Tag Archives: Austria

NanoFARM: food, agriculture, and nanoparticles

The research focus for the NanoFARM consortium is on pesticides according to an October 19, 2017 news item on Nanowerk,

The answer to the growing, worldwide food production problem may have a tiny solution—nanoparticles, which are being explored as both fertilizers and fungicides for crops.

NanoFARM – research consortium formed between Carnegie Mellon University [US], the University of Kentucky [US], the University of Vienna [Austria], and Aveiro University in Prague [Czech Republic] – is studying the effects of nanoparticles on agriculture. The four universities received grants from their countries’ respective National Science Foundations to discover how these tiny particles – some just 4 nanometers in diameter – can revolutionize how farmers grow their food.

An October ??, 2017 Carnegie Mellon University news release by Adam Dove, which originated the news item, fills in a few more details,

“What we’re doing is getting a fundamental understanding of nanoparticle-to-plant interactions to enable future applications,” says Civil and Environmental Engineering (CEE) Professor Greg Lowry, the principal investigator for the nanoFARM project. “With pesticides, less than 5% goes into the crop—the rest just goes into the environment and does harmful things. What we’re trying to do is minimize that waste and corresponding environmental damage by doing a better job of targeting the delivery.”

The teams are looking at related questions: How much nanomaterial is needed to help crops when it comes to driving away pests and delivering nutrients, and how much could potentially hurt plants or surrounding ecosystems?

Applied pesticides and fertilizers are vulnerable to washing away—especially if there’s a rainstorm soon after application. But nanoparticles are not so easily washed off, making them extremely efficient for delivering micronutrients like zinc or copper to crops.

“If you put in zinc oxide nanoparticles instead, it might take days or weeks to dissolve, providing a slow, long-term delivery system.”

Gao researches the rate at which nanoparticles dissolve. His most recent finding is that nanoparticles of copper oxide take up to 20-30 days to dissolve in soil, meaning that they can deliver nutrients to plants at a steady rate over that time period.

“In many developing countries, a huge number of people are starving,” says Gao. “This kind of technology can help provide food and save energy.”

But Gao’s research is only one piece of the NanoFARM puzzle. Lowry recently traveled to Australia with Ph.D. student Eleanor Spielman-Sun to explore how differently charged nanoparticles were absorbed into wheat plants.

They learned that negatively charged particles were able to move into the veins of a plant—making them a good fit for a farmer who wanted to apply a fungicide. Neutrally charged particles went into the tissue of the leaves, which would be beneficial for growers who wanted to fortify a food with nutritional value.

Lowry said they are still a long way from signing off on a finished product for all crops—right now they are concentrating on tomato and wheat plants. But with the help of their university partners, they are slowly creating new nano-enabled agrochemicals for more efficient and environmentally friendly agriculture.

For more information, you can find the NanoFARM website here.

Europe’s cathedrals get a ‘lift’ with nanoparticles

That headline is a teensy bit laboured but I couldn’t resist the levels of wordplay available to me. They’re working on a cathedral close to the leaning Tower of Pisa in this video about the latest in stone preservation in Europe.

I have covered the topic of preserving stone monuments before (most recently in my Oct. 21, 2014 posting). The action in this field seems to be taking place mostly in Europe, specifically Italy, although other countries are also quite involved.

Finally, getting to the European Commission’s latest stone monument preservation project, Nano-Cathedral, a Sept. 26, 2017 news item on Nanowerk announces the latest developments,

Just a few meters from Pisa’s famous Leaning Tower, restorers are defying scorching temperatures to bring back shine to the city’s Cathedral.

Ordinary restoration techniques like laser are being used on much of the stonework that dates back to the 11th century. But a brand new technique is also being used: a new material made of innovative nanoparticles. The aim is to consolidate the inner structure of the stones. It’s being applied mainly on marble.

A March 7, 2017 item on the Euro News website, which originated the Nanowerk news item, provides more detail,

“Marble has very low porosity, which means we have to use nanometric particles in order to go deep inside the stone, to ensure that the treatment is both efficient while still allowing the stone to breathe,” explains Roberto Cela, civil engineer at Opera Della Primaziale Pisana.

The material developed by the European research team includes calcium carbonate, which is a mix of calcium oxide, water and carbon dioxide.

The nano-particles penetrate the stone cementing its decaying structure.

“It is important that these particles have the same chemical nature as the stones that are being treated, so that the physical and mechanical processes that occur over time don’t lead to the break-up of the stones,” says Dario Paolucci, chemist at the University of Pisa.

Vienna’s St Stephen’s is another of the five cathedrals where the new restoration materials are being tested.

The first challenge for researchers is to determine the mechanical characteristics of the cathedral’s stones. Since there are few original samples to work on, they had to figure out a way of “ageing” samples of stones of similar nature to those originally used.

“We tried different things: we tried freeze storage, we tried salts and acids, and we decided to go for thermal ageing,” explains Matea Ban, material scientist at the University of Technology in Vienna. “So what happens is that we heat the stone at certain temperatures. Minerals inside then expand in certain directions, and when they expand they build up stresses to neighbouring minerals and then they crack, and we need those cracks in order to consolidate them.”

Consolidating materials were then applied on a variety of limestones, sandstones and marble – a selection of the different types of stones that were used to build cathedrals around Europe.

What researchers are looking for are very specific properties.

