Tag Archives: Dexter Johnson

Searchable database for hazardous nanomaterials and a Graphene Verification Programme

I have two relatively recent news bits about nanomaterials, the second being entirely focused on graphene.

Searchable database

A July 9, 2019 news item on Nanowerk announces a means of finding out what hazards may be associated with 300 different nanomaterials (Note: A Link has been removed),

A new search tool for nanomaterials has been published on the European Union Observatory for Nanomaterials (EUON) website. It will enable regulators to form a better view of available data and give consumers access to chemicals safety information.

The tool combines data submitted by companies in their REACH registrations [Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) ], data collected about nanomaterials used as ingredients in cosmetic products under the Cosmetics Regulation and data from the public national nanomaterial inventories of Belgium and France.

A July 3, 2019 EUON press release, which originated the news item, provides a bit more detail,

The EUON’s search brings data from these sources together in one place, allowing users to easily search for nanomaterials that are currently on the EU market. The results are linked to ECHA’s [European Chemicals Agency] database of chemicals registered in the EU and, for the first time, summarised information about the substances, their properties as well as detailed safety and characterisation data can be easily found.

Background

While there are over 300 nanomaterials on the EU market, 37 are currently covered by an existing registration under REACH. The information requirements for REACH were revised last year with explicit obligations for nanomaterials manufactured in or imported to the EU. The new requirements enter into force in January 2020 and will result in more publicly available information.

The EUON aims to increase the transparency of information available to the public on the safety and markets of nanomaterials in the EU. A key aim of the observatory is to create a one-stop shop for information, where EU citizens and stakeholders including NGOs, industry, and regulators can all easily find accessible and relevant safety information on nanomaterials on the EU market.

Here’s the searchable database.

Graphene verification

There was a bit of a scandal about fake graphene in the Fall of 2018 (my May 28, 2019 posting gives details). Dexter Johnson provides additional insight and information about the launch of a new graphene verification programme and news of a slightly older graphene verification programme in his July 9, 2019 article for the Nanoclast blog on the IEEE (Institute of Electrical and Electronics Engineers) website (Note: Links have been removed),

Last year [2018], the graphene community was rocked by a series of critical articles that appeared in some high-profile journals. First there was an Advanced Material’s article with the rather innocuously title: “The Worldwide Graphene Flake Production”. It was perhaps the follow-up article that appeared in the journal Nature that really shook things up with its incendiary title: “The war on fake graphene”.

In these two articles it was revealed that material that had been claimed to be high-quality (and high-priced) graphene was little more than graphite powder. Boosted by their appearance in high-impact journals, these articles threatened the foundations of the graphene marketplace.

But while these articles triggered a lot of hand wringing among the buyers and sellers of graphene, it’s not clear that their impact extended much beyond the supply chain of graphene. Whether or not graphene has aggregated back to being graphite is one question. An even bigger one is whether or not consumers are actually being sold a better product on the basis that it incorporates graphene.

Dexter details some of the issues from the consumer’s perspective (Note: Links have been removed),

Consumer products featuring graphene today include everything from headphones to light bulbs. Consequently, there is already confusion among buyers about the tangible benefits graphene is supposed to provide. And of course the situation becomes even worse if the graphene sold to make products may not even be graphene: how are consumers supposed to determine whether graphene infuses their products with anything other than a buzzword?

Another source of confusion arises because when graphene is incorporated into a product it is effectively a different animal from graphene in isolation. There is ample scientific evidence that graphene when included in a material matrix, like a polymer or even paper, can impart new properties to the materials. “You can transfer some very useful properties of graphene into other materials by adding graphene, but just because the resultant material contains graphene it does not mean it will behave like free-standing graphene, explains Tom Eldridge, of UK-based Fullerex, a consultancy that provides companies with information on how to include graphene in a material matrix

The rest of Dexter’s posting goes on to mention two new graphene verification progammes (producer and product) available through The Graphene Council. As for what the council is, there’s this from council’s About webpage,

The Graphene Council was founded in 2013 with a mission to serve the global community of graphene professionals. Today, The Graphene Council is the largest community in the world for graphene researchers, academics, producers, developers, investors, nanotechnologists, regulatory agencies, research institutes, material science specialists and even the general public. We reach more than 50,000 people with an interest in this amazing material. 

Interestingly the council’s offices are located in the US state of North Carolina. (I would have guessed that its headquarters would be in the UK, given the ‘ownership’ the UK has been attempting to establish over graphene Let me clarify, by ownership I mean the Brits want to be recognized as dominant or preeminent in graphene research and commercialization.)

The council’s first verified graphene producer is a company based in the UK as can be seen in an April 1, 2019 posting by council director Terrance Barkan on the council’s blog,

The Graphene Council is pleased to announce that Versarien plc is the first graphene company in the world to successfully complete the Verified Graphene Producer™ program, an independent, third party verification system that involves a physical inspection of the production facilities, a review of the entire production process, a random sample of product material and rigorous characterization and testing by a first class, international materials laboratory.

The Verified Graphene Producer™ program is an important step to bring transparency and clarity to a rapidly changing and opaque market for graphene materials, providing graphene customers with a level of confidence that has not existed before.

“We are pleased to have worked with the National Physical Laboratory (NPL) in the UK, regarded as one of the absolute top facilities for metrology and graphene characterization in the world.
 
They have provided outstanding analytical expertise for the materials testing portion of the program including Raman Spectroscopy, XPS, AFM and SEM testing services.” stated Terrance Barkan CAE, Executive Director of The Graphene Council.
 
Andrew Pollard, Science Area Leader of the Surface Technology Group, National Physical Laboratory, said: “In order to develop real-world products that can benefit from the ‘wonder material’, graphene, we first need to fully understand its properties, reliably and reproducibly.
 
“Whilst international measurement standards are currently being developed, it is critical that material characterisation is performed to the highest possible level.
 
As the UK’s National Measurement Institute (NMI) with a focus on developing the metrology of graphene and related 2D materials, we aim to be an independent third party in the testing of graphene material for companies and associations around the world, such as The Graphene Council.” 
 
Neill Ricketts, CEO of Versarien said: “We are delighted that Versarien is the first graphene producer in the world to successfully complete the Graphene Council’s Verified Graphene Producer™ programme.”
 
“This is a huge validation of our technology and will enable our partners and potential customers to have confidence that the graphene we produce meets globally accepted standards.”
 
“There are many companies that claim to be graphene producers, but to enjoy the benefits that this material can deliver requires high quality, consistent product to be supplied.  The Verified Producer programme is designed to verify that our production facilities, processes and tested material meet the stringent requirements laid down by The Graphene Council.”

“I am proud that Versarien has been independently acclaimed as a Verified Graphene Producer™ and look forward to making further progress with our collaboration partners and numerous other parties that we are in discussions with.”

James Baker CEng FIET, the CEO of Graphene@Manchester (which includes coordinating the efforts of the National Graphene Institute and the Graphene Engineering and Innovation Centre [GEIC]) stated: “We applaud The Graphene Council for promoting independent third party verification for graphene producers that is supported by world class metrology and characterization services.”

“This is an important contribution to the commercialization of graphene as an industrial material and are proud to have The Graphene Council as an Affiliate Member of the Graphene Engineering and Innovation Centre (GEIC) here in Manchester ”.

Successful commercialization of graphene materials requires not only the ability to produce graphene to a declared specification but to be able to do so at a commercial scale.
It is nearly impossible for a graphene customer to verify the type of material they are receiving without going through an expensive and time consuming process of having sample materials fully characterized by a laboratory that has the equipment and expertise to test graphene.

The Verified Graphene Producer™ program developed by The Graphene Councilprovides a level of independent inspection and verification that is not available anywhere else.

As for the “Verified Graphene Product” programme mentioned in Dexter’s article (it’s not included in the excerpts here), I can’t find any sign of it ion the council’s website.

