Monthly Archives: April 2016

An atom without properties?

There’s rather intriguing Swiss research into atoms and so-called Bell Correlations according to an April 21, 2016 news item on ScienceDaily,

The microscopic world is governed by the rules of quantum mechanics, where the properties of a particle can be completely undetermined and yet strongly correlated with those of other particles. Physicists from the University of Basel have observed these so-called Bell correlations for the first time between hundreds of atoms. Their findings are published in the scientific journal Science.

Everyday objects possess properties independently of each other and regardless of whether we observe them or not. Einstein famously asked whether the moon still exists if no one is there to look at it; we answer with a resounding yes. This apparent certainty does not exist in the realm of small particles. The location, speed or magnetic moment of an atom can be entirely indeterminate and yet still depend greatly on the measurements of other distant atoms.

An April 21, 2016 University of Basel (Switzerland) press release (also on EurekAlert), which originated the news item, provides further explanation,

With the (false) assumption that atoms possess their properties independently of measurements and independently of each other, a so-called Bell inequality can be derived. If it is violated by the results of an experiment, it follows that the properties of the atoms must be interdependent. This is described as Bell correlations between atoms, which also imply that each atom takes on its properties only at the moment of the measurement. Before the measurement, these properties are not only unknown – they do not even exist.

A team of researchers led by professors Nicolas Sangouard and Philipp Treutlein from the University of Basel, along with colleagues from Singapore, have now observed these Bell correlations for the first time in a relatively large system, specifically among 480 atoms in a Bose-Einstein condensate. Earlier experiments showed Bell correlations with a maximum of four light particles or 14 atoms. The results mean that these peculiar quantum effects may also play a role in larger systems.

Large number of interacting particles

In order to observe Bell correlations in systems consisting of many particles, the researchers first had to develop a new method that does not require measuring each particle individually – which would require a level of control beyond what is currently possible. The team succeeded in this task with the help of a Bell inequality that was only recently discovered. The Basel researchers tested their method in the lab with small clouds of ultracold atoms cooled with laser light down to a few billionths of a degree above absolute zero. The atoms in the cloud constantly collide, causing their magnetic moments to become slowly entangled. When this entanglement reaches a certain magnitude, Bell correlations can be detected. Author Roman Schmied explains: “One would expect that random collisions simply cause disorder. Instead, the quantum-mechanical properties become entangled so strongly that they violate classical statistics.”

More specifically, each atom is first brought into a quantum superposition of two states. After the atoms have become entangled through collisions, researchers count how many of the atoms are actually in each of the two states. This division varies randomly between trials. If these variations fall below a certain threshold, it appears as if the atoms have ‘agreed’ on their measurement results; this agreement describes precisely the Bell correlations.

New scientific territory

The work presented, which was funded by the National Centre of Competence in Research Quantum Science and Technology (NCCR QSIT), may open up new possibilities in quantum technology; for example, for generating random numbers or for quantum-secure data transmission. New prospects in basic research open up as well: “Bell correlations in many-particle systems are a largely unexplored field with many open questions – we are entering uncharted territory with our experiments,” says Philipp Treutlein.

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

Bell correlations in a Bose-Einstein condensate by Roman Schmied, Jean-Daniel Bancal, Baptiste Allard, Matteo Fadel, Valerio Scarani, Philipp Treutlein, Nicolas Sangouard. Science  22 Apr 2016: Vol. 352, Issue 6284, pp. 441-444 DOI: 10.1126/science.aad8665

This paper is behind a paywall.

A ‘Candy Crush’ like video game for malaria

Yesterday*, April 25, 2016 was* World Malaria Day and the launch date for a new video game according to an April 25, 2016 news item on ScienceDaily,

Shoot bubbles while helping research against malaria? It is possible with MalariaSpot Bubbles, an online game that launches on April 25, World Malaria Day. Players analyze digitalized images of parasites to differentiate between the five species that cause malaria. They do it while having fun shooting at mosquitoes and bubbles. It is an application to learning through play and to contribute to the research of new diagnosis methods. MalariaSpot Bubbles has been developed by researchers of the Biomedical Imaging Technologies Group at the Technical University of Madrid — International Excellence Campus Moncloa.

An April 25, 2016 Universidad Politécnica de Madrid (Technical University of Madrid) press release, which originated the news item, describes the game and the goal in more detail (Note 1: A link has been removed; Note 2: I believe this text was originally in Spanish and then translated by machine resulting in a few unusual grammatical structures),

MalariaSpot Bubbles is an educational tool to research how young students acquire skills through gaming. During World Malaria Day thousands of students will participate in “Olympic Malaria Videogames” playing MalariaSpot Bubbles, a video game that uses images of digitized blood samples. During this day school teams will compete to become the best virtual hunters of malaria parasites.

“Digital natives around the world spend millions of hours a day playing video games. MalariaSpot Bubbles is an experiment to explore this potential as a new solution to global health problems” says Daniel Cuadrado, MalariaSpot developer and researcher at the Technical University of Madrid.

Diagnosis for everyone by everyone

MalariaSpot Bubbles not only allow players to learn, but also to participate in the research of new tools for collaborative diagnosis online. Malaria is diagnosed by observing a blood smear with a microscope and looking for parasites. Part of the diagnostic protocol is to identify which of the five different species that cause malaria is present in the blood. “This is especially important to provide the proper treatment to the patients”, says María Linares, researcher at Hospital 12 de Octubre and MalariaSpot biomedical specialist. The aim of MalariaSpot Bubbles is to research if remote diagnosis could be performed collectively by non experts, expanding the concept initiated four years ago with the first version of the game MalariaSpot. This project has been recently featured in the prestigious medical journal The Lancet.