“First of all, the consolidating material has to be well absorbed by the stone,” says petrologist Johannes Weber of the University of Applied Arts in Vienna. “Then, as it evaporates, it has to settle properly within the stone structure. It should not shrink too much. All materials shrink when drying, including consolidating materials. They should adhere to the particles of the stone but shouldn’t completely obstruct its pores.”

Further tests are underway in cathedrals across Europe in the hope of better protecting our invaluable cultural heritage.

There’s a bit more detail about Nano-Cathedral on the Opera della Primaziale Pisana (O₽A) website (from their Nano-Cathedral project page),

With the meeting of June 3 this year the Nano Cathedral project kicked off, supported by the European Union within the nanotechnology field applied to Horizon 2020 cultural heritage with a fund of about 6.5 million euro.

A total of six monumental buildings will be for three years under the eyes and hands of petrographers, geologists, chemists and restorers of the institutes belonging to the Consortium: five cathedrals have been selected to represent the cultural diversity within Europe from the perspective of developing shared values and transnational identity, and a contemporary monumental building entirely clad in Carrara marble, the Opera House of Oslo.

Purpose: the testing of nanomaterials for the conservation of marble and the outer surfaces of our ‘cathedrals’.
The field of investigation to check degradation, testing new consolidating and protective products is the Cathedral of Pisa together with the Cathedrals of Cologne, Vienna, Ghent and Vitoria.
For the selection of case studies we have crosschecked requirements for their historical and architectural value but also for the different types of construction materials – marble, limestone and sandstone – as well as the relocation of six monumental buildings according to European climates.

The Cathedral of Pisa is the most southern, fully positioned in Mediterranean climate, therefore subject to degradation and very different from those which the weather conditions of the Scandinavian peninsula recorded; all the intermediate climate phases are modulated through Ghent, Vitoria, Cologne and Vienna.

At the conclusion of the three-year project, once the analysis in situ and in the laboratory are completed and all the experiments are tested on each different identified portion in each monumental building, an intervention protocol will be defined in detail in order to identify the mineralogical and petrographic characteristics of stone materials and of their degradation, the assessment of the causes and mechanisms of associated alteration, including interactions with factors of environmental pollution. Then we will be able to identify the most appropriate method of restoration and testing of nanotechnology products for the consolidation and protection of different stone materials.

In 2018 we hope to have new materials to protect and safeguard the ‘skin’ of our historic buildings and monuments for a long time.

Back to my headline and the second piece of wordplay, ‘lift’ as in ‘skin lift’ in that last sentence.

I realize this is a bit off topic but it’s worth taking a look at ORA’s home page,

Gabriele D’Annunzio effectively condenses the wonder and admiration that catch whoever visits the Duomo Square of Pisa.

The Opera della Primaziale Pisana (O₽A) is a non-profit organisation which was established in order to oversee the first works for the construction of the monuments in the Piazza del Duomo, subject to its own charter which includes the protection, promotion and enhancement of its heritage, in order to pass the religious and artistic meaning onto future generations.

«L’Ardea roteò nel cielo di Cristo, sul prato dei Miracoli.»
Gabriele d’Annunzio in Forse che sì forse che no (1910)

If you go to the home page, you can buy tickets to visit the monuments surrounding the square and there are other notices including one for a competition (it’s too late to apply but the details are interesting) to construct four stained glass windows for the Pisa cathedral.

Cotton that glows ‘naturally’

Interesting, non? This is causing a bit of excitement but before first, here’s more from the Sept. 14, 2017 American Association for the Advancement of Science (AAAS) news release on EurekAlert,

Cotton that’s grown with molecules that endow appealing properties – like fluorescence or magnetism – may one day eliminate the need for applying chemical treatments to fabrics to achieve such qualities, a new study suggests. Applying synthetic polymers to fabrics can result in a range of appealing properties, but anything added to a fabric can get washed or worn away. Furthermore, while many fibers used in fabrics are synthetic (e.g., polyester), some consumers prefer natural fibers to avoid issues related to sensation, skin irritation, smoothness, and weight. Here, Filipe Natalio and colleagues created cotton fibers that incorporate composites with fluorescent and magnetic properties. They synthesized glucose derivatives that deliver the desirable molecules into the growing ovules of the cotton plant, Gossypium hirsutum. Thus, the molecules are embedded into the cotton fibers themselves, rather than added in the form of a chemical treatment. The resulting fibers exhibited fluorescent or magnetic properties, respectively, although they were weaker than raw fibers lacking the embedded composites, the authors report. They propose that similar techniques could be expanded to other biological systems such as bacteria, bamboo, silk, and flax – essentially opening a new era of “material farming.”

Robert Service’s Sept. 14, 2017 article for Science explores the potential of growing cotton with new properties (Note: A link has been removed),

You may have heard about smartphones and smart homes. But scientists are also designing smart clothes, textiles that can harvest energy, light up, detect pollution, and even communicate with the internet. The problem? Even when they work, these often chemically treated fabrics wear out rapidly over time. Now, researchers have figured out a way to “grow” some of these functions directly into cotton fibers. If the work holds, it could lead to stronger, lighter, and brighter textiles that don’t wear out.

Yet, as the new paper went to press today in Science, editors at the journal were made aware of mistakes in a figure in the supplemental material that prompted them to issue an Editorial Expression of Concern, at least until they receive clarification from the authors. Filipe Natalio, lead author and chemist at the Weizmann Institute of Science in Rehovot, Israel, says the mistakes were errors in the names of pigments used in control experiments, which he is working with the editors to fix.

