Tag Archives: Russia

Canadian researchers develop bone implant material from cellulose nanocrystals (CNC) while Russian scientists restore internal structure of bone with polycaprolactone nanofibers

Two research groups are working to the same end where bone marrow is concerned, encourage bone cell growth, but they are using different strategies.

University of British Columbia and McMaster University (Canada)

Caption: Researchers treated nanocrystals derived from plant cellulose so that they can link up and form a strong but lightweight sponge (an aerogel) that can compress or expand as needed to completely fill out a bone cavity. Credit: Clare Kiernan, UBC

The samples look a little like teeth, don’t they?

Before diving into the research news, there’s a terminology issue that should be noted as you’ll see when you read the news/press releases. Nanocrystal cellulose/nanocrystalline cellulose (NCC) is a term coined by Canadian researchers. Since those early day, most researchers, internationally, have adopted the term cellulose nanocrystals (CNC) as the standard term. It fits better with the naming conventions for other nnanocellulose materials such as cellulose nanofibrils, etc. By the way, a Canadian company (CelluForce) that produces CNC retained the term nanocrystalline cellulose (NCC) as a trademark for the product, CelluForce NCC®.

For anyone not familiar with aerogels, what the University of British Columbia (UBC) and McMaster University researchers are developing, are also popularly known known as ‘frozen smoke’ (see the Aerogel Wikipedia entry for more).

A March 19, 2019 news item on ScienceDaily announces the research,

Researchers from the University of British Columbia and McMaster University have developed what could be the bone implant material of the future: an airy, foamlike substance that can be injected into the body and provide scaffolding for the growth of new bone.

It’s made by treating nanocrystals derived from plant cellulose so that they link up and form a strong but lightweight sponge — technically speaking, an aerogel — that can compress or expand as needed to completely fill out a bone cavity.

A March 19, 2019 UBC news release (also on EurekAlert), which originated the news item, describes the research in more detail,

“Most bone graft or implants are made of hard, brittle ceramic that doesn’t always conform to the shape of the hole, and those gaps can lead to poor growth of the bone and implant failure,” said study author Daniel Osorio, a PhD student in chemical engineering at McMaster. “We created this cellulose nanocrystal aerogel as a more effective alternative to these synthetic materials.”

For their research, the team worked with two groups of rats, with the first group receiving the aerogel implants and the second group receiving none. Results showed that the group with implants saw 33 per cent more bone growth at the three-week mark and 50 per cent more bone growth at the 12-week mark, compared to the controls.

“These findings show, for the first time in a lab setting, that a cellulose nanocrystal aerogel can support new bone growth,” said study co-author Emily Cranston, a professor of wood science and chemical and biological engineering who holds the President’s Excellence Chair in Forest Bio-products at UBC. She added that the implant should break down into non-toxic components in the body as the bone starts to heal.

The innovation can potentially fill a niche in the $2-billion bone graft market in North America, said study co-author Kathryn Grandfield, a professor of materials science and engineering, and biomedical engineering at McMaster who supervised the work.

“We can see this aerogel being used for a number of applications including dental implants and spinal and joint replacement surgeries,” said Grandfield. “And it will be economical because the raw material, the nanocellulose, is already being produced in commercial quantities.”

The researchers say it will be some time before the aerogel makes it out of the lab and into the operating room.

“This summer, we will study the mechanisms between the bone and implant that lead to bone growth,” said Grandfield. “We’ll also look at how the implant degrades using advanced microscopes. After that, more biological testing will be required before it is ready for clinical trials.”

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

Cross-linked cellulose nanocrystal aerogels as viable bone tissue scaffolds by Daniel A. Osorio, Bryan E. J. Lee, Jacek M. Kwiecien, Xiaoyue Wang, Iflah Shahid, Ariana L. Hurley, Emily D. Cranston and Kathryn Grandfield. Acta Biomaterialia Volume 87, 15 March 2019, Pages 152-165 DOI: https://doi.org/10.1016/j.actbio.2019.01.049

This paper is behind a paywall

Now for the Russian team.

National University of Science and Technology “MISIS” (formerly part of the Moscow Mining Academy)

These scientists have adopted a different strategy as you’ll see in the March 19, 2019 news item on Nanwerk, which, coincidentally, was published on the same day as the Canadian research,

Scientists from the National University of Science and Technology “MISIS” developed a nanomaterial, which will be able to rstore the internal structure of bones damaged due to osteoporosis and osteomyelitis. A special bioactive coating of the material helped to increase the rate of division of bone cells by 3 times. In the future, it can allow to abandon bone marrow transplantation and patients will no longer need to wait for suitable donor material.

A March 19, 2019 National University of Science and Technology (MISIS) press release (also on EurekAlert), which originated the news item, provides detail about the impetus for the research and the technique being developed,

Such diseases as osteoporosis and osteomyelitis cause irreversible degenerative changes in the bone structure. Such diseases require serious complex treatment and surgery and transplantation of the destroyed bone marrow in severe stages. Donor material should have a number of compatibility indicators and even close relationship with the donor cannot guarantee full compatibility.

Research group from the National University of Science and Technology “MISIS” (NUST MISIS), led by Anton Manakhov (Laboratory for Inorganic Nanomaterials) developed material that will allow to restore damaged internal bone structure without bone marrow transplantation.
It is based on nanofibers of polycaprolactone, which is biocompatible self-dissolvable material. Earlier, the same research group has already worked with this material: by adding antibiotics to the nanofibers, scientists have managed to create non-changeable healing bandages.

“If we want the implant to take, not only biocompatibility is needed, but also activation of the natural cell growth on the surface of the material. Polycaprolactone as such is a hydrophobic material, meaning, and cells feel uncomfortable on its surface. They gather on the smooth surface and divide extremely slow”, Elizaveta Permyakova, one of the co-authors and researcher at NUST MISIS Laboratory for Inorganic Nanomaterials, explains.

To increase the hydrophilicity of the material, a thin layer of bioactive film consisting of titanium, calcium, phosphorus, carbon, oxygen and nitrogen (TiCaPCON) was deposited on it. The structure of nanofibers identical to the cell surface was preserved. These films, when immersed in a special salt medium, which chemical composition is identical to human blood plasma, are able to form on its surface a special layer of calcium and phosphorus, which in natural conditions forms the main part of the bone. Due to the chemical similarity and the structure of nanofibers, new bone tissue begins to grow rapidly on this layer. Most importantly, polycaprolactone nanofibers dissolve, having fulfilled their functions. Only new “native” tissue remains in the bone.

In the experimental part of the study, the researchers compared the rate of division of osteoblastic bone cells on the surface of the modified and unmodified material. It was found that the modified material TiCaPCON has a high hydrophilicity. In contrast to the unmodified material, the cells on its surface felt clearly more comfortable, and divided three times faster.

According to scientists, such results open up great prospects for further work with modified polycaprolactone nanofibers as an alternative to bone marrow transplantation.

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

Bioactive TiCaPCON-coated PCL nanofibers as a promising material for bone tissue engineering by Anton Manakhov, Elizaveta S. Permyakova, Sergey Ershov, Alexander Sheveyko, Andrey Kovalskii, Josef Polčák, Irina Y. Zhitnyak, Natalia A. Gloushankova, Lenka Zajíčková, Dmitry V. Shtansky. Applied Surface Science Volume 479, 15 June 2019, Pages 796-802 DOI: https://doi.org/10.1016/j.apsusc.2019.02.163

This paper is behind a paywall.

