Category Archives: nanotechnology

New podcast—Mission: Interplanetary and Event Rap: a one-stop custom rap shop Kickstarter

I received two email notices recently, one from Dr. Andrew Maynard (Arizona State University; ASU) and one from Baba Brinkman (Canadian rapper of science and other topics now based in New York).

Mission: Interplanetary

I found a “Mission: Interplanetary— a podcast on the future of humans as a spacefaring species!” webpage (Link: https://collegeofglobalfutures.asu.edu/blog/2021/03/23/mission-interplanetary-redefining-how-we-talk-about-humans-in-space/) on the Arizona State University College of Global Futures website,

Back in January 2019 I got an email from my good friend and colleague Lance Gharavi with the title “Podcast brainstorming.” Two years on, we’ve just launched the Mission: Interplanetary podcast–and it’s amazing!

It’s been a long journey — especially with a global pandemic thrown in along the way — but on March 23 [2021], the Mission: Interplanetary podcast with Slate and ASU finally launched.

After two years of planning, many discussions, a bunch dry runs, and lots (and by that I mean lots) of Zoom meetings, we are live!

As the team behind the podcast talked about and developed the ideas underpinning the Mission: Interplanetary,we were interested in exploring new ways of thinking and talking about the future of humanity as a space-faring species as part of Arizona State University’s Interplanetary Initiative. We also wanted to go big with these conversations — really big!

And that is exactly what we’ve done in this partnership with Slate.

The guests we’re hosting, the conversations we have lined up, the issues we grapple with, are all literally out of this world. But don’t just take my word for it — listen to the first episode above with the incredible Lindy Elkins-Tanton talking about NASA’s mission to the asteroid 16 Psyche.

And this is just a taste of what’s to come over the next few weeks as we talk to an amazing lineup of guests.

So if you’re looking for a space podcast with a difference, and one that grapples with big questions around our space-based future, please do subscribe on your favorite podcast platform. And join me and the fabulous former NASA astronaut Cady Coleman as we explore the future of humanity in space.

See you there!

Slate’s webpage (Mission: Interplanetary; Link: https://slate.com/podcasts/mission-interplanetary) offers more details about the co-hosts and the programmes along with embedded podcasts,

Cady Coleman is a former NASA astronaut and Air Force colonel. She flew aboard the International Space Station on a six-month expedition as the lead science and robotics officer. A frequent speaker on space and STEM topics, Coleman is also a musician who’s played from space with the Chieftains and Ian Anderson of Jethro Tull.

Andrew Maynard is a scientist, author, and expert in risk innovation. His books include Films From the Future: The Technology and Morality of Sci-Fi Movies and Future Rising

Latest Episodes

April 27, 2021

Murder in Space

What laws govern us when we leave Earth?

Happy listening. And, I apologize for the awkward links.

Event Rap Kickstarter

Baba Brinkman’s April 27, 2021 email notice has this to say about his latest venture,

Join the Movement, Get Rewards

My new Kickstarter campaign for Event Rap is live as of right now! Anyone who backs the project is helping to launch an exciting new company, actually a new kind of company, the first creator marketplace for rappers. Please take a few minutes to read the campaign description, I put a lot of love into it.

The campaign goal is to raise $26K in 30 days, an average of $2K per artist participating. If we succeed, this platform becomes a new income stream for independent artists during the pandemic and beyond. That’s the vision, and I’m asking for your help to share it and support it.

But instead of why it matters, let’s talk about what you get if you support the campaign!

$10-$50 gets you an advance copy of my new science rap album, Bright Future. I’m extremely proud of this record, which you can preview here, and Bright Future is also a prototype for Event Rap, since all ten of the songs were commissioned by people like you.

$250 – $500 gets you a Custom Rap Video written and produced by one of our artists, and you have twelve artists and infinite topics to choose from. This is an insanely low starting price for an original rap video from a seasoned professional, and it applies only during the Kickstarter. What can the video be about? Anything at all. You choose!