Here’s a video introduction to the game,

And, here’s a link to and a citation for the paper in Lancet,

Gamers join real-life fight against malaria and tuberculosis by Leonore Albers. Lancet Volume 16, No. 4, p418, April 2016 DOI: http://dx.doi.org/10.1016/S1473-3099(16)00136-5

This paper is behind a paywall.

Should you wish to play, the MalariaSpot Bubbles website is here.

*Oops! ‘Today’ changed to ‘Yesterday’ and ‘is’ changed to ‘was’ since today is April 26, 2016.

Artificial intelligence used for wildlife protection

PAWS (Protection Assistant for Wildlife Security), an artificial intelligence (AI) program, has been tested in Uganda and Malaysia. according to an April 22, 2016 US National Science Foundation (NSF) news release (also on EurekAlert but dated April 21, 2016), Note: Links have been removed,

A century ago, more than 60,000 tigers roamed the wild. Today, the worldwide estimate has dwindled to around 3,200. Poaching is one of the main drivers of this precipitous drop. Whether killed for skins, medicine or trophy hunting, humans have pushed tigers to near-extinction. The same applies to other large animal species like elephants and rhinoceros that play unique and crucial roles in the ecosystems where they live.

Human patrols serve as the most direct form of protection of endangered animals, especially in large national parks. However, protection agencies have limited resources for patrols.

With support from the National Science Foundation (NSF) and the Army Research Office, researchers are using artificial intelligence (AI) and game theory to solve poaching, illegal logging and other problems worldwide, in collaboration with researchers and conservationists in the U.S., Singapore, Netherlands and Malaysia.

“In most parks, ranger patrols are poorly planned, reactive rather than pro-active, and habitual,” according to Fei Fang, a Ph.D. candidate in the computer science department at the University of Southern California (USC).

Fang is part of an NSF-funded team at USC led by Milind Tambe, professor of computer science and industrial and systems engineering and director of the Teamcore Research Group on Agents and Multiagent Systems.

Their research builds on the idea of “green security games” — the application of game theory to wildlife protection. Game theory uses mathematical and computer models of conflict and cooperation between rational decision-makers to predict the behavior of adversaries and plan optimal approaches for containment. The Coast Guard and Transportation Security Administration have used similar methods developed by Tambe and others to protect airports and waterways.

“This research is a step in demonstrating that AI can have a really significant positive impact on society and allow us to assist humanity in solving some of the major challenges we face,” Tambe said.

PAWS puts the claws in anti-poaching

The team presented papers describing how they use their methods to improve the success of human patrols around the world at the AAAI Conference on Artificial Intelligence in February [2016].

The researchers first created an AI-driven application called PAWS (Protection Assistant for Wildlife Security) in 2013 and tested the application in Uganda and Malaysia in 2014. Pilot implementations of PAWS revealed some limitations, but also led to significant improvements.

Here’s a video describing the issues and PAWS,

For those who prefer to read about details rather listen, there’s more from the news release,

PAWS uses data on past patrols and evidence of poaching. As it receives more data, the system “learns” and improves its patrol planning. Already, the system has led to more observations of poacher activities per kilometer.

Its key technical advance lies in its ability to incorporate complex terrain information, including the topography of protected areas. That results in practical patrol routes that minimize elevation changes, saving time and energy. Moreover, the system can also take into account the natural transit paths that have the most animal traffic – and thus the most poaching – creating a “street map” for patrols.

“We need to provide actual patrol routes that can be practically followed,” Fang said. “These routes need to go back to a base camp and the patrols can’t be too long. We list all possible patrol routes and then determine which is most effective.”

The application also randomizes patrols to avoid falling into predictable patterns.

“If the poachers observe that patrols go to some areas more often than others, then the poachers place their snares elsewhere,” Fang said.

Since 2015, two non-governmental organizations, Panthera and Rimbat, have used PAWS to protect forests in Malaysia. The research won the Innovative Applications of Artificial Intelligence award for deployed application, as one of the best AI applications with measurable benefits.

The team recently combined PAWS with a new tool called CAPTURE (Comprehensive Anti-Poaching Tool with Temporal and Observation Uncertainty Reasoning) that predicts attacking probability even more accurately.

In addition to helping patrols find poachers, the tools may assist them with intercepting trafficked wildlife products and other high-risk cargo, adding another layer to wildlife protection. The researchers are in conversations with wildlife authorities in Uganda to deploy the system later this year. They will present their findings at the 15th International Conference on Autonomous Agents and Multiagent Systems (AAMAS 2016) in May.

“There is an urgent need to protect the natural resources and wildlife on our beautiful planet, and we computer scientists can help in various ways,” Fang said. “Our work on PAWS addresses one facet of the problem, improving the efficiency of patrols to combat poaching.”

There is yet another potential use for PAWS, the prevention of illegal logging,

While Fang and her colleagues work to develop effective anti-poaching patrol planning systems, other members of the USC team are developing complementary methods to prevent illegal logging, a major economic and environmental problem for many developing countries.

The World Wildlife Fund estimates trade in illegally harvested timber to be worth between $30 billion and $100 billion annually. The practice also threatens ancient forests and critical habitats for wildlife.

Researchers at USC, the University of Texas at El Paso and Michigan State University recently partnered with the non-profit organization Alliance Vohoary Gasy to limit the illegal logging of rosewood and ebony trees in Madagascar, which has caused a loss of forest cover on the island nation.

Forest protection agencies also face limited budgets and must cover large areas, making sound investments in security resources critical.

