (IoT), and the capabilities of existing computers. The increases in speed, efficiency and performance of computer technology cannot continue in the same manner as it has done since the 1960s.

To date, most memristor research has focussed on the electronic switching properties of the device. However, for many applications it is useful to have an additional handle (or degree of freedom) on the device to control its resistive state. For example memory and processing in the brain also involves numerous chemical and bio-chemical reactions that control the brain structure and its evolution through development.

To emulate this in a simple solid-state system composed of just switches alone is not possible. In our research, we are interested in using light to mediate this essential control.

We have demonstrated that light can be used to make short and long-term memory and we have shown how light can modulate a special type of learning, called spike timing dependent plasticity (STDP). STDP involves two neuronal spikes incident across a synapse at the same time. Depending on the relative timing of the spikes and their overlap across the synaptic cleft, the connection strength is other strengthened or weakened.

In our earlier work, we were only able to achieve to small switching effects in memristors using light. In our latest work (Advanced Electronic Materials, “Percolation Threshold Enables Optical Resistive-Memory Switching and Light-Tuneable Synaptic Learning in Segregated Nanocomposites”), we take advantage of a percolating-like nanoparticle morphology to vastly increase the magnitude of the switching between electronic resistance states when light is incident on the device.

We have used an inhomogeneous percolating network consisting of metallic nanoparticles distributed in filamentary-like conduction paths. Electronic conduction and the resistance of the device is very sensitive to any disruption of the conduction path(s).

By embedding the nanoparticles in a polymer that can expand or contract with light the conduction pathways are broken or re-connected causing very large changes in the electrical resistance and memristance of the device.

Our devices could lead to the development of new memristor-based artificial intelligence systems that are adaptive and reconfigurable using a combination of optical and electronic signalling. Furthermore, they have the potential for the development of very fast optical cameras for artificial intelligence recognition systems.

Our work provides a nice proof-of-concept but the materials used means the optical switching is slow. The materials are also not well suited to industry fabrication. In our on-going work we are addressing these switching speed issues whilst also focussing on industry compatible materials.

Currently we are working on a new type of optical memristor device that should give us orders of magnitude improvement in the optical switching speeds whilst also retaining a large difference between the resistance on and off states. We hope to be able to achieve nanosecond switching speeds. The materials used are also compatible with industry standard methods of fabrication.

The new devices should also have applications in optical communications, interfacing and photonic computing. We are currently looking for commercial investors to help fund the research on these devices so that we can bring the device specifications to a level of commercial interest.

If you’re interested in memristors, Kemp’s article is well written and quite informative for nonexperts, assuming of course you can tolerate not understanding everything perfectly.

Here are links and citations for two papers. The first is the latest referred to in the article, a May 2019 paper and the second is a paper appearing in July 2019.

Percolation Threshold Enables Optical Resistive‐Memory Switching and Light‐Tuneable Synaptic Learning in Segregated Nanocomposites by Ayoub H. Jaafar, Mary O’Neill, Stephen M. Kelly, Emanuele Verrelli, Neil T. Kemp. Advanced Electronic Materials DOI: https://doi.org/10.1002/aelm.201900197 First published: 28 May 2019

Wavelength dependent light tunable resistive switching graphene oxide nonvolatile memory devices by Ayoub H.Jaafar, N.T.Kemp. DOI: https://doi.org/10.1016/j.carbon.2019.07.007 Carbon Available online 3 July 2019

The first paper (May 2019) is definitely behind a paywall and the second paper (July 2019) appears to be behind a paywall.

Dr. Kemp’s work has been featured here previously in a January 3, 2018 posting in the subsection titled, Shining a light on the memristor.

China

This work from China was announced in a June 20, 2019 news item on Nanowerk,

Memristors, demonstrated by solid-state devices with continuously tunable resistance, have emerged as a new paradigm for self-adaptive networks that require synapse-like functions. Spin-based memristors offer advantages over other types of memristors because of their significant endurance and high energy effciency.

However, it remains a challenge to build dense and functional spintronic memristors with structures and materials that are compatible with existing ferromagnetic devices. Ta/CoFeB/MgO heterostructures are commonly used in interfacial PMA-based [perpendicular magnetic anisotropy] magnetic tunnel junctions, which exhibit large tunnel magnetoresistance and are implemented in commercial MRAM [magnetic random access memory] products.

“To achieve the memristive function, DW is driven back and forth in a continuous manner in the CoFeB layer by applying in-plane positive or negative current pulses along the Ta layer, utilizing SOT that the current exerts on the CoFeB magnetization,” said Shuai Zhang, a coauthor in the paper. “Slowly propagating domain wall generates a creep in the detection area of the device, which yields a broad range of intermediate resistive states in the AHE [anomalous Hall effect] measurements. Consequently, AHE resistance is modulated in an analog manner, being controlled by the pulsed current characteristics including amplitude, duration, and repetition number.”

“For a follow-up study, we are working on more neuromorphic operations, such as spike-timing-dependent plasticity and paired pulsed facilitation,” concludes You. …

Here’s are links to and citations for the paper (Note: It’s a little confusing but I believe that one of the links will take you to the online version, as for the ‘open access’ link, keep reading),

A Spin–Orbit‐Torque Memristive Device by Shuai Zhang, Shijiang Luo, Nuo Xu, Qiming Zou, Min Song, Jijun Yun, Qiang Luo, Zhe Guo, Ruofan Li, Weicheng Tian, Xin Li, Hengan Zhou, Huiming Chen, Yue Zhang, Xiaofei Yang, Wanjun Jiang, Ka Shen, Jeongmin Hong, Zhe Yuan, Li Xi, Ke Xia, Sayeef Salahuddin, Bernard Dieny, Long You. Advanced Electronic Materials Volume 5, Issue 4 April 2019 (print version) 1800782 DOI: https://doi.org/10.1002/aelm.201800782 First published [online]: 30 January 2019 Note: there is another DOI, https://doi.org/10.1002/aelm.201970022 where you can have open access to Memristors: A Spin–Orbit‐Torque Memristive Device (Adv. Electron. Mater. 4/2019)

The paper published online in January 2019 is behind a paywall and the paper (almost the same title) published in April 2019 has a new DOI and is open access. Final note: I tried accessing the ‘free’ paper and opened up a free file for the artwork featuring the work from China on the back cover of the April 2019 of Advanced Electronic Materials.