In case it’s helpful, here’s a guide I wrote entitled “How to Brief a Rapper

$750 – $1,500 gets you a live rap performance at your virtual event. This is also an amazingly low price, especially since you can choose to have the artist freestyle interactively with your audience, write and perform a custom rap live, or best of all compose a “Rap Up” summary of the event, written during the event, that the artist will perform as the grand finale.

That’s about as fresh and fun as rap gets.

$3,000 – $5,000 the highest tiers bring the highest quality, a brand new custom-written, recorded, mixed and mastered studio track, or studio track plus full rap music video, with an exclusive beat and lyrics that amplify your message in the impactful, entertaining way that rap does best.

I know this higher price range isn’t for everyone, but check out some of the music videos our artists have made, and maybe you can think of a friend to send this to who has a budget and a worthy cause.

Okay, that’s it!

Those prices are in US dollars.

I gather at least one person has backed given enough money to request a custom rap on cycling culture in the Netherlands.

The campaign runs for another 26 days. It has amassed over $8,400 CAD towards a goal of $32,008 CAD. (The site doesn’t show me the goal in USD although the pledges/reward are listed in that currency.)

Uniting oil and water for a manufacturing-friendly approach to gel production

This is a newish type of gel for which a new manufacturing has been developed jointly by the US National Institute of Standards and Technology (NIST) and the University of Delaware as described in a February 11, 2021 news item on phys.org (Note: A link has been removed),

Oil and water may not mix, but adding the right nanoparticles to the recipe can convert these two immiscible fluids into an exotic gel with uses ranging from batteries to water filters to tint-changing smart windows. A new approach to creating this unusual class of soft materials could carry them out of the laboratory and into the marketplace.

Scientists at the National Institute of Standards and Technology (NIST) and the University of Delaware have found what appears to be a better way to create these gels, which have been an area of intense research focus for more than a decade. Part of their potentially broad utility is the complex set of interconnected microscopic channels that form within them, creating a spongelike structure. These channels not only offer passageways for other materials to travel through, making them useful for filtration, but also give the gel a high amount of internal surface area, a characteristic valuable for speeding up chemical reactions or as scaffolding on which living tissue can grow.

..

It seems they have great hopes for what they’ve called ‘SeedGel’, if this image is anything to go by,

Unlike other gel-creation approaches, where nanoparticles remain at the interface between the gel’s two constituent solvents (top left), the new approach concentrates nanoparticles in the interior of one of the solvents (top right), giving the resulting “SeedGel” unusual mechanical strength. The method could lead to gels that could be manufactured at industrial scales for a wide variety of potential applications. Credit: N. Hanacek / NIST

A February 10, 2021 NIST news release (also on EurekAlert), which originated the news item, delves further into the topic,

While these and other advantages make it sound like gel innovators have struck oil, their creations have not yet mixed well with the marketplace. The gels are commonly formed of two liquid solvents mingled together. As with oil and water, these solvents do not mix well, but to prevent them from completely separating, researchers add custom-designed nanoparticles that can stay at the interface between them. Carefully cooking these ingredients allows a cohesive gel to form. However, the process is demanding because custom-designing nanoparticles for each application has been difficult, and forming the gels has required carefully controlled rapid temperature change. These constraints have made it hard to create this type of gel in any more than small quantities suitable for lab experiments rather than on an industrial scale.

As described in a new Nature Communications paper, the NIST/Delaware team has found ways to sidestep many of these problems. Its novel approach forms what the researchers refer to as a “SeedGel,” an abbreviation for “solvent segregation driven gel.” Instead of designing nanoparticles to remain at the interface between the two solvents, their chosen particles concentrate within one of them. While these particles tend to repel one another, the particles’ affinity toward one of the solvents is stronger and keeps them together in the channel. Using neutron scattering tools at the NIST Center for Neutron Research (NCNR), the team unambiguously proved that it had succeeded at concentrating the nanoparticles where it wanted. 