The research team worked to determine the balance of security resources in which Madagascar should invest to maximize protection, and to figure out how to best deploy those resources.

Past work in game theory-based security typically involved specified teams — the security workers assigned to airport checkpoints, for example, or the air marshals deployed on flight tours. Finding optimal security solutions for those scenarios is difficult; a solution involving an open-ended team had not previously been feasible.

To solve this problem, the researchers developed a new method called SORT (Simultaneous Optimization of Resource Teams) that they have been experimentally validating using real data from Madagascar.

The research team created maps of the national parks, modeled the costs of all possible security resources using local salaries and budgets, and computed the best combination of resources given these conditions.

“We compared the value of using an optimal team determined by our algorithm versus a randomly chosen team and the algorithm did significantly better,” said Sara Mc Carthy, a Ph.D. student in computer science at USC.

The algorithm is simple and fast, and can be generalized to other national parks with different characteristics. The team is working to deploy it in Madagascar in association with the Alliance Vohoary Gasy.

“I am very proud of what my PhD students Fei Fang and Sara Mc Carthy have accomplished in this research on AI for wildlife security and forest protection,” said Tambe, the team lead. “Interdisciplinary collaboration with practitioners in the field was key in this research and allowed us to improve our research in artificial intelligence.”

Moreover, the project shows other computer science researchers the potential impact of applying their research to the world’s problems.

“This work is not only important because of the direct beneficial impact that it has on the environment, protecting wildlife and forests, but on the way that it can inspire other to dedicate their efforts into making the world a better place,” Mc Carthy said.

The curious can find out more about Panthera here and about Alliance Vohoary Gasy here (be prepared to use your French language skills). Unfortunately, I could not find more information about Rimbat.

3D printed clothing

A seamless garment or article of footwear would minimize skin irritation for those of us not able to afford custom couture and an April 19, 2016 news item on ScienceDaily offers hope in an announcement of efforts by a team of UK scientists to change the textile industry’s approach to garment and footwear construction,

Loughborough University has teamed up with global textile and garment manufacturer the Yeh Group, to embark on landmark work in 3D textile printing that could revolutionise how clothes and footwear are made.

Personalised 3D printed fashion — manufactured within 24 hours — is the end goal of a new project led by Loughborough University that’s set to change the way we shop for clothes.

An April 18, 2016 Loughborough University press release, which originated the news item, describes the project (Note: Links have been removed),

Dr Guy Bingham, Senior Lecturer in Product and Industrial Design, has teamed up with global textile and garment manufacturer the Yeh Group, to embark on landmark work in 3D textile printing that could revolutionise how clothes and footwear are made.

The 18-month project[1], known as 3D Fashion, will see Dr Bingham – a world leader in his field – produce 3D wearable, full size, Additive Manufacturing (AM) textile garments and footwear – with design input from a major fashion house.

Advancements in AM textiles have made it possible to produce 3D printed garments directly from raw material, such as polymer, in a single manufacturing operation. This technology not only has the potential to reduce waste, labour costs and CO2e, but can modernise clothing production by encouraging localised manufacturing and production.

Currently, garment manufacture generates 1.8 million tonnes of waste material – equivalent to 70kg or 100 pairs of jeans per UK household, with 6.3 billion m³ of water used in the process – equivalent to 200,000 litres per year per household or 1,000 filled bathtubs[2].

Dr Bingham said: “With 3D printing there is no limit to what you can build and it is this design freedom which makes the technology so exciting by bringing to life what was previously considered to be impossible.

“This landmark technology allows us as designers to innovate faster and create personalised, ready-to-wear fashion in a digital world with no geometrical constraints and almost zero waste material. We envisage that with further development of the technology, we could 3D print a garment within 24 hours.

David Yeh, Managing Director, Tong Siang (Yeh Group), said: “3D Fashion supports the Yeh Group vision of direct polymer to garment manufacture. The Yeh Group is always striving to cut out unnecessary waste and resource use, and support the industries goals of faster to market, creating a manufacturing technology that brands and retailers can install closer to their customers. This is all with no compromise to performance.”

Loughborough University has produced a video about this project,

You can find out more about the Yeh Group on their website or on their Facebook page. I believe the company is headquartered in Thailand but I can’t tell if Tong Siang (the Yeh Group? on LinkedIn) is the corporate parent, the subsidiary, or an alternate company name.

MIT.nano building update

A few years ago I featured a story (my May 6, 2014 posting) about a new building, the MIT.nano, being constructed on the Massachusetts Institute of Technology campus. Now at about 1/2 way through the construction (the building is due to open in 2018) MIT has issued an update in an April 20, 2016 news release by Leda Zimmerman,

A spectacular show has been going on outside the windows of central-campus buildings all spring. An enormous steel structure has been growing — piece by piece, and bolt by bolt — out of a giant hole in the ground formerly occupied by Building 12. At a March 24 [2016] “tool talk” information session for the MIT community on the construction of MIT.nano, representatives from MIT Facilities and the contractors who are building the new 200,000 square foot nanoscale characterization and fabrication facility gave an overview not only of where things stand with the project, but how they got stood up.

“In our structural-steel erection progress log, we’ve been averaging around 23 tons per day,” said Peter Johnson of Turner Construction. “We’re putting up 2,101 tons total, and we’re 22 percent complete.”

There is a Canadian connection,

Working with Ontario-based steel fabricator, Canatal, Johnson and his colleagues at Turner developed a four-dimensional plan for steel engineering, delivery, and installation. “We went through a painstaking process to maximize efficiency of this sequence,” says Johnson. “This allows us to avoid times when a crane is down because it’s waiting” for a delivery of steel.