Korea

Usually when I see the words transparency and flexibility, I expect to see graphene is one of the materials. That’s not the case for this paper (link to and citation for),

Transparent and flexible photonic artificial synapse with piezo-phototronic modulator: Versatile memory capability and higher order learning algorithm by Mohit Kumar, Joondong Kim, Ching-Ping Wong. Nano Energy Volume 63, September 2019, 103843 DOI: https://doi.org/10.1016/j.nanoen.2019.06.039 Available online 22 June 2019

Here’s the abstract for the paper where you’ll see that the material is made up of zinc oxide silver nanowires,

An artificial photonic synapse having tunable manifold synaptic response can be an essential step forward for the advancement of novel neuromorphic computing. In this work, we reported the development of highly transparent and flexible two-terminal ZnO/Ag-nanowires/PET photonic artificial synapse [emphasis mine]. The device shows purely photo-triggered all essential synaptic functions such as transition from short-to long-term plasticity, paired-pulse facilitation, and spike-timing-dependent plasticity, including in the versatile memory capability. Importantly, strain-induced piezo-phototronic effect within ZnO provides an additional degree of regulation to modulate all of the synaptic functions in multi-levels. The observed effect is quantitatively explained as a dynamic of photo-induced electron-hole trapping/detraining via the defect states such as oxygen vacancies. We revealed that the synaptic functions can be consolidated and converted by applied strain, which is not previously applied any of the reported synaptic devices. This study will open a new avenue to the scientific community to control and design highly transparent wearable neuromorphic computing.

This paper is behind a paywall.

Better anti-parasitic medicine delivery with chitosan-based nanocapsules

I mage: The common liver fluke which can cause fascioliasis. Credit: Wikimedia creative commons Courtesy: Leeds University

It looks like a pair of lips to me but, according to a December 12, 2018 news item on Nanowerk, this liver fluke heralds a flatworm infection is a serious health problem,

An international team, led by Professor Francisco Goycoolea from the University of Leeds [UK] and Dr Claudio Salomon from the Universidad Nacional de Rosario, Argentina, and in collaboration with colleagues at the University of Münster, Germany, have developed a novel pharmaceutical formulation to administer triclabendazole – an anti-parasitic drug used to treat a type of flatworm infection – in billions of tiny capsules.

The World Health Organisation estimates that 2.4 million people are infected with fascioliasis, the disease caused by flatworms and treated with triclabendazole.

A December 12, 2018 University of Leeds  press release (also on EurekAlert), which originated the news item,

Anti-parasitic drugs do not become effective until they dissolve and are absorbed. Traditionally, these medicines are highly insoluble and this limits their therapeutic effect.
In a bid to overcome this limitation and accomplish the new formulation, the team used “soft” nanotechnology and nanomedicine approaches, which utilises the self-assembly properties of organic nanostructures and uses techniques in which components, such as polymers and surfactants in solution, play key roles.

Their formulation produces capsules that are less than one micron in size – the diameter of a human hair is roughly 75 microns. These tiny capsules are loaded with triclabendazole and then bundled together to deliver the required dose.

The team used chitosan, a naturally-occurring sugar polymer found in the exoskeleton of shellfish and the cell walls of certain fungi, to coat the oil-core of capsules and bind the drug together, while stabilising the capsule and helping to preserve it.
In its nanocapsule form, the drug would be 100 times more soluble than its current tablet form.

Professor Goycoolea, from the School of Food Science and Nutrition at Leeds, said: “Solubility is critical challenge for effective anti-parasite medicine. We looked to tackle this problem at the particle level. Triclabendazole taken as a dose made up of billions of tiny capsules would mean the medicine would be more efficiently and quickly absorbed

“Through the use of nanocapsules and nanoemulsions, drug efficiency can be enhanced and new solutions can be considered for the best ways to target medicine delivery.”
Dr Salomon said: “To date, this is the first report on triclabendazole nanoencapsulation and we believe this type of formulation could be applied to other anti-parasitic drugs as well. But more research is needed to ensure this new pharmaceutical formulation of the drug does not diminish the anti-parasitic effect. Our ongoing research is working to answer this very question.”

Although there have been cases of fascioliasis in more than 70 countries worldwide, with increasing reports from Europe and the Americas, it is considered a neglected disease, as it does not receive much attention and often goes untreated.
Symptoms of the disease when it reaches the chronic phase include intermittent pain, jaundice and anaemia. Patients can also experience hardening of the liver in the case of long-term inflammation.

Because of the highly insoluble nature of anti-parasitic drugs, they need to be administered in very high dosages to ensure enough of the active ingredient is absorbed. This is particularly problematic when treating children for parasites. Tablets needs to be divided into smaller pieces to adjust the dosage and make swallowing easier, but this can cause side effects due to incorrect dosage.

The team’s technique to formulate triclabendazole into nanocapsules, published today [Dec. 12, 2018] in the journal PLOS ONE, would also allow for lower doses to be administered. s

Here’s a link to and a citation for the paper,

Chitosan-based nanodelivery systems applied to the development of novel triclabendazole formulations by Daniel Real, Stefan Hoffmann, Darío Leonardi, Claudio Salomon, Francisco M. Goycoolea. PLOS DOI https://doi.org/10.1371/journal.pone.0207625 Published: December 12, 2018

This paper is open access. BTW, I loved the title for the press release (Helping the anti-parasitic medicine go down) for its reference to the song, A spoonful of sugar helps the medicine go down, in the 1964 film musical, Mary Poppins, and the shout out for the sort of sequel, Mary Poppins Returns, released on Dec. 19, 2018.