The resulting gel could be far easier to create, as its two solvents are essentially oil and water, and its nanoparticles are silicon dioxide — essentially tiny spheres of common quartz. It also could have a variety of industrial uses. 

“Our SeedGel has great mechanical strength, it’s much easier to make, and the process is scalable to what manufacturers would need,” said Yun Liu, who is both an NCNR scientist and an affiliated full professor at the University of Delaware. “Plus it’s thermo-reversible.”

This reversibility refers to an optical property that the finished SeedGel possesses: It can switch from transparent to opaque and back again, just by changing its temperature. This property could be harnessed in smart windows that sandwich a thin layer of the gel between two panes of glass.

“This optical property could make the SeedGel useful in other light-sensitive applications as well,” said Yuyin Xi, a researcher from the University of Delaware also working at the NCNR. “They could be useful in sensors.”

Because the team’s gel-creation approach could be used with other solvent-and-nanoparticle combinations, it could become useful in filters for water purification and possibly other filtration processes depending on what type of nanoparticles are used.

Liu also said that the creation approach allows for the size of the channels within the gel to be tuned by changing the rate at which the temperature changes during the formation process, offering application designers another degree of freedom to explore.

“Ours is a generic approach working for many different nanoparticles and solvents,” he said. “It greatly extends the applications of these sorts of gels.”

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

Tunable thermo-reversible bicontinuous nanoparticle gel driven by the binary solvent segregation by Yuyin Xi, Ronald S. Lankone, Li-Piin Sung & Yun Liu. Nature Communications volume 12, Article number: 910 (2021) DOI: https://doi.org/10.1038/s41467-020-20701-3 Published: 10 February 2021

This is paper is open access.

Hot nano-chisel for creating artificial bones?

If ‘chisel’ made you think of sculpting, you are correct. The researchers are alluding to the process of sculpting in their research.

Researchers were able to replicate — with sub-15 nm resolution — bone tissue structure in a biocompatible material using thermal scanning probe lithography. This method opens up unprecedented possibilities for pioneering new stem cell studies and biomedical applications. Courtesy: New York University Tandon School of Engineering

From a February 9, 2021 news item on phys.org (Note: Links have been removed),

A holy grail for orthopedic research is a method for not only creating artificial bone tissue that precisely matches the real thing, but does so in such microscopic detail that it includes tiny structures potentially important for stem cell differentiation, which is key to bone regeneration.

Researchers at the NYU [New York University] Tandon School of Engineering and New York Stem Cell Foundation Research Institute (NYSF) have taken a major step by creating the exact replica of a bone using a system that pairs biothermal imaging with a heated “nano-chisel.” In a study, “Cost and Time Effective Lithography of Reusable Millimeter Size Bone Tissue Replicas with Sub-15 nm Feature Size on a Biocompatible Polymer,” which appears in the journal Advanced Functional Materials, the investigators detail a system allowing them to sculpt, in a biocompatible material, the exact structure of the bone tissue, with features smaller than the size of a single protein—a billion times smaller than a meter. This platform, called, bio-thermal scanning probe lithography (bio-tSPL), takes a “photograph” of the bone tissue, and then uses the photograph to produce a bona-fide replica of it.

The team, led by Elisa Riedo, professor of chemical and biomolecular engineering at NYU Tandon, and Giuseppe Maria de Peppo, a Ralph Lauren Senior Principal Investigator at the NYSF, demonstrated that it is possible to scale up bio-tSPL to produce bone replicas on a size meaningful for biomedical studies and applications, at an affordable cost. These bone replicas support the growth of bone cells derived from a patient’s own stem cells, creating the possibility of pioneering new stem cell applications with broad research and therapeutic potential. This technology could revolutionize drug discovery and result in the development of better orthopedic implants and devices.