That hasn’t dampened enthusiasm for the work. “I like this paper a lot,” says Michael Strano, a chemical engineer at the Massachusetts Institute of Technology in Cambridge. The study, he says, lays out a new way to add new functions into plants without changing their genes through genetic engineering. Those approaches face steep regulatory hurdles for widespread use. “Assuming the methods claimed are correct, that’s a big advantage,” Strano says.

Sam Lemonick’s Sept. 14, 2017 article for forbes.com describes how the researchers introduced new properties (in this case, glowing colours) into the cotton plants,

His [Filipe Natalio] team of researchers in Israel, Germany, and Austria used sugar molecules to sneak new properties into cotton. Like a Trojan horse, Natalio says. They tested the method by tagging glucose with a fluorescent dye molecule that glows green when hit with the right kind of light.

They bathed cotton ovules—the part of the plant that makes the fibers—in the glucose. And just like flowers suck up dyed water in grade school experiments, the ovules absorbed the sugar solution and piped the tagged glucose molecules to their cells. As the fibers grew, they took on a yellowish tinge—and glowed bright green under ultraviolet light.

Glowing cotton wasn’t enough for Natalio. It took his group about six months to be sure they were actually delivering the fluorescent protein into the cotton cells and not just coating the fibers in it. Once they were certain, they decided to push the envelope with something very unnatural: magnets.

This time, Natalio’s team modified glucose with the rare earth metal dysprosium, making a molecule that acts like a magnet. And just like they did with the dye, the researchers fed it to cotton ovules and ended up with fibers with magnetic properties.

Both Service and Lemonwick note that the editor of the journal Science (where the research paper was published) Jeremy Berg has written an expression of editorial concern as of Sept. 14, 2017,

In the 15 September [2017] issue, Science published the Report “Biological fabrication of cellulose fibers with tailored properties” by F. Natalio et al. (1). After the issue went to press, we became aware of errors in the labeling and/or identification of the pigments used for the control experiments detailed in figs. S1 and S2 of the supplementary materials. Science is publishing this Editorial Expression of Concern to alert our readers to this information as we await full explanation and clarification from the authors.

The problem seems to be one of terminology (from the Lemonwick article),

… Filipe Natalio, lead author and chemist at the Weizmann Institute of Science in Rehovot, Israel, says the mistakes were errors in the names of pigments used in control experiments, which he is working with the editors to fix.

These things happen. Terminology and spelling aren’t always the same from one country to the next and it can result in confusion. I’m glad to see the discussion is being held openly.

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

Biological fabrication of cellulose fibers with tailored properties by Filipe Natalio, Regina Fuchs, Sidney R. Cohen, Gregory Leitus, Gerhard Fritz-Popovski, Oskar Paris, Michael Kappl, Hans-Jürgen Butt. Science 15 Sep 2017: Vol. 357, Issue 6356, pp. 1118-1122 DOI: 10.1126/science.aan5830

This paper is behind a paywall.

Brain composer

This is a representation of the work they are doing on brain-computer interfaces (BCI) at the Technical University of Graz (TU Graz; Austria),

A Sept. 11, 2017 news item on phys.org announces the research into thinking melodies turning them into a musical score,

TU Graz researchers develop new brain-computer interface application that allows music to be composed by the power of thought. They have published their results in the current issue of the journal PLOS ONE.

Brain-computer interfaces (BCI) can replace bodily functions to a certain degree. Thanks to BCI, physically impaired persons can control special prostheses via their minds, surf the internet and write emails.

A group led by BCI expert Gernot Müller-Putz from TU Graz’s Institute of Neural Engineering shows that experiences of quite a different tone can be sounded from the keys of brain-computer interfaces. Derived from an established BCI method for writing, the team has developed a new application by which music can be composed and transferred onto a musical score through the power of thought. It employs a special cap that measures brain waves, the adapted BCI, music composition software, and a bit of musical knowledge.

A Sept. 6, 2017 TU Graz press release by Suzanne Eigner, which originated the news item, explains the research in more detail,

The basic principle of the BCI method used, which is called P300, can be briefly described: various options, such as letters or notes, pauses, chords, etc. flash by one after the other in a table. If you’re trained and can focus on the desired option while it lights up, you cause a minute change in your brain waves. The BCI recognises this change and draws conclusions about the chosen option.

Musical test persons

18 test persons chosen for the study by Gernot Müller-Putz, Andreas Pinegger and Selina C. Wriessnegger from TU Graz’s Institute of Neural Engineering as well as Hannah Hiebel, meanwhile at the Institute of Cognitive Psychology & Neuroscience at the University of Graz, had to “think” melodies onto a musical score. All test subjects were of sound bodily health during the study and had a certain degree of basic musical and compositional knowledge since they all played musical instruments to some degree. Among the test persons was the late Graz composer and clarinettist, Franz Cibulka. “The results of the BCI compositions can really be heard. And what is more important: the test persons enjoyed it. After a short training session, all of them could start composing and seeing their melodies on the score and then play them. The very positive results of the study with bodily healthy test persons are the first step in a possible expansion of the BCI composition to patients,” stresses Müller-Putz.