Cellulose biosensor heralds new bioimaging approach to tissue engineering

I keep an eye on how nanocellulose is being used in various applications and I’m not sure that this cellulose biosensor quite fits the bill as nanocellulose, nonetheless, it’s interesting and that’s enough for me. From a December 12, 2018 Sechenov University (Russia) press release on EurekAlert,

I.M. Sechenov First Moscow State Medical University teamed up together with Irish colleagues to develop a new imaging approach for tissue engineering. The team produced so-called ‘hybrid biosensor’ scaffold materials, which are based on cellulose matrices labeled with pH- and calcium-sensitive fluorescent proteins. These materials enable visualization of the metabolism and other important biomarkers in the engineered artificial tissues by microscopy. The results of the work were published in the Acta Biomaterialia journal.
The success of tissue engineering is based on the use of scaffold matrices – materials that support the viability and direct the growth of cells, tissues, and organoids. Scaffolds are important for basic and applied biomedical research, tissue engineering and regenerative medicine, and are promising for development of new therapeutics. However, the ability ‘to see’ what happens within the scaffolds during the tissue growth poses a significant research challenge

“We developed a new approach allowing visualization of scaffold-grown tissue and cells by using labeling with biosensor fluorescent proteins. Due to the high specificity of labeling and the use of fluorescence microscopy FLIM, we can quantify changes in pH and calcium in the vicinity of cells,” says Dr. Ruslan Dmitriev, Group Leader at the University College Cork and the Institute for Regenerative Medicine (I.M. Sechenov First Moscow State Medical University).
To achieve the specific labeling of cellulose matrices, researchers used well-known cellulose-binding proteins. The use of extracellular pH- and calcium-sensitive biosensors allow for analysis of cell metabolism: indeed, the extracellular acidification is directly associated with the balance of cell energy production pathways and the glycolytic flux (release of lactate). It is also a frequent hallmark of cancer and transformed cell types. On the other hand, calcium plays a key role in the extra- and intracellular signaling affecting cell growth and differentiation.

The approach was tested on different types of cellulose matrices (bacterial and produced from decellularised plant tissues) using 3D culture of human colon cancer cells and stem-cell derived mouse small intestinal organoids. The scaffolds informed on changes in the extracellular acidification and were used together with the analysis of real-time oxygenation of intestinal organoids. The resulting data can be presented in the form of colour maps, corresponding to the areas of cell growth within different microenvironments.

“Our results open new prospects in the imaging of tissue-engineered constructs for regenerative medicine. They enable deeper understanding of tissue metabolism in 3D and are also highly promising for commercialisation,” concludes Dr. Dmitriev.

The researchers have provided an image to illustrate their work,

Caption: A 3D reconstruction of a cellulose matrix stained with a pH-sensitive biosensor. Credit: Dr. R. Dmitriev

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

Cellulose-based scaffolds for fluorescence lifetime imaging-assisted tissue engineering by Neil O’Donnell, Irina A. Okkelman, Peter Timashev, Tatyana I.Gromovykh, Dmitri B. Papkovsky, Ruslan I.Dmitriev. Acta Biomaterialia Volume 80, 15 October 2018, Pages 85-96 DOI: https://doi.org/10.1016/j.actbio.2018.09.034


This paper is behind a paywall.

Two approaches to memristors

Within one day of each other in October 2018, two different teams working on memristors with applications to neuroprosthetics and neuromorphic computing (brainlike computing) announced their results.

Russian team

An October 15, 2018 (?) Lobachevsky University press release (also published on October 15, 2018 on EurekAlert) describes a new approach to memristors,

Biological neurons are coupled unidirectionally through a special junction called a synapse. An electrical signal is transmitted along a neuron after some biochemical reactions initiate a chemical release to activate an adjacent neuron. These junctions are crucial for cognitive functions, such as perception, learning and memory.

A group of researchers from Lobachevsky University in Nizhny Novgorod investigates the dynamics of an individual memristive device when it receives a neuron-like signal as well as the dynamics of a network of analog electronic neurons connected by means of a memristive device. According to Svetlana Gerasimova, junior researcher at the Physics and Technology Research Institute and at the Neurotechnology Department of Lobachevsky University, this system simulates the interaction between synaptically coupled brain neurons while the memristive device imitates a neuron axon.

A memristive device is a physical model of Chua’s [Dr. Leon Chua, University of California at Berkeley; see my May 9, 2008 posting for a brief description Dr. Chua’s theory] memristor, which is an electric circuit element capable of changing its resistance depending on the electric signal received at the input. The device based on a Au/ZrO2(Y)/TiN/Ti structure demonstrates reproducible bipolar switching between the low and high resistance states. Resistive switching is determined by the oxidation and reduction of segments of conducting channels (filaments) in the oxide film when voltage with different polarity is applied to it. In the context of the present work, the ability of a memristive device to change conductivity under the action of pulsed signals makes it an almost ideal electronic analog of a synapse.

Lobachevsky University scientists and engineers supported by the Russian Science Foundation (project No.16-19-00144) have experimentally implemented and theoretically described the synaptic connection of neuron-like generators using the memristive interface and investigated the characteristics of this connection.

“Each neuron is implemented in the form of a pulse signal generator based on the FitzHugh-Nagumo model. This model provides a qualitative description of the main neurons’ characteristics: the presence of the excitation threshold, the presence of excitable and self-oscillatory regimes with the possibility of a changeover. At the initial time moment, the master generator is in the self-oscillatory mode, the slave generator is in the excitable mode, and the memristive device is used as a synapse. The signal from the master generator is conveyed to the input of the memristive device, the signal from the output of the memristive device is transmitted to the input of the slave generator via the loading resistance. When the memristive device switches from a high resistance to a low resistance state, the connection between the two neuron-like generators is established. The master generator goes into the oscillatory mode and the signals of the generators are synchronized. Different signal modulation mode synchronizations were demonstrated for the Au/ZrO2(Y)/TiN/Ti memristive device,” – says Svetlana Gerasimova.

UNN researchers believe that the next important stage in the development of neuromorphic systems based on memristive devices is to apply such systems in neuroprosthetics. Memristive systems will provide a highly efficient imitation of synaptic connection due to the stochastic nature of the memristive phenomenon and can be used to increase the flexibility of the connections for neuroprosthetic purposes. Lobachevsky University scientists have vast experience in the development of neurohybrid systems. In particular, a series of experiments was performed with the aim of connecting the FitzHugh-Nagumo oscillator with a biological object, a rat brain hippocampal slice. The signal from the electronic neuron generator was transmitted through the optic fiber communication channel to the bipolar electrode which stimulated Schaffer collaterals (axons of pyramidal neurons in the CA3 field) in the hippocampal slices. “We are going to combine our efforts in the design of artificial neuromorphic systems and our experience of working with living cells to improve flexibility of prosthetics,” concludes S. Gerasimova.

The results of this research were presented at the 38th International Conference on Nonlinear Dynamics (Dynamics Days Europe) at Loughborough University (Great Britain).

This diagram illustrates an aspect of the work,

Caption: Schematic of electronic neurons coupling via a memristive device. Credit: Lobachevsky University

US team

The American Institute of Physics (AIP) announced the publication of a ‘memristor paper’ by a team from the University of Southern California (USC) in an October 16, 2018 news item on phys.org,

Just like their biological counterparts, hardware that mimics the neural circuitry of the brain requires building blocks that can adjust how they synapse, with some connections strengthening at the expense of others. One such approach, called memristors, uses current resistance to store this information. New work looks to overcome reliability issues in these devices by scaling memristors to the atomic level.

An October 16, 2018 AIP news release (also on EurekAlert), which originated the news item, delves further into the particulars of this particular piece of memristor research,

A group of researchers demonstrated a new type of compound synapse that can achieve synaptic weight programming and conduct vector-matrix multiplication with significant advances over the current state of the art. Publishing its work in the Journal of Applied Physics, from AIP Publishing, the group’s compound synapse is constructed with atomically thin boron nitride memristors running in parallel to ensure efficiency and accuracy.

The article appears in a special topic section of the journal devoted to “New Physics and Materials for Neuromorphic Computation,” which highlights new developments in physical and materials science research that hold promise for developing the very large-scale, integrated “neuromorphic” systems of tomorrow that will carry computation beyond the limitations of current semiconductors today.

“There’s a lot of interest in using new types of materials for memristors,” said Ivan Sanchez Esqueda, an author on the paper. “What we’re showing is that filamentary devices can work well for neuromorphic computing applications, when constructed in new clever ways.”