In six hours billions of plastic nanoparticles accumulate in marine organisms

For the sake of comparison, I wish they’d thought to include an image of a giant scallop that hadn’t been used in the research (I have an ‘unplastic’ giant scallop image at the end of this posting),

Caption: These are some of the scallops used as part of the current research. Credit: University of Plymouth

But, they did do this,

A scan showing nanoplastic particles accumulated within the scallop’s gills (GI), kidney (K), gonad (GO), intestine (I), hepatopancreas (HP) and muscle (M). Credit: University of Plymouth [downloaded from https://phys.org/news/2018-12-billions-nanoplastics-accumulate-marine-hours.html]

A December 3, 2018 news item on phys.org announces the research,

A ground-breaking study has shown it takes a matter of hours for billions of minute plastic nanoparticles to become embedded throughout the major organs of a marine organism.

The research, led by the University of Plymouth, examined the uptake of nanoparticles by a commercially important mollusc, the great scallop (Pecten maximus).

After six hours exposure in the laboratory, billions of particles measuring 250nm (around 0.00025mm) had accumulated within the scallop’s intestines.

However, considerably more even smaller particles measuring 20nm (0.00002mm) had become dispersed throughout the body including the kidney, gill, muscle and other organs.

A December 3, 2018 University of Plymouth press release (also on EurekAlert), which originated the news item, adds more detail,

The study is the first to quantify the uptake of nanoparticles at predicted environmentally relevant conditions, with previous research having been conducted at far higher concentrations than scientists believe are found in our oceans.

Dr Maya Al Sid Cheikh, Postdoctoral Research Fellow at the University of Plymouth, led the study. She said: “For this experiment, we needed to develop an entirely novel scientific approach. We made nanoparticles of plastic in our laboratories and incorporated a label so that we could trace the particles in the body of the scallop at environmentally relevant concentrations. The results of the study show for the first time that nanoparticles can be rapidly taken up by a marine organism, and that in just a few hours they become distributed across most of the major organs.”

Professor Richard Thompson OBE, Head of the University’s International Marine Litter Research Unit, added: “This is a ground breaking study, in terms of both the scientific approach and the findings. We only exposed the scallops to nanoparticles for a few hours and, despite them being transferred to clean conditions, traces were still present several weeks later. Understanding the dynamics of nanoparticle uptake and release, as well as their distribution in body tissues, is essential if we are to understand any potential effects on organisms. A key next step will be to use this approach to guide research investigating any potential effects of nanoparticles and in particular to consider the consequences of longer term exposures.”

Accepted for publication in the Environmental Science and Technology journal, the study also involved scientists from the Charles River Laboratories in Elphinstone, Scotland; the Institute Maurice la Montagne in Canada; and Heriot-Watt University.

It was conducted as part of RealRiskNano, a £1.1million project funded by the Natural Environment Research Council (NERC). Led by Heriot-Watt and Plymouth, it is exploring the effects which microscopic plastic particles can have on the marine environment.

In this study, the scallops were exposed to quantities of carbon-radiolabeled nanopolystyrene and after six hours, autoradiography was used to show the number of particles present in organs and tissue.

It was also used to demonstrate that the 20nm particles were no longer detectable after 14 days, whereas 250nm particles took 48 days to disappear.

Ted Henry, Professor of Environmental Toxicology at Heriot-Watt University, said: “Understanding whether plastic particles are absorbed across biological membranes and accumulate within internal organs is critical for assessing the risk these particles pose to both organism and human health. The novel use of radiolabelled plastic particles pioneered in Plymouth provides the most compelling evidence to date on the level of absorption of plastic particles in a marine organism.”

Here’s a link to and a citation for the paper,

Uptake, Whole-Body Distribution, and Depuration of Nanoplastics by the Scallop Pecten maximus at Environmentally Realistic Concentrations by Maya Al-Sid-Cheikh, Steve J. Rowland, Karen Stevenson, Claude Rouleau, Theodore B. Henry, and Richard C. Thompson. Environ. Sci. Technol., Article ASAP DOI: 10.1021/acs.est.8b05266 Publication Date (Web): November 20, 2018

Copyright © 2018 American Chemical Society

This paper is behind a paywall.

‘Unplastic giant scallop’

The sea scallop (Placopecten magellanicus) has over 100 blue eyes along the edge of its mantle, with which it senses light intensity. This mollusk has the ability to scoot away from potential danger by flapping the two parts of its shell, like a swimming castenet. Credit: Dann Blackwood, USGS – http://www.sanctuaries.nos.noaa.gov/pgallery/pgstellwagen/living/living_17.html Public Domain

Stunning, isn’t it?

Graphene and smart textiles

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.

A Dec. 3, 2018 University of Exeter press release (also on EurekAlert), provides more detail about the problems associated with wearable electronics and the solution being offered (Note: A link has been removed),

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.

Here’s a link to and a citation for the paper,

Graphene electronic fibres with touch-sensing and light-emitting functionalities for smart textiles by Elias Torres Alonso, Daniela P. Rodrigues, Mukond Khetani, Dong-Wook Shin, Adolfo De Sanctis, Hugo Joulie, Isabel de Schrijver, Anna Baldycheva, Helena Alves, Ana I. S. Neves, Saverio Russo & Monica F. Craciun. Flexible Electronicsvolume 2, Article number: 25 (2018) DOI: https://doi.org/10.1038/s41528-018-0040-2 Published 25 September 2018

This paper is open access.

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,

baesystemsinc

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.