A February 8, 2021 NYU Tandon School of Engineering news release (also on EurekAlert but published February 9, 2021), which originated the news item, explains the work in further detail,

In the human body, cells live in specific environments that control their behavior and support tissue regeneration via provision of morphological and chemical signals at the molecular scale. In particular, bone stem cells are embedded in a matrix of fibers — aggregates of collagen molecules, bone proteins, and minerals. The bone hierarchical structure consists of an assembly of micro- and nano- structures, whose complexity has hindered their replication by standard fabrication methods so far.

“tSPL is a powerful nanofabrication method that my lab pioneered a few years ago, and it is at present implemented by using a commercially available instrument, the NanoFrazor,” said Riedo. “However, until today, limitations in terms of throughput and biocompatibility of the materials have prevented its use in biological research. We are very excited to have broken these barriers and to have led tSPL into the realm of biomedical applications.”

Its time- and cost-effectiveness, as well as the cell compatibility and reusability of the bone replicas, make bio-tSPL an affordable platform for the production of surfaces that perfectly reproduce any biological tissue with unprecedented precision.

“I am excited about the precision achieved using bio-tSPL. Bone-mimetic surfaces, such as the one reproduced in this study, create unique possibilities for understanding cell biology and modeling bone diseases, and for developing more advanced drug screening platforms,” said de Peppo. “As a tissue engineer, I am especially excited that this new platform could also help us create more effective orthopedic implants to treat skeletal and maxillofacial defects resulting from injury or disease.”

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

Cost and Time Effective Lithography of Reusable Millimeter Size Bone Tissue Replicas With Sub‐15 nm Feature Size on A Biocompatible Polymer by Xiangyu Liu, Alessandra Zanut, Martina Sladkova‐Faure, Liyuan Xie, Marcus Weck, Xiaorui Zheng, Elisa Riedo, Giuseppe Maria de Peppo. Advanced Functional Materials DOI: https://doi.org/10.1002/adfm.202008662 First published: 05 February 2021

This paper is behind a paywall.

Graphene and its magnetism

I have two news bits about graphene and magnetism. If I understood what I was reading, one is more focused on applications and the other is focused on further establishing the field of valleytronics.

University of Cambridge and superconductivity

A February 8, 2021 news item on Nanowerk announces ‘magnetic work’ from the University of Cambridge (Note: A link has been removed),

The researchers, led by the University of Cambridge, were able to control the conductivity and magnetism of iron thiophosphate (FePS3), a two-dimensional material which undergoes a transition from an insulator to a metal when compressed. This class of magnetic materials offers new routes to understanding the physics of new magnetic states and superconductivity.

Using new high-pressure techniques, the researchers have shown what happens to magnetic graphene during the transition from insulator to conductor and into its unconventional metallic state, realised only under ultra-high pressure conditions. When the material becomes metallic, it remains magnetic, which is contrary to previous results and provides clues as to how the electrical conduction in the metallic phase works. The newly discovered high-pressure magnetic phase likely forms a precursor to superconductivity so understanding its mechanisms is vital.

Their results, published in the journal Physical Review X, also suggest a way that new materials could be engineered to have combined conduction and magnetic properties, which could be useful in the development of new technologies such as spintronics, which could transform the way in which computers process information.

A February 8, 2021 University of Cambridge press release (also on EurekAlert), which originated the news item, delves into the topic,

Properties of matter can alter dramatically with changing dimensionality. For example, graphene, carbon nanotubes, graphite and diamond are all made of carbon atoms, but have very different properties due to their different structure and dimensionality.

“But imagine if you were also able to change all of these properties by adding magnetism,” said first author Dr Matthew Coak, who is jointly based at Cambridge’s Cavendish Laboratory and the University of Warwick. “A material which could be mechanically flexible and form a new kind of circuit to store information and perform computation. This is why these materials are so interesting, and because they drastically change their properties when put under pressure so we can control their behaviour.”