Current memristor technology suffers from a wide variation in how signals are stored and read across devices, both for different types of memristors as well as different runs of the same memristor. To overcome this, the researchers ran several memristors in parallel. The combined output can achieve accuracies up to five times those of conventional devices, an advantage that compounds as devices become more complex.

The choice to go to the subnanometer level, Sanchez said, was born out of an interest to keep all of these parallel memristors energy-efficient. An array of the group’s memristors were found to be 10,000 times more energy-efficient than memristors currently available.

“It turns out if you start to increase the number of devices in parallel, you can see large benefits in accuracy while still conserving power,” Sanchez said. Sanchez said the team next looks to further showcase the potential of the compound synapses by demonstrating their use completing increasingly complex tasks, such as image and pattern recognition.

Here’s an image illustrating the parallel artificial synapses,

Caption: Hardware that mimics the neural circuitry of the brain requires building blocks that can adjust how they synapse. One such approach, called memristors, uses current resistance to store this information. New work looks to overcome reliability issues in these devices by scaling memristors to the atomic level. Researchers demonstrated a new type of compound synapse that can achieve synaptic weight programming and conduct vector-matrix multiplication with significant advances over the current state of the art. They discuss their work in this week’s Journal of Applied Physics. This image shows a conceptual schematic of the 3D implementation of compound synapses constructed with boron nitride oxide (BNOx) binary memristors, and the crossbar array with compound BNOx synapses for neuromorphic computing applications. Credit: Ivan Sanchez Esqueda

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

Efficient learning and crossbar operations with atomically-thin 2-D material compound synapses by Ivan Sanchez Esqueda, Huan Zhao and Han Wang. The article will appear in the Journal of Applied Physics Oct. 16, 2018 (DOI: 10.1063/1.5042468).

This paper is behind a paywall.

*Title corrected from ‘Two approaches to memristors featuring’ to ‘Two approaches to memristors’ on May 31, 2019 at 1455 hours PDT.

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.

Build nanoparticles using techniques from the ancient Egyptians

Great Pyramid of Giza and Sphinx [downloaded from http://news.ifmo.ru/en/science/photonics/news/7731/]

Russian and German scientists have taken a closer look at the Great Pyramid as they investigate better ways of designing sensors and solar cells. From a July 30, 2018 news item on Nanowerk,

An international research group applied methods of theoretical physics to investigate the electromagnetic response of the Great Pyramid to radio waves. Scientists predicted that under resonance conditions the pyramid can concentrate electromagnetic energy in its internal chambers and under the base. The research group plans to use these theoretical results to design nanoparticles capable of reproducing similar effects in the optical range. Such nanoparticles may be used, for example, to develop sensors and highly efficient solar cells.

A July 30, 2018 ITMO University press release, which originated the news item,  expands on the theme,

While Egyptian pyramids are surrounded by many myths and legends, we have little scientifically reliable information about their physical properties. As it turns out, sometimes this information proves to be more fascinating than any fiction. This idea found confirmation in a new joint study undertaken by scientists from ITMO University and the Laser Zentrum Hannover. The physicists took an interest in how the Great Pyramid would interact with electromagnetic waves of a proportional, or resonant, length. Calculations showed that in the resonant state the pyramid can concentrate electromagnetic energy in its internal chambers as well as under its base, where the third unfinished chamber is located.

These conclusions were derived on the basis of numerical modeling and analytical methods of physics. The researchers first estimated that resonances in the pyramid can be induced by radio waves with a length ranging from 200 to 600 meters. Then they made a model of the electromagnetic response of the pyramid and calculated the extinction cross section. This value helps to estimate which part of the incident wave energy can be scattered or absorbed by the pyramid under resonant conditions. Finally, for the same conditions, the scientists obtained the electromagnetic fields distribution inside the pyramid.

3D model of the pyramid. Credit: cheops.SU
3D model of the pyramid. Credit: cheops.SU

In order to explain the results, the scientists conducted a multipole analysis. This method is widely used in physics to study the interaction between a complex object and electromagnetic field. The object scattering the field is replaced by a set of simpler sources of radiation: multipoles. The collection of multipoles radiation coincides with the field scattering by an entire object. Therefore, by knowing the type of each multipole, it is possible to predict and explain the distribution and configuration of the scattered fields in the whole system.

The Great Pyramid attracted the researchers’ attention while they were studying the interaction between light and dielectric nanoparticles. The scattering of light by nanoparticles depends on their size, shape, and refractive index of the source material. By varying these parameters, it is possible to determine the resonance scattering regimes and use them to develop devices for controlling light at the nanoscale.

“Egyptian pyramids have always attracted great attention. We as scientists were interested in them as well, and so we decided to look at the Great Pyramid as a particle resonantly dissipating radio waves. Due to the lack of information about the physical properties of the pyramid, we had to make some assumptions. For example, we assumed that there are no unknown cavities inside, and the building material has the properties of an ordinary limestone and is evenly distributed in and out of the pyramid. With these assumptions, we obtained interesting results that can have important practical applications,” says Andrey Evlyukhin, DSc, scientific supervisor and coordinator of the research.

Now the scientists plan to use the results to reproduce similar effects at the nanoscale.

Polina Kapitanova
Polina Kapitanova

“By choosing a material with suitable electromagnetic properties, we can obtain pyramidal nanoparticles with a potential for practical application in nanosensors and effective solar cells,” says Polina Kapitanova, PhD, associate at the Faculty of Physics and Engineering of ITMO University.

The research was supported by the Russian Science Foundation and the Deutsche Forschungsgemeinschaft (grants № 17-79-20379 and №16-12-10287).

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

Electromagnetic properties of the Great Pyramid: First multipole resonances and energy concentration featured by Mikhail Balezin, Kseniia V. Baryshnikova, Polina Kapitanova, and Andrey B. Evlyukhin. Journal of Applied Physics 124, 034903 (2018) https://doi.org/10.1063/1.5026556 or Journal of Applied Physics, Volume 124, Issue 3. 10.1063/1.5026556 Published Online 20 July 2018

This paper is behind a paywall..

Scientometrics and science typologies

Caption: As of 2013, there were 7.8 million researchers globally, according to UNESCO. This means that 0.1 percent of the people in the world professionally do science. Their work is largely financed by governments, yet public officials are not themselves researchers. To help governments make sense of the scientific community, Russian mathematicians have devised a researcher typology. The authors initially identified three clusters, which they tentatively labeled as “leaders,” “successors,” and “toilers.” Credit: Lion_on_helium/MIPT Press Office

A June 28, 2018 Moscow Institute of Physics and Technology (MIPT; Russia) press release (also on EurekAlert) announces some intriguing research,

Researchers in various fields, from psychology to economics, build models of human behavior and reasoning to categorize people. But it does not happen as often that scientists undertake an analysis to classify their own kind.

However, research evaluation, and therefore scientist stratification as well, remain highly relevant. Six years ago, the government outlined the objective that Russian scientists should have 50 percent more publications in Web of Science- and Scopus-indexed journals. As of 2011, papers by researchers from Russia accounted for 1.66 percent of publications globally. By 2015, this number was supposed to reach 2.44%. It did grow but this has also sparked a discussion in the scientific community about the criteria used for evaluating research work.

The most common way of gauging the impact of a researcher is in terms of his or her publications. Namely, whether they are in a prestigious journal and how many times they have been cited. As with any good idea, however, one runs the risk of overdoing it. In 2005, U.S. physicist Jorge Hirsch proposed his h-index, which takes into account the number of publications by a given researcher and the number of times they have been cited. Now, scientists are increasingly doubting the adequacy of using bibliometric data as the sole independent criterion for evaluating research work. One obvious example of a flaw of this metric is that a paper can be frequently cited to point out a mistake in it.

