Category Archives: space exploration

Making nanoscale transistor chips out of thin air—sort of

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Caption: The nano-gap transistors operating in air. As gaps become smaller than the mean-free path of electrons in air, there is ballistic electron transport. Credit: RMIT University

A November 19, 2018 news item on Nanowerk describes the ‘airy’ work ( Note: A link has been removed),

Researchers at RMIT University [Ausralia] have engineered a new type of transistor, the building block for all electronics. Instead of sending electrical currents through silicon, these transistors send electrons through narrow air gaps, where they can travel unimpeded as if in space.

The device unveiled in material sciences journal Nano Letters (“Metal–Air Transistors: Semiconductor-free field-emission air-channel nanoelectronics”), eliminates the use of any semiconductor at all, making it faster and less prone to heating up.

A November 19, 2018 RMIT University news release on EurkeAlert, which originated the news item, describes the work and possibilities in more detail,

Lead author and PhD candidate in RMIT’s Functional Materials and Microsystems Research Group, Ms Shruti Nirantar, said this promising proof-of-concept design for nanochips as a combination of metal and air gaps could revolutionise electronics.

“Every computer and phone has millions to billions of electronic transistors made from silicon, but this technology is reaching its physical limits where the silicon atoms get in the way of the current flow, limiting speed and causing heat,” Nirantar said.

“Our air channel transistor technology has the current flowing through air, so there are no collisions to slow it down and no resistance in the material to produce heat.”

The power of computer chips – or number of transistors squeezed onto a silicon chip – has increased on a predictable path for decades, roughly doubling every two years. But this rate of progress, known as Moore’s Law, has slowed in recent years as engineers struggle to make transistor parts, which are already smaller than the tiniest viruses, smaller still.

Nirantar says their research is a promising way forward for nano electronics in response to the limitation of silicon-based electronics.

“This technology simply takes a different pathway to the miniaturisation of a transistor in an effort to uphold Moore’s Law for several more decades,” Shruti said.

Research team leader Associate Professor Sharath Sriram said the design solved a major flaw in traditional solid channel transistors – they are packed with atoms – which meant electrons passing through them collided, slowed down and wasted energy as heat.

“Imagine walking on a densely crowded street in an effort to get from point A to B. The crowd slows your progress and drains your energy,” Sriram said.

“Travelling in a vacuum on the other hand is like an empty highway where you can drive faster with higher energy efficiency.”

But while this concept is obvious, vacuum packaging solutions around transistors to make them faster would also make them much bigger, so are not viable.

“We address this by creating a nanoscale gap between two metal points. The gap is only a few tens of nanometers, or 50,000 times smaller than the width of a human hair, but it’s enough to fool electrons into thinking that they are travelling through a vacuum and re-create a virtual outer-space for electrons within the nanoscale air gap,” he said.

The nanoscale device is designed to be compatible with modern industry fabrication and development processes. It also has applications in space – both as electronics resistant to radiation and to use electron emission for steering and positioning ‘nano-satellites’.

“This is a step towards an exciting technology which aims to create something out of nothing to significantly increase speed of electronics and maintain pace of rapid technological progress,” Sriram said.

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

Metal–Air Transistors: Semiconductor-free field-emission air-channel nanoelectronics by
Shruti Nirantar, Taimur Ahmed, Guanghui Ren, Philipp Gutruf, Chenglong Xu, Madhu Bhaskaran, Sumeet Walia, and Sharath Sriram. Nano Lett., DOI: 10.1021/acs.nanolett.8b02849 Publication Date (Web): November 16, 2018

Copyright © 2018 American Chemical Society

This paper is behind a paywall.

A Café Scientifique Vancouver (Canada) May 28, 2019 talk ‘Getting to the heart of Mars with insight’ and an update on Baba Brinkman (former Vancouverite) and his science raps

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It’s been a while since I’ve received any notices about upcoming talks from the local Café Scientifique crowd but on May 22, 2019 there was this announcement in an email,

Dear Café Scientifiquers,

Our next café will happen on TUESDAY, MAY 28TH [2019] at 7:30PM in the back room at YAGGER’S DOWNTOWN (433 W Pender). Our speaker for the evening will be DR. CATHERINE JOHNSON from the Department of Earth, Ocean and Atmospheric Sciences at UBC [University of British Columbia] .