In a previous study by Sebastian Haines of Cambridge’s Cavendish Laboratory and the Department of Earth Sciences, researchers established that the material becomes a metal at high pressure, and outlined how the crystal structure and arrangement of atoms in the layers of this 2D material change through the transition.

“The missing piece has remained however, the magnetism,” said Coak. “With no experimental techniques able to probe the signatures of magnetism in this material at pressures this high, our international team had to develop and test our own new techniques to make it possible.”

The researchers used new techniques to measure the magnetic structure up to record-breaking high pressures, using specially designed diamond anvils and neutrons to act as the probe of magnetism. They were then able to follow the evolution of the magnetism into the metallic state.

“To our surprise, we found that the magnetism survives and is in some ways strengthened,” co-author Dr Siddharth Saxena, group leader at the Cavendish Laboratory. “This is unexpected, as the newly-freely-roaming electrons in a newly conducting material can no longer be locked to their parent iron atoms, generating magnetic moments there – unless the conduction is coming from an unexpected source.”

In their previous paper, the researchers showed these electrons were ‘frozen’ in a sense. But when they made them flow or move, they started interacting more and more. The magnetism survives, but gets modified into new forms, giving rise to new quantum properties in a new type of magnetic metal.

How a material behaves, whether conductor or insulator, is mostly based on how the electrons, or charge, move around. However, the ‘spin’ of the electrons has been shown to be the source of magnetism. Spin makes electrons behave a bit like tiny bar magnets and point a certain way. Magnetism from the arrangement of electron spins is used in most memory devices: harnessing and controlling it is important for developing new technologies such as spintronics, which could transform the way in which computers process information.

“The combination of the two, the charge and the spin, is key to how this material behaves,” said co-author Dr David Jarvis from the Institut Laue-Langevin, France, who carried out this work as the basis of his PhD studies at the Cavendish Laboratory. “Finding this sort of quantum multi-functionality is another leap forward in the study of these materials.”

“We don’t know exactly what’s happening at the quantum level, but at the same time, we can manipulate it,” said Saxena. “It’s like those famous ‘unknown unknowns’: we’ve opened up a new door to properties of quantum information, but we don’t yet know what those properties might be.”

There are more potential chemical compounds to synthesise than could ever be fully explored and characterised. But by carefully selecting and tuning materials with special properties, it is possible to show the way towards the creation of compounds and systems, but without having to apply huge amounts of pressure.

Additionally, gaining fundamental understanding of phenomena such as low-dimensional magnetism and superconductivity allows researchers to make the next leaps in materials science and engineering, with particular potential in energy efficiency, generation and storage.

As for the case of magnetic graphene, the researchers next plan to continue the search for superconductivity within this unique material. “Now that we have some idea what happens to this material at high pressure, we can make some predictions about what might happen if we try to tune its properties through adding free electrons by compressing it further,” said Coak.

“The thing we’re chasing is superconductivity,” said Saxena. “If we can find a type of superconductivity that’s related to magnetism in a two-dimensional material, it could give us a shot at solving a problem that’s gone back decades.”

The citation and link to the paper are at the end of this blog posting.

Aalto University’s valleytronics

Further north in Finland, researchers at Aalto University make some advances applicable to the field of valleytronics, from a February 5, 2021 Aalto University press release (also on EurekAltert but published February 8, 2021),

Electrons in materials have a property known as ‘spin’, which is responsible for a variety of properties, the most well-known of which is magnetism. Permanent magnets, like the ones used for refrigerator doors, have all the spins in their electrons aligned in the same direction. Scientists refer to this behaviour as ferromagnetism, and the research field of trying to manipulate spin as spintronics.

Down in the quantum world, spins can arrange in more exotic ways, giving rise to frustrated states and entangled magnets. Interestingly, a property similar to spin, known as “the valley,” appears in graphene materials. This unique feature has given rise to the field of valleytronics, which aims to exploit the valley property for emergent physics and information processing, very much like spintronics relies on pure spin physics.