Scientists are increasingly under pressure to publish more often. Research that might have reasonably been published in one paper is being split up into stages for separate publication. This calls for new approaches to the evaluation of work done by research groups and individual authors. Similarly, attempts to systematize the existing methods in scientometrics and stratify scientists are becoming more relevant, too. This is arguably even more important for Russia, where the research reform has been stretching for years.

One of the challenges in scientometrics is identifying the prominent types of researchers in different fields. A typology of scientists has been proposed by Moscow Institute of Physics and Technology Professor Pavel Chebotarev, who also heads the Laboratory of Mathematical Methods for Multiagent Systems Analysis at the Institute of Control Sciences of the Russian Academy of Sciences, and Ilya Vasilyev, a master’s student at MIPT.

In their paper, the two authors determined distinct types of scientists based on an indirect analysis of the style of research work, how papers are received by colleagues, and what impact they make. A further question addressed by the authors is to what degree researcher typology is affected by the scientific discipline.

“Each science has its own style of work. Publication strategies and citation practices vary, and leaders are distinguished in different ways,” says Chebotarev. “Even within a given discipline, things may be very different. This means that it is, unfortunately, not possible to have a universal system that would apply to anyone from a biologist to a philologist.”

“All of the reasonable systems that already exist are adjusted to particular disciplines,” he goes on. “They take into account the criteria used by the researchers themselves to judge who is who in their field. For example, scientists at the Institute for Nuclear Research of the Russian Academy of Sciences are divided into five groups based on what research they do, and they see a direct comparison of members of different groups as inadequate.”

The study was based on the citation data from the Google Scholar bibliographic database. To identify researcher types, the authors analyzed citation statistics for a large number of scientists, isolating and interpreting clusters of similar researchers.

Chebotarev and Vasilyev looked at the citation statistics for four groups of researchers returned by a Google Scholar search using the tags “Mathematics,” “Physics,” and “Psychology.” The first 515 and 556 search hits were considered in the case of physicists and psychologists, respectively. The authors studied two sets of mathematicians: the top 500 hits and hit Nos. 199-742. The four sets thus included frequently cited scientists from three disciplines indicating their general field of research in their profiles. Citation dynamics over each scientist’s career were examined using a range of indexes.

The authors initially identified three clusters, which they tentatively labeled as “leaders,” “successors,” and “toilers.” The leaders are experienced scientists widely recognized in their fields for research that has secured an annual citation count increase for them. The successors are young scientists who have more citations than toilers. The latter earn their high citation metrics owing to yearslong work, but they lack the illustrious scientific achievements.

Among the top 500 researchers indicating mathematics as their field of interest, 52 percent accounted for toilers, with successors and leaders making up 25.8 and 22.2 percent, respectively.

For physicists, the distribution was slightly different, with 48.5 percent of the set classified as toilers, 31.7 percent as successors, and 19.8 percent as leaders. That is, there were more successful young scientists, at the expense of leaders and toilers. This may be seen as a confirmation of the solitary nature of mathematical research, as compared with physics.

Finally, in the case of psychologists, toilers made up 47.7 percent of the set, with successors and leaders accounting for 18.3 and 34 percent. Comparing the distributions for the three disciplines investigated in the study, the authors conclude that there are more young achievers among those doing mathematical research.

A closer look enabled the authors to determine a more fine-grained cluster structure, which turned out to be remarkably similar for mathematicians and physicists. In particular, they identified a cluster of the youngest and most successful researchers, dubbed “precocious,” making up 4 percent of the mathematicians and 4.3 percent of the physicists in the set, along with the “youth” — successful researchers whose debuts were somewhat less dramatic: 29 and 31.7 percent of scientists doing math and physics research, respectively. Two further clusters were interpreted as recognized scientific authorities, or “luminaries,” and experienced researchers who have not seen an appreciable growth in the number of citations recently. Luminaries and the so-called inertia accounted for 52 and 15 percent of mathematicians and 50 and 14 percent of physicists, respectively.

There is an alternative way of clustering physicists, which recognizes a segment of researchers, who “caught the wave.” The authors suggest this might happen after joining major international research groups.

Among psychologists, 18.3 percent have been classified as precocious, though not as young as the physicists and mathematicians in the corresponding group. The most experienced and respected psychology researchers account for 22.5 percent, but there is no subdivision into luminaries and inertia, because those actively cited generally continue to be. Relatively young psychologists make up 59.2 percent of the set. The borders between clusters are relatively blurred in the case of psychology, which might be a feature of the humanities, according to the authors.

“Our pilot study showed even more similarity than we’d expected in how mathematicians and physicists are clustered,” says Chebotarev. “Whereas with psychology, things are noticeably different, yet the breakdown is slightly closer to math than physics. Perhaps, there is a certain connection between psychology and math after all, as some people say.”

“The next stage of this research features more disciplines. Hopefully, we will be ready to present the new results soon,” he concludes.

I think that they are attempting to create a new way of measuring scientific progress (scientometrics) by establishing a more representative means of measuring individual contributions based on the analysis they provide of the ways in which these ‘typologies’ are expressed across various disciplines.

For anyone who wants to investigate further, you will need to be able to read Russian. You can download the paper from here on MathNet.ru,.

Here’s my best attempt at a citation for the paper,

Making a typology of scientists on the basis of bibliometric data by I. Vasilyev, P. Yu. Chebotarev. Large-scale System Control (UBS), 2018, Issue 72, Pages 138–195 (Mi ubs948)

I’m glad to see this as there is a fair degree of dissatisfaction about the current measures for scientific progress used in any number of reports on the topic. As far as I can tell, this dissatisfaction is felt internationally.

Sound-absorbing nanofoam

In these increasingly noisy days (there’s construction going on around me), news of a cheaper, easier way to dull the noise is very attractive. From a June 25, 2018 Far Eastern Federal University (Russia) press release on EurekAlert,

The breakthrough material reduces a noise level by 100% more efficient comparing to standard analogs, cutting the level of noise transmission by 20-22 dB. The new foam reacts to sound waves not only of high but also of low frequencies, which can damage human health. A young scientist from the Far Eastern Federal University (FEFU) took part in the development.

PARTNERSHIP DEVELOPMENT

Alexey Zavjalov, postdoc, researcher at the Academic Department of Nuclear Technologies School of Natural Science, FEFU, worked as a part of the international team of Russian and South Korean scientists under professor S.P. Bardakhanov. Alexey’s research performance led to the creation of nanofoam – the new noise-absorbing composite material. The results of the work are published in ‘Applied Acoustics’.

‘The problem of noise is the problem of modern technogenic civilization. In South Korea, cities are equipped with round-the-clock working stationary and mobile networks for noise levels monitoring. The urbanization level of such territorially small countries as South Korea is much higher than in Russia. However, in our country this problem is still crucial for big cities,’ – explained Alexey Zavjalov. – ‘The development of new noise-absorbing materials is especially interesting for the automotive industry. Modern people spend a lot of time driving cars and the noise level inside the vehicles’ directly determines the quality of life. For East Asian countries, the issue of noise control is relevant for high-speed rail lines.’ Porous materials are excellent sound absorbers but their noise-absorbing properties can be significantly enhanced by nanoporous grit injected into the foam structure and formed internal channels in it. Alexey Zavjalov has developed approaches for saturation of macroporous foam material with nanoporous grit.

HARMFULNESS OF THE LOW FREQUENCIES NOISES.

Along with the rapid development of nanotechnology, there have been many attempts to mix nano- and microsized materials to create a modified material with enhanced strength, elastic, dynamical and vibrational properties. The acoustic parameters of such materials could not be fundamentally enhanced thus far.

Foam materials are most often used for soundproofing purposes. They provide the proper quality at a reasonable cost, but until today have been effective against high-frequency noise only. At the same time, low frequencies can be much more harmful to human health.

Infra- and low-frequency vibrations and noise (less than 0.4 kHz) are most harmful and dangerous for human health and life. Especially unfavorable is their long-lasting impact, since leads to serious diseases and pathologies. Complaints on such oppressions exceed 35% of the sum total of complaints on harmful environmental conditions.