GETTING TO THE HEART OF MARS WITH INSIGHT

Catherine Johnson is a professor of geophysics in the Dept of Earth, Ocean and Atmospheric Sciences at UBC Vancouver [campus], and a senior scientist at the Planetary Science Institute, Tucson.  She is a Co-Investigator on the InSight mission to Mars, the OSIRIS-REx mission to asteroid Bennu and was previously a Participating Scientist on the MESSENGER mission to Mercury.

We hope to see you there!

I did some digging and found two articles about Johnson, the InSight mission, and Mars. The first one is an October 21, 2012 article by James Keller on the Huffington Post Canada website,

As NASA’s Curiosity rover beams back photos of the rocky surface of Mars, another group of scientists, including one from British Columbia, is preparing the next mission to uncover what’s underneath.

Prof. Catherine Johnson, of the University of British Columbia, is among the scientists whose project, named Insight, was selected by NASA this week as part of the U.S. space agency’s Discovery program, which invites proposals from within the scientific community.

Insight will send a stationary robotic lander to Mars in 2016, drilling down several metres into the surface as it uses a combination of temperature readings and seismic measurements to help scientists on this planet learn more about the Martian core.

…

The second one is a May 6, 2018 article (I gather it took them longer to get to Mars than they anticipated in 2012) by Ivan Semeniuk for the Globe and Mail newspaper website,

Thanks to a thick bank of predawn fog, Catherine Johnson couldn’t see the rocket when it blasted off early Saturday morning at the Vandenberg Air Force Base in California – but she could hear the roar as NASA’s InSight mission set off on its 6½-month journey to Mars.

“It was really impressive,” said Dr. Johnson, a planetary scientist at the University of British Columbia and a member of the mission’s science team. Describing the mood at the launch as a mixture of relief and joy, Dr. Johnson added that “the spacecraft is finally en route to do what we have worked toward for many years.”

But while InSight’s mission is just getting under way, it also marks the last stage in a particularly fruitful period for the U.S. space agency’s Mars program. In the past two decades, multiple, complementary spacecraft tackled different aspects of Mars science.

Unlike the Curiosity rover, which landed on Mars nearly six years ago and is in the process of climbing a mountain in the middle of an ancient crater, InSight is designed to stay in one place after it touches down Nov. 26 [2018]. Its purpose is to open a new direction in Mars exploration – one that leads straight down as the spacecraft deploys a unique set of instruments to spy on the planet’s interior.

“What we will learn … will help us understand the earliest history of rocky planets, including Earth,” Dr. Johnson said.

It has been a prolonged voyage to the red planet. In 2015, technical problems forced program managers to postpone InSight’s launch for 2½ years. Now, scientists are hoping for smooth sailing to Mars and an uneventful landing a few hundred kilometres north of Curiosity, at a site that Dr. Johnson cheerfully describes as “boring.”

…

Does the timing of this talk mean you’ll be getting the latest news since InSight landed on Mars roughly six months ago? One can only hope. Finally, Johnson’s UBC bio webpage is here.

Baba Brinkman brings us up-to-date

Here’s most of a May 22, 2019 newsletter update (received via email) from former Vancouverite and current rapper, playwright, and science communicator, Baba Brinkman,

… Over the past five years I have been collaborating frequently with a company in California called SpectorDance, after the artistic director Fran Spector Atkins invited me to write and perform a rap soundtrack to one of her dance productions. Well, a few weeks ago we played our biggest venue yet with our latest collaborative show, Ocean Trilogy, which is all about the impact of human activities including climate change on marine ecosystems. The show was developed in collaboration with scientists at the Monterey Bay Aquarium Research Institute, and for the first time there’s now a full video of the production online. Have you ever seen scientifically-informed eco rap music combined in live performance with ballet and modern dance? Enjoy.

Speaking of “Science is Everywhere”, about a year ago I got to perform my song “Can’t Stop” about the neurobiology of free will for a sold-out crowd at the Brooklyn Academy of Music alongside physicist Brian Greene, comedian Chuck Nice, and Neil deGrasse Tyson. The song is half scripted and half freestyle (can you tell which part is which?) They just released the video.

Over the past few months I’ve been performing Rap Guide to Evolution, Consciousness, and Climate Chaos off-Broadway 2-3 times per week, which has been a roller coaster. Some nights I have 80 people and it’s rocking, other nights I step on stage and play to 15 people and it takes effort to keep it lively. But since this is New York, occasionally when there’s only 15 people one of them will turn out to be a former Obama Administration Energy Advisor or will publish a five star review, which keeps it exciting.