‘Valleytronics would potentially allow encoding information in the quantum valley degree of freedom, similar to how electronics do it with charge and spintronics with the spin.’ Explains Professor Jose Lado, from Aalto’s Department of applied physics, and one of the authors of the work. ‘What’s more, valleytronic devices would offer a dramatic increase in the processing speeds in comparison with electronics, and with much higher stability towards magnetic field noise in comparison with spintronic devices.’

Structures made of rotated, ultra-thin materials provide a rich solid-state platform for designing novel devices. In particular, slightly twisted graphene layers have recently been shown to have exciting unconventional properties, that can ultimately lead to a new family of materials for quantum technologies. These unconventional states which are already being explored depend on electrical charge or spin. The open question is if the valley can also lead to its own family of exciting states.

Making materials for valleytronics

For this goal, it turns out that conventional ferromagnets play a vital role, pushing graphene to the realms of valley physics. In a recent work, Ph.D. student Tobias Wolf, together with Profs. Oded Zilberberg and Gianni Blatter at ETH Zurich, and Prof. Jose Lado at Aalto University, showed a new direction for correlated physics in magnetic van der Waals materials.

The team showed that sandwiching two slightly rotated layers of graphene between a ferromagnetic insulator provides a unique setting for new electronic states. The combination of ferromagnets, graphene’s twist engineering, and relativistic effects force the “valley” property to dominate the electrons behaviour in the material. In particular, the researchers showed how these valley-only states can be tuned electrically, providing a materials platform in which valley-only states can be generated. Building on top of the recent breakthrough in spintronics and van der Waals materials, valley physics in magnetic twisted van der Waals multilayers opens the door to the new realm of correlated twisted valleytronics.

‘Demonstrating these states represents the starting point towards new exotic entangled valley states.’ Said Professor Lado, ‘Ultimately, engineering these valley states can allow realizing quantum entangled valley liquids and fractional quantum valley Hall states. These two exotic states of matter have not been found in nature yet, and would open exciting possibilities towards a potentially new graphene-based platform for topological quantum computing.’

Citations and links

Here’s a link to and a citation for the University of Cambridge research,

Emergent Magnetic Phases in Pressure-Tuned van der Waals Antiferromagnet FePS3 by Matthew J. Coak, David M. Jarvis, Hayrullo Hamidov, Andrew R. Wildes, Joseph A. M. Paddison, Cheng Liu, Charles R. S. Haines, Ngoc T. Dang, Sergey E. Kichanov, Boris N. Savenko, Sungmin Lee, Marie Kratochvílová, Stefan Klotz, Thomas C. Hansen, Denis P. Kozlenko, Je-Geun Park, and Siddharth S. Saxena. Phys. Rev. X 11, 011024 DOI: https://doi.org/10.1103/PhysRevX.11.011024 Published 5 February 2021

This article appears to be open access.

Here’s a link to and a citation for the Aalto University research,

Spontaneous Valley Spirals in Magnetically Encapsulated Twisted Bilayer Graphene by Tobias M. R. Wolf, Oded Zilberberg, Gianni Blatter, and Jose L. Lado. Phys. Rev. Lett. 126, 056803 DOI: https://doi.org/10.1103/PhysRevLett.126.056803 Published 4 February 2021

This paper is behind a paywall.

Removing vandals’ graffiti from street art with nanotechnology-enabled method and Happy Italian Research in the World Day and more …

Happy Italian Research in the World Day! Each year since 2018 this has been celebrated on the day that Leonardo da Vinci was born over 500 years ago on April 15. It’s also the start of World Creativity and Innovation Week (WCIW), April 15 – 21, 2021 with over 80 countries (Italy, The Gambia, Mauritius, Belarus, Iceland, US, Syria, Vietnam, Indonesia, Denmark, etc.) celebrating. By the way, April 21, 2021 is the United Nations’ World Creativity and Innovation Day. Now, onto some of the latest research, coming from Italy, on art conservation.