Neurons and graphene carpets

I don’t entirely grasp the carpet analogy. Actually, I have no why they used a carpet analogy but here’s the June 12, 2018 ScienceDaily news item about the research,

A work led by SISSA [Scuola Internazionale Superiore di Studi Avanzati] and published on Nature Nanotechnology reports for the first time experimentally the phenomenon of ion ‘trapping’ by graphene carpets and its effect on the communication between neurons. The researchers have observed an increase in the activity of nerve cells grown on a single layer of graphene. Combining theoretical and experimental approaches they have shown that the phenomenon is due to the ability of the material to ‘trap’ several ions present in the surrounding environment on its surface, modulating its composition. Graphene is the thinnest bi-dimensional material available today, characterised by incredible properties of conductivity, flexibility and transparency. Although there are great expectations for its applications in the biomedical field, only very few works have analysed its interactions with neuronal tissue.

A June 12, 2018 SISSA press release (also on EurekAlert), which originated the news item, provides more detail,

A study conducted by SISSA – Scuola Internazionale Superiore di Studi Avanzati, in association with the University of Antwerp (Belgium), the University of Trieste and the Institute of Science and Technology of Barcelona (Spain), has analysed the behaviour of neurons grown on a single layer of graphene, observing a strengthening in their activity. Through theoretical and experimental approaches the researchers have shown that such behaviour is due to reduced ion mobility, in particular of potassium, to the neuron-graphene interface. This phenomenon is commonly called ‘ion trapping’, already known at theoretical level, but observed experimentally for the first time only now. “It is as if graphene behaves as an ultra-thin magnet on whose surface some of the potassium ions present in the extra cellular solution between the cells and the graphene remain trapped. It is this small variation that determines the increase in neuronal excitability” comments Denis Scaini, researcher at SISSA who has led the research alongside Laura Ballerini.

The study has also shown that this strengthening occurs when the graphene itself is supported by an insulator, like glass, or suspended in solution, while it disappears when lying on a conductor. “Graphene is a highly conductive material which could potentially be used to coat any surface. Understanding how its behaviour varies according to the substratum on which it is laid is essential for its future applications, above all in the neurological field” continues Scaini, “considering the unique properties of graphene it is natural to think for example about the development of innovative electrodes of cerebral stimulation or visual devices”.

It is a study with a double outcome. Laura Ballerini comments as follows: “This ‘ion trap’ effect was described only in theory. Studying the impact of the ‘technology of materials’ on biological systems, we have documented a mechanism to regulate membrane excitability, but at the same time we have also experimentally described a property of the material through the biology of neurons.”

Dexter Johnson in a June 13, 2018 posting, on his Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers] website), provides more context for the work (Note: Links have been removed),

While graphene has been tapped to deliver on everything from electronics to optoelectronics, it’s a bit harder to picture how it may offer a key tool for addressing neurological damage and disorders. But that’s exactly what researchers have been looking at lately because of the wonder material’s conductivity and transparency.

In the most recent development, a team from Europe has offered a deeper understanding of how graphene can be combined with neurological tissue and, in so doing, may have not only given us an additional tool for neurological medicine, but also provided a tool for gaining insights into other biological processes.

“The results demonstrate that, depending on how the interface with [single-layer graphene] is engineered, the material may tune neuronal activities by altering the ion mobility, in particular potassium, at the cell/substrate interface,” said Laura Ballerini, a researcher in neurons and nanomaterials at SISSA.

Ballerini provided some context for this most recent development by explaining that graphene-based nanomaterials have come to represent potential tools in neurology and neurosurgery.

“These materials are increasingly engineered as components of a variety of applications such as biosensors, interfaces, or drug-delivery platforms,” said Ballerini. “In particular, in neural electrode or interfaces, a precise requirement is the stable device/neuronal electrical coupling, which requires governing the interactions between the electrode surface and the cell membrane.”

This neuro-electrode hybrid is at the core of numerous studies, she explained, and graphene, thanks to its electrical properties, transparency, and flexibility represents an ideal material candidate.

In all of this work, the real challenge has been to investigate the ability of a single atomic layer to tune neuronal excitability and to demonstrate unequivocally that graphene selectively modifies membrane-associated neuronal functions.

I encourage you to read Dexter’s posting as it clarifies the work described in the SISSA press release for those of us (me) who may fail to grasp the implications.

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

Single-layer graphene modulates neuronal communication and augments membrane ion currents by Niccolò Paolo Pampaloni, Martin Lottner, Michele Giugliano, Alessia Matruglio, Francesco D’Amico, Maurizio Prato, Josè Antonio Garrido, Laura Ballerini, & Denis Scaini. Nature Nanotechnology (2018) DOI: https://doi.org/10.1038/s41565-018-0163-6 Published online June 13, 2018

This paper is behind a paywall.

All this brings to mind a prediction made about the Graphene Flagship and the Human Brain Project shortly after the European Commission announced in January 2013 that each project had won funding of 1B Euros to be paid out over a period of 10 years. The prediction was that scientists would work on graphene/human brain research.

Announcing the ‘memtransistor’

Yet another advance toward ‘brainlike’ computing (how many times have I written this or a variation thereof in the last 10 years? See: Dexter Johnson’s take on the situation at the end of this post): Northwestern University announced their latest memristor research in a February 21, 2018 news item on Nanowerk,

Computer algorithms might be performing brain-like functions, such as facial recognition and language translation, but the computers themselves have yet to operate like brains.

“Computers have separate processing and memory storage units, whereas the brain uses neurons to perform both functions,” said Northwestern University’s Mark C. Hersam. “Neural networks can achieve complicated computation with significantly lower energy consumption compared to a digital computer.”

A February 21, 2018 Northwestern University news release (also on EurekAlert), which originated the news item, provides more information about the latest work from this team,

In recent years, researchers have searched for ways to make computers more neuromorphic, or brain-like, in order to perform increasingly complicated tasks with high efficiency. Now Hersam, a Walter P. Murphy Professor of Materials Science and Engineering in Northwestern’s McCormick School of Engineering, and his team are bringing the world closer to realizing this goal.

The research team has developed a novel device called a “memtransistor,” which operates much like a neuron by performing both memory and information processing. With combined characteristics of a memristor and transistor, the memtransistor also encompasses multiple terminals that operate more similarly to a neural network.

Supported by the National Institute of Standards and Technology and the National Science Foundation, the research was published online today, February 22 [2018], in Nature. Vinod K. Sangwan and Hong-Sub Lee, postdoctoral fellows advised by Hersam, served as the paper’s co-first authors.

The memtransistor builds upon work published in 2015, in which Hersam, Sangwan, and their collaborators used single-layer molybdenum disulfide (MoS2) to create a three-terminal, gate-tunable memristor for fast, reliable digital memory storage. Memristor, which is short for “memory resistors,” are resistors in a current that “remember” the voltage previously applied to them. Typical memristors are two-terminal electronic devices, which can only control one voltage channel. By transforming it into a three-terminal device, Hersam paved the way for memristors to be used in more complex electronic circuits and systems, such as neuromorphic computing.

To develop the memtransistor, Hersam’s team again used atomically thin MoS2 with well-defined grain boundaries, which influence the flow of current. Similar to the way fibers are arranged in wood, atoms are arranged into ordered domains – called “grains” – within a material. When a large voltage is applied, the grain boundaries facilitate atomic motion, causing a change in resistance.

“Because molybdenum disulfide is atomically thin, it is easily influenced by applied electric fields,” Hersam explained. “This property allows us to make a transistor. The memristor characteristics come from the fact that the defects in the material are relatively mobile, especially in the presence of grain boundaries.”

But unlike his previous memristor, which used individual, small flakes of MoS2, Hersam’s memtransistor makes use of a continuous film of polycrystalline MoS2 that comprises a large number of smaller flakes. This enabled the research team to scale up the device from one flake to many devices across an entire wafer.

“When length of the device is larger than the individual grain size, you are guaranteed to have grain boundaries in every device across the wafer,” Hersam said. “Thus, we see reproducible, gate-tunable memristive responses across large arrays of devices.”