Tonight I fly to the UK where I’ll be performing all next week, including the premiere of my newest show Rap Guide to Culture, with upcoming shows in Brighton, followed by off-Broadway previews in June, followed by a full run at the Edinburgh Fringe in August (plus encores of my other shows), followed by… well I can’t really see any further than August at the moment, but the next few months promise to be action-packed.

What’s Rap Guide to Culture about? Cultural evolution and the psychology of norms of course. I recently attended a conference at the National Institute for Mathematical and Biological Synthesis in Knoxville, TN where I performed a sneak preview and did a “Rap Up” of the various conference talks, summarizing the scientific content at the end of the day, check out the video.

Okay, time to get back to packing and hit the road. More to come soon, and wish me luck continuing to dominate my lonely genre.

Brinkman has been featured here many times (just use his name as the term in the blog’s search engine). While he lives in New York City these days, he does retain a connection to Vancouver in that his mother Joyce Murray is the Member of Parliament for Vancouver Quadra and, currently, the president of the Treasury Board.

Cryptology exhibit and special breakfast celebrating Canadian astronaut David Saint-Jacques’ Dec. 3, 2018 launch in Ontario (Canada)

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I wish I was near either Ottawa or Kingston in December as there are a couple of very interesting events, assuming you have an interest in cryptology and/or space travel.

Cipher/Decipher

This show has been on tour in Ontario and, until Dec. 2, 2018, it will be at the Canada Science and Technology Museum before moving to Kingston (from the Canada Science and Technology Museum’s exhibitions page),

Cipher | Decipher

Pssst…want to know a secret?

One way to safely share secret information is through encryption — which means converting your message into something only the intended recipient can understand. For as long as we’ve had secret information, individuals and organizations have encrypted and analyzed encrypted communications. One way people encrypt their secrets is through ciphers that replace the original message with other letters, numbers, words, or symbols. From schoolyard gossip to military plans, ciphers keep secrets out of the wrong hands.

Cipher | Decipher is an interactive, new exhibition exploring the past and present of communications cryptology — what it is, how it works, and how it affects our lives. See an authentic Enigma cipher machine, or try your hand at logic puzzles and games to see if you have what it takes to work in the field of cryptology!

Developed by the Canada Science and Technology Museum, in partnership with the Communications Security Establishment, this 750 sq. ft. travelling exhibition is already on the move!

Mark your calendar to see Cipher | Decipher at the following locations:

  • Library and Archives Canada: October 5 to October 31, 2018
  • Canada Science and Technology Museum: November 6 to December 2, 2018
  • Military Communications and Electronics Museum, Kingston: December 7, 2018 to March 31, 2019

Blast-off!

This information came in a November 27, 2018 special announcement (received via email) from Ingenium (formerly Canada Science and Technology Museums Corporation and not to be confused with the Canada Science and Technology Museum),

Join the Canada Aviation and Space Museum for a special breakfast at the museum, as we witness the historic launch of Canadian astronaut David Saint-Jacques!

Start your day with a breakfast and a big cup of “rocket fuel” (a.k.a. coffee) as we watch the launch of this important space mission.

You’ll hear from Jesse Rogerson, the museum’s Science Advisor, and Iain Christie,

Executive Vice President of the Aerospace Industries Association of Canada about the intricacies of space travel. Canadian astronauts Bob Thirsk and Jenni Sidey-Gibbons will also join the conversation via livestream!

Take a selfie with our cut-out image of David Saint-Jacques, while the kids work on fun space-themed crafts. David Saint-Jacques themed merchandise will be 10% off during the event. Each purchase of a breakfast ticket/group of tickets will receive one FREE family pass, to visit the museum in 2019.

December 3, 2018
6 a.m. – 8:30 a.m.
Tickets: $16 (+ taxes)
Parking fees are additional.

Buy Tickets!

3… 2… 1… liftoff!

Enjoy!

Interstellar fullerenes

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This work from Russia on fullerenes (also known as buckministerfullerenes, C60, and/or buckyballs) is quite interesting and dates back more than a year. I’m not sure why the work is being publicized now but nanotechnology and interstellar space is not covered here often enough so, here goes, (from a January 29, 2018 Kazan Federal University press release (also on EurekAlert), Note: Links have been removed,

Currently, materials based on spherical carbon nanostructures can cost up to USD 150 million per 1 gram.

Fullerenes were first discovered by Harry Kroto in the 1970s, a feat for which he and his colleagues Robert Curl and Richard Smalley received a Nobel Prize in Chemistry. Recently, fullerenes have been found in winds emitted by red giants and in interstellar medium.