There’s graffiti and there’s graffiti as Michele Baglioni points out in an April 13, 2021 American Chemical Society (ACS) press conference (Rescuing street art from vandals’ graffiti) held during the ACS Spring 2021 Meeting being held online April 5-30, 2021.

An April 13, 2021 news item on ScienceDaily announced the research,

From Los Angeles and the Lower East Side of New York City to Paris and Penang, street art by famous and not-so-famous artists adorns highways, roads and alleys. In addition to creating social statements, works of beauty and tourist attractions, street art sometimes attracts vandals who add their unwanted graffiti, which is hard to remove without destroying the underlying painting. Now, researchers report novel, environmentally friendly techniques that quickly and safely remove over-paintings on street art.

A new eco-friendly method can remove the graffiti that this person is about to spray on the street art behind them. Credit: FOTOKITA/Shutterstock.com

An April 13, 2021 ACS news release (also on EurekAlert), which originated the news item, provides details about this latest work and how it fits into the field of art conservation,

“For decades, we have focused on cleaning or restoring classical artworks that used paints designed to last centuries,” says Piero Baglioni, Ph.D., the project’s principal investigator. “In contrast, modern art and street art, as well as the coatings and graffiti applied on top, use materials that were never intended to stand the test of time.”

Research fellow Michele Baglioni, Ph.D., (no relation to Piero Baglioni) and coworkers built on their colleagues’ work and designed a nanostructured fluid, based on nontoxic solvents and surfactants, loaded in highly retentive hydrogels that very slowly release cleaning agents to just the top layer — a few microns in depth. The undesired top layer is removed in seconds to minutes, with no damage or alteration to the original painting.

Street art and overlying graffiti usually contain one or more of three classes of paint binders — acrylic, vinyl or alkyd polymers. Because these paints are similar in composition, removing the top layer frequently damages the underlying layer. Until now, the only way to remove unwanted graffiti was by using chemical cleaners or mechanical action such as scraping or sand blasting. These traditional methods are hard to control and often damaged the original art.

“We have to know exactly what is going on at the surface of the paintings if we want to design cleaners,” explains Michele Baglioni, who is at the University of Florence (Italy). “In some respects, the chemistry is simple — we are using known surfactants, solvents and polymers. The challenge is combining them in the right way to get all the properties we need.”

Michele Baglioni and coworkers used Fourier transform infrared spectroscopy to characterize the binders, fillers and pigments in the three classes of paints. After screening for suitable low-toxicity, “green” solvents and biodegradable surfactants, he used small angle X-ray scattering analyses to study the behavior of four alkyl carbonate solvents and a biodegradable nonionic surfactant in water.

The final step was formulating the nanostructured cleaning combination. The system that worked well also included 2-butanol and a readily biodegradable alkyl glycoside hydrotrope as co-solvents/co-surfactants. Hydrotropes are water-soluble, surface-active compounds used at low levels that allow more concentrated formulations of surfactants to be developed. The system was then loaded into highly retentive hydrogels and tested for its ability to remove overpaintings on laboratory mockups using selected paints in all possible combinations.

After dozens of tests, which helped determine how long the gel should be applied and removed without damaging the underlying painting, he tested the gels on a real piece of street art in Florence, successfully removing graffiti without affecting the original work.

“This is the first systematic study on the selective and controlled removal of modern paints from paints with similar chemical composition,” Michele Baglioni says. The hydrogels can also be used for the removal of top coatings on modern art that were originally intended to preserve the paintings but have turned out to be damaging. The hydrogels will become available commercially from CSGI Solutions for Conservation of Cultural Heritage, a company founded by Piero Baglioni and others. CSGI, the Center for Colloid and Surface Science, is a university consortium mainly funded through programs of the European Union.