You can find CenTexBel (Belgian Textile Rsearch Centre) here and Graphenea here. Both are mentioned in the University of Exeter press release.

Fake graphene

Michael Berger’s October 9, 2018 Nanowerk Spotlight article about graphene brings to light a problem, which in hindsight seems obvious, fake graphene (Note: Links have been removed),

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.

Peter Bøggild’s October 8, 2018 opinion piece in Nature

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.

Wearable electronic textiles from the UK, India, and Canada: two different carbon materials

It seems wearable electronic textiles may be getting nearer to the marketplace. I have three research items (two teams working with graphene and one working with carbon nanotubes) that appeared on my various feeds within two days of each other.

UK/China

This research study is the result of a collaboration between UK and Chinese scientists. From a May 15, 2019 news item on phys.org (Note: Links have been removed),


Wearable electronic components incorporated directly into fabrics have been developed by researchers at the University of Cambridge. The devices could be used for flexible circuits, healthcare monitoring, energy conversion, and other applications.

The Cambridge researchers, working in collaboration with colleagues at Jiangnan University in China, have shown how graphene – a two-dimensional form of carbon – and other related materials can be directly incorporated into fabrics to produce charge storage elements such as capacitors, paving the way to textile-based power supplies which are washable, flexible and comfortable to wear.

The research, published in the journal Nanoscale, demonstrates that graphene inks can be used in textiles able to store electrical charge and release it when required. The new textile electronic devices are based on low-cost, sustainable and scalable dyeing of polyester fabric. The inks are produced by standard solution processing techniques.

Building on previous work by the same team, the researchers designed inks which can be directly coated onto a polyester fabric in a simple dyeing process. The versatility of the process allows various types of electronic components to be incorporated into the fabric.

Schematic of the textile-based capacitor integrating GNP/polyesters as electrodes and h-BN/polyesters as dielectrics. Credit: Felice Torrisi

A May 16, 2019 University of Cambridge press release, which originated the news item, probes further,

Most other wearable electronics rely on rigid electronic components mounted on plastic or textiles. These offer limited compatibility with the skin in many circumstances, are damaged when washed and are uncomfortable to wear because they are not breathable.

“Other techniques to incorporate electronic components directly into textiles are expensive to produce and usually require toxic solvents, which makes them unsuitable to be worn,” said Dr Felice Torrisi from the Cambridge Graphene Centre, and the paper’s corresponding author. “Our inks are cheap, safe and environmentally-friendly, and can be combined to create electronic circuits by simply overlaying different fabrics made of two-dimensional materials on the fabric.”

The researchers suspended individual graphene sheets in a low boiling point solvent, which is easily removed after deposition on the fabric, resulting in a thin and uniform conducting network made up of multiple graphene sheets. The subsequent overlay of several graphene and hexagonal boron nitride (h-BN) fabrics creates an active region, which enables charge storage. This sort of ‘battery’ on fabric is bendable and can withstand washing cycles in a normal washing machine.

“Textile dyeing has been around for centuries using simple pigments, but our result demonstrates for the first time that inks based on graphene and related materials can be used to produce textiles that could store and release energy,” said co-author Professor Chaoxia Wang from Jiangnan University in China. “Our process is scalable and there are no fundamental obstacles to the technological development of wearable electronic devices both in terms of their complexity and performance.”

The work done by the Cambridge researchers opens a number of commercial opportunities for ink based on two-dimensional materials, ranging from personal health and well-being technology, to wearable energy and data storage, military garments, wearable computing and fashion.

“Turning textiles into functional energy storage elements can open up an entirely new set of applications, from body-energy harvesting and storage to the Internet of Things,” said Torrisi “In the future our clothes could incorporate these textile-based charge storage elements and power wearable textile devices.”

Here’s a link to and a citation for the paper,

Wearable solid-state capacitors based on two-dimensional material all-textile heterostructures by Siyu Qiang, Tian Carey, Adrees Arbab, Weihua Song, Chaoxia Wang and Felice Torris. Nanoscale, 2019, Advance Article DOI: 10.1039/C9NR00463G First published on 18 Apr 2019

This paper is behind a paywall.

India

Prior to graphene’s reign as the ‘it’ carbon material, carbon nanotubes (CNTs) ruled. It’s been quieter on the CNT front since graphene took over but a May 15, 2019 Nanowerk Spotlight article by Michael Berger highlights some of the latest CNT research coming out of India,


The most important technical challenge is to blend the chemical nature of raw materials with fabrication techniques and processability, all of which are diametrically conflicting for textiles and conventional energy storage devices. A team from Indian Institute of Technology Bombay has come out with a comprehensive approach involving simple and facile steps to fabricate a wearable energy storage device. Several scientific and technological challenges were overcome during this process.

First, to achieve user-comfort and computability with clothing, the scaffold employed was the the same as what a regular fabric is made up of – cellulose fibers. However, cotton yarns are electrical insulators and therefore practically useless for any electronics. Therefore, the yarns are coated with single-wall carbon nanotubes (SWNTs).

SWNTs are hollow, cylindrical allotropes of carbon and combine excellent mechanical strength with electrical conductivity and surface area. Such a coating converts the electrical insulating cotton yarn to a metallic conductor with high specific surface area. At the same time, using carbon-based materials ensures that the final material remains light-weight and does not cause user discomfort that can arise from metallic wires such as copper and gold. This CNT-coated cotton yarn (CNT-wires) forms the electrode for the energy storage device.

Next, the electrolyte is composed of solid-state electrolyte sheets since no liquid-state electrolytes can be used for this purpose. However, solid state electrolytes suffer from poor ionic conductivity – a major disadvantage for energy storage applications. Therefore, a steam-based infiltration approach that enhances the ionic conductivity of the electrolyte is adopted. Such enhancement of humidity significantly increases the energy storage capacity of the device.