Fullerenes are very potent antioxidants and are used in antiviral medications. In particular, fullerenes with anti-HIV properties have also been discovered. Apart from that, they are also used as semiconductors and even high temperature superconductors (if decorated with alkali metal atoms). Their sphere of use is constantly growing, and research is ongoing to find ways of mass production. So far, they are produced in near-gram quantities. One of the more popular methods is the graphite electrode arc process. It is hypothesized that in deep vacuum conditions with low density fullerenes can by synthesized in other yet unknown ways.

A group of astronomers is currently engaged in studies of fullerenes in interstellar medium. Among them are KFU alumni Gazinur Galazutdinov (Catholic University of the North, Chile) and Gennady Valyavin (Special Astrophysical Observatory of the Russian Academy of Sciences) and current KFU employee, Associate Professor at the Department of Astronomy and Space Geodesy Vladislav Shimansky. Together, they contributed to a recent paper in Monthly Notices of the Royal Astronomical Society.

The nearest interstellar clouds with confirmed fullerene presence are about 1,000 light years away from Earth. Electromagnetic spectra of 19 distant stars were provided by the VLT telescope in Chile, one of the largest in the world. The authors found fullerenes which left traces – absorption lines in certain frequencies.

Dr. Shimansky comments, “We know for sure which frequencies have lines of fullerenes, but the main difficulty is to separate the interstellar medium spectrum from the star spectrum. That’s why we can obtain fullerene lines by ‘subtracting’ star spectra from the existing spectrum, and that’s a complicated process. Firstly, we discovered some parameters of stars, and some of these stars are unique objects.”

“We compare fullerene-bearing clouds with non-fullerene clouds to find out which environmental parameters capacitate the formation of such molecules. In our research, we found that in some clouds the molecules are in an excited state, and in some they are not. This leads us to believe that the ways of their formation are different.”

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

C60+ – looking for the bucky-ball in interstellar space by G. A. Galazutdinov, V. V. Shimansky, A. Bondar, G. Valyavin, J. Krełowski. Monthly Notices of the Royal Astronomical Society, Volume 465, Issue 4, 11 March 2017, Pages 3956–3964, https://doi.org/10.1093/mnras/stw2948 Published: 22 December 2016

This paper is behind a paywall.

h/t January 29, 2018 news item on Nanowerk

Materials that may protect astronauts from radiation in space

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Sparing astronauts from harmful radiation  is one of the goals for this project according to a July 3, 2017 news item on Nanowerk (Note: A link has been removed),

Scientists at The Australian National University (ANU) have designed a new nano material that can reflect or transmit light on demand with temperature control, opening the door to technology that protects astronauts in space from harmful radiation (Advanced Functional Materials, “Reversible Thermal Tuning of All-Dielectric Metasurfaces”).

Lead researcher Dr Mohsen Rahmani from ANU said the material was so thin that hundreds of layers could fit on the tip of a needle and could be applied to any surface, including spacesuits.

The first speaker’s enthusiasm leaps off the screen,

For whose who prefer to read their news, a July 4, 2017 ANU press release, which originated the news item, provides more detail,

“Our invention has a lot of potential applications, such as protecting astronauts or satellites with an ultra-thin film that can be adjusted to reflect various dangerous ultraviolet or infrared radiation in different environments,” said Dr Rahmani, an Australian Research Council (ARC) Discovery Early Career Research Fellow at the Nonlinear Physics Centre within the ANU Research School of Physics and Engineering.

“Our technology significantly increases the resistance threshold against harmful radiation compared to today’s technologies, which rely on absorbing radiation with thick filters.”

Co-researcher Associate Professor Andrey Miroshnichenko said the invention could be tailored for other light spectrums including visible light, which opened up a whole array of innovations, including architectural and energy saving applications.

“For instance, you could have a window that can turn into a mirror in a bathroom on demand, or control the amount of light passing through your house windows in different seasons,” said Dr Miroshnichenko from the Nonlinear Physics Centre within the ANU Research School of Physics and Engineering.

“What I love about this invention is that the design involved different research disciplines including physics, materials science and engineering.”

Co-lead researcher Dr Lei Xu said achieving cost-efficient and confined temperature control such as local heating was feasible.

“Much like your car has a series of parallel resistive wires on the back windscreen to defog the rear view, a similar arrangement could be used with our invention to confine the temperature control to a precise location,” said Dr Xu from the Nonlinear Physics Centre within the ANU Research School of Physics and Engineering.