After fabricating memtransistors uniformly across an entire wafer, Hersam’s team added additional electrical contacts. Typical transistors and Hersam’s previously developed memristor each have three terminals. In their new paper, however, the team realized a seven-terminal device, in which one terminal controls the current among the other six terminals.

“This is even more similar to neurons in the brain,” Hersam said, “because in the brain, we don’t usually have one neuron connected to only one other neuron. Instead, one neuron is connected to multiple other neurons to form a network. Our device structure allows multiple contacts, which is similar to the multiple synapses in neurons.”

Next, Hersam and his team are working to make the memtransistor faster and smaller. Hersam also plans to continue scaling up the device for manufacturing purposes.

“We believe that the memtransistor can be a foundational circuit element for new forms of neuromorphic computing,” he said. “However, making dozens of devices, as we have done in our paper, is different than making a billion, which is done with conventional transistor technology today. Thus far, we do not see any fundamental barriers that will prevent further scale up of our approach.”

The researchers have made this illustration available,

Caption: This is the memtransistor symbol overlaid on an artistic rendering of a hypothetical circuit layout in the shape of a brain. Credit; Hersam Research Group

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

Multi-terminal memtransistors from polycrystalline monolayer molybdenum disulfide by Vinod K. Sangwan, Hong-Sub Lee, Hadallia Bergeron, Itamar Balla, Megan E. Beck, Kan-Sheng Chen, & Mark C. Hersam. Nature volume 554, pages 500–504 (22 February 2018 doi:10.1038/nature25747 Published online: 21 February 2018

This paper is behind a paywall.

The team’s earlier work referenced in the news release was featured here in an April 10, 2015 posting.

Dexter Johnson

From a Feb. 23, 2018 posting by Dexter Johnson on the Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers] website),

While this all seems promising, one of the big shortcomings in neuromorphic computing has been that it doesn’t mimic the brain in a very important way. In the brain, for every neuron there are a thousand synapses—the electrical signal sent between the neurons of the brain. This poses a problem because a transistor only has a single terminal, hardly an accommodating architecture for multiplying signals.

Now researchers at Northwestern University, led by Mark Hersam, have developed a new device that combines memristors—two-terminal non-volatile memory devices based on resistance switching—with transistors to create what Hersam and his colleagues have dubbed a “memtransistor” that performs both memory storage and information processing.

This most recent research builds on work that Hersam and his team conducted back in 2015 in which the researchers developed a three-terminal, gate-tunable memristor that operated like a kind of synapse.

While this work was recognized as mimicking the low-power computing of the human brain, critics didn’t really believe that it was acting like a neuron since it could only transmit a signal from one artificial neuron to another. This was far short of a human brain that is capable of making tens of thousands of such connections.

“Traditional memristors are two-terminal devices, whereas our memtransistors combine the non-volatility of a two-terminal memristor with the gate-tunability of a three-terminal transistor,” said Hersam to IEEE Spectrum. “Our device design accommodates additional terminals, which mimic the multiple synapses in neurons.”

Hersam believes that these unique attributes of these multi-terminal memtransistors are likely to present a range of new opportunities for non-volatile memory and neuromorphic computing.

If you have the time and the interest, Dexter’s post provides more context,

How small can a carbon nanotube get before it stops being ‘electrical’?

Research, which began as an attempt to get reproducible electronics (?) measurements, yielded some unexpected results according ta January 3, 2018 news item on phys.org,

Carbon nanotubes bound for electronics not only need to be as clean as possible to maximize their utility in next-generation nanoscale devices, but contact effects may limit how small a nano device can be, according to researchers at the Energy Safety Research Institute (ESRI) at Swansea University [UK] in collaboration with researchers at Rice University [US].

ESRI Director Andrew Barron, also a professor at Rice University in the USA, and his team have figured out how to get nanotubes clean enough to obtain reproducible electronic measurements and in the process not only explained why the electrical properties of nanotubes have historically been so difficult to measure consistently, but have shown that there may be a limit to how “nano” future electronic devices can be using carbon nanotubes.

Swansea University Issued a January 3, 2018 press release (also on EurekAlert), which originated the news item, explains the work in more detail,

Like any normal wire, semiconducting nanotubes are progressively more resistant to current along their length. But conductivity measurements of nanotubes over the years have been anything but consistent. The ESRI team wanted to know why.

“We are interested in the creation of nanotube based conductors, and while people have been able to make wires their conduction has not met expectations. We were interested in determining the basic sconce behind the variability observed by other researchers.”

They discovered that hard-to-remove contaminants — leftover iron catalyst, carbon and water — could easily skew the results of conductivity tests. Burning them away, Barron said, creates new possibilities for carbon nanotubes in nanoscale electronics.

The new study appears in the American Chemical Society journal Nano Letters.

The researchers first made multiwalled carbon nanotubes between 40 and 200 nanometers in diameter and up to 30 microns long. They then either heated the nanotubes in a vacuum or bombarded them with argon ions to clean their surfaces.

They tested individual nanotubes the same way one would test any electrical conductor: By touching them with two probes to see how much current passes through the material from one tip to the other. In this case, their tungsten probes were attached to a scanning tunneling microscope.

In clean nanotubes, resistance got progressively stronger as the distance increased, as it should. But the results were skewed when the probes encountered surface contaminants, which increased the electric field strength at the tip. And when measurements were taken within 4 microns of each other, regions of depleted conductivity caused by contaminants overlapped, further scrambling the results.

“We think this is why there’s such inconsistency in the literature,” Barron said.

“If nanotubes are to be the next generation lightweight conductor, then consistent results, batch-to-batch, and sample-to-sample, is needed for devices such as motors and generators as well as power systems.”

Annealing the nanotubes in a vacuum above 200 degrees Celsius (392 degrees Fahrenheit) reduced surface contamination, but not enough to eliminate inconsistent results, they found. Argon ion bombardment also cleaned the tubes, but led to an increase in defects that degrade conductivity.

Ultimately they discovered vacuum annealing nanotubes at 500 degrees Celsius (932 Fahrenheit) reduced contamination enough to accurately measure resistance, they reported.

To now, Barron said, engineers who use nanotube fibers or films in devices modify the material through doping or other means to get the conductive properties they require. But if the source nanotubes are sufficiently decontaminated, they should be able to get the right conductivity by simply putting their contacts in the right spot.

“A key result of our work was that if contacts on a nanotube are less than 1 micron apart, the electronic properties of the nanotube changes from conductor to semiconductor, due to the presence of overlapping depletion zones” said Barron, “this has a potential limiting factor on the size of nanotube based electronic devices – this would limit the application of Moore’s law to nanotube devices.”

Chris Barnett of Swansea is lead author of the paper. Co-authors are Cathren Gowenlock and Kathryn Welsby, and Rice alumnus Alvin Orbaek White of Swansea. Barron is the Sêr Cymru Chair of Low Carbon Energy and Environment at Swansea and the Charles W. Duncan Jr.–Welch Professor of Chemistry and a professor of materials science and nanoengineering at Rice.

The Welsh Government Sêr Cymru National Research Network in Advanced Engineering and Materials, the Sêr Cymru Chair Program, the Office of Naval Research and the Robert A. Welch Foundation supported the research.

Rice University has published a January 4, 2018 Rice University news release (also on EurekAlert), which is almost (95%) identical to the press release from Swansea. That’s a bit unusual as collaborating institutions usually like to focus on their unique contributions to the research, hence, multiple news/press releases.

Dexter Johnson, in a January 11, 2018 post on his Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers] website,  adds a detail or two while writing in an accessible style.

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

Spatial and Contamination-Dependent Electrical Properties of Carbon Nanotubes by Chris J. Barnett, Cathren E. Gowenlock, Kathryn Welsby, Alvin Orbaek White, and Andrew R. Barron. Nano Lett., Article ASAP DOI: 10.1021/acs.nanolett.7b03390 Publication Date (Web): December 19, 2017

Copyright © 2017 American Chemical Society

This paper is behind a paywall.