There are some very interesting details in the news release but if you don’t have the time, there is this picture,

MIT.nano steel structure, looking northwest. Photo: Lillie Paquette/School of Engineering

MIT.nano steel structure, looking northwest. Photo: Lillie Paquette/School of Engineering

The colours are quite striking (I suspect they have been enhanced).

Self-assembling molecular rings from McMaster University (Canada)

An April 21, 2016 news item on Nanotechnology Now highlights some research from Canada’s McMaster University,

Imagine throwing Lego pieces into the air and seeing them fall to the ground assembled into the shape of a house or plane.

Nature effortlessly does the equivalent all the time, using molecules as building blocks.

The right combination of ingredients and conditions spontaneously assembles structures as complex as viruses or cellular membranes. Chemists marvel at this very efficient approach to creating large molecular structures and keep searching for new ways to emulate the process using their own components.

Now, in a McMaster University laboratory, chemistry researchers have managed to coax molecules known as tellurazole oxides into assembling themselves into cyclic structures – a major advance in their field that creates a new and promising set of materials.

An April 20, 2016 McMaster University news release by Wade Hemsworth, which originated the news item, provides more detail,

“This is a seed we have found – one we have never seen. It has sprouted, now we need to see how tall the tree will grow and what kind of fruit it will bear,” says Ignacio Vargas Baca, an associate professor in McMaster’s Department of Chemistry and Chemical Biology. “Once we understand the properties of these new materials, we can look at their potential applications.”

Barca’s group works in the realm of supramolecular chemistry, where the key is to exploit the forces that keep molecules together. Hydrogen atoms, for example, can form strong bridges between water molecules or pairs of DNA strands.

Earlier, the realization that atoms of iodine and bromine can act in a similar way had sparked great excitement in chemistry circles, giving rise to the hot field of “halogen bonding,” where other researchers have had success with enormous assemblies, but have had difficulties controlling the association of just a few molecules.

Meanwhile, Vargas’ group moved over one column on the periodic table of elements to work with chalcogens instead.

They discovered that certain molecules that contain the element tellurium assemble automatically into rings in solution, a success that has no rival in halogen bonding and constitutes a significant advance in supramolecular chemistry.

For now, he and his team envision uses in areas as diverse as communication technologies, gas storage and catalysis.

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

Supramolecular macrocycles reversibly assembled by Te…O chalcogen bonding by Peter C. Ho, Patrick Szydlowski, Jocelyn Sinclair, Philip J. W. Elder, Joachim Kübel, Chris Gendy, Lucia Myongwon Lee, Hilary Jenkins, James F. Britten, Derek R. Morim, & Ignacio Vargas-Baca.    Nature Communications 7, Article number: 11299  doi:10.1038/ncomms11299 Published 19 April 2016

This is an open access paper.

Memristor-based electronic synapses for neural networks

Caption: Neuron connections in biological neural networks. Credit: MIPT press office

Caption: Neuron connections in biological neural networks. Credit: MIPT press office

Russian scientists have recently published a paper about neural networks and electronic synapses based on ‘thin film’ memristors according to an April 19, 2016 news item on Nanowerk,

A team of scientists from the Moscow Institute of Physics and Technology (MIPT) have created prototypes of “electronic synapses” based on ultra-thin films of hafnium oxide (HfO2). These prototypes could potentially be used in fundamentally new computing systems.

An April 20, 2016 MIPT press release (also on EurekAlert), which originated the news item (the date inconsistency likely due to timezone differences) explains the connection between thin films and memristors,

The group of researchers from MIPT have made HfO2-based memristors measuring just 40×40 nm2. The nanostructures they built exhibit properties similar to biological synapses. Using newly developed technology, the memristors were integrated in matrices: in the future this technology may be used to design computers that function similar to biological neural networks.

Memristors (resistors with memory) are devices that are able to change their state (conductivity) depending on the charge passing through them, and they therefore have a memory of their “history”. In this study, the scientists used devices based on thin-film hafnium oxide, a material that is already used in the production of modern processors. This means that this new lab technology could, if required, easily be used in industrial processes.

“In a simpler version, memristors are promising binary non-volatile memory cells, in which information is written by switching the electric resistance – from high to low and back again. What we are trying to demonstrate are much more complex functions of memristors – that they behave similar to biological synapses,” said Yury Matveyev, the corresponding author of the paper, and senior researcher of MIPT’s Laboratory of Functional Materials and Devices for Nanoelectronics, commenting on the study.

The press release offers a description of biological synapses and their relationship to learning and memory,

A synapse is point of connection between neurons, the main function of which is to transmit a signal (a spike – a particular type of signal, see fig. 2) from one neuron to another. Each neuron may have thousands of synapses, i.e. connect with a large number of other neurons. This means that information can be processed in parallel, rather than sequentially (as in modern computers). This is the reason why “living” neural networks are so immensely effective both in terms of speed and energy consumption in solving large range of tasks, such as image / voice recognition, etc.

Over time, synapses may change their “weight”, i.e. their ability to transmit a signal. This property is believed to be the key to understanding the learning and memory functions of thebrain.

From the physical point of view, synaptic “memory” and “learning” in the brain can be interpreted as follows: the neural connection possesses a certain “conductivity”, which is determined by the previous “history” of signals that have passed through the connection. If a synapse transmits a signal from one neuron to another, we can say that it has high “conductivity”, and if it does not, we say it has low “conductivity”. However, synapses do not simply function in on/off mode; they can have any intermediate “weight” (intermediate conductivity value). Accordingly, if we want to simulate them using certain devices, these devices will also have to have analogous characteristics.