The innovation builds on more than 15 years of research supported by the ARC through CUDOS, a Centre of Excellence, and the Australian National Fabrication Facility.

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

Reversible Thermal Tuning of All-Dielectric Metasurfaces by Mohsen Rahmani, Lei Xu, Andrey E. Miroshnichenko, Andrei Komar, Rocio Camacho-Morales, Haitao Chen, Yair Zárate, Sergey Kruk, Guoquan Zhang, Dragomir N. Neshev, and Yuri S. Kivshar. Advanced Functional Materials DOI: 10.1002/adfm.201700580 Version of Record online: 3 JUL 2017

© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

Ultra-thin superconducting film for outer space

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Truth in a press release? But first, there’s this April 6, 2017 news item on Nanowerk announcing research that may have applications in aerospace and other sectors,

Experimental physicists in the research group led by Professor Uwe Hartmann at Saarland University have developed a thin nanomaterial with superconducting properties. Below about -200 °C these materials conduct electricity without loss, levitate magnets and can screen magnetic fields.

The particularly interesting aspect of this work is that the research team has succeeded in creating superconducting nanowires that can be woven into an ultra-thin film that is as flexible as cling film. As a result, novel coatings for applications ranging from aerospace to medical technology are becoming possible.

The research team will be exhibiting their superconducting film at Hannover Messe from April 24th to April 28th [2017] (Hall 2, Stand B46) and are looking for commercial and industrial partners with whom they can develop their system for practical applications.

An April 6, 2017 University of Saarland press release (also on EurekAlert), which originated the news item, provides more details along with a line that rings with the truth,

A team of experimental physicists at Saarland University have developed something that – it has to be said – seems pretty unremarkable at first sight. [emphasis mine] It looks like nothing more than a charred black piece of paper. But appearances can be deceiving. This unassuming object is a superconductor. The term ‘superconductor’ is given to a material that (usually at a very low temperatures) has zero electrical resistance and can therefore conduct an electric current without loss. Put simply, the electrons in the material can flow unrestricted through the cold immobilized atomic lattice. In the absence of electrical resistance, if a magnet is brought up close to a cold superconductor, the magnet effectively ‘sees’ a mirror image of itself in the superconducting material. So if a superconductor and a magnet are placed in close proximity to one another and cooled with liquid nitrogen they will repel each another and the magnet levitates above the superconductor. The term ‘levitation’ comes from the Latin word levitas meaning lightness. It’s a bit like a low-temperature version of the hoverboard from the ‘Back to the Future’ films. If the temperature is too high, however, frictionless sliding is just not going to happen.
Many of the common superconducting materials available today are rigid, brittle and dense, which makes them heavy. The Saarbrücken physicists have now succeeded in packing superconducting properties into a thin flexible film. The material is a essentially a woven fabric of plastic fibres and high-temperature superconducting nanowires. ‘That makes the material very pliable and adaptable – like cling film (or ‘plastic wrap’ as it’s also known). Theoretically, the material can be made to any size. And we need fewer resources than are typically required to make superconducting ceramics, so our superconducting mesh is also cheaper to fabricate,’ explains Uwe Hartmann, Professor of Nanostructure Research and Nanotechnology at Saarland University.

The low weight of the film is particularly advantageous. ‘With a density of only 0.05 grams per cubic centimetre, the material is very light, weighing about a hundred times less than a conventional superconductor. This makes the material very promising for all those applications where weight is an issue, such as in space technology. There are also potential applications in medical technology,’ explains Hartmann. The material could be used as a novel coating to provide low-temperature screening from electromagnetic fields, or it could be used in flexible cables or to facilitate friction-free motion.

In order to be able to weave this new material, the experimental physicists made use of a technique known as electrospinning, which is usually used in the manufacture of polymeric fibres. ‘We force a liquid material through a very fine nozzle known as a spinneret to which a high electrical voltage has been applied. This produces nanowire filaments that are a thousand times thinner than the diameter of a human hair, typically about 300 nanometres or less. We then heat the mesh of fibres so that superconductors of the right composition are created. The superconducting material itself is typically an yttrium-barium-copper-oxide or similar compound,’ explains Dr. Michael Koblischka, one of the research scientists in Hartmann‘s group.