Canada’s ‘Smart Cities’ will need new technology (5G wireless) and, maybe, graphene

I recently published [March 20, 2018] a piece on ‘smart cities’ both an art/science event in Toronto and a Canadian government initiative without mentioning the necessity of new technology to support all of the grand plans. On that note, it seems the Canadian federal government and two provincial (Québec and Ontario) governments are prepared to invest in one of the necessary ‘new’ technologies, 5G wireless. The Canadian Broadcasting Corporation’s (CBC) Shawn Benjamin reports about Canada’s 5G plans in suitably breathless (even in text only) tones of excitement in a March 19, 2018 article,

The federal, Ontario and Quebec governments say they will spend $200 million to help fund research into 5G wireless technology, the next-generation networks with download speeds 100 times faster than current ones can handle.

The so-called “5G corridor,” known as ENCQOR, will see tech companies such as Ericsson, Ciena Canada, Thales Canada, IBM and CGI kick in another $200 million to develop facilities to get the project up and running.

The idea is to set up a network of linked research facilities and laboratories that these companies — and as many as 1,000 more across Canada — will be able to use to test products and services that run on 5G networks.

Benjamin’s description of 5G is focused on what it will make possible in the future,

If you think things are moving too fast, buckle up, because a new 5G cellular network is just around the corner and it promises to transform our lives by connecting nearly everything to a new, much faster, reliable wireless network.

The first networks won’t be operational for at least a few years, but technology and telecom companies around the world are already planning to spend billions to make sure they aren’t left behind, says Lawrence Surtees, a communications analyst with the research firm IDC.

The new 5G is no tentative baby step toward the future. Rather, as Surtees puts it, “the move from 4G to 5G is a quantum leap.”

In a downtown Toronto soundstage, Alan Smithson recently demonstrated a few virtual reality and augmented reality projects that his company MetaVRse is working on.

The potential for VR and AR technology is endless, he said, in large part for its potential to help hurdle some of the walls we are already seeing with current networks.

Virtual Reality technology on the market today is continually increasing things like frame rates and screen resolutions in a constant quest to make their devices even more lifelike.

… They [current 4G networks] can’t handle the load. But 5G can do so easily, Smithson said, so much so that the current era of bulky augmented reality headsets could be replaced buy a pair of normal looking glasses.

In a 5G world, those internet-connected glasses will automatically recognize everyone you meet, and possibly be able to overlay their name in your field of vision, along with a link to their online profile. …

Benjamin also mentions ‘smart cities’,

In a University of Toronto laboratory, Professor Alberto Leon-Garcia researches connected vehicles and smart power grids. “My passion right now is enabling smart cities — making smart cities a reality — and that means having much more immediate and detailed sense of the environment,” he said.

Faster 5G networks will assist his projects in many ways, by giving planners more, instant data on things like traffic patterns, energy consumption, variou carbon footprints and much more.

Leon-Garcia points to a brightly lit map of Toronto [image embedded in Benjamin’s article] in his office, and explains that every dot of light represents a sensor transmitting real time data.

Currently, the network is hooked up to things like city buses, traffic cameras and the city-owned fleet of shared bicycles. He currently has thousands of data points feeding him info on his map, but in a 5G world, the network will support about a million sensors per square kilometre.

Very exciting but where is all this data going? What computers will be processing the information? Where are these sensors located? Benjamin does not venture into those waters nor does The Economist in a February 13, 2018 article about 5G, the Olympic Games in Pyeonchang, South Korea, but the magazine does note another barrier to 5G implementation,

“FASTER, higher, stronger,” goes the Olympic motto. So it is only appropriate that the next generation of wireless technology, “5G” for short, should get its first showcase at the Winter Olympics  under way in Pyeongchang, South Korea. Once fully developed, it is supposed to offer download speeds of at least 20 gigabits per second (4G manages about half that at best) and response times (“latency”) of below 1 millisecond. So the new networks will be able to transfer a high-resolution movie in two seconds and respond to requests in less than a hundredth of the time it takes to blink an eye. But 5G is not just about faster and swifter wireless connections.

The technology is meant to enable all sorts of new services. One such would offer virtual- or augmented-reality experiences. At the Olympics, for example, many contestants are being followed by 360-degree video cameras. At special venues sports fans can don virtual-reality goggles to put themselves right into the action. But 5G is also supposed to become the connective tissue for the internet of things, to link anything from smartphones to wireless sensors and industrial robots to self-driving cars. This will be made possible by a technique called “network slicing”, which allows operators quickly to create bespoke networks that give each set of devices exactly the connectivity they need.

Despite its versatility, it is not clear how quickly 5G will take off. The biggest brake will be economic. [emphasis mine] When the GSMA, an industry group, last year asked 750 telecoms bosses about the most salient impediment to delivering 5G, more than half cited the lack of a clear business case. People may want more bandwidth, but they are not willing to pay for it—an attitude even the lure of the fanciest virtual-reality applications may not change. …

That may not be the only brake, Dexter Johnson in a March 19, 2018 posting on his Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers] website), covers some of the others (Note: Links have been removed),

Graphene has been heralded as a “wonder material” for well over a decade now, and 5G has been marketed as the next big thing for at least the past five years. Analysts have suggested that 5G could be the golden ticket to virtual reality and artificial intelligence, and promised that graphene could improve technologies within electronics and optoelectronics.

But proponents of both graphene and 5G have also been accused of stirring up hype. There now seems to be a rising sense within industry circles that these glowing technological prospects will not come anytime soon.

At Mobile World Congress (MWC) in Barcelona last month [February 2018], some misgivings for these long promised technologies may have been put to rest, though, thanks in large part to each other.

In a meeting at MWC with Jari Kinaret, a professor at Chalmers University in Sweden and director of the Graphene Flagship, I took a guided tour around the Pavilion to see some of the technologies poised to have an impact on the development of 5G.

Being invited back to the MWC for three years is a pretty clear indication of how important graphene is to those who are trying to raise the fortunes of 5G. But just how important became more obvious to me in an interview with Frank Koppens, the leader of the quantum nano-optoelectronic group at Institute of Photonic Sciences (ICFO) just outside of Barcelona, last year.

He said: “5G cannot just scale. Some new technology is needed. And that’s why we have several companies in the Graphene Flagship that are putting a lot of pressure on us to address this issue.”

In a collaboration led by CNIT—a consortium of Italian universities and national laboratories focused on communication technologies—researchers from AMO GmbH, Ericsson, Nokia Bell Labs, and Imec have developed graphene-based photodetectors and modulators capable of receiving and transmitting optical data faster than ever before.

The aim of all this speed for transmitting data is to support the ultrafast data streams with extreme bandwidth that will be part of 5G. In fact, at another section during MWC, Ericsson was presenting the switching of a 100 Gigabits per second (Gbps) channel based on the technology.

“The fact that Ericsson is demonstrating another version of this technology demonstrates that from Ericsson’s point of view, this is no longer just research” said Kinaret.

It’s no mystery why the big mobile companies are jumping on this technology. Not only does it provide high-speed data transmission, but it also does it 10 times more efficiently than silicon or doped silicon devices, and will eventually do it more cheaply than those devices, according to Vito Sorianello, senior researcher at CNIT.

Interestingly, Ericsson is one of the tech companies mentioned with regard to Canada’s 5G project, ENCQOR and Sweden’s Chalmers University, as Dexter Johnson notes, is the lead institution for the Graphene Flagship.. One other fact to note, Canada’s resources include graphite mines with ‘premium’ flakes for producing graphene. Canada’s graphite mines are located (as far as I know) in only two Canadian provinces, Ontario and Québec, which also happen to be pitching money into ENCQOR. My March 21, 2018 posting describes the latest entry into the Canadian graphite mining stakes.