The researchers have provided an illustration of a biological synapse,

Fig.2 The type of electrical signal transmitted by neurons (a “spike”). The red lines are various other biological signals, the black line is the averaged signal. Source: MIPT press office

Fig.2 The type of electrical signal transmitted by neurons (a “spike”). The red lines are various other biological signals, the black line is the averaged signal. Source: MIPT press office

Now, the press release ties the memristor information together with the biological synapse information to describe the new work at the MIPT,

As in a biological synapse, the value of the electrical conductivity of a memristor is the result of its previous “life” – from the moment it was made.

There is a number of physical effects that can be exploited to design memristors. In this study, the authors used devices based on ultrathin-film hafnium oxide, which exhibit the effect of soft (reversible) electrical breakdown under an applied external electric field. Most often, these devices use only two different states encoding logic zero and one. However, in order to simulate biological synapses, a continuous spectrum of conductivities had to be used in the devices.

“The detailed physical mechanism behind the function of the memristors in question is still debated. However, the qualitative model is as follows: in the metal–ultrathin oxide–metal structure, charged point defects, such as vacancies of oxygen atoms, are formed and move around in the oxide layer when exposed to an electric field. It is these defects that are responsible for the reversible change in the conductivity of the oxide layer,” says the co-author of the paper and researcher of MIPT’s Laboratory of Functional Materials and Devices for Nanoelectronics, Sergey Zakharchenko.

The authors used the newly developed “analogue” memristors to model various learning mechanisms (“plasticity”) of biological synapses. In particular, this involved functions such as long-term potentiation (LTP) or long-term depression (LTD) of a connection between two neurons. It is generally accepted that these functions are the underlying mechanisms of  memory in the brain.

The authors also succeeded in demonstrating a more complex mechanism – spike-timing-dependent plasticity, i.e. the dependence of the value of the connection between neurons on the relative time taken for them to be “triggered”. It had previously been shown that this mechanism is responsible for associative learning – the ability of the brain to find connections between different events.

To demonstrate this function in their memristor devices, the authors purposefully used an electric signal which reproduced, as far as possible, the signals in living neurons, and they obtained a dependency very similar to those observed in living synapses (see fig. 3).

Fig.3. The change in conductivity of memristors depending on the temporal separation between "spikes"(rigth) and thr change in potential of the neuron connections in biological neural networks. Source: MIPT press office

Fig.3. The change in conductivity of memristors depending on the temporal separation between “spikes”(rigth) and thr change in potential of the neuron connections in biological neural networks. Source: MIPT press office

These results allowed the authors to confirm that the elements that they had developed could be considered a prototype of the “electronic synapse”, which could be used as a basis for the hardware implementation of artificial neural networks.

“We have created a baseline matrix of nanoscale memristors demonstrating the properties of biological synapses. Thanks to this research, we are now one step closer to building an artificial neural network. It may only be the very simplest of networks, but it is nevertheless a hardware prototype,” said the head of MIPT’s Laboratory of Functional Materials and Devices for Nanoelectronics, Andrey Zenkevich.

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

Crossbar Nanoscale HfO2-Based Electronic Synapses by Yury Matveyev, Roman Kirtaev, Alena Fetisova, Sergey Zakharchenko, Dmitry Negrov and Andrey Zenkevich. Nanoscale Research Letters201611:147 DOI: 10.1186/s11671-016-1360-6

Published: 15 March 2016

This is an open access paper.

Graphene Flagship high points

The European Union’s Graphene Flagship project has provided a series of highlights in place of an overview for the project’s ramp-up phase (in 2013 the Graphene Flagship was announced as one of two winners of a science competition, the other winner was the Human Brain Project, with two prizes of 1B Euros for each project). Here are the highlights from the April 19, 2016 Graphene Flagship press release,

Graphene and Neurons – the Best of Friends

Flagship researchers have shown that it is possible to interface untreated graphene with neuron cells whilst maintaining the integrity of these vital cells [1]. This result is a significant first step towards using graphene to produce better deep brain implants which can both harness and control the brain.

Graphene and Neurons
 

This paper emerged from the Graphene Flagship Work Package Health and Environment. Prof. Prato, the WP leader from the University of Trieste in Italy, commented that “We are currently involved in frontline research in graphene technology towards biomedical applications, exploring the interactions between graphene nano- and micro-sheets with the sophisticated signalling machinery of nerve cells. Our work is a first step in that direction.”

[1] Fabbro A., et al., Graphene-Based Interfaces do not Alter Target Nerve Cells. ACS Nano, 10 (1), 615 (2016).

Pressure Sensing with Graphene: Quite a Squeeze

The Graphene Flagship developed a small, robust, highly efficient squeeze film pressure sensor [2]. Pressure sensors are present in most mobile handsets and by replacing current sensor membranes with a graphene membrane they allow the sensor to decrease in size and significantly increase its responsiveness and lifetime.

Discussing this work which emerged from the Graphene Flagship Work Package Sensors is the paper’s lead author, Robin Dolleman from the Technical University of Delft in The Netherlands “After spending a year modelling various systems the idea of the squeeze-film pressure sensor was formed. Funding from the Graphene Flagship provided the opportunity to perform the experiments and we obtained very good results. We built a squeeze-film pressure sensor from 31 layers of graphene, which showed a 45 times higher response than silicon based devices, while reducing the area of the device by a factor of 25. Currently, our work is focused on obtaining similar results on monolayer graphene.”