The research project received €100,000 in funding from the Volkswagen Foundation as part of its ‘Experiment!’ initiative. The initiative aims to encourage curiosity-driven, blue-skies research. The positive results from the Saarbrücken research team demonstrate the value of this type of funding. Since September 2016, the project has been supported by the German Research Foundation (DFG). Total funds of around €425,000 will be provided over a three-year period during which the research team will be carrying out more detailed investigations into the properties of the nanowires.

I’d say the “unremarkable but appearances can be deceiving” comments are true more often than not. I think that’s one of the hard things about science. Big advances can look nondescript.

What looks like a pretty unremarkable piece of burnt paper is in fact an ultrathin superconductor that has been developed by the team lead by Uwe Hartmann (r.) shown here with doctoral student XianLin Zeng. Courtesy: Saarland University

In any event, here’s a link to and a citation for the paper,

Preparation of granular Bi-2212 nanowires by electrospinning by Xian Lin Zeng, Michael R Koblischka, Thomas Karwoth, Thomas Hauet, and Uwe Hartmann. Superconductor Science and Technology, Volume 30, Number 3 Published 1 February 2017

© 2017 IOP Publishing Ltd

This paper is behind a paywall.

Figuring out how stars are born by watching neutrons ‘quantum tunnelling’ on graphene

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A Feb. 3, 2017 news item on Nanowerk announces research that could help us better understand how stars are ‘born’,

Graphene is known as the world’s thinnest material due to its 2D structure, where each sheet is only one carbon atom thick, allowing each atom to engage in a chemical reaction from two sides. Graphene flakes can have a very large proportion of edge atoms, all of which have a particular chemical reactivity.

In addition, chemically active voids created by missing atoms are a surface defect of graphene sheets. These structural defects and edges play a vital role in carbon chemistry and physics, as they alter the chemical reactivity of graphene. In fact, chemical reactions have repeatedly been shown to be favoured at these defect sites.

Interstellar molecular clouds are predominantly composed of hydrogen in molecular form (H2), but also contain a small percentage of dust particles mostly in the form of carbon nanostructures, called polyaromatic hydrocarbons (PAH). These clouds are often referred to as ‘star nurseries’ as their low temperature and high density allows gravity to locally condense matter in such a way that it initiates H fusion, the nuclear reaction at the heart of each star.

Graphene-based materials, prepared from the exfoliation of graphite oxide, are used as a model of interstellar carbon dust as they contain a relatively large amount of atomic defects, either at their edges or on their surface. These defects are thought to sustain the Eley-Rideal chemical reaction, which recombines two H atoms into one H2 molecule. The observation of interstellar clouds in inhospitable regions of space, including in the direct proximity of giant stars, poses the question of the origin of the stability of hydrogen in the molecular form (H2).

This question stands because the clouds are constantly being washed out by intense radiation, hence cracking the hydrogen molecules into atoms. Astrochemists suggest that the chemical mechanism responsible for the recombination of atomic H into molecular H2 is catalysed by carbon flakes in interstellar clouds.

A Feb. 2, 2017 Institut Laue-Langevin press release, which originated the news item, provides more insight into the research,

Their [astrochemists’s] theories are challenged by the need for a very efficient surface chemistry scenario to explain the observed equilibrium between dissociation and recombination. They had to introduce highly reactive sites into their models so that the capture of an atomic H nearby occurs without fail. These sites, in the form of atomic defects at the surface or edge of the carbon flakes, should be such that the C-H bond formed thereafter allows the H atom to be released easily to recombine with another H atom flying nearby.

A collaboration between the Institut Laue-Langevin (ILL), France, the University of Parma, Italy, and the ISIS Neutron and Muon Source, UK, combined neutron spectroscopy with density functional theory (DFT) molecular dynamics simulations in order to characterise the local environment and vibrations of hydrogen atoms chemically bonded at the surface of substantially defected graphene flakes. Additional analyses were carried out using muon spectroscopy (muSR) and nuclear magnetic resonance (NMR). As availability of the samples is very low, these highly specific techniques were necessary to study the samples; neutron spectroscopy is highly sensitive to hydrogen and allowed accurate data to be gathered at small concentrations.

For the first time ever, this study showed ‘quantum tunnelling’ in these systems, allowing the H atoms bound to C atoms to explore relatively long distances at temperatures as low as those in interstitial clouds. The process involves hydrogen ‘quantum hopping’ from one carbon atom to another in its direct vicinity, tunnelling through energy barriers which could not be overcome given the lack of heat in the interstellar cloud environment. This movement is sustained by the fluctuations of the graphene structure, which bring the H atom into unstable regions and catalyse the recombination process by allowing the release of the chemically bonded H atom. Therefore, it is believed that quantum tunnelling facilitates the reaction for the formation of molecular H2.