Sideshow of BCI research

This little-noticed sideshow of the lively BCI research at TU Graz, with its distinct focus on disabled persons, shows us which other avenues may yet be worth exploring. Meanwhile there are some initial attempts at BCI systems on smart phones. This makes it easier for people to use BCI applications, since the smart phone as powerful computer is becoming part of the BCI system. It is thus conceivable, for instance, to have BCI apps which can analyse brain signals for various applications. “20 years ago, the idea of composing a piece of music using the power of the mind was unimaginable. Now we can do it, and at the same time have tens of new, different ideas which are in part, once again, a long way from becoming reality. We still need a bit more time before it is mature enough for daily applications. The BCI community is working in many directions at high pressure.

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

Composing only by thought: Novel application of the P300 brain-computer interface by Andreas Pinegger, Hannah Hiebel, Selina C. Wriessnegger, Gernot R. Müller-Putz. PLOS https://doi.org/10.1371/journal.pone.0181584 Published: September 6, 2017

This paper is open access.

This BCI ‘sideshow’ reminded me of The Music Man, a musical by Meredith Wilson. It was both a play and a film  and I’ve only ever seen the 1962 film. It features a con man, Harold Hill, who sells musical instruments and uniforms in small towns in Iowa. He has no musical training but while he’s conning the townspeople he convinces them that he can provide musical training with his ‘think method’. After falling in love with one of the townsfolk, he is hunted down and made to prove his method works. This is a clip from a Broadway revival of the play where Harold Hill is hoping that his ‘think method’ while yield results,

Of course, the people in this study had musicaltraining so they could think a melody into a musical score but I find the echo from the past amusing nonetheless.

Nanocar Race winners: The US-Austrian team

Sadly, I didn’t stumble across the news about the US-Austrian team sooner but it was not published until a May 8, 2017 news item on Nanowerk,

Rice University chemist James Tour and his international team have won the first Nanocar Race.

The Rice and University of Graz team finished first in the inaugural Nanocar Race in Toulouse, France, April 28, completing a 150-nanometer course — roughly a thousandth of the width of a human hair — in about 1½ hours. (The race was declared over after 30 hours.)

Interestingly the Rice University news release announcing the win was issued prior to the ‘winning’ Swiss team’s and it explains why the Swiss team was declared a co-winner despite the additional hours (6.5 hours as compared to 1.5 hours [see my May 9, 2017 posting: Nanocar Race winners! where the Swiss appear to claiming they raced 38 hours]) before completing the race. From an April 28, 2017 Rice University news release,

The team led by Tour and Graz physicist Leonhard Grill deployed a two-wheeled, single-molecule vehicle with adamantane tires on its home track in Graz, Austria, achieving an average speed of 95 nanometers per hour. Tour said the speed ranged from more than 300 to less than 1 nanometer per hour, depending upon the location along the course.

The Swiss Nano Dragster team finished next, five hours later. But organizers at the French National Center for Scientific Research declared them a co-winner of first place as they were tops among teams that raced on a gold track.

Because the scanning tunneling microscope track in Toulouse could only accommodate four cars, two of the six competing international teams — Ohio University and Rice-Graz — ran their vehicles on their home tracks (Ohio on gold) and operated them remotely from the Toulouse headquarters.

The Dipolar Racer designed at Rice.

The Dipolar Racer designed at Rice.

Five cars were driven across gold surfaces in a vacuum near absolute zero by electrons from the tips of microscopes in Toulouse and Ohio, but the Rice-Graz team got permission to use a silver track at Graz. “Gold was the surface of choice, so we tested it there, but it turns out it’s too fast,” Grill said. “It’s so fast, we can’t even image it.”

The team got permission from organizers in advance of the race to use the slower silver surface, but with an additional handicap. “We had to go 150 nanometers around two pylons instead of 100 nanometers since our car was so much faster,” Tour said.

Tour said the race directors used the Paris-Rouen auto race in 1894, considered by some to be the world’s first auto race, as precedent for their decision April 29. “I am told there will be two first prizes regardless of the time difference and handicap,” he said.

The Rice-Graz car, called the Dipolar Racer, was designed by Tour and former Rice graduate student Victor Garcia-Lopez and raced by the Graz team, which included postdoctoral researcher and pilot Grant Simpson and undergraduate and co-pilot Philipp Petermeier.

The silver track under the microscope. Two Rice nanocars are in the blue circle at top. The lower car was the first to run the race, finishing in an hour-and-a-half. The top car was put through the course later, finishing in 2 hours.

The silver track under the microscope. Two Rice nanocars are in the blue circle at top. The lower car was the first to run the race, finishing in a 1½ hours. The top car was put through the course later, finishing in 2 hours. Click on the image for a larger version.

The purpose of the competition, according to organizers, was to push the science of how single molecules can be manipulated as they interact with surfaces.

“We chose our fastest wheels and our strongest dipole so that it could be pulled by the electric field more efficiently,” said Tour, whose lab has been designing nanocars since 1998. ‘We gave it two (side-by-side) wheels to minimize interaction with the surface and to lower the molecular weight.

“We built in every possible design parameter that we could to optimize speed,” he said.

While details of the Dipolar Racer remained a closely held secret until race time, Tour and Grill said they will be revealed in a forthcoming paper.

“This is the beginning of our ability to demonstrate nanoscale manipulation with control around obstacles and speed and will pave the way for much faster paces and eventually for carrying cargo and doing bottom-up assembly.