 

[2] Dolleman R. J. et al., Graphene Squeeze-Film Pressure Sensors. Nano Lett., 16, 568 (2016)

Frictionless Graphene


Image caption: A graphene nanoribbon was anchored at the tip of a atomic force microscope and dragged over a gold surface. The observed friction force was extremely low.

Image caption: A graphene nanoribbon was anchored at the tip of a atomic force microscope and dragged over a gold surface. The observed friction force was extremely low.

Research done within the Graphene Flagship, has observed the onset of superlubricity in graphene nanoribbons sliding on a surface, unravelling the role played by ribbon size and elasticity [3]. This important finding opens up the development potential of nanographene frictionless coatings. This research lead by the Graphene Flagship Work Package Nanocomposites also involved researchers from Work Package Materials and Work Package Health and the Environment, a shining example of the inter-disciplinary, cross-collaborative approach to research undertaken within the Graphene Flagship. Discussing this further is the Work Package Nanocomposites Leader, Dr Vincenzo Palermo from CNR National Research Council, Italy “Strengthening the collaboration and interactions with other Flagship Work Packages created added value through a strong exchange of materials, samples and information”.

[3] Kawai S., et al., Superlubricity of graphene nanoribbons on gold surfaces. Science. 351, 6276, 957 (2016) 

​Graphene Paddles Forward

Work undertaken within the Graphene Flagship saw Spanish automotive interiors specialist, and Flagship partner, Grupo Antolin SA work in collaboration with Roman Kayaks to develop an innovative kayak that incorporates graphene into its thermoset polymeric matrices. The use of graphene and related materials results in a significant increase in both impact strength and stiffness, improving the resistance to breakage in critical areas of the boat. Pushing the graphene canoe well beyond the prototype demonstration bubble, Roman Kayaks chose to use the K-1 kayak in the Canoe Marathon World Championships held in September in Gyor, Hungary where the Graphene Canoe was really put through its paces.

Talking further about this collaboration from the Graphene Flagship Work Package Production is the WP leader, Dr Ken Teo from Aixtron Ltd., UK “In the Graphene Flagship project, Work Package Production works as a technology enabler for real-world applications. Here we show the worlds first K-1 kayak (5.2 meters long), using graphene related materials developed by Grupo Antolin. We are very happy to see that graphene is creating value beyond traditional industries.” 

​Graphene Production – a Kitchen Sink Approach

Researchers from the Graphene Flagship have devised a way of producing large quantities of graphene by separating graphite flakes in liquids with a rotating tool that works in much the same way as a kitchen blender [4]. This paves the way to mass production of high quality graphene at a low cost.

The method was produced within the Graphene Flagship Work Package Production and is talked about further here by the WP deputy leader, Prof. Jonathan Coleman from Trinity College Dublin, Ireland “This technique produced graphene at higher rates than most other methods, and produced sheets of 2D materials that will be useful in a range of applications, from printed electronics to energy generation.” 

[4] Paton K.R., et al., Scalable production of large quantities of defect-free few-layer graphene by shear exfoliation in liquids. Nat. Mater. 13, 624 (2014).

Flexible Displays – Rolled Up in your Pocket

Working with researchers from the Graphene Flagship the Flagship partner, FlexEnable, demonstrated the world’s first flexible display with graphene incorporated into its pixel backplane. Combined with an electrophoretic imaging film, the result is a low-power, durable display suitable for use in many and varied environments.

Emerging from the Graphene Flagship Work Package Flexible Electronics this illustrates the power of collaboration.  Talking about this is the WP leader Dr Henrik Sandberg from the VTT Technical Research Centre of Finland Ltd., Finland “Here we show the power of collaboration. To deliver these flexible demonstrators and prototypes we have seen materials experts working together with components manufacturers and system integrators. These devices will have a potential impact in several emerging fields such as wearables and the Internet of Things.”

​Fibre-Optics Data Boost from Graphene

A team of researches from the Graphene Flagship have demonstrated high-performance photo detectors for infrared fibre-optic communication systems based on wafer-scale graphene [5]. This can increase the amount of information transferred whilst at the same time make the devises smaller and more cost effective.

Discussing this work which emerged from the Graphene Flagship Work Package Optoelectronics is the paper’s lead author, Daniel Schall from AMO, Germany “Graphene has outstanding properties when it comes to the mobility of its electric charge carriers, and this can increase the speed at which electronic devices operate.”

[5] Schall D., et al., 50 GBit/s Photodetectors Based on Wafer-Scale Graphene for Integrated Silicon Photonic Communication Systems. ACS Photonics. 1 (9), 781 (2014)

​Rechargeable Batteries with Graphene

A number of different research groups within the Graphene Flagship are working on rechargeable batteries. One group has developed a graphene-based rechargeable battery of the lithium-ion type used in portable electronic devices [6]. Graphene is incorporated into the battery anode in the form of a spreadable ink containing a suspension of graphene nanoflakes giving an increased energy efficiency of 20%. A second group of researchers have demonstrated a lithium-oxygen battery with high energy density, efficiency and stability [7]. They produced a device with over 90% efficiency that may be recharged more than 2,000 times. Their lithium-oxygen cell features a porous, ‘fluffy’ electrode made from graphene together with additives that alter the chemical reactions at work in the battery.

Graphene Flagship researchers show how the 2D material graphene can improve the energy capacity, efficiency and stability of lithium-oxygen batteries.

Both devices were developed in different groups within the Graphene Flagship Work Package Energy and speaking of the technology further is Prof. Clare Grey from Cambridge University, UK “What we’ve achieved is a significant advance for this technology, and suggests whole new areas for research – we haven’t solved all the problems inherent to this chemistry, but our results do show routes forward towards a practical device”.