ILL scientist and carbon nanostructure specialist, Stéphane Rols says: “The question of how molecular hydrogen forms at the low temperatures in interstellar clouds has always been a driver in astrochemistry research. We’re proud to have combined spectroscopy expertise with the sensitivity of neutrons to identify the intriguing quantum tunnelling phenomenon as a possible mechanism behind the formation of H2; these observations are significant in furthering our understanding of the universe.”

Here’s a link to and a citation for the paper (which dates from Aug. 2016),

Hydrogen motions in defective graphene: the role of surface defects by Chiara Cavallari, Daniele Pontiroli, Mónica Jiménez-Ruiz, Mark Johnson, Matteo Aramini, Mattia Gaboardi, Stewart F. Parker, Mauro Riccó, and Stéphane Rols. Phys. Chem. Chem. Phys., 2016, Issue 36, 18, 24820-24824 DOI: 10.1039/C6CP04727K First published online 22 Aug 2016

This paper is behind a paywall.

Testing ‘smart’ antibacterial surfaces and eating haute cuisine in space

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Housekeeping in space, eh? This seems to be a French initiative. From a Nov. 15, 2016 news item on Nanowerk,

Leti [Laboratoire d’électronique des technologies de l’information (LETI)], an institute of CEA [French Alternative Energies and Atomic Energy Commission or Commissariat a l’Energie Atomique (CEA)] Tech, and three French partners are collaborating in a “house-cleaning” project aboard the International Space Station that will investigate antibacterial properties of new materials in a zero-gravity environment to see if they can improve and simplify cleaning inside spacecraft.

The Matiss experiment, as part of the Proxima Mission sponsored by France’s CNES space agency [Centre national d’études spatiales (CNES); National Centre for Space Studies (CNES)], is based on four identical plaques that European Space Agency (ESA) astronaut Thomas Pesquet, the 10th French citizen to go into space, will take with him and install when he joins the space station in November for a six-month mission. The plaques will be in the European Columbus laboratory in the space station for at least three months, and Pesquet will bring them back to earth for analysis at the conclusion of his mission.

A November 15, 2016 CEA-LETI press release on Business Wire (you may also download it from here), which originated the news item, describes the proposed experiments in more detail,

Leti, in collaboration with the ENS de Lyon, CNRS, the French company Saint Gobain and CNES, selected five advanced materials that could stop bacteria from settling and growing on “smart” surfaces. A sixth material, made of glass, will be used as control material.

The experiment will test the new smart surfaces in a gravity-free, enclosed environment. These surfaces are called “smart” because of their ability to provide an appropriate response to a given stimulus. For example, they may repel bacteria, prevent them from growing on the surface, or create their own biofilms that protect them from the bacteria.

The materials are a mix of advanced technology – from self-assembly monolayers and green polymers to ceramic polymers and water-repellent hybrid silica. By responding protectively to air-borne bacteria they become easier to clean and more hygienic. The experiment will determine which one is most effective and could lead to antibacterial surfaces on elevator buttons and bars in mass-transit cars, for example.

“Leveraging its unique chemistry platform, Leti has been developing gas, liquid and supercritical-phase-collective processes of surface functionalization for more than 10 years,” said Guillaume Nonglaton, Leti’s project manager for surface chemistry for biology and health-care applications. “Three Leti-developed surfaces will be part of the space-station experiment: a fluorinated thin layer, an organic silica and a biocompatible polymer. They were chosen for their hydrophobicity, or lack of attraction properties, their level of reproducibility and their rapid integration within Pesquet’s six-month mission.”

Now, for Haute Cusine

Pesquet is bringing meals from top French chefs Alain Ducasse and Thierry Marx for delectation. The menu includes beef tongue with truffled foie gras and duck breast confit. Here’s more from a Nov. 17, 2016 article by Thibault Marchand (Agence France Presse) ong phys.org,

“We will have food prepared by a Michelin-starred chef at the station. We have food for the big feasts: for Christmas, New Year’s and birthdays. We’ll have two birthdays, mine and Peggy’s,” said the Frenchman, who is also taking a saxophone up with him.

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French space rookie Thomas Pesquet, 38, will lift off from the Baikonur cosmodrome in Kazakhstan with veteran US and Russian colleagues Peggy Whitson and Oleg Novitsky, for a six-month mission to the ISS.