The integration of the CNT-wire electrode with the electrolyte sheet was carried out by a simple and elegant approach of interweaving the CNT-wire through the electrolyte (see Figure 1). This resulted in cross-intersections which are actually junctions where the electrical energy can be stored. Each such junction is now an energy storage unit, referred to as sewcap.

The advantage of this process is that several 100s and 1000s of sewcaps can be made in a small area and integrated to increase the total amount of energy stored in the system. This scalability is unique and critical aspect of this work and stems from the approach of interweaving.

Further, this process is completely adaptable with current processes used in textile industries. Hence, a proportionately large energy-storage is achieved by creating sewcap-junctions in various combinations.

All components of the final sewcap device are flexible. However, they need to be protected from environmental effects such as temperature, humidity and sweat while retaining the mechanical flexibility. This is achieved by laminating the entire device between polymer sheets. The process is exactly similar to the one used for protecting documents and ID cards.

The laminated sewcap can be integrated easily on clothing and fabrics while retaining the flexibility and sturdiness. This is demonstrated by the unchanged performance of the device during extreme and harsh mechanical testing such as striking repeatedly with a hammer, complete flexing, bending and rolling and washing in a laundry machine.

In fact, this is the first device that has been proven to be stable under rigorous washing conditions in the presence of hot water, detergents and high torque (spinning action of washing machine). This provides the device with comprehensive mechanical stability.


CNTs have high surface area and electrical conductivity. The CNT-wire combines these properties of CNTs with stability and porosity of cellulose yarns. The junction created by interweaving is essentially comprised of two such CNT-wires that are sandwiching an electrolyte. Application of potential difference leads to polarization of the electrolyte thus enabling energy storage similar to the way in which a conventional capacitor acts.

“We use the advantage of the interweaving process and create several such junctions. So, with each junction being able to store a certain amount of electrical energy, all the junctions synchronized are able to store a large amount of energy. This provides high energy density to the device,” Prof. C. Subramaniam, Department of Chemistry, IIT Bombay and corresponding author of the paper points out.

The device has also been employed for lighting up an LED [light-emitting diode]. This can be potentially scaled to provide electrical energy demanded by the application.

This image accompanies the paper written by Prof. C. Subramaniam and his team,

Courtesy: IACS Applied Materials Interfaces

Here’s a link to and a citation for the paper,

Interwoven Carbon Nanotube Wires for High-Performing, Mechanically Robust, Washable, and Wearable Supercapacitors by Mihir Kumar Jha, Kenji Hata, and Chandramouli Subramaniam. ACS Appl. Mater. Interfaces, Article ASAP DOI: 10.1021/acsami.8b22233 Publication Date (Web): April 29, 2019 Copyright © 2019 American Chemical Society

This paper is behind a paywall.

Canada

A research team from the University of British Columbia (UBC at the Okanagan Campus) joined the pack with a May 16, 2019 news item on ScienceDaily,

Forget the smart watch. Bring on the smart shirt.

Researchers at UBC Okanagan’s School of Engineering have developed a low-cost sensor that can be interlaced into textiles and composite materials. While the research is still new, the sensor may pave the way for smart clothing that can monitor human movement.

A May 16, 2019 UBC news release (also on EurekAlert), which originated the news item, describes the work in more detail,


“Microscopic sensors are changing the way we monitor machines and humans,” says Hoorfar, lead researcher at the Advanced Thermo-Fluidic Lab at UBC’s Okanagan campus. “Combining the shrinking of technology along with improved accuracy, the future is very bright in this area.”

This ‘shrinking technology’ uses a phenomenon called piezo-resistivity—an electromechanical response of a material when it is under strain. These tiny sensors have shown a great promise in detecting human movements and can be used for heart rate monitoring or temperature control, explains Hoorfar.

Her research, conducted in partnership with UBC Okanagan’s Materials and Manufacturing Research Institute, shows the potential of a low-cost, sensitive and stretchable yarn sensor. The sensor can be woven into spandex material and then wrapped into a stretchable silicone sheath. This sheath protects the conductive layer against harsh conditions and allows for the creation of washable wearable sensors.

While the idea of smart clothing—fabrics that can tell the user when to hydrate, or when to rest—may change the athletics industry, UBC Professor Abbas Milani says the sensor has other uses. It can monitor deformations in fibre-reinforced composite fabrics currently used in advanced industries such as automotive, aerospace and marine manufacturing.

The low-cost stretchable composite sensor has also shown a high sensitivity and can detect small deformations such as yarn stretching as well as out-of-plane deformations at inaccessible places within composite laminates, says Milani, director of the UBC Materials and Manufacturing Research Institute.

The testing indicates that further improvements in its accuracy could be achieved by fine-tuning the sensor’s material blend and improving its electrical conductivity and sensitivity This can eventually make it able to capture major flaws like “fibre wrinkling” during the manufacturing of advanced composite structures such as those currently used in airplanes or car bodies.

“Advanced textile composite materials make the most of combining the strengths of different reinforcement materials and patterns with different resin options,” he says. “Integrating sensor technologies like piezo-resistive sensors made of flexible materials compatible with the host textile reinforcement is becoming a real game-changer in the emerging era of smart manufacturing and current automated industry trends.”

Here’s a link to and a citation for the paper,

Graphene‐Coated Spandex Sensors Embedded into Silicone Sheath for Composites Health Monitoring and Wearable Applications by Hossein Montazerian, Armin Rashidi, Arash Dalili, Homayoun Najjaran, Abbas S. Milani, Mina Hoorfar. Small Volume15, Issue17 April 26, 2019 1804991 DOI: https://doi.org/10.1002/smll.201804991 First published: 28 March 2019

This paper is behind a paywall.

Will there be one winner or will they find CNTs better for one type of wearable tech textile while graphene excels for another type of wearable tech textile?