[6] Liu T., et al. Cycling Li-O2 batteries via LiOH formation and decomposition. Science. 350, 6260, 530 (2015)

[7] Hassoun J., et al., An Advanced Lithium-Ion Battery Based on a Graphene Anode and a Lithium Iron Phosphate Cathode. Nano Lett., 14 (8), 4901 (2014)

Graphene – What and Why?

Graphene is a two-dimensional material formed by a single atom-thick layer of carbon, with the carbon atoms arranged in a honeycomb-like lattice. This transparent, flexible material has a number of unique properties. For example, it is 100 times stronger than steel, and conducts electricity and heat with great efficiency.

A number of practical applications for graphene are currently being developed. These include flexible and wearable electronics and antennas, sensors, optoelectronics and data communication systems, medical and bioengineering technologies, filtration, super-strong composites, photovoltaics and energy storage.

Graphene and Beyond

The Graphene Flagship also covers other layered materials, as well as hybrids formed by combining graphene with these complementary materials, or with other materials and structures, ranging from polymers, to metals, cement, and traditional semiconductors such as silicon. Graphene is just the first of thousands of possible single layer materials. The Flagship plans to accelerate their journey from laboratory to factory floor.

Especially exciting is the possibility of stacking monolayers of different elements to create materials not found in nature, with properties tailored for specific applications. Such composite layered materials could be combined with other nanomaterials, such as metal nanoparticles, in order to further enhance their properties and uses.​

Graphene – the Fruit of European Scientific Excellence

Europe, North America and Asia are all active centres of graphene R&D, but Europe has special claim to be at the centre of this activity. The ground-breaking experiments on graphene recognised in the award of the 2010 Nobel Prize in Physics were conducted by European physicists, Andre Geim and Konstantin Novoselov, both at Manchester University. Since then, graphene research in Europe has continued apace, with major public funding for specialist centres, and the stimulation of academic-industrial partnerships devoted to graphene and related materials. It is European scientists and engineers who as part of the Graphene Flagship are closely coordinating research efforts, and accelerating the transfer of layered materials from the laboratory to factory floor.

For anyone who would like links to the published papers, you can check out an April 20, 2016 news item featuring the Graphene Flagship highlights on Nanowerk.

Results in for Generation Nano: Small Science, Superheroes contest

The Generation Nano: Small Science, Superheroes contest last mentioned in my March 31, 2016 posting has ended and the placement of the winners, in a field of three finalists, announced at the 2016 USA Science and Engineering Festival according to an April 18, 2016 US National Science Foundation news release,

On behalf of the National Science Foundation (NSF), actor Wil Wheaton and legendary superhero creator Stan Lee yesterday announced the winners of the Generation Nano: Small Science, Superheroescompetition, sponsored by NSF and the National Nanotechnology Initiative (NNI).

The competition challenged high school students to think big — or, in this case, small — to create superheroes that harness their powers from nanotechnology.

Wheaton applauded the students’ creative storylines, noting that when he was Wesley Crusher on the TV series Star Trek: The Next Generation, such plots were only imaginary. “It is amazing what is today plausible due to the power of nanotechnonlogy,” he said.

In a video introduction before Wheaton announced top prize winners, Stan Lee said it was “great that I can virtually join you today.” He remarked on the winners’ “creativity, ingenuity and initiative.”

“From one superhero storyteller to the next, congratulations,” Lee said.

The winners

  • First Prize: Eric Liu from Thomas Jefferson High School for Science and Technology in Virginia, for his “Nanoman,” who fights the malignant crab-monster “Cancer.”
  • Second Prize and the People’s Choice Award: Madeleine Chang from Bergen County Academies in New Jersey, for her superhero “Radio Blitz,” who disposes of local waste.
  • Third Prize: Vuong Mai from Martha Ellen Stilwell School of the Arts in Georgia, for her protector “Nine,” who dons a nanosuit for strength to save a kidnapping victim.

All weekend, the students displayed their superheroes and described the nanoscience behind them to thousands of attendees at the 2016 USA Science & Engineering Festival in Washington, D.C.

“All three finalists immersed themselves in the worlds of nanotechnology and art, told a great story, entertained and educated — all at the same time,” said Lisa Friedersdorf, deputy director of the National Nanotechnology Coordination Office. “Their creations will surely motivate additional students to imagine and learn more about what is possible with nanotechnology.”

Top award winners in this competition show that with imagination and nanotechnology, possibilities abound, said Mihail C. Roco, NSF senior advisor for science and engineering and a key architect of NNI.

“These school students have aimed higher than ever in their lives, pushing their abilities in novel domains where seeds for their high-tech future may germinate,” Roco said. “We need a constant regeneration of new talent to exploit this general purpose science and technology field to its outstanding potential. These students are well on their way.”

Competition details

NSF and NNI challenges students to submit written entries explaining their superhero and nanotechnology-driven gear, along with a one-page comic or 90-second video. A panel of judges from academia and multimedia platforms selected semifinalists and finalists, from which the public selected Madeline Chang as its People’s Choice winner.

Top prizes were determined by judges Elise Lemle, director of special projects at Two Bit Circus; Lizabeth Fogel, director of Education for the Walt Disney Company and Chair of the Board for the Partnership for 21st Century Learning; and James Murday, director of physical sciences at the University of Southern California’s Washington, D.C., office of research advancement.