As for the questions I posed about processing power, etc. It seems the South Koreans have found answers of some kind but it’s hard to evaluate as I haven’t found any additional information about 5G and its implementation in South Korea. If anyone has answers, please feel free to leave them in the ‘comments’. Thank you.

FrogHeart’s good-bye to 2017 and hello to 2018

This is going to be relatively short and sweet(ish). Starting with the 2017 review:

Nano blogosphere and the Canadian blogosphere

From my perspective there’s been a change taking place in the nano blogosphere over the last few years. There are fewer blogs along with fewer postings from those who still blog. Interestingly, some blogs are becoming more generalized. At the same time, Foresight Institute’s Nanodot blog (as has FrogHeart) has expanded its range of topics to include artificial intelligence and other topics. Andrew Maynard’s 2020 Science blog now exists in an archived from but before its demise, it, too, had started to include other topics, notably risk in its many forms as opposed to risk and nanomaterials. Dexter Johnson’s blog, Nanoclast (on the IEEE [Institute for Electrical and Electronics Engineers] website), maintains its 3x weekly postings. Tim Harper who often wrote about nanotechnology on his Cientifica blog appears to have found a more freewheeling approach that is dominated by his Twitter feed although he also seems (I can’t confirm that the latest posts were written in 2017) to blog here on timharper.net.

The Canadian science blogosphere seems to be getting quieter if Science Borealis (blog aggregator) is a measure. My overall impression is that the bloggers have been a bit quieter this year with fewer postings on the feed or perhaps that’s due to some technical issues (sometimes FrogHeart posts do not get onto the feed). On the promising side, Science Borealis teamed with the Science Writers and Communicators of Canada Association to run a contest, “2017 People’s Choice Awards: Canada’s Favourite Science Online!”  There were two categories (Favourite Science Blog and Favourite Science Site) and you can find a list of the finalists with links to the winners here.

Big congratulations for the winners: Canada’s Favourite Blog 2017: Body of Evidence (Dec. 6, 2017 article by Alina Fisher for Science Borealis) and Let’s Talk Science won Canada’s Favourite Science Online 2017 category as per this announcement.

However, I can’t help wondering: where were ASAP Science, Acapella Science, Quirks & Quarks, IFLS (I f***ing love science), and others on the list for finalists? I would have thought any of these would have a lock on a position as a finalist. These are Canadian online science purveyors and they are hugely popular, which should mean they’d have no problem getting nominated and getting votes. I can’t find the criteria for nominations (or any hint there will be a 2018 contest) so I imagine their nonpresence on the 2017 finalists list will remain a mystery to me.

Looking forward to 2018, I think that the nano blogosphere will continue with its transformation into a more general science/technology-oriented community. To some extent, I believe this reflects the fact that nanotechnology is being absorbed into the larger science/technology effort as foundational (something wiser folks than me predicted some years ago).

As for Science Borealis and the Canadian science online effort, I’m going to interpret the quieter feeds as a sign of a maturing community. After all, there are always ups and downs in terms of enthusiasm and participation and as I noted earlier the launch of an online contest is promising as is the collaboration with Science Writers and Communicators of Canada.

Canadian science policy

It was a big year.

Canada’s Chief Science Advisor

With Canada’s first chief science advisor in many years, being announced Dr. Mona Nemer stepped into her position sometime in Fall 2017. The official announcement was made on Sept. 26, 2017. I covered the event in my Sept. 26, 2017 posting, which includes a few more details than found the official announcement.

You’ll also find in that Sept. 26, 2017 posting a brief discourse on the Naylor report (also known as the Review of Fundamental Science) and some speculation on why, to my knowledge, there has been no action taken as a consequence.  The Naylor report was released April 10, 2017 and was covered here in a three-part review, published on June 8, 2017,

INVESTING IN CANADA’S FUTURE; Strengthening the Foundations of Canadian Research (Review of fundamental research final report): 1 of 3

INVESTING IN CANADA’S FUTURE; Strengthening the Foundations of Canadian Research (Review of fundamental research final report): 2 of 3

INVESTING IN CANADA’S FUTURE; Strengthening the Foundations of Canadian Research (Review of fundamental research final report): 3 of 3

I have found another commentary (much briefer than mine) by Paul Dufour on the Canadian Science Policy Centre website. (November 9, 2017)

Subnational and regional science funding

This began in 2016 with a workshop mentioned in my November 10, 2016 posting: ‘Council of Canadian Academies and science policy for Alberta.” By the time the report was published the endeavour had been transformed into: Science Policy: Considerations for Subnational Governments (report here and my June 22, 2017 commentary here).

I don’t know what will come of this but I imagine scientists will be supportive as it means more money and they are always looking for more money. Still, the new government in British Columbia has only one ‘science entity’ and I’m not sure it’s still operational but i was called the Premier’s Technology Council. To my knowledge, there is no ministry or other agency that is focused primarily or partially on science.

Meanwhile, a couple of representatives from the health sciences (neither of whom were involved in the production of the report) seem quite enthused about the prospects for provincial money in their (Bev Holmes, Interim CEO, Michael Smith Foundation for Health Research, British Columbia, and Patrick Odnokon (CEO, Saskatchewan Health Research Foundation) October 27, 2017 opinion piece for the Canadian Science Policy Centre.

Artificial intelligence and Canadians

An event which I find more interesting with time was the announcement of the Pan=Canadian Artificial Intelligence Strategy in the 2017 Canadian federal budget. Since then there has been a veritable gold rush mentality with regard to artificial intelligence in Canada. One announcement after the next about various corporations opening new offices in Toronto or Montréal has been made in the months since.

What has really piqued my interest recently is a report being written for Canada’s Treasury Board by Michael Karlin (you can learn more from his Twitter feed although you may need to scroll down past some of his more personal tweets (something cassoulet in the Dec. 29, 2017 tweets).  As for Karlin’s report, which is a work in progress, you can find out more about the report and Karlin in a December 12, 2017 article by Rob Hunt for the Algorithmic Media Observatory (sponsored by the Social Sciences and Humanities Research Council of Canada [SHRCC], the Centre for Study of Democratic Citizenship, and the Fonds de recherche du Québec: Société et culture).

You can ring in 2018 by reading and making comments, which could influence the final version, on Karlin’s “Responsible Artificial Intelligence in the Government of Canada” part of the government’s Digital Disruption White Paper Series.

As for other 2018 news, the Council of Canadian Academies is expected to publish “The State of Science and Technology and Industrial Research and Development in Canada” at some point soon (we hope). This report follows and incorporates two previous ‘states’, The State of Science and Technology in Canada, 2012 (the first of these was a 2006 report) and the 2013 version of The State of Industrial R&D in Canada. There is already some preliminary data for this latest ‘state of’  (you can find a link and commentary in my December 15, 2016 posting).

FrogHeart then (2017) and soon (2018)

On looking back I see that the year started out at quite a clip as I was attempting to hit the 5000th blog posting mark, which I did on March 3,  2017. I have cut back somewhat from the 3 postings/day high to approximately 1 posting/day. It makes things more manageable allowing me to focus on other matters.

By the way, you may note that the ‘Donate’ button has disappeared from my sidebard. I thank everyone who donated from the bottom of my heart. The money was more than currency, it also symbolized encouragement. On the sad side, I moved from one hosting service to a new one (Sibername) late in December 2016 and have been experiencing serious bandwidth issues which result on FrogHeart’s disappearance from the web for days at a time. I am trying to resolve the issues and hope that such actions as removing the ‘Donate’ button will help.

I wish my readers all the best for 2018 as we explore nanotechnology and other emerging technologies!

(I apologize for any and all errors. I usually take a little more time to write this end-of-year and coming-year piece but due to bandwidth issues I was unable to access my draft and give it at least one review. And at this point, I’m too tired to try spotting error. If you see any, please do let me know.)

‘Nano-hashtags’ for Majorana particles?

The ‘nano-hashtags’ are in fact (assuming a minor leap of imagination) nanowires that resemble hashtags.