It’s a very ‘carbony’ time: graphene jacket, graphene-skinned airplane, and schwarzite

In August 2018, I been stumbled across several stories about graphene-based products and a new form of carbon.

Graphene jacket

The company producing this jacket has as its goal “… creating bionic clothing that is both bulletproof and intelligent.” Well, ‘bionic‘ means biologically-inspired engineering and ‘intelligent‘ usually means there’s some kind of computing capability in the product. This jacket, which is the first step towards the company’s goal, is not bionic, bulletproof, or intelligent. Nonetheless, it represents a very interesting science experiment in which you, the consumer, are part of step two in the company’s R&D (research and development).

Onto Vollebak’s graphene jacket,

Courtesy: Vollebak

From an August 14, 2018 article by Jesus Diaz for Fast Company,

Graphene is the thinnest possible form of graphite, which you can find in your everyday pencil. It’s purely bi-dimensional, a single layer of carbon atoms that has unbelievable properties that have long threatened to revolutionize everything from aerospace engineering to medicine. …

Despite its immense promise, graphene still hasn’t found much use in consumer products, thanks to the fact that it’s hard to manipulate and manufacture in industrial quantities. The process of developing Vollebak’s jacket, according to the company’s cofounders, brothers Steve and Nick Tidball, took years of intensive research, during which the company worked with the same material scientists who built Michael Phelps’ 2008 Olympic Speedo swimsuit (which was famously banned for shattering records at the event).

The jacket is made out of a two-sided material, which the company invented during the extensive R&D process. The graphene side looks gunmetal gray, while the flipside appears matte black. To create it, the scientists turned raw graphite into something called graphene “nanoplatelets,” which are stacks of graphene that were then blended with polyurethane to create a membrane. That, in turn, is bonded to nylon to form the other side of the material, which Vollebak says alters the properties of the nylon itself. “Adding graphene to the nylon fundamentally changes its mechanical and chemical properties–a nylon fabric that couldn’t naturally conduct heat or energy, for instance, now can,” the company claims.

The company says that it’s reversible so you can enjoy graphene’s properties in different ways as the material interacts with either your skin or the world around you. “As physicists at the Max Planck Institute revealed, graphene challenges the fundamental laws of heat conduction, which means your jacket will not only conduct the heat from your body around itself to equalize your skin temperature and increase it, but the jacket can also theoretically store an unlimited amount of heat, which means it can work like a radiator,” Tidball explains.

He means it literally. You can leave the jacket out in the sun, or on another source of warmth, as it absorbs heat. Then, the company explains on its website, “If you then turn it inside out and wear the graphene next to your skin, it acts like a radiator, retaining its heat and spreading it around your body. The effect can be visibly demonstrated by placing your hand on the fabric, taking it away and then shooting the jacket with a thermal imaging camera. The heat of the handprint stays long after the hand has left.”

There’s a lot more to the article although it does feature some hype and I’m not sure I believe Diaz’s claim (August 14, 2018 article) that ‘graphene-based’ hair dye is perfectly safe ( Note: A link has been removed),

Graphene is the thinnest possible form of graphite, which you can find in your everyday pencil. It’s purely bi-dimensional, a single layer of carbon atoms that has unbelievable properties that will one day revolutionize everything from aerospace engineering to medicine. Its diverse uses are seemingly endless: It can stop a bullet if you add enough layers. It can change the color of your hair with no adverse effects. [emphasis mine] It can turn the walls of your home into a giant fire detector. “It’s so strong and so stretchy that the fibers of a spider web coated in graphene could catch a falling plane,” as Vollebak puts it in its marketing materials.

Not unless things have changed greatly since March 2018. My August 2, 2018 posting featured the graphene-based hair dye announcement from March 2018 and a cautionary note from Dr. Andrew Maynard (scroll down ab out 50% of the way for a longer excerpt of Maynard’s comments),

Northwestern University’s press release proudly announced, “Graphene finds new application as nontoxic, anti-static hair dye.” The announcement spawned headlines like “Enough with the toxic hair dyes. We could use graphene instead,” and “’Miracle material’ graphene used to create the ultimate hair dye.”

From these headlines, you might be forgiven for getting the idea that the safety of graphene-based hair dyes is a done deal. Yet having studied the potential health and environmental impacts of engineered nanomaterials for more years than I care to remember, I find such overly optimistic pronouncements worrying – especially when they’re not backed up by clear evidence.

These studies need to be approached with care, as the precise risks of graphene exposure will depend on how the material is used, how exposure occurs and how much of it is encountered. Yet there’s sufficient evidence to suggest that this substance should be used with caution – especially where there’s a high chance of exposure or that it could be released into the environment.

The full text of Dr. Maynard’s comments about graphene hair dyes and risk can be found here.

Bearing in mind  that graphene-based hair dye is an entirely different class of product from the jacket, I wouldn’t necessarily dismiss risks; I would like to know what kind of risk assessment and safety testing has been done. Due to their understandable enthusiasm, the brothers Tidball have focused all their marketing on the benefits and the opportunity for the consumer to test their product (from graphene jacket product webpage),

While it’s completely invisible and only a single atom thick, graphene is the lightest, strongest, most conductive material ever discovered, and has the same potential to change life on Earth as stone, bronze and iron once did. But it remains difficult to work with, extremely expensive to produce at scale, and lives mostly in pioneering research labs. So following in the footsteps of the scientists who discovered it through their own highly speculative experiments, we’re releasing graphene-coated jackets into the world as experimental prototypes. Our aim is to open up our R&D and accelerate discovery by getting graphene out of the lab and into the field so that we can harness the collective power of early adopters as a test group. No-one yet knows the true limits of what graphene can do, so the first edition of the Graphene Jacket is fully reversible with one side coated in graphene and the other side not. If you’d like to take part in the next stage of this supermaterial’s history, the experiment is now open. You can now buy it, test it and tell us about it. [emphasis mine]

How maverick experiments won the Nobel Prize

While graphene’s existence was first theorised in the 1940s, it wasn’t until 2004 that two maverick scientists, Andre Geim and Konstantin Novoselov, were able to isolate and test it. Through highly speculative and unfunded experimentation known as their ‘Friday night experiments,’ they peeled layer after layer off a shaving of graphite using Scotch tape until they produced a sample of graphene just one atom thick. After similarly leftfield thinking won Geim the 2000 Ig Nobel prize for levitating frogs using magnets, the pair won the Nobel prize in 2010 for the isolation of graphene.