Bon appétit! By the way, this is not the first time astronauts have been treated to haute cuisine (see a Dec. 2, 2006 article on the BBC [British Broadcasting Corporation] website.)

The launch

Mark Garcia’s Nov. 17, 2016 posting on one of the NASA (US National Aeronautics and Space Administration) blogs describes this latest launch into space,

The Soyuz MS-03 launched from the Baikonur Cosmodrome in Kazakhstan to the International Space Station at 3:20 p.m. EST Thursday, Nov. 17 (2:20 a.m. Baikonur time, Nov. 18). At the time of launch, the space station was flying about 250 miles over the south Atlantic east of Argentina. NASA astronaut Peggy Whitson, Oleg Novitskiy of Roscosmos and Thomas Pesquet of ESA (European Space Agency) are now safely in orbit.

Over the next two days, the trio will orbit the Earth for approximately two days before docking to the space station’s Rassvet module, at 5:01 p.m. on Saturday, Nov. 19. NASA TV coverage of the docking will begin at 4:15 p.m. Saturday.

Garcia’s post gives you details about how to access more information about the mission. The European Space Agency also offers more information as does Thomas Pesquet on his website.

Watching a nanosized space rocket under a microscope

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That is a silent video depicting the research. For anyone who may be puzzled, there’s an Aug. 8, 2016 news item on Nanowerk featuring the research announcement from Michigan Technological University (Note: A link has been removed),

Researchers at the University of Maryland and Michigan Technological University have operated a tiny proposed satellite ion rocket under a microscope to see how it works (Nanotechnology, “Radiation-induced solidification of ionic liquid under extreme electric field”).

The rocket, called an electrospray thruster, is a drop of molten salt. When electricity is applied, it creates a field on the tip of the droplet, until ions begin streaming off the end. The force created by the rocket is less than the weight of a human hair, but in the vacuum of space it is enough to push a small object forward with a constant acceleration. Many of these tiny thrusters packed together could propel a spacecraft over great distances, maybe even to the nearest exoplanet, and they are particularly useful for Earth-orbiting nanosatellites, which can be as small as a shoe box. These thrusters are currently being tested on the European Space Agency’s LISA Pathfinder, which hopes to poise objects in space so precisely that they would only be disturbed by gravitational waves.

An Aug, 8, 2016 Michigan Technological University news release on EurekAlert, which originated the news item, explains further,

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these droplet engines have a problem: sometimes they form needle-like spikes that disrupt the way the thruster works – they get in the way of the ions flowing outward and turn the liquid to a gel. Lyon B. King and Kurt Terhune, mechanical engineers at Michigan Tech, wanted to find out how this actually happens.

“The challenge is making measurements of features as small as a few molecules in the presence of a strong electric field, which is why we turned to John Cumings at the University of Maryland,” King says, explaining Cumings is known for his work with challenging materials and that they needed to look for a needle in a haystack. “Getting a close look at these droplets is like looking through a straw to find a penny somewhere on the floor of a room–and if that penny moves out of view, like the tip of the molten salt needles do–then you have to start searching for it all over again.”

At the Advanced Imaging and Microscopy Lab at the University of Maryland, Cumings put the tiny thruster in a transmission electron microscope – an advanced scope that can see things down to millionths of a meter. They watched as the droplet elongated and sharpened to a point, and then started emitting ions. Then the tree-like defects began to appear.

The researchers say that figuring out why these branched structures grow could help prevent them from forming. The problem occurs when high-energy electrons, like those used in the microscope’s imaging beam, impact the fluid causing damage to the molecules that they strike. This damages the molten salt’s molecular structure, so it thickens into a gel and no longer flows properly.

“We were able to watch the dendritic structures accumulate in real time,” says Kurt Terhune, a mechanical engineering graduate student and the study’s lead author. “The specific mechanism still needs to be investigated, but this could have importance for spacecraft in high-radiation environments.”

He adds that the microscope’s electron beam is more powerful than natural settings, but the gelling effect could affect the lifetime of electrospray thrusters in low-Earth and geosynchronous orbit.

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

Radiation-induced solidification of ionic liquid under extreme electric field by Kurt J Terhune, Lyon B King, Kai He, and John Cumings. Nanotechnology, Volume 27, Number 37 DOI: http://dx.doi.org/10.1088/0957-4484/27/37/375701 Published 3 August 2016

© 2016 IOP Publishing Ltd

This paper is behind a paywall.