Scanning electron microscope image of the device wherein clearly a ‘hashtag’ is formed. Credit: Eindhoven University of Technology

An August 23, 2017 news item on ScienceDaily makes the announcement,

In Nature, an international team of researchers from Eindhoven University of Technology [Netherlands], Delft University of Technology [Netherlands] and the University of California — Santa Barbara presents an advanced quantum chip that will be able to provide definitive proof of the mysterious Majorana particles. These particles, first demonstrated in 2012, are their own antiparticle at one and the same time. The chip, which comprises ultrathin networks of nanowires in the shape of ‘hashtags’, has all the qualities to allow Majorana particles to exchange places. This feature is regarded as the smoking gun for proving their existence and is a crucial step towards their use as a building block for future quantum computers.

An August 23, 2017 Eindhoven University press release (also on EurekAlert), which originated the news item, provides some context and information about the work,

In 2012 it was big news: researchers from Delft University of Technology and Eindhoven University of Technology presented the first experimental signatures for the existence of the Majorana fermion. This particle had been predicted in 1937 by the Italian physicist Ettore Majorana and has the distinctive property of also being its own anti-particle. The Majorana particles emerge at the ends of a semiconductor wire, when in contact with a superconductor material.

Smoking gun

While the discovered particles may have properties typical to Majoranas, the most exciting proof could be obtained by allowing two Majorana particles to exchange places, or ‘braid’ as it is scientifically known. “That’s the smoking gun,” suggests Erik Bakkers, one of the researchers from Eindhoven University of Technology. “The behavior we then see could be the most conclusive evidence yet of Majoranas.”

Crossroads

In the Nature paper that is published today [August 23, 2017], Bakkers and his colleagues present a new device that should be able to show this exchanging of Majoranas. In the original experiment in 2012 two Majorana particles were found in a single wire but they were not able to pass each other without immediately destroying the other. Thus the researchers quite literally had to create space. In the presented experiment they formed intersections using the same kinds of nanowire so that four of these intersections form a ‘hashtag’, #, and thus create a closed circuit along which Majoranas are able to move.

Etch and grow

The researchers built their hashtag device starting from scratch. The nanowires are grown from a specially etched substrate such that they form exactly the desired network which they then expose to a stream of aluminium particles, creating layers of aluminium, a superconductor, on specific spots on the wires – the contacts where the Majorana particles emerge. Places that lie ‘in the shadow’ of other wires stay uncovered.

Leap in quality

The entire process happens in a vacuum and at ultra-cold temperature (around -273 degree Celsius). “This ensures very clean, pure contacts,” says Bakkers, “and enables us to make a considerable leap in the quality of this kind of quantum device.” The measurements demonstrate for a number of electronic and magnetic properties that all the ingredients are present for the Majoranas to braid.

Quantum computers

If the researchers succeed in enabling the Majorana particles to braid, they will at once have killed two birds with one stone. Given their robustness, Majoranas are regarded as the ideal building block for future quantum computers that will be able to perform many calculations simultaneously and thus many times faster than current computers. The braiding of two Majorana particles could form the basis for a qubit, the calculation unit of these computers.

Travel around the world

An interesting detail is that the samples have traveled around the world during the fabrication, combining unique and synergetic activities of each research institution. It started in Delft with patterning and etching the substrate, then to Eindhoven for nanowire growth and to Santa Barbara for aluminium contact formation. Finally back to Delft via Eindhoven for the measurements.

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

Epitaxy of advanced nanowire quantum devices by Sasa Gazibegovic, Diana Car, Hao Zhang, Stijn C. Balk, John A. Logan, Michiel W. A. de Moor, Maja C. Cassidy, Rudi Schmits, Di Xu, Guanzhong Wang, Peter Krogstrup, Roy L. M. Op het Veld, Kun Zuo, Yoram Vos, Jie Shen, Daniël Bouman, Borzoyeh Shojaei, Daniel Pennachio, Joon Sue Lee, Petrus J. van Veldhoven, Sebastian Koelling, Marcel A. Verheijen, Leo P. Kouwenhoven, Chris J. Palmstrøm, & Erik P. A. M. Bakkers. Nature 548, 434–438 (24 August 2017) doi:10.1038/nature23468 Published online 23 August 2017

This paper is behind a paywall.

Dexter Johnson has some additional insight (interview with one of the researchers) in an Aug. 29, 2017 posting on his Nanoclast blog (on the IEEE [institute of Electrical and Electronics Engineers] website).

Yarns that harvest and generate energy

The researchers involved in this work are confident enough about their prospects that they will be  patenting their research into yarns. From an August 25, 2017 news item on Nanowerk,

An international research team led by scientists at The University of Texas at Dallas and Hanyang University in South Korea has developed high-tech yarns that generate electricity when they are stretched or twisted.

In a study published in the Aug. 25 [2017] issue of the journal Science (“Harvesting electrical energy from carbon nanotube yarn twist”), researchers describe “twistron” yarns and their possible applications, such as harvesting energy from the motion of ocean waves or from temperature fluctuations. When sewn into a shirt, these yarns served as a self-powered breathing monitor.

“The easiest way to think of twistron harvesters is, you have a piece of yarn, you stretch it, and out comes electricity,” said Dr. Carter Haines, associate research professor in the Alan G. MacDiarmid NanoTech Institute at UT Dallas and co-lead author of the article. The article also includes researchers from South Korea, Virginia Tech, Wright-Patterson Air Force Base and China.

An August 25, 2017 University of Texas at Dallas news release, which originated the news item, expands on the theme,

Yarns Based on Nanotechnology

The yarns are constructed from carbon nanotubes, which are hollow cylinders of carbon 10,000 times smaller in diameter than a human hair. The researchers first twist-spun the nanotubes into high-strength, lightweight yarns. To make the yarns highly elastic, they introduced so much twist that the yarns coiled like an over-twisted rubber band.

In order to generate electricity, the yarns must be either submerged in or coated with an ionically conducting material, or electrolyte, which can be as simple as a mixture of ordinary table salt and water.

“Fundamentally, these yarns are supercapacitors,” said Dr. Na Li, a research scientist at the NanoTech Institute and co-lead author of the study. “In a normal capacitor, you use energy — like from a battery — to add charges to the capacitor. But in our case, when you insert the carbon nanotube yarn into an electrolyte bath, the yarns are charged by the electrolyte itself. No external battery, or voltage, is needed.”

When a harvester yarn is twisted or stretched, the volume of the carbon nanotube yarn decreases, bringing the electric charges on the yarn closer together and increasing their energy, Haines said. This increases the voltage associated with the charge stored in the yarn, enabling the harvesting of electricity.

Stretching the coiled twistron yarns 30 times a second generated 250 watts per kilogram of peak electrical power when normalized to the harvester’s weight, said Dr. Ray Baughman, director of the NanoTech Institute and a corresponding author of the study.

“Although numerous alternative harvesters have been investigated for many decades, no other reported harvester provides such high electrical power or energy output per cycle as ours for stretching rates between a few cycles per second and 600 cycles per second.”

Lab Tests Show Potential Applications

In the lab, the researchers showed that a twistron yarn weighing less than a housefly could power a small LED, which lit up each time the yarn was stretched.

To show that twistrons can harvest waste thermal energy from the environment, Li connected a twistron yarn to a polymer artificial muscle that contracts and expands when heated and cooled. The twistron harvester converted the mechanical energy generated by the polymer muscle to electrical energy.

“There is a lot of interest in using waste energy to power the Internet of Things, such as arrays of distributed sensors,” Li said. “Twistron technology might be exploited for such applications where changing batteries is impractical.”

The researchers also sewed twistron harvesters into a shirt. Normal breathing stretched the yarn and generated an electrical signal, demonstrating its potential as a self-powered respiration sensor.

“Electronic textiles are of major commercial interest, but how are you going to power them?” Baughman said. “Harvesting electrical energy from human motion is one strategy for eliminating the need for batteries. Our yarns produced over a hundred times higher electrical power per weight when stretched compared to other weavable fibers reported in the literature.”