The foam material, developed by Russian and Korean scientists, demonstrated promising results at medium frequencies and, therefore, more specialized low-frequency noise tests are needed.

CHEAPER AND EASIER FOR APPLICATION THAN AEROGEL.

The improved acoustic characteristics of the newest hybrid nanofoam were obtained by additional impregnation of the standard off-the-shelf sound-absorbing foam with porous granules of silica and magnetite nanoparticles. The porous foam was immersed in nanopowder suspensions in the liquid, subjected to ultrasonic treatment and dried.

The nanoparticles granules formed in the result can be compared structurally to a widely known class of materials – aerogel. It has not only excellent thermal insulation properties but also has a good noise-proof. However, aerogels are quite expensive and complex when used in structures. The new material, created according to the scheme developed by the FEFU researcher, is structurally similar to aerogel but is free of such shortcomings as a high price and engineering problems.

COMPOSITE TECHNOLOGY

The mechanism of sound absorption of a new foam is based on the fact that its sound-absorbing surface is significantly scaled due to the presence of a large number of nanopores in the particles injected, as well as the location of these particles in the foam matrix in the form of distinct channels. Nanoparticles dissipate the energy of a sound wave transforming it into heat. The soundproof properties of the material increase.

Scientists found out that the composite structure is most effective for noise reduction. Thin layers of foam impregnated with nanoparticles are connected to each other in a “sandwich”-construction. This design significantly improves the soundproof properties of the resulting material. The outcome of the study also suggests that the more foamy material is impregnated with nanoparticles, the better it’s sound absorption is.

‘In some approximation, any material can be represented as a network of weights connected by springs. Such a mechanical system always has its own frequency bands, in which the oscillations propagate in the system relatively freely. There are also forbidden frequency bands in which the oscillations rapidly fade out in the system. To effectively extinguish the transmission of oscillations, including sound waves, the materials should be alternated in such a way that the fluctuations that propagate freely in the first material would be in the forbidden band for the second layer,’- commented Alexey Zavjalov. – ‘Of course, for our foam material, this idealization is too crude. However, it allows us to clearly illustrate the fundamentally conditioned necessity of creating a “sandwich” structure.’

RESEARCH OUTCOME

The study showed the effectiveness of the method of foams impregnation with nanosilica or nanomagnetite, which form granules up to several hundred micrometers (in accordance with the pore sizes of the modified foam material) and having pores about 15 nm. This small addition provided a more complex and branched 3D network of nanochannels which led to an additional absorption of noise energy.

Due to the method used, the noise absorption efficiency was achieved in the range of 2.0-6.3 kHz and at lower frequencies 0.5-1.6 kHz. The degree of absorption was increased by 60-100% and the sound transmission was reduced by 20-22 dB, regardless of the type of nanofiller.

‘There is room to further improve the sound absorbing properties of the new material for medium and low frequencies using the” active control” strategy’. – Alexey Zavjalov comments on the plans for further development of such an important scientific topic. – ‘First of all, this refers to the materials obtained by using a magnetite nanopowder. Active noise protection systems have long been used in the world. The main idea is to detect the noise acoustic fields “online” and to generate sound waves in antiphase by means of loudspeakers. That allows achieving a significant reduction of noise in a given area. Concerning the nanofoam, it’s proposed to adapt this approach and to actively exert on a material saturated with granules of magnetite nanoparticles by magnetic fields. This will achieve even better noise reduction.’

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

Hybrid sound-absorbing foam materials with nanostructured grit-impregnated pores by S.P.Bardakhanov, C.M.Lee, V.N.Goverdovskiy, A.P.Zavjalov, K.V.Zobov, M.Chen, Z.H.Xu, I.K.Chakin, D.Yu.Trufanov. Applied Acoustics Volume 139, October 2018, Pages 69-74
https://doi.org/10.1016/j.apacoust.2018.04.024 Available online 23 April 2018.

This paper is behind a paywall.

If you have difficulty seeing the press release on EurekAlert, there is a June 26, 2018 news item on a Russian news site, RSF News and there is an edited version in a June 26, 2018 news item on Azonano.

A potpourri of robot/AI stories: killers , kindergarten teachers, a Balenciaga-inspired AI fashion designer, a conversational android, and more

Following on my August 29, 2018 post (Sexbots, sexbot ethics, families, and marriage), I’m following up with a more general piece.

Robots, AI (artificial intelligence), and androids (humanoid robots), the terms can be confusing since there’s a tendency to use them interchangeably. Confession: I do it too, but, not this time. That said, I have multiple news bits.

Killer ‘bots and ethics

The U.S. military is already testing a Modular Advanced Armed Robotic System. Credit: Lance Cpl. Julien Rodarte, U.S. Marine Corps

That is a robot.

For the purposes of this posting, a robot is a piece of hardware which may or may not include an AI system and does not mimic a human or other biological organism such that you might, under circumstances, mistake the robot for a biological organism.

As for what precipitated this feature (in part), it seems there’s been a United Nations meeting in Geneva, Switzerland held from August 27 – 31, 2018 about war and the use of autonomous robots, i.e., robots equipped with AI systems and designed for independent action. BTW, it’s the not first meeting the UN has held on this topic.

Bonnie Docherty, lecturer on law and associate director of armed conflict and civilian protection, international human rights clinic, Harvard Law School, has written an August 21, 2018 essay on The Conversation (also on phys.org) describing the history and the current rules around the conduct of war, as well as, outlining the issues with the military use of autonomous robots (Note: Links have been removed),

When drafting a treaty on the laws of war at the end of the 19th century, diplomats could not foresee the future of weapons development. But they did adopt a legal and moral standard for judging new technology not covered by existing treaty language.

This standard, known as the Martens Clause, has survived generations of international humanitarian law and gained renewed relevance in a world where autonomous weapons are on the brink of making their own determinations about whom to shoot and when. The Martens Clause calls on countries not to use weapons that depart “from the principles of humanity and from the dictates of public conscience.”

I was the lead author of a new report by Human Rights Watch and the Harvard Law School International Human Rights Clinic that explains why fully autonomous weapons would run counter to the principles of humanity and the dictates of public conscience. We found that to comply with the Martens Clause, countries should adopt a treaty banning the development, production and use of these weapons.

Representatives of more than 70 nations will gather from August 27 to 31 [2018] at the United Nations in Geneva to debate how to address the problems with what they call lethal autonomous weapon systems. These countries, which are parties to the Convention on Conventional Weapons, have discussed the issue for five years. My co-authors and I believe it is time they took action and agreed to start negotiating a ban next year.

Docherty elaborates on her points (Note: A link has been removed),

The Martens Clause provides a baseline of protection for civilians and soldiers in the absence of specific treaty law. The clause also sets out a standard for evaluating new situations and technologies that were not previously envisioned.

Fully autonomous weapons, sometimes called “killer robots,” would select and engage targets without meaningful human control. They would be a dangerous step beyond current armed drones because there would be no human in the loop to determine when to fire and at what target. Although fully autonomous weapons do not yet exist, China, Israel, Russia, South Korea, the United Kingdom and the United States are all working to develop them. They argue that the technology would process information faster and keep soldiers off the battlefield.

The possibility that fully autonomous weapons could soon become a reality makes it imperative for those and other countries to apply the Martens Clause and assess whether the technology would offend basic humanity and the public conscience. Our analysis finds that fully autonomous weapons would fail the test on both counts.

I encourage you to read the essay in its entirety and for anyone who thinks the discussion about ethics and killer ‘bots is new or limited to military use, there’s my July 25, 2016 posting about police use of a robot in Dallas, Texas. (I imagine the discussion predates 2016 but that’s the earliest instance I have here.)