Should you be interested, in beta-testing the jacket, it will cost you $695 (presumably USD); order here. One last thing, Vollebak is based in the UK.

Graphene skinned plane

An August 14, 2018 news item (also published as an August 1, 2018 Haydale press release) by Sue Keighley on Azonano heralds a new technology for airplans,

Haydale, (AIM: HAYD), the global advanced materials group, notes the announcement made yesterday from the University of Central Lancashire (UCLAN) about the recent unveiling of the world’s first graphene skinned plane at the internationally renowned Farnborough air show.

The prepreg material, developed by Haydale, has potential value for fuselage and wing surfaces in larger scale aero and space applications especially for the rapidly expanding drone market and, in the longer term, the commercial aerospace sector. By incorporating functionalised nanoparticles into epoxy resins, the electrical conductivity of fibre-reinforced composites has been significantly improved for lightning-strike protection, thereby achieving substantial weight saving and removing some manufacturing complexities.

Before getting to the photo, here’s a definition for pre-preg from its Wikipedia entry (Note: Links have been removed),

Pre-preg is “pre-impregnated” composite fibers where a thermoset polymer matrix material, such as epoxy, or a thermoplastic resin is already present. The fibers often take the form of a weave and the matrix is used to bond them together and to other components during manufacture.

Haydale has supplied graphene enhanced prepreg material for Juno, a three-metre wide graphene-enhanced composite skinned aircraft, that was revealed as part of the ‘Futures Day’ at Farnborough Air Show 2018. [downloaded from https://www.azonano.com/news.aspx?newsID=36298]

A July 31, 2018 University of Central Lancashire (UCLan) press release provides a tiny bit more (pun intended) detail,

The University of Central Lancashire (UCLan) has unveiled the world’s first graphene skinned plane at an internationally renowned air show.

Juno, a three-and-a-half-metre wide graphene skinned aircraft, was revealed on the North West Aerospace Alliance (NWAA) stand as part of the ‘Futures Day’ at Farnborough Air Show 2018.

The University’s aerospace engineering team has worked in partnership with the Sheffield Advanced Manufacturing Research Centre (AMRC), the University of Manchester’s National Graphene Institute (NGI), Haydale Graphene Industries (Haydale) and a range of other businesses to develop the unmanned aerial vehicle (UAV), which also includes graphene batteries and 3D printed parts.

Billy Beggs, UCLan’s Engineering Innovation Manager, said: “The industry reaction to Juno at Farnborough was superb with many positive comments about the work we’re doing. Having Juno at one the world’s biggest air shows demonstrates the great strides we’re making in leading a programme to accelerate the uptake of graphene and other nano-materials into industry.

“The programme supports the objectives of the UK Industrial Strategy and the University’s Engineering Innovation Centre (EIC) to increase industry relevant research and applications linked to key local specialisms. Given that Lancashire represents the fourth largest aerospace cluster in the world, there is perhaps no better place to be developing next generation technologies for the UK aerospace industry.”

Previous graphene developments at UCLan have included the world’s first flight of a graphene skinned wing and the launch of a specially designed graphene-enhanced capsule into near space using high altitude balloons.

UCLan engineering students have been involved in the hands-on project, helping build Juno on the Preston Campus.

Haydale supplied much of the material and all the graphene used in the aircraft. Ray Gibbs, Chief Executive Officer, said: “We are delighted to be part of the project team. Juno has highlighted the capability and benefit of using graphene to meet key issues faced by the market, such as reducing weight to increase range and payload, defeating lightning strike and protecting aircraft skins against ice build-up.”

David Bailey Chief Executive of the North West Aerospace Alliance added: “The North West aerospace cluster contributes over £7 billion to the UK economy, accounting for one quarter of the UK aerospace turnover. It is essential that the sector continues to develop next generation technologies so that it can help the UK retain its competitive advantage. It has been a pleasure to support the Engineering Innovation Centre team at the University in developing the world’s first full graphene skinned aircraft.”

The Juno project team represents the latest phase in a long-term strategic partnership between the University and a range of organisations. The partnership is expected to go from strength to strength following the opening of the £32m EIC facility in February 2019.

The next step is to fly Juno and conduct further tests over the next two months.

Next item, a new carbon material.

Schwarzite

I love watching this gif of a schwarzite,

The three-dimensional cage structure of a schwarzite that was formed inside the pores of a zeolite. (Graphics by Yongjin Lee and Efrem Braun)

An August 13, 2018 news item on Nanowerk announces the new carbon structure,

The discovery of buckyballs [also known as fullerenes, C60, or buckminsterfullerenes] surprised and delighted chemists in the 1980s, nanotubes jazzed physicists in the 1990s, and graphene charged up materials scientists in the 2000s, but one nanoscale carbon structure – a negatively curved surface called a schwarzite – has eluded everyone. Until now.

University of California, Berkeley [UC Berkeley], chemists have proved that three carbon structures recently created by scientists in South Korea and Japan are in fact the long-sought schwarzites, which researchers predict will have unique electrical and storage properties like those now being discovered in buckminsterfullerenes (buckyballs or fullerenes for short), nanotubes and graphene.