“It’s a great day for nanotechnology,” Tour said. “And a great day for Rice University and the University of Graz.”

Clearly all the winners were very excited. Still, there’s a little shade being thrown (one of the scientists is just a tiny bit miffed) as you can see in James Tour’s quote given after noting the US-Austrian racer was too fast for the gold surface so the team used the slower silver surface and were given another handicap. As per the Rice University news release: ““I am told [emphasis mine] there will be two first prizes regardless of the time difference and handicap,” he said.” Of course, the Swiss team’s news release didn’t mention the US-Austrian team’s speedier finish nor did it name (Dipolar Racer) the US-Austrian racer. As I noted before, scientists are people too.

Nanocar Race winners!

In fact, there was a tie although it seems the Swiss winners were a little more excited. A May 1, 2017 news item on swissinfo.ch provides fascinating detail,

“Swiss Nano Dragster”, driven by scientists from Basel, has won the first international car race involving molecular machines. The race involved four nano cars zipping round a pure gold racetrack measuring 100 nanometres – or one ten-thousandth of a millimetre.

The two Swiss pilots, Rémy Pawlak and Tobias Meier from the Swiss Nanoscience Institute and the Department of Physicsexternal link at the University of Basel, had to reach the chequered flag – negotiating two curves en route – within 38 hours. [emphasis mine*]

The winning drivers, who actually shared first place with a US-Austrian team, were not sitting behind a steering wheel but in front of a computer. They used this to propel their single-molecule vehicle with a small electric shock from a scanning tunnelling microscope.

During such a race, a tunnelling current flows between the tip of the microscope and the molecule, with the size of the current depending on the distance between molecule and tip. If the current is high enough, the molecule starts to move and can be steered over the racetrack, a bit like a hovercraft.


The race track was maintained at a very low temperature (-268 degrees Celsius) so that the molecules didn’t move without the current.

What’s more, any nudging of the molecule by the microscope tip would have led to disqualification.

Miniature motors

The race, held in Toulouse, France, and organised by the National Centre for Scientific Research (CNRS), was originally going to be held in October 2016, but problems with some cars resulted in a slight delay. In the end, organisers selected four of nine applicants since there were only four racetracks.

The cars measured between one and three nanometres – about 30,000 times smaller than a human hair. The Swiss Nano Dragster is, in technical language, a 4′-(4-Tolyl)-2,2′:6′,2”-terpyridine molecule.

The Swiss and US-Austrian teams outraced rivals from the US and Germany.

The race is not just a bit of fun for scientists. The researchers hope to gain insights into how molecules move.

I believe this Basel University .gif is from the race,

*Emphasis added on May 9, 2017 at 12:26 pm PT. See my May 9, 2017 posting: Nanocar Race winners: The US-Austrian team for the other half of this story.

Off to the Nanocar Race: April 28, 2017

The Nanocar Race (which at one point was the NanoCar Race) took place on April 28 -29, 2017 in Toulouse, France. Presumably the fall 2016 race did not take place (as I had reported in my May 26, 2016 posting). A March 23, 2017 news item on ScienceDaily gave the latest news about the race,

Nanocars will compete for the first time ever during an international molecule-car race on April 28-29, 2017 in Toulouse (south-western France). The vehicles, which consist of a few hundred atoms, will be powered by minute electrical pulses during the 36 hours of the race, in which they must navigate a racecourse made of gold atoms, and measuring a maximum of a 100 nanometers in length. They will square off beneath the four tips of a unique microscope located at the CNRS’s Centre d’élaboration de matériaux et d’études structurales (CEMES) in Toulouse. The race, which was organized by the CNRS, is first and foremost a scientific and technological challenge, and will be broadcast live on the YouTube Nanocar Race channel. Beyond the competition, the overarching objective is to advance research in the observation and control of molecule-machines.

More than just a competition, the Nanocar Race is an international scientific experiment that will be conducted in real time, with the aim of testing the performance of molecule-machines and the scientific instruments used to control them. The years ahead will probably see the use of such molecular machinery — activated individually or in synchronized fashion — in the manufacture of common machines: atom-by-atom construction of electronic circuits, atom-by-atom deconstruction of industrial waste, capture of energy…The Nanocar Race is therefore a unique opportunity for researchers to implement cutting-edge techniques for the simultaneous observation and independent maneuvering of such nano-machines.

The experiment began in 2013 as part of an overview of nano-machine research for a scientific journal, when the idea for a car race took shape in the minds of CNRS senior researcher Christian Joachim (now the director of the race) and Gwénaël Rapenne, a Professor of chemistry at Université Toulouse III — Paul Sabatier. …

An April 19, 2017 article by Davide Castelvecchi for Nature (magazine) provided more detail about the race (Note: Links have been removed),

The term nanocar is actually a misnomer, because the molecules involved in this race have no motors. (Future races may incorporate them, Joachim says.) And it is not clear whether the molecules will even roll along like wagons: a few designs might, but many lack axles and wheels. Drivers will use electrons from the tip of a scanning tunnelling microscope (STM) to help jolt their molecules along, typically by just 0.3 nano-metres each time — making 100 nanometres “a pretty long distance”, notes physicist Leonhard Grill of the University of Graz, Austria, who co-leads a US–Austrian team in the race.