Teacher bots

Robots come in many forms and this one is on the humanoid end of the spectum,

Children watch a Keeko robot at the Yiswind Institute of Multicultural Education in Beijing, where the intelligent machines are telling stories and challenging kids with logic problems  [donwloaded from https://phys.org/news/2018-08-robot-teachers-invade-chinese-kindergartens.html]

Don’t those ‘eyes’ look almost heart-shaped? No wonder the kids love these robots, if an August  29, 2018 news item on phys.org can be believed,

The Chinese kindergarten children giggled as they worked to solve puzzles assigned by their new teaching assistant: a roundish, short educator with a screen for a face.

Just under 60 centimetres (two feet) high, the autonomous robot named Keeko has been a hit in several kindergartens, telling stories and challenging children with logic problems.

Round and white with a tubby body, the armless robot zips around on tiny wheels, its inbuilt cameras doubling up both as navigational sensors and a front-facing camera allowing users to record video journals.

In China, robots are being developed to deliver groceries, provide companionship to the elderly, dispense legal advice and now, as Keeko’s creators hope, join the ranks of educators.

At the Yiswind Institute of Multicultural Education on the outskirts of Beijing, the children have been tasked to help a prince find his way through a desert—by putting together square mats that represent a path taken by the robot—part storytelling and part problem-solving.

Each time they get an answer right, the device reacts with delight, its face flashing heart-shaped eyes.

“Education today is no longer a one-way street, where the teacher teaches and students just learn,” said Candy Xiong, a teacher trained in early childhood education who now works with Keeko Robot Xiamen Technology as a trainer.

“When children see Keeko with its round head and body, it looks adorable and children love it. So when they see Keeko, they almost instantly take to it,” she added.

Keeko robots have entered more than 600 kindergartens across the country with its makers hoping to expand into Greater China and Southeast Asia.

Beijing has invested money and manpower in developing artificial intelligence as part of its “Made in China 2025” plan, with a Chinese firm last year unveiling the country’s first human-like robot that can hold simple conversations and make facial expressions.

According to the International Federation of Robots, China has the world’s top industrial robot stock, with some 340,000 units in factories across the country engaged in manufacturing and the automotive industry.

Moving on from hardware/software to a software only story.

AI fashion designer better than Balenciaga?

Despite the title for Katharine Schwab’s August 22, 2018 article for Fast Company, I don’t think this AI designer is better than Balenciaga but from the pictures I’ve seen the designs are as good and it does present some intriguing possibilities courtesy of its neural network (Note: Links have been removed),

The AI, created by researcher Robbie Barat, has created an entire collection based on Balenciaga’s previous styles. There’s a fabulous pink and red gradient jumpsuit that wraps all the way around the model’s feet–like a onesie for fashionistas–paired with a dark slouchy coat. There’s a textural color-blocked dress, paired with aqua-green tights. And for menswear, there’s a multi-colored, shimmery button-up with skinny jeans and mismatched shoes. None of these looks would be out of place on the runway.

To create the styles, Barat collected images of Balenciaga’s designs via the designer’s lookbooks, ad campaigns, runway shows, and online catalog over the last two months, and then used them to train the pix2pix neural net. While some of the images closely resemble humans wearing fashionable clothes, many others are a bit off–some models are missing distinct limbs, and don’t get me started on how creepy [emphasis mine] their faces are. Even if the outfits aren’t quite ready to be fabricated, Barat thinks that designers could potentially use a tool like this to find inspiration. Because it’s not constrained by human taste, style, and history, the AI comes up with designs that may never occur to a person. “I love how the network doesn’t really understand or care about symmetry,” Barat writes on Twitter.

You can see the ‘creepy’ faces and some of the designs here,

Image: Robbie Barat

In contrast to the previous two stories, this all about algorithms, no machinery with independent movement (robot hardware) needed.

Conversational android: Erica

Hiroshi Ishiguro and his lifelike (definitely humanoid) robots have featured here many, many times before. The most recent posting is a March 27, 2017 posting about his and his android’s participation at the 2017 SXSW festival.

His latest work is featured in an August 21, 2018 news news item on ScienceDaily,

We’ve all tried talking with devices, and in some cases they talk back. But, it’s a far cry from having a conversation with a real person.

Now a research team from Kyoto University, Osaka University, and the Advanced Telecommunications Research Institute, or ATR, have significantly upgraded the interaction system for conversational android ERICA, giving her even greater dialog skills.

ERICA is an android created by Hiroshi Ishiguro of Osaka University and ATR, specifically designed for natural conversation through incorporation of human-like facial expressions and gestures. The research team demonstrated the updates during a symposium at the National Museum of Emerging Science in Tokyo.

Here’s the latest conversational android, Erica

Caption: The experimental set up when the subject (left) talks with ERICA (right) Credit: Kyoto University / Kawahara lab

An August 20, 2018 Kyoto University press release on EurekAlert, which originated the news item, offers more details,

When we talk to one another, it’s never a simple back and forward progression of information,” states Tatsuya Kawahara of Kyoto University’s Graduate School of Informatics, and an expert in speech and audio processing.

“Listening is active. We express agreement by nodding or saying ‘uh-huh’ to maintain the momentum of conversation. This is called ‘backchanneling’, and is something we wanted to implement with ERICA.”

The team also focused on developing a system for ‘attentive listening’. This is when a listener asks elaborating questions, or repeats the last word of the speaker’s sentence, allowing for more engaging dialogue.

Deploying a series of distance sensors, facial recognition cameras, and microphone arrays, the team began collecting data on parameters necessary for a fluid dialog between ERICA and a human subject.

“We looked at three qualities when studying backchanneling,” continues Kawahara. “These were: timing — when a response happens; lexical form — what is being said; and prosody, or how the response happens.”

Responses were generated through machine learning using a counseling dialogue corpus, resulting in dramatically improved dialog engagement. Testing in five-minute sessions with a human subject, ERICA demonstrated significantly more dynamic speaking skill, including the use of backchanneling, partial repeats, and statement assessments.

“Making a human-like conversational robot is a major challenge,” states Kawahara. “This project reveals how much complexity there is in listening, which we might consider mundane. We are getting closer to a day where a robot can pass a Total Turing Test.”

Erica seems to have been first introduced publicly in Spring 2017, from an April 2017 Erica: Man Made webpage on The Guardian website,

Erica is 23. She has a beautiful, neutral face and speaks with a synthesised voice. She has a degree of autonomy – but can’t move her hands yet. Hiroshi Ishiguro is her ‘father’ and the bad boy of Japanese robotics. Together they will redefine what it means to be human and reveal that the future is closer than we might think.

Hiroshi Ishiguro and his colleague Dylan Glas are interested in what makes a human. Erica is their latest creation – a semi-autonomous android, the product of the most funded scientific project in Japan. But these men regard themselves as artists more than scientists, and the Erica project – the result of a collaboration between Osaka and Kyoto universities and the Advanced Telecommunications Research Institute International – is a philosophical one as much as technological one.

Erica is interviewed about her hope and dreams – to be able to leave her room and to be able to move her arms and legs. She likes to chat with visitors and has one of the most advanced speech synthesis systems yet developed. Can she be regarded as being alive or as a comparable being to ourselves? Will she help us to understand ourselves and our interactions as humans better?

Erica and her creators are interviewed in the science fiction atmosphere of Ishiguro’s laboratory, and this film asks how we might form close relationships with robots in the future. Ishiguro thinks that for Japanese people especially, everything has a soul, whether human or not. If we don’t understand how human hearts, minds and personalities work, can we truly claim that humans have authenticity that machines don’t?

Ishiguro and Glas want to release Erica and her fellow robots into human society. Soon, Erica may be an essential part of our everyday life, as one of the new children of humanity.

Key credits

  • Director/Editor: Ilinca Calugareanu
  • Producer: Mara Adina
  • Executive producers for the Guardian: Charlie Phillips and Laurence Topham
  • This video is produced in collaboration with the Sundance Institute Short Documentary Fund supported by the John D and Catherine T MacArthur Foundation

You can also view the 14 min. film here.

Artworks generated by an AI system are to be sold at Christie’s auction house

KC Ifeanyi’s August 22, 2018 article for Fast Company may send a chill down some artists’ spines,

For the first time in its 252-year history, Christie’s will auction artwork generated by artificial intelligence.