An August 13, 2018 UC Berkeley news release by Robert Sanders, which originated the news item, describes how the Berkeley scientists and the members of their international  collaboration from Germany, Switzerland, Russia, and Italy, have contributed to the current state of schwarzite research,

The new structures were built inside the pores of zeolites, crystalline forms of silicon dioxide – sand – more commonly used as water softeners in laundry detergents and to catalytically crack petroleum into gasoline. Called zeolite-templated carbons (ZTC), the structures were being investigated for possible interesting properties, though the creators were unaware of their identity as schwarzites, which theoretical chemists have worked on for decades.

Based on this theoretical work, chemists predict that schwarzites will have unique electronic, magnetic and optical properties that would make them useful as supercapacitors, battery electrodes and catalysts, and with large internal spaces ideal for gas storage and separation.

UC Berkeley postdoctoral fellow Efrem Braun and his colleagues identified these ZTC materials as schwarzites based of their negative curvature, and developed a way to predict which zeolites can be used to make schwarzites and which can’t.

“We now have the recipe for how to make these structures, which is important because, if we can make them, we can explore their behavior, which we are working hard to do now,” said Berend Smit, an adjunct professor of chemical and biomolecular engineering at UC Berkeley and an expert on porous materials such as zeolites and metal-organic frameworks.

Smit, the paper’s corresponding author, Braun and their colleagues in Switzerland, China, Germany, Italy and Russia will report their discovery this week in the journal Proceedings of the National Academy of Sciences. Smit is also a faculty scientist at Lawrence Berkeley National Laboratory.

Playing with carbon

Diamond and graphite are well-known three-dimensional crystalline arrangements of pure carbon, but carbon atoms can also form two-dimensional “crystals” — hexagonal arrangements patterned like chicken wire. Graphene is one such arrangement: a flat sheet of carbon atoms that is not only the strongest material on Earth, but also has a high electrical conductivity that makes it a promising component of electronic devices.

schwarzite carbon cage

The cage structure of a schwarzite that was formed inside the pores of a zeolite. The zeolite is subsequently dissolved to release the new material. (Graphics by Yongjin Lee and Efrem Braun)

Graphene sheets can be wadded up to form soccer ball-shaped fullerenes – spherical carbon cages that can store molecules and are being used today to deliver drugs and genes into the body. Rolling graphene into a cylinder yields fullerenes called nanotubes, which are being explored today as highly conductive wires in electronics and storage vessels for gases like hydrogen and carbon dioxide. All of these are submicroscopic, 10,000 times smaller than the width of a human hair.

To date, however, only positively curved fullerenes and graphene, which has zero curvature, have been synthesized, feats rewarded by Nobel Prizes in 1996 and 2010, respectively.

In the 1880s, German physicist Hermann Schwarz investigated negatively curved structures that resemble soap-bubble surfaces, and when theoretical work on carbon cage molecules ramped up in the 1990s, Schwarz’s name became attached to the hypothetical negatively curved carbon sheets.

“The experimental validation of schwarzites thus completes the triumvirate of possible curvatures to graphene; positively curved, flat, and now negatively curved,” Braun added.

Minimize me

Like soap bubbles on wire frames, schwarzites are topologically minimal surfaces. When made inside a zeolite, a vapor of carbon-containing molecules is injected, allowing the carbon to assemble into a two-dimensional graphene-like sheet lining the walls of the pores in the zeolite. The surface is stretched tautly to minimize its area, which makes all the surfaces curve negatively, like a saddle. The zeolite is then dissolved, leaving behind the schwarzite.

soap bubble schwarzite structure

A computer-rendered negatively curved soap bubble that exhibits the geometry of a carbon schwarzite. (Felix Knöppel image)

“These negatively-curved carbons have been very hard to synthesize on their own, but it turns out that you can grow the carbon film catalytically at the surface of a zeolite,” Braun said. “But the schwarzites synthesized to date have been made by choosing zeolite templates through trial and error. We provide very simple instructions you can follow to rationally make schwarzites and we show that, by choosing the right zeolite, you can tune schwarzites to optimize the properties you want.”

Researchers should be able to pack unusually large amounts of electrical charge into schwarzites, which would make them better capacitors than conventional ones used today in electronics. Their large interior volume would also allow storage of atoms and molecules, which is also being explored with fullerenes and nanotubes. And their large surface area, equivalent to the surface areas of the zeolites they’re grown in, could make them as versatile as zeolites for catalyzing reactions in the petroleum and natural gas industries.

Braun modeled ZTC structures computationally using the known structures of zeolites, and worked with topological mathematician Senja Barthel of the École Polytechnique Fédérale de Lausanne in Sion, Switzerland, to determine which of the minimal surfaces the structures resembled.

The team determined that, of the approximately 200 zeolites created to date, only 15 can be used as a template to make schwarzites, and only three of them have been used to date to produce schwarzite ZTCs. Over a million zeolite structures have been predicted, however, so there could be many more possible schwarzite carbon structures made using the zeolite-templating method.

Other co-authors of the paper are Yongjin Lee, Seyed Mohamad Moosavi and Barthel of the École Polytechnique Fédérale de Lausanne, Rocio Mercado of UC Berkeley, Igor Baburin of the Technische Universität Dresden in Germany and Davide Proserpio of the Università degli Studi di Milano in Italy and Samara State Technical University in Russia.

Here’s a link to and a citation for the paper,

Generating carbon schwarzites via zeolite-templating by Efrem Braun, Yongjin Lee, Seyed Mohamad Moosavi, Senja Barthel, Rocio Mercado, Igor A. Baburin, Davide M. Proserpio, and Berend Smit. PNAS August 14, 2018. 201805062; published ahead of print August 14, 2018. https://doi.org/10.1073/pnas.1805062115

This paper appears to be open access.