Electricity from Ocean Waves

“In the lab we showed that our energy harvesters worked using a solution of table salt as the electrolyte,” said Baughman, who holds the Robert A. Welch Distinguished Chair in Chemistry in the School of Natural Sciences and Mathematics. “But we wanted to show that they would also work in ocean water, which is chemically more complex.”

In a proof-of-concept demonstration, co-lead author Dr. Shi Hyeong Kim, a postdoctoral researcher at the NanoTech Institute, waded into the frigid surf off the east coast of South Korea to deploy a coiled twistron in the sea. He attached a 10 centimeter-long yarn, weighing only 1 milligram (about the weight of a mosquito), between a balloon and a sinker that rested on the seabed.

Every time an ocean wave arrived, the balloon would rise, stretching the yarn up to 25 percent, thereby generating measured electricity.

Even though the investigators used very small amounts of twistron yarn in the current study, they have shown that harvester performance is scalable, both by increasing twistron diameter and by operating many yarns in parallel.

“If our twistron harvesters could be made less expensively, they might ultimately be able to harvest the enormous amount of energy available from ocean waves,” Baughman said. “However, at present these harvesters are most suitable for powering sensors and sensor communications. Based on demonstrated average power output, just 31 milligrams of carbon nanotube yarn harvester could provide the electrical energy needed to transmit a 2-kilobyte packet of data over a 100-meter radius every 10 seconds for the Internet of Things.”

Researchers from the UT Dallas Erik Jonsson School of Engineering and Computer Science and Lintec of America’s Nano-Science & Technology Center also participated in the study.

The investigators have filed a patent on the technology.

In the U.S., the research was funded by the Air Force, the Air Force Office of Scientific Research, NASA, the Office of Naval Research and the Robert A. Welch Foundation. In Korea, the research was supported by the Korea-U.S. Air Force Cooperation Program and the Creative Research Initiative Center for Self-powered Actuation of the National Research Foundation and the Ministry of Science.

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

Harvesting electrical energy from carbon nanotube yarn twist by Shi Hyeong Kim, Carter S. Haines, Na Li, Keon Jung Kim, Tae Jin Mun, Changsoon Choi, Jiangtao Di, Young Jun Oh, Juan Pablo Oviedo, Julia Bykova, Shaoli Fang, Nan Jiang, Zunfeng Liu, Run Wang, Prashant Kumar, Rui Qiao, Shashank Priya, Kyeongjae Cho, Moon Kim, Matthew Steven Lucas, Lawrence F. Drummy, Benji Maruyama, Dong Youn Lee, Xavier Lepró, Enlai Gao, Dawood Albarq, Raquel Ovalle-Robles, Seon Jeong Kim, Ray H. Baughman. Science 25 Aug 2017: Vol. 357, Issue 6353, pp. 773-778 DOI: 10.1126/science.aam8771

This paper is behind a paywall.

Dexter Johnson in an Aug. 25, 2017 posting on his Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers] website) delves further into the research,

“Basically what’s happening is when we stretch the yarn, we’re getting a change in capacitance of the yarn. It’s that change that allows us to get energy out,” explains Carter Haines, associate research professor at UT Dallas and co-lead author of the paper describing the research, in an interview with IEEE Spectrum.

This makes it similar in many ways to other types of energy harvesters. For instance, in other research, it has been demonstrated—with sheets of rubber with coated electrodes on both sides—that you can increase the capacitance of a material when you stretch it and it becomes thinner. As a result, if you have charge on that capacitor, you can change the voltage associated with that charge.

“We’re more or less exploiting the same effect but what we’re doing differently is we’re using an electric chemical cell to do this,” says Haines. “So we’re not changing double layer capacitance in normal parallel plate capacitors. But we’re actually changing the electric chemical capacitance on the surface of a super capacitor yarn.”

While there are other capacitance-based energy harvesters, those other devices require extremely high voltages to work because they’re using parallel plate capacitors, according to Haines.

Dexter asks good questions and his post is very informative.

Cyborg bacteria to reduce carbon dioxide

This video is a bit technical but then it is about work being presented to chemists at the American Chemical Society’s (ACS) at the 254th National Meeting & Exposition Aug. 20 -24, 2017,

For a more plain language explanation, there’s an August 22, 2017 ACS news release (also on EurekAlert),

Photosynthesis provides energy for the vast majority of life on Earth. But chlorophyll, the green pigment that plants use to harvest sunlight, is relatively inefficient. To enable humans to capture more of the sun’s energy than natural photosynthesis can, scientists have taught bacteria to cover themselves in tiny, highly efficient solar panels to produce useful compounds.

“Rather than rely on inefficient chlorophyll to harvest sunlight, I’ve taught bacteria how to grow and cover their bodies with tiny semiconductor nanocrystals,” says Kelsey K. Sakimoto, Ph.D., who carried out the research in the lab of Peidong Yang, Ph.D. “These nanocrystals are much more efficient than chlorophyll and can be grown at a fraction of the cost of manufactured solar panels.”

Humans increasingly are looking to find alternatives to fossil fuels as sources of energy and feedstocks for chemical production. Many scientists have worked to create artificial photosynthetic systems to generate renewable energy and simple organic chemicals using sunlight. Progress has been made, but the systems are not efficient enough for commercial production of fuels and feedstocks.

Research in Yang’s lab at the University of California, Berkeley, where Sakimoto earned his Ph.D., focuses on harnessing inorganic semiconductors that can capture sunlight to organisms such as bacteria that can then use the energy to produce useful chemicals from carbon dioxide and water. “The thrust of research in my lab is to essentially ‘supercharge’ nonphotosynthetic bacteria by providing them energy in the form of electrons from inorganic semiconductors, like cadmium sulfide, that are efficient light absorbers,” Yang says. “We are now looking for more benign light absorbers than cadmium sulfide to provide bacteria with energy from light.”

Sakimoto worked with a naturally occurring, nonphotosynthetic bacterium, Moorella thermoacetica, which, as part of its normal respiration, produces acetic acid from carbon dioxide (CO2). Acetic acid is a versatile chemical that can be readily upgraded to a number of fuels, polymers, pharmaceuticals and commodity chemicals through complementary, genetically engineered bacteria.

When Sakimoto fed cadmium and the amino acid cysteine, which contains a sulfur atom, to the bacteria, they synthesized cadmium sulfide (CdS) nanoparticles, which function as solar panels on their surfaces. The hybrid organism, M. thermoacetica-CdS, produces acetic acid from CO2, water and light. “Once covered with these tiny solar panels, the bacteria can synthesize food, fuels and plastics, all using solar energy,” Sakimoto says. “These bacteria outperform natural photosynthesis.”

The bacteria operate at an efficiency of more than 80 percent, and the process is self-replicating and self-regenerating, making this a zero-waste technology. “Synthetic biology and the ability to expand the product scope of CO2 reduction will be crucial to poising this technology as a replacement, or one of many replacements, for the petrochemical industry,” Sakimoto says.

So, do the inorganic-biological hybrids have commercial potential? “I sure hope so!” he says. “Many current systems in artificial photosynthesis require solid electrodes, which is a huge cost. Our algal biofuels are much more attractive, as the whole CO2-to-chemical apparatus is self-contained and only requires a big vat out in the sun.” But he points out that the system still requires some tweaking to tune both the semiconductor and the bacteria. He also suggests that it is possible that the hybrid bacteria he created may have some naturally occurring analog. “A future direction, if this phenomenon exists in nature, would be to bioprospect for these organisms and put them to use,” he says.

For more insight into the work, check out Dexter Johnson’s Aug. 22, 2017 posting on his Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers] website),

“It’s actually a natural, overlooked feature of their biology,” explains Sakimoto in an e-mail interview with IEEE Spectrum. “This bacterium has a detoxification pathway, meaning if it encounters a toxic metal, like cadmium, it will try to precipitate it out, thereby detoxifying it. So when we introduce cadmium ions into the growth medium in which M. thermoacetica is hanging out, it will convert the amino acid cysteine into sulfide, which precipitates out cadmium as cadmium sulfide. The crystals then assemble and stick onto the bacterium through normal electrostatic interactions.”