Created by the French art collective Obvious, “Portrait of Edmond de Belamy” is part of a series of paintings of the fictional Belamy family that was created using a two-part algorithm. …

The portrait is estimated to sell anywhere between $7,000-$10,000, and Obvious says the proceeds will go toward furthering its algorithm.

… Famed collector Nicolas Laugero-Lasserre bought one of Obvious’s Belamy works in February, which could’ve been written off as a novel purchase where the story behind it is worth more than the piece itself. However, with validation from a storied auction house like Christie’s, AI art could shake the contemporary art scene.

“Edmond de Belamy” goes up for auction from October 23-25 [2018].

Jobs safe from automation? Are there any?

Michael Grothaus expresses more optimism about future job markets than I’m feeling in an August 30, 2018 article for Fast Company,

A 2017 McKinsey Global Institute study of 800 occupations across 46 countries found that by 2030, 800 million people will lose their jobs to automation. That’s one-fifth of the global workforce. A further one-third of the global workforce will need to retrain if they want to keep their current jobs as well. And looking at the effects of automation on American jobs alone, researchers from Oxford University found that “47 percent of U.S. workers have a high probability of seeing their jobs automated over the next 20 years.”

The good news is that while the above stats are rightly cause for concern, they also reveal that 53% of American jobs and four-fifths of global jobs are unlikely to be affected by advances in artificial intelligence and robotics. But just what are those fields? I spoke to three experts in artificial intelligence, robotics, and human productivity to get their automation-proof career advice.

Creatives

“Although I believe every single job can, and will, benefit from a level of AI or robotic influence, there are some roles that, in my view, will never be replaced by technology,” says Tom Pickersgill, …

Maintenance foreman

When running a production line, problems and bottlenecks are inevitable–and usually that’s a bad thing. But in this case, those unavoidable issues will save human jobs because their solutions will require human ingenuity, says Mark Williams, head of product at People First, …

Hairdressers

Mat Hunter, director of the Central Research Laboratory, a tech-focused co-working space and accelerator for tech startups, have seen startups trying to create all kinds of new technologies, which has given him insight into just what machines can and can’t pull off. It’s lead him to believe that jobs like the humble hairdresser are safer from automation than those of, says, accountancy.

Therapists and social workers

Another automation-proof career is likely to be one involved in helping people heal the mind, says Pickersgill. “People visit therapists because there is a need for emotional support and guidance. This can only be provided through real human interaction–by someone who can empathize and understand, and who can offer advice based on shared experiences, rather than just data-driven logic.”

Teachers

Teachers are so often the unsung heroes of our society. They are overworked and underpaid–yet charged with one of the most important tasks anyone can have: nurturing the growth of young people. The good news for teachers is that their jobs won’t be going anywhere.

Healthcare workers

Doctors and nurses will also likely never see their jobs taken by automation, says Williams. While automation will no doubt better enhance the treatments provided by doctors and nurses the fact of the matter is that robots aren’t going to outdo healthcare workers’ ability to connect with patients and make them feel understood the way a human can.

Caretakers

While humans might be fine with robots flipping their burgers and artificial intelligence managing their finances, being comfortable with a robot nannying your children or looking after your elderly mother is a much bigger ask. And that’s to say nothing of the fact that even today’s most advanced robots don’t have the physical dexterity to perform the movements and actions carers do every day.

Grothaus does offer a proviso in his conclusion: certain types of jobs are relatively safe until developers learn to replicate qualities such as empathy in robots/AI.

It’s very confusing

There’s so much news about robots, artificial intelligence, androids, and cyborgs that it’s hard to keep up with it let alone attempt to get a feeling for where all this might be headed. When you add the fact that the term robots/artificial inteligence are often used interchangeably and that the distinction between robots/androids/cyborgs is not always clear any attempts to peer into the future become even more challenging.

At this point I content myself with tracking the situation and finding definitions so I can better understand what I’m tracking. Carmen Wong’s August 23, 2018 posting on the Signals blog published by Canada’s Centre for Commercialization of Regenerative Medicine (CCRM) offers some useful definitions in the context of an article about the use of artificial intelligence in the life sciences, particularly in Canada (Note: Links have been removed),

Artificial intelligence (AI). Machine learning. To most people, these are just buzzwords and synonymous. Whether or not we fully understand what both are, they are slowly integrating into our everyday lives. Virtual assistants such as Siri? AI is at work. The personalized ads you see when you are browsing on the web or movie recommendations provided on Netflix? Thank AI for that too.

AI is defined as machines having intelligence that imitates human behaviour such as learning, planning and problem solving. A process used to achieve AI is called machine learning, where a computer uses lots of data to “train” or “teach” itself, without human intervention, to accomplish a pre-determined task. Essentially, the computer keeps on modifying its algorithm based on the information provided to get to the desired goal.

Another term you may have heard of is deep learning. Deep learning is a particular type of machine learning where algorithms are set up like the structure and function of human brains. It is similar to a network of brain cells interconnecting with each other.

Toronto has seen its fair share of media-worthy AI activity. The Government of Canada, Government of Ontario, industry and multiple universities came together in March 2018 to launch the Vector Institute, with the goal of using AI to promote economic growth and improve the lives of Canadians. In May, Samsung opened its AI Centre in the MaRS Discovery District, joining a network of Samsung centres located in California, United Kingdom and Russia.

There has been a boom in AI companies over the past few years, which span a variety of industries. This year’s ranking of the top 100 most promising private AI companies covers 25 fields with cybersecurity, enterprise and robotics being the hot focus areas.

Wong goes on to explore AI deployment in the life sciences and concludes that human scientists and doctors will still be needed although she does note this in closing (Note: A link has been removed),

More importantly, empathy and support from a fellow human being could never be fully replaced by a machine (could it?), but maybe this will change in the future. We will just have to wait and see.

Artificial empathy is the term used in Lisa Morgan’s April 25, 2018 article for Information Week which unfortunately does not include any links to actual projects or researchers working on artificial empathy. Instead, the article is focused on how business interests and marketers would like to see it employed. FWIW, I have found a few references: (1) Artificial empathy Wikipedia essay (look for the references at the end of the essay for more) and (2) this open access article: Towards Artificial Empathy; How Can Artificial Empathy Follow the Developmental Pathway of Natural Empathy? by Minoru Asada.

Please let me know in the comments if you should have an insights on the matter in the comments section of this blog.

AI x 2: the Amnesty International and Artificial Intelligence story

Amnesty International and artificial intelligence seem like an unexpected combination but it all makes sense when you read a June 13, 2018 article by Steven Melendez for Fast Company (Note: Links have been removed),

If companies working on artificial intelligence don’t take steps to safeguard human rights, “nightmare scenarios” could unfold, warns Rasha Abdul Rahim, an arms control and artificial intelligence researcher at Amnesty International in a blog post. Those scenarios could involve armed, autonomous systems choosing military targets with little human oversight, or discrimination caused by biased algorithms, she warns.

Rahim pointed at recent reports of Google’s involvement in the Pentagon’s Project Maven, which involves harnessing AI image recognition technology to rapidly process photos taken by drones. Google recently unveiled new AI ethics policies and has said it won’t continue with the project once its current contract expires next year after high-profile employee dissent over the project. …

“Compliance with the laws of war requires human judgement [sic] –the ability to analyze the intentions behind actions and make complex decisions about the proportionality or necessity of an attack,” Rahim writes. “Machines and algorithms cannot recreate these human skills, and nor can they negotiate, produce empathy, or respond to unpredictable situations. In light of these risks, Amnesty International and its partners in the Campaign to Stop Killer Robots are calling for a total ban on the development, deployment, and use of fully autonomous weapon systems.”