Contestants are not allowed to directly push on their molecules with the STM tip. Some teams have designed their molecules so that the incoming electrons raise their energy states, causing vibrations or changes to molecular structures that jolt the racers along. Others expect electrostatic repulsion from the electrons to be the main driving force. Waka Nakanishi, an organic chemist at the National Institute for Materials Science in Tsukuba, Japan, has designed a nanocar with two sets of ‘flaps’ that are intended to flutter like butterfly wings when the molecule is energized by the STM tip (see ‘Molecular race’). Part of the reason for entering the race, she says, was to gain access to the Toulouse lab’s state-of-the-art STM to better understand the molecule’s behaviour.

Eric Masson, a chemist at Ohio University in Athens, hopes to find out whether the ‘wheels’ (pumpkin-shaped groups of atoms) of his team’s car will roll on the surface or simply slide. “We want to better understand the nature of the interaction between the molecule and the surface,” says Masson..

Adapted from www.nanocar-race.cnrs.fr

Simply watching the race progress is half the battle. After each attempted jolt, teams will take three minutes to scan their race track with the STM, and after each hour they will produce a short animation that will immediately be posted online. That way, says Joachim, everyone will be able to see the race streamed almost live.

Nanoscale races

The Toulouse laboratory has an unusual STM with four scanning tips — most have only one — that will allow four teams to race at the same time, each on a different section of the gold surface. Six teams will compete this week to qualify for one of the four spots; the final race will begin on 28 April at 11 a.m. local time. The competitors will face many obstacles during the contest. Individual molecules in the race will often be lost or get stuck, and the trickiest part may be to negotiate the two turns in the track, Joachim says. He thinks the racers may require multiple restarts to cover the distance.

For anyone who wants more information, go to the Nanocar Race website. There is also a highlights video,

Published on Apr 29, 2017

The best moments of the first-ever international race of molecule- cars.

An easier way to make highly ordered porous films for commercial sensors

An April 3, 2017 news item on Nanowerk describes Japanese research into a new technique for producing MOF’s (metallic organic frameworks),

Osaka-based researchers developed a new method to create films of porous metal–organic frameworks fully aligned on inorganic substrates. The method is simple, requiring only that the substrate and an organic linker are mixed under mild conditions, and fast, producing perfectly aligned films within minutes. The films oriented fluorescent dye molecules within their pores, and the fluorescence response of these dyes was switched on or off simply by rotating the material in polarized light.

An April 3, 2017 Osaka University press release on the Alpha Gallileo news service, which originated the news item, explains more about MOFs and gives some details about the new technique,,

Metal–organic frameworks, or MOFs, are highly ordered crystalline structures made of metal ion nodes and organic molecule linkers. Many MOFs can take up and store gases, such as carbon dioxide or hydrogen, thanks to their porous, sponge-like structures.

MOFs are also potential chemical sensors. They can be designed to change color or display another optical signal if a particular molecule is taken up into the framework. However, most studies on MOFs are performed on tiny single crystals, which is not practical for the commercial development of these materials.

Chemists have now come a step closer to making commercially viable sensors that contain highly ordered MOFs, thanks to the collaboration of an international team of researchers at Osaka Prefecture University, Osaka University and Graz University of Technology. The method will allow researchers to fabricate large tailor-made MOF films on any substrate of any size, which will vastly improve their prospects for commercial development.

In a study recently published in Nature Materials and highlighted on the cover and in the ‘News and Views’ section of the journal, the Osaka-based researchers report a one-step method to prepare thin MOF films directly on inorganic copper hydroxide substrates. Using this method, the researchers produced large MOF films with areas of more than 1 cm2 that were, for the first time, fully aligned with the crystal lattice of the underlying substrate.

Noting that microcrystals of copper hydroxide can be converted into MOFs by adding organic linker molecules under mild conditions, the researchers used the same strategy to create a thin MOF layer on larger copper hydroxide substrates. They carefully chose the carboxylic acid-based linker molecule 1,4-dibenzenedicarboxylic acid because it fit exactly to the spacing between the copper atoms on the substrate surface.

A MOF film began to grow on the copper hydroxide substrates within minutes of mixing it with the linker molecule, making this technique much easier and faster than previous step-wise approaches to build up MOF films. Using microscopy and X-ray diffraction techniques, the researchers found that the film was precisely oriented along the copper hydroxide lattice.

To demonstrate the unique optical behavior of their films, the researchers filled the MOF’s ordered pores with fluorescent molecules, which fluoresce when light is shone on them in a particular direction. When they shone polarized light on the ordered material, the researchers found that they could easily switch the fluorescence response on or off simply by rotating the material.

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

Centimetre-scale micropore alignment in oriented polycrystalline metal–organic framework films via heteroepitaxial growth by Paolo Falcaro, Kenji Okada, Takaaki Hara, Ken Ikigaki, Yasuaki Tokudome, Aaron W. Thornton, Anita J. Hill, Timothy Williams, Christian Doonan, & Masahide Takahashi. Nature Materials 16, 342–348  (2017) doi:10.1038/nmat4815 Published online 05 December 2016

This paper is behind a paywall.

Monitoring the life of bacteria in microdroplets

Trying to establish better ways to test the effect of drugs on bacteria has led the Institute of Physical Chemistry of the Polish Academy of Sciences to develop a new monitoring technique. From a Jan.  11, 2017 news item on Nanowerk,

So far, however, there has been no quick or accurate method of assessing the oxygen conditions in individual microdroplets. This key obstacle has been overcome at the Institute of Physical Chemistry of the Polish Academy of Sciences.