I’ve just excerpted one bit, there’s more in Dexter’s posting.

Training drugs

This summarizes some of what’s happening in nanomedicine and provides a plug (boost) for the  University of Cambridge’s nanotechnology programmes (from a June 26, 2017 news item on Nanowerk),

Nanotechnology is creating new opportunities for fighting disease – from delivering drugs in smart packaging to nanobots powered by the world’s tiniest engines.

Chemotherapy benefits a great many patients but the side effects can be brutal.
When a patient is injected with an anti-cancer drug, the idea is that the molecules will seek out and destroy rogue tumour cells. However, relatively large amounts need to be administered to reach the target in high enough concentrations to be effective. As a result of this high drug concentration, healthy cells may be killed as well as cancer cells, leaving many patients weak, nauseated and vulnerable to infection.

One way that researchers are attempting to improve the safety and efficacy of drugs is to use a relatively new area of research known as nanothrapeutics to target drug delivery just to the cells that need it.

Professor Sir Mark Welland is Head of the Electrical Engineering Division at Cambridge. In recent years, his research has focused on nanotherapeutics, working in collaboration with clinicians and industry to develop better, safer drugs. He and his colleagues don’t design new drugs; instead, they design and build smart packaging for existing drugs.

The University of Cambridge has produced a video interview (referencing a 1966 movie ‘Fantastic Voyage‘ in its title)  with Sir Mark Welland,

A June 23, 2017 University of Cambridge press release, which originated the news item, delves further into the topic of nanotherapeutics (nanomedicine) and nanomachines,

Nanotherapeutics come in many different configurations, but the easiest way to think about them is as small, benign particles filled with a drug. They can be injected in the same way as a normal drug, and are carried through the bloodstream to the target organ, tissue or cell. At this point, a change in the local environment, such as pH, or the use of light or ultrasound, causes the nanoparticles to release their cargo.

Nano-sized tools are increasingly being looked at for diagnosis, drug delivery and therapy. “There are a huge number of possibilities right now, and probably more to come, which is why there’s been so much interest,” says Welland. Using clever chemistry and engineering at the nanoscale, drugs can be ‘taught’ to behave like a Trojan horse, or to hold their fire until just the right moment, or to recognise the target they’re looking for.

“We always try to use techniques that can be scaled up – we avoid using expensive chemistries or expensive equipment, and we’ve been reasonably successful in that,” he adds. “By keeping costs down and using scalable techniques, we’ve got a far better chance of making a successful treatment for patients.”

In 2014, he and collaborators demonstrated that gold nanoparticles could be used to ‘smuggle’ chemotherapy drugs into cancer cells in glioblastoma multiforme, the most common and aggressive type of brain cancer in adults, which is notoriously difficult to treat. The team engineered nanostructures containing gold and cisplatin, a conventional chemotherapy drug. A coating on the particles made them attracted to tumour cells from glioblastoma patients, so that the nanostructures bound and were absorbed into the cancer cells.

Once inside, these nanostructures were exposed to radiotherapy. This caused the gold to release electrons that damaged the cancer cell’s DNA and its overall structure, enhancing the impact of the chemotherapy drug. The process was so effective that 20 days later, the cell culture showed no evidence of any revival, suggesting that the tumour cells had been destroyed.

While the technique is still several years away from use in humans, tests have begun in mice. Welland’s group is working with MedImmune, the biologics R&D arm of pharmaceutical company AstraZeneca, to study the stability of drugs and to design ways to deliver them more effectively using nanotechnology.

“One of the great advantages of working with MedImmune is they understand precisely what the requirements are for a drug to be approved. We would shut down lines of research where we thought it was never going to get to the point of approval by the regulators,” says Welland. “It’s important to be pragmatic about it so that only the approaches with the best chance of working in patients are taken forward.”

The researchers are also targeting diseases like tuberculosis (TB). With funding from the Rosetrees Trust, Welland and postdoctoral researcher Dr Íris da luz Batalha are working with Professor Andres Floto in the Department of Medicine to improve the efficacy of TB drugs.

Their solution has been to design and develop nontoxic, biodegradable polymers that can be ‘fused’ with TB drug molecules. As polymer molecules have a long, chain-like shape, drugs can be attached along the length of the polymer backbone, meaning that very large amounts of the drug can be loaded onto each polymer molecule. The polymers are stable in the bloodstream and release the drugs they carry when they reach the target cell. Inside the cell, the pH drops, which causes the polymer to release the drug.

In fact, the polymers worked so well for TB drugs that another of Welland’s postdoctoral researchers, Dr Myriam Ouberaï, has formed a start-up company, Spirea, which is raising funding to develop the polymers for use with oncology drugs. Ouberaï is hoping to establish a collaboration with a pharma company in the next two years.

“Designing these particles, loading them with drugs and making them clever so that they release their cargo in a controlled and precise way: it’s quite a technical challenge,” adds Welland. “The main reason I’m interested in the challenge is I want to see something working in the clinic – I want to see something working in patients.”

Could nanotechnology move beyond therapeutics to a time when nanomachines keep us healthy by patrolling, monitoring and repairing the body?

Nanomachines have long been a dream of scientists and public alike. But working out how to make them move has meant they’ve remained in the realm of science fiction.

But last year, Professor Jeremy Baumberg and colleagues in Cambridge and the University of Bath developed the world’s tiniest engine – just a few billionths of a metre [nanometre] in size. It’s biocompatible, cost-effective to manufacture, fast to respond and energy efficient.

The forces exerted by these ‘ANTs’ (for ‘actuating nano-transducers’) are nearly a hundred times larger than those for any known device, motor or muscle. To make them, tiny charged particles of gold, bound together with a temperature-responsive polymer gel, are heated with a laser. As the polymer coatings expel water from the gel and collapse, a large amount of elastic energy is stored in a fraction of a second. On cooling, the particles spring apart and release energy.

The researchers hope to use this ability of ANTs to produce very large forces relative to their weight to develop three-dimensional machines that swim, have pumps that take on fluid to sense the environment and are small enough to move around our bloodstream.

Working with Cambridge Enterprise, the University’s commercialisation arm, the team in Cambridge’s Nanophotonics Centre hopes to commercialise the technology for microfluidics bio-applications. The work is funded by the Engineering and Physical Sciences Research Council and the European Research Council.

“There’s a revolution happening in personalised healthcare, and for that we need sensors not just on the outside but on the inside,” explains Baumberg, who leads an interdisciplinary Strategic Research Network and Doctoral Training Centre focused on nanoscience and nanotechnology.

“Nanoscience is driving this. We are now building technology that allows us to even imagine these futures.”

I have featured Welland and his work here before and noted his penchant for wanting to insert nanodevices into humans as per this excerpt from an April 30, 2010 posting,
Getting back to the Cambridge University video, do go and watch it on the Nanowerk site. It is fun and very informative and approximately 17 mins. I noticed that they reused part of their Nokia morph animation (last mentioned on this blog here) and offered some thoughts from Professor Mark Welland, the team leader on that project. Interestingly, Welland was talking about yet another possibility. (Sometimes I think nano goes too far!) He was suggesting that we could have chips/devices in our brains that would allow us to think about phoning someone and an immediate connection would be made to that person. Bluntly—no. Just think what would happen if the marketers got access and I don’t even want to think what a person who suffers psychotic breaks (i.e., hearing voices) would do with even more input. Welland starts to talk at the 11 minute mark (I think). For an alternative take on the video and more details, visit Dexter Johnson’s blog, Nanoclast, for this posting. Hint, he likes the idea of a phone in the brain much better than I do.

I’m not sure what could have occasioned this latest press release and related video featuring Welland and nanotherapeutics other than guessing that it was a slow news period.