Rasha Abdul Rahim’s June 14, 2018 posting (I’m putting the discrepancy in publication dates down to timezone differences) on the Amnesty International website (Note: Links have been removed),

Last week [June 7, 2018] Google released a set of principles to govern its development of AI technologies. They include a broad commitment not to design or deploy AI in weaponry, and come in the wake of the company’s announcement that it will not renew its existing contract for Project Maven, the US Department of Defense’s AI initiative, when it expires in 2019.

The fact that Google maintains its existing Project Maven contract for now raises an important question. Does Google consider that continuing to provide AI technology to the US government’s drone programme is in line with its new principles? Project Maven is a litmus test that allows us to see what Google’s new principles mean in practice.

As details of the US drone programme are shrouded in secrecy, it is unclear precisely what role Google plays in Project Maven. What we do know is that US drone programme, under successive administrations, has been beset by credible allegations of unlawful killings and civilian casualties. The cooperation of Google, in any capacity, is extremely troubling and could potentially implicate it in unlawful strikes.

As AI technology advances, the question of who will be held accountable for associated human rights abuses is becoming increasingly urgent. Machine learning, and AI more broadly, impact a range of human rights including privacy, freedom of expression and the right to life. It is partly in the hands of companies like Google to safeguard these rights in relation to their operations – for us and for future generations. If they don’t, some nightmare scenarios could unfold.

Warfare has already changed dramatically in recent years – a couple of decades ago the idea of remote controlled bomber planes would have seemed like science fiction. While the drones currently in use are still controlled by humans, China, France, Israel, Russia, South Korea, the UK and the US are all known to be developing military robots which are getting smaller and more autonomous.

For example, the UK is developing a number of autonomous systems, including the BAE [Systems] Taranis, an unmanned combat aircraft system which can fly in autonomous mode and automatically identify a target within a programmed area. Kalashnikov, the Russian arms manufacturer, is developing a fully automated, high-calibre gun that uses artificial neural networks to choose targets. The US Army Research Laboratory in Maryland, in collaboration with BAE Systems and several academic institutions, has been developing micro drones which weigh less than 30 grams, as well as pocket-sized robots that can hop or crawl.

Of course, it’s not just in conflict zones that AI is threatening human rights. Machine learning is already being used by governments in a wide range of contexts that directly impact people’s lives, including policing [emphasis mine], welfare systems, criminal justice and healthcare. Some US courts use algorithms to predict future behaviour of defendants and determine their sentence lengths accordingly. The potential for this approach to reinforce power structures, discrimination or inequalities is huge.

In july 2017, the Vancouver Police Department announced its use of predictive policing software, the first such jurisdiction in Canada to make use of the technology. My Nov. 23, 2017 posting featured the announcement.

The almost too aptly named Campaign to Stop Killer Robots can be found here. Their About Us page provides a brief history,

Formed by the following non-governmental organizations (NGOs) at a meeting in New York on 19 October 2012 and launched in London in April 2013, the Campaign to Stop Killer Robots is an international coalition working to preemptively ban fully autonomous weapons. See the Chronology charting our major actions and achievements to date.

Steering Committee

The Steering Committee is the campaign’s principal leadership and decision-making body. It is comprised of five international NGOs, a regional NGO network, and four national NGOs that work internationally:

Human Rights Watch
Article 36
Association for Aid and Relief Japan
International Committee for Robot Arms Control
Mines Action Canada
Nobel Women’s Initiative
PAX (formerly known as IKV Pax Christi)
Pugwash Conferences on Science & World Affairs
Seguridad Humana en América Latina y el Caribe (SEHLAC)
Women’s International League for Peace and Freedom

For more information, see this Overview. A Terms of Reference is also available on request, detailing the committee’s selection process, mandate, decision-making, meetings and communication, and expected commitments.

For anyone who may be interested in joining Amnesty International, go here.

Seeing into silicon nanoparticles with ‘mining’ hardware

This was not the mining hardware I expected and it enters the picture after this paragraph which has been excerpted from a February 28, 2018 news item on Nanowerk,

For the first time, researchers developed a three-dimensional dynamic model of an interaction between light and nanoparticles. They used a supercomputer with graphic accelerators for calculations. Results showed that silicon particles exposed to short intense laser pulses lose their symmetry temporarily. Their optical properties become strongly heterogeneous. Such a change in properties depends on particle size, therefore it can be used for light control in ultrafast information processing nanoscale devices. …

A March 2, 2018 ITMO University (Russia) press release (also on EurekAlert), which originated the news item, provides more detail and a mention of ‘cryptocurrency mining’ hardware,

Improvement of computing devices today focuses on increasing information processing speeds. Nanophotonics is one of the sciences that can solve this problem by means of optical devices. Although optical signals can be transmitted and processed much faster than electronic ones, first, it is necessary to learn how to quickly control light on a small scale. For this purpose, one could use metal particles. They are efficient at localizing light, but weaken the signal, causing significant losses. However, dielectric and semiconducting materials, such as silicon, can be used instead of metal.

Silicon nanoparticles are now actively studied by researchers all around the world, including those at ITMO University. The long-term goal of such studies is to create ultrafast, compact optical signal modulators. They can serve as a basis for computers of the future. However, this technology will become feasible only once we understand how nanoparticles interact with light.

Silicon nanoparticles
Silicon nanoparticles

“When a laser pulse hits the particle, a lot of free electrons are formed inside,” explains Sergey Makarov, head of ITMO’s Laboratory of Hybrid Nanophotonics and Optoelectronics. “A region saturated with oppositely charged particles is created. It is usually called electron-hole plasma. Plasma changes optical properties of particles and, up until today, it was believed that it spreads over the whole particle simultaneously, so that the particle’s symmetry is preserved. We demonstrated that this is not entirely true and an even distribution of plasma inside particles is not the only possible scenario.”

Scientists found that the electromagnetic field caused by an interaction between light and particles has a more complex structure. This leads to a light distortion which varies with time. Therefore, the symmetry of particles is disturbed and optical properties become different throughout one particle.

“Using analytical and numerical methods, we were the first to look inside the particle and we proved that the processes taking place there are far more complicated than we thought,” says Konstantin Ladutenko, staff member of ITMO’s International Research Center of Nanophotonics and Metamaterials.  “Moreover, we found that by changing the particle size, we can affect its interaction with the light signal. This means we might be able to predict the signal path in an entire system of nanoparticles.”

In order to create a tool to study processes inside nanoparticles, scientists from ITMO University joined forces with colleagues from Jean Monnet University in France.

Sergey Makarov
Sergey Makarov

We developed analytical methods to determine the size range of the particles and their refractive index which would make a change in optical properties likely. Afterwards, we used powerful computational methods to monitor processes inside particles. Our colleagues performed calculations on a computer with graphics accelerators. Such computers are often used for cryptocurrency mining [emphasis mine]. However, we decided to enrich humanity with new knowledge, rather than enrich ourselves. Besides, bitcoin rate had just started to go down then,” adds Konstantin.

Devices based on these nanoparticles may become basic elements of optical computers, just as transistors are basic elements of electronics today. They will make it possible to distribute and redirect or branch the signal.

“Such asymmetric structures have a variety of applications, but we are focusing on ultra-fast signal processing,” continues Sergey.We now have a powerful theoretical tool which will help us develop light management systems that will operate on a small scale – in terms of both time and space”.

Here’s a little more about ITMO University from its Wikipedia entry (Note: Links have been removed),

ITMO University (Russian: Университет ИТМО) is a large state university in Saint Petersburg and is one of Russia’s National Research Universities.[1] ITMO University is one of 15 Russian universities that were selected to participate in Russian Academic Excellence Project 5-100[2] by the government of the Russian Federation to improve their international competitiveness among the world’s leading research and educational centers.[3]

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

Photogenerated Free Carrier-Induced Symmetry Breaking in Spherical Silicon Nanoparticle by Anton Rudenko, Konstantin Ladutenko, Sergey Makarov, and Tatiana E. Itina.Advanced Optical Materials Vol. 6 Issue 5 DOI: 10.1002/adom.201701153 Version of Record online: 29 JAN 2018

© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.