Not in rows of large industrial tanks, nor on shelves laden with test tubes and beakers. The future of chemistry and biology is barely visible to the eye: it’s hundreds and thousands of microdroplets, whizzing through thin tubules of microfluidic devices. The race is on to find technologies that will make it possible to carry out controlled chemical and biological experiments in microdroplets. At the Institute of Physical Chemistry of the Polish Academy of Sciences (IPC PAS) in Warsaw a method of remote, yet rapid and accurate assessment of oxygen consumption by micro-organisms living in individual microdroplets has been demonstrated for the first time.

“Devices for the cultivation of bacteria in microdroplets have the chance to revolutionize work on the development of new antibiotics and the study of mechanisms responsible for the acquisition of drug resistance by bacteria. In one small microfluidic system it is possible to accommodate several hundred or even several thousand microdroplets – and to carry out a different experiment in each of them, for example with different types of microorganisms and at different concentrations of antibiotic in each drop,” describes Prof. Piotr Garstecki (IPC PAS), then explains: “For such studies to be possible, one has to provide the bacteria with conditions for development for even a few weeks. Thus, knowledge about the flow of oxygen to the droplets and the rate of its consumption by the microorganisms becomes extremely important. In our latest system we demonstrate how to read this key information.”

A Jan. 11, 2017 IPC PAS press release on EurekAlert, which originated the  news item, describes the work in more detail,

The bioreactors of the future are water droplets with culture medium suspended in a carrier liquid with which they are immiscible (usually this is oil). In the channel of the microfluidic device each droplet is longer than it is wide and it almost completely fills its lumen; sizes matched in this manner ensure that the drops do not swop places in the channel and throughout the duration of the experiment they can be identified without any problems. At the same time, there has to be a thin layer of oil maintained continuously between each microdroplet and the wall of the channel. Without this, the bacteria would be in direct contact with the walls of the channel so they would be able to settle on them and move from drop to drop. Unfortunately, when the microdroplet is stationary, with time it pushes out the oil separating it from the walls, laying it open to contamination. For this reason the drops must be kept in constant motion – even for weeks.

Growing bacteria need culture medium, and waste products need to be removed from their environment at an appropriate rate. Information about the bacterial oxygen consumption in individual droplets is therefore crucial to the operation of microbioreactors.

“It is immediately obvious where the problem lies. In each of the hundreds of moving droplets measurements need to be carried out at a frequency corresponding to the frequency of division of the bacteria or more, in practice at least once every 15 minutes. In addition, the measurement cannot cause any interference in the microdroplets,” says PhD student Michal Horka (IPC PAS), a co-author of the publication in the journal Analytical Chemistry.

Help was at hand for the Warsaw researchers from chemists from the Austrian Institute of Analytical Chemistry and Food Chemistry at the Graz University of Technology. They provided polymer nanoparticles with a phosphorescent dye, which after excitation emit light for longer the higher the concentration of oxygen in the surrounding solution (the nanoparticles underwent tests at the IPC PAS on bacteria in order to determine their possible toxicity – none was found).

Research on monitoring oxygen consumption in the droplets commenced with the preparation of an aqueous solution with the bacteria, the culture medium and a suitable quantity of nanoparticles. The mixture was injected into the microfluidic system constructed of tubing with Teflon connectors with correspondingly shaped channels. The first module formed droplets with a volume of approx. 4 microlitres, which were directed to the incubation tube wound on a spool. In the middle of its length there was another module, with detectors for measuring oxygen and absorbance.

“In the incubation part in one phase of the cycle the droplets flowed in one direction, in the second – in another, electronically controlled by means of suitable solenoid valves. All this looks seemingly simple enough, but in practice one of the biggest challenges was to ensure a smooth transition between the detection module and the tubing, so that bacterial contamination did not occur at the connections,” explains PhD student Horka.

During their passage through the detection module the droplets flowed under an optical sensor which measured the so-called optical density, which is the standard parameter used to evaluate the number of cells (the more bacteria in the droplets, the less light passes through them). In turn, the measurement of the duration of the phosphorescence of the nanoparticles, evaluating the concentration of oxygen in the microdroplets, was carried out using the Piccolo2 optical detector, provided by the Austrian group. This detector, which looks like a big pen drive, was connected directly to the USB port on the control computer. Comparing information from both sensors, IPC PAS researchers showed that the microfluidic device they had constructed made it possible to regularly and quickly monitor the metabolic activity of bacteria in the individual microdroplets.

“We carried out our tests both with bacteria floating in water singly – this is how the common Escherichia coli bacteria behave – as well as with those having a tendency to stick together in clumps – as is the case for tuberculosis bacilli or others belonging to the same family including Mycobacterium smegmatis which we studied. Evaluation of the rate of oxygen consumption by both species of microorganisms proved to be not only possible, but also reliable,” stresses PhD student Artur Ruszczak (IPC PAS).

The results of the research, funded by the European ERC Starting Grant (Polish side) and the Maria Sklodowska-Curie grant (Austrian side) are an important step in the process of building fully functional microfluidic devices for conducting biological experiments lasting many weeks. A system for culturing bacteria in microdroplets was developed at the IPC PAS a few years ago, however it was constructed on a polycarbonate plate. The maximum dimensions of the plate did not exceed 10 cm, which greatly limited the number of droplets; in addition, as a result of interaction with the polycarbonate, after four days the channels were contaminated with bacteria. Devices of Teflon modules and tubing would not have these disadvantages, and would be suitable for practical applications.