Visit the Generation Nano competition website for competition details such as eligibility criteria, entry guidelines, timeline, prizes and videos/comics from the finalists and semifinalists. And stay tuned for information on next year’s competition.

Here’s a photo of Wil Wheaton officiating at the ceremony,

Actor, writer and blogger Wil Wheaton hosted the Gen Nano competition award ceremony.

Actor, writer and blogger Wil Wheaton hosted the Gen Nano competition award ceremony. Courtesy of the NSF.

Honestly, this could be anyone but there are videos of the ceremony featuring Wil Wheaton, each of the winner’s pieces, and Stan Lee attending the ceremony virtually (five videos in all).

Chinese scientists develop a novel 3D fabrication technique for bio-inspired hierarchical structures

An April 14, 2016 news item on phys.org describes a new 3D fabrication technique devised by Chinese scientists,

Nature is no doubt the world’s best biological engineer, whose simple, exquisite but powerful designs have inspired scientists and engineers to tackle the challenges of technologies for centuries. Scientists recently mimicked the surface structure of a moth’s eye, a unique structure with an antireflective property, to develop a highly light-absorbent graphene material. This is breakthrough [sic] in solar cell technology. Rice leaves and butterfly wings also have unique self-cleaning surface characteristics, which inspire scientists to develop novel materials resistant to biofouling. The bio-inspired periodic multi-scale structures, called hierarchical structures, have recently caught broad attention among scientists in various applications such as solar cells, Light-emitting diodes (LEDs), biomaterials and anti-bacterial surfaces.

An April 14, 2016 Optical Society of American news release (also on EurekAlert), which originated the news item, provides more detail,

Although a number of techniques for fabricating bio-inspired hierarchical structures already exist, most conventional methods either involve complicated processes or are highly time-consuming and low cost-efficiency for industrial applications. Now, a team of researchers from Changchun University of Science and Technology, China, have developed a novel method for the rapid and maskless fabrication of bio-inspired hierarchical structures, using a technique called laser interference lithography.

Specifically, the researchers use the interference pattern of three-and four-beam lasers to fabricate ordered multi-scale surface structures on silicon substrates, with the pattern of hierarchical structures controllable by adjusting the parameters of incident light. In accordance with the theoretical and computer analysis, the researchers have experimentally demonstrated the novel technique’s potential in large-area, low-cost and high-volume 3D fabrication of micro and nanostructures. …

“We presented a flexible and direct method for fabricating ordered multi-scale 3D structures using three- and four-beam interference lithography,” said Zuobin Wang, the primary author and a professor of International Research Centre for Nano Handling and Manufacturing of China at the Changchun University of Science and Technology, China. “Compared with other patterning technologies, our method is simple and efficient in terms of obtaining bio-inspired hierarchical structures.”

Wang mentioned that for certain complicated surface structures, conventional techniques such as electron beam lithography may take several hours or a day to fabricate the pattern, while the laser interference approach only takes several minutes to generate the structure, which makes the technique suitable for high-volume industrial production.

“Laser interference lithography is a maskless patterning technique that uses the interference patterns generated from two or several coherent laser beams to fabricate micro and nanometer periodic patterns over large areas,” Wang said. Different from conventional patterning techniques like electron beam lithography, the laser interference technique enables fabricating the entire substrate surface with one single exposure or one-step lithography.

For example, in Wang’s experiment, the one-dimension multi-scale structure, that is, one-dimension oriented arrangement with the sinusoidal grooves covered with periodic line-like structures was fabricated by exposing the silicon substrate to three or four interfered beams for one time. The resultant surface pattern, though arranged in one direction, has three-dimension spatial structure. To obtain more complicated structures such as two-dimension oriented multi-scale structures, the researchers simply rotated the substrate by 90 degrees in the plane and applied second laser exposure to the surface.

“Laser interference lithography is capable of fabricating homogeneous micro and nanometer structured patterns over areas more than one square meter, which is either impossible or highly time or cost consuming for conventional techniques,” Wang said. These features make laser interference lithography superior to other techniques in terms of efficiency and high-volume production.

According to Wang, their experimental process is simple: a high power laser beam was split into three or four equal beams, which then were directed by mirrors to generate interference patterns to fabricate the surface structures. The laser parameters such as incident angle and azimuthal angle of each beam were adjusted by beam splitters and mirror positions. Other optical devices such as quarter-wave plates and polarizers were used to select the polarization mode and control the energy of laser beams.

“The laser beam parameters are selected according to the desired surface structure and corresponding interference energy distribution calculated from theoretical simulation. In other words, the shapes or patterns of hierarchical structures in our method are controllable by adjusting the parameters of each incident beams,” Wang noted.

According to Wang, the proposed technique could be used to fabricate optical or medical devices such as solar cells, antireflective coatings, self-cleaning and antibacterial surfaces and long-life artificial hip joints.

The researchers’ next step is to develop functional surface structures with controllable wettability, adhesion and reflectivity properties for optical, medical and mechanical applications.

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

Bio-inspired hierarchical patterning of silicon by laser interference lithography by Yaowei Hu, Zuobin Wang, Zhankun Weng, Miao Yu, and Dapeng Wang. Applied Optics Vol. 55, Issue 12, pp. 3226-3232 (2016) doi: 10.1364/AO.55.003226

I believe this paper is behind a paywall.

The researchers have provided this image as an illustration of their concept,

 Caption: This is a Scanning Electron Microscope (SEM) image of a moth eye. Credit: Zuobin Wang/Changchun University of Science and Technology, China


Caption: This is a Scanning Electron Microscope (SEM) image of a moth eye. Credit: Zuobin Wang/Changchun University of Science and Technology, China