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

Lifetime of Phosphorescence from Nanoparticles Yields Accurate Measurement of Concentration of Oxygen in Microdroplets, Allowing One To Monitor the Metabolism of Bacteria by Michał Horka, Shiwen Sun, Artur Ruszczak, Piotr Garstecki, and Torsten Mayr. Anal. Chem., 2016, 88 (24), pp 12006–12012 DOI: 10.1021/acs.analchem.6b03758 Publication Date (Web): November 23, 2016

Copyright © 2016 American Chemical Society

This paper is behind a paywall.

Creating quantum dots (artificial atoms) in graphene

An Aug. 22, 2016 news item on phys.org describes some recent work on artificial atoms and graphene from the Technical University of Vienna (Austria) and partners in Germany and the UK,

In a tiny quantum prison, electrons behave quite differently as compared to their counterparts in free space. They can only occupy discrete energy levels, much like the electrons in an atom – for this reason, such electron prisons are often called “artificial atoms”. Artificial atoms may also feature properties beyond those of conventional ones, with the potential for many applications for example in quantum computing. Such additional properties have now been shown for artificial atoms in the carbon material graphene. The results have been published in the journal Nano Letters, the project was a collaboration of scientists from TU Wien (Vienna, Austria), RWTH Aachen (Germany) and the University of Manchester (GB).

“Artificial atoms open up new, exciting possibilities, because we can directly tune their properties”, says Professor Joachim Burgdörfer (TU Wien, Vienna). In semiconductor materials such as gallium arsenide, trapping electrons in tiny confinements has already been shown to be possible. These structures are often referred to as “quantum dots”. Just like in an atom, where the electrons can only circle the nucleus on certain orbits, electrons in these quantum dots are forced into discrete quantum states.

Even more interesting possibilities are opened up by using graphene, a material consisting of a single layer of carbon atoms, which has attracted a lot of attention in the last few years. “In most materials, electrons may occupy two different quantum states at a given energy. The high symmetry of the graphene lattice allows for four different quantum states. This opens up new pathways for quantum information processing and storage” explains Florian Libisch from TU Wien. However, creating well-controlled artificial atoms in graphene turned out to be extremely challenging.

Florian Libisch, explaining the structure of graphene. Courtesy Technical University of Vienna

Florian Libisch, explaining the structure of graphene. Courtesy Technical University of Vienna

An Aug. 22, 2016 Technical University of Vienna press release (also on EurekAlert), which originated the news item, provides more detail,

There are different ways of creating artificial atoms: The simplest one is putting electrons into tiny flakes, cut out of a thin layer of the material. While this works for graphene, the symmetry of the material is broken by the edges of the flake which can never be perfectly smooth. Consequently, the special four-fold multiplicity of states in graphene is reduced to the conventional two-fold one.

Therefore, different ways had to be found: It is not necessary to use small graphene flakes to capture electrons. Using clever combinations of electrical and magnetic fields is a much better option. With the tip of a scanning tunnelling microscope, an electric field can be applied locally. That way, a tiny region is created within the graphene surface, in which low energy electrons can be trapped. At the same time, the electrons are forced into tiny circular orbits by applying a magnetic field. “If we would only use an electric field, quantum effects allow the electrons to quickly leave the trap” explains Libisch.

The artificial atoms were measured at the RWTH Aachen by Nils Freitag and Peter Nemes-Incze in the group of Professor Markus Morgenstern. Simulations and theoretical models were developed at TU Wien (Vienna) by Larisa Chizhova, Florian Libisch and Joachim Burgdörfer. The exceptionally clean graphene sample came from the team around Andre Geim and Kostya Novoselov from Manchester (GB) – these two researchers were awarded the Nobel Prize in 2010 for creating graphene sheets for the first time.

The new artificial atoms now open up new possibilities for many quantum technological experiments: “Four localized electron states with the same energy allow for switching between different quantum states to store information”, says Joachim Burgdörfer. The electrons can preserve arbitrary superpositions for a long time, ideal properties for quantum computers. In addition, the new method has the big advantage of scalability: it should be possible to fit many such artificial atoms on a small chip in order to use them for quantum information applications.

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

Electrostatically Confined Monolayer Graphene Quantum Dots with Orbital and Valley Splittings by Nils M. Freitag, Larisa A. Chizhova, Peter Nemes-Incze, Colin R. Woods, Roman V. Gorbachev, Yang Cao, Andre K. Geim, Kostya S. Novoselov, Joachim Burgdörfer, Florian Libisch, and Markus Morgenstern. Nano Lett., Article ASAP DOI: 10.1021/acs.nanolett.6b02548 Publication Date (Web): July 28, 2016

Copyright © 2016 American Chemical Society

This paper is behind a paywall.

Dexter Johnson in an Aug. 23, 2016 post on his Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers] website) provides some additional insight into the world of quantum dots,

Quantum dots made from semiconductor materials, like silicon, are beginning to transform the display market. While it is their optoelectronic properties that are being leveraged in displays, the peculiar property of quantum dots that allows their electrons to be forced into discrete quantum states has long held out the promise of enabling quantum computing.

If you have time to read it, Dexter’s post features an email interview with Florian Libisch where they further discuss quantum dots and quantum computing.