And, there was this after the end of the news release,

The researchers acknowledge support and funding from the European Union NANORESTART (Nanomaterials for the Restoration of Works of Art) Program [or NanoRestArt] and CSGI.

The NanoRestArt project has been mentioned here a number of times,

The project ended in November 2018 but the NanoRestArt website can still be accessed.

The need for Wi-Fi speed

Yes, it’s a ‘Top Gun’ movie quote (1986) or more accurately, a paraphrasing of Tom Cruise’s line “I feel the need for speed.” I understand there’s a sequel, which is due to arrive in movie theatres or elsewhere at sometime in this decade.

Where wireless and WiFi are concerned I think there is a dog/poodle situation. ‘Dog’ is a general description where ‘poodle’ is a specific description. All poodles (specific) are dogs (general) but not all dogs are poodles. So, wireless is a general description and Wi-Fi is a specific type of wireless communication. All WiFi is wireless but not all wireless is Wi-Fi. That said, onto the research.

Given what seems to be an insatiable desire for speed in the wireless world, the quote seems quite à propos in relation to the latest work on quantum tunneling and its impact on Wi-Fi speed from the Moscow Institute of Physics and Technology (from a February 3, 2021 news item on phys.org,

Scientists from MIPT (Moscow Institute of Physics and Technology), Moscow Pedagogical State University and the University of Manchester have created a highly sensitive terahertz detector based on the effect of quantum-mechanical tunneling in graphene. The sensitivity of the device is already superior to commercially available analogs based on semiconductors and superconductors, which opens up prospects for applications of the graphene detector in wireless communications, security systems, radio astronomy, and medical diagnostics. The research results are published in Nature Communications.

A February 3, 2021 MIPT press release (also on EurekAlert), which originated the news item, provides more technical detail about the work and its relation WiFi,

Information transfer in wireless networks is based on transformation of a high-frequency continuous electromagnetic wave into a discrete sequence of bits. This technique is known as signal modulation. To transfer the bits faster, one has to increase the modulation frequency. However, this requires synchronous increase in carrier frequency. A common FM-radio transmits at frequencies of hundred megahertz, a Wi-Fi receiver uses signals of roughly five gigahertz frequency, while the 5G mobile networks can transmit up to 20 gigahertz signals. This is far from the limit, and further increase in carrier frequency admits a proportional increase in data transfer rates. Unfortunately, picking up signals with hundred gigahertz frequencies and higher is an increasingly challenging problem.

A typical receiver used in wireless communications consists of a transistor-based amplifier of weak signals and a demodulator that rectifies the sequence of bits from the modulated signal. This scheme originated in the age of radio and television, and becomes inefficient at frequencies of hundreds of gigahertz desirable for mobile systems. The fact is that most of the existing transistors aren’t fast enough to recharge at such a high frequency.

An evolutionary way to solve this problem is just to increase the maximum operation frequency of a transistor. Most specialists in the area of nanoelectronics work hard in this direction. A revolutionary way to solve the problem was theoretically proposed in the beginning of 1990’s by physicists Michael Dyakonov and Michael Shur, and realized, among others, by the group of authors in 2018. It implies abandoning active amplification by transistor, and abandoning a separate demodulator. What’s left in the circuit is a single transistor, but its role is now different. It transforms a modulated signal into bit sequence or voice signal by itself, due to non-linear relation between its current and voltage drop.

In the present work, the authors have proved that the detection of a terahertz signal is very efficient in the so-called tunneling field-effect transistor. To understand its work, one can just recall the principle of an electromechanical relay, where the passage of current through control contacts leads to a mechanical connection between two conductors and, hence, to the emergence of current. In a tunneling transistor, applying voltage to the control contact (termed as ”gate”) leads to alignment of the energy levels of the source and channel. This also leads to the flow of current. A distinctive feature of a tunneling transistor is its very strong sensitivity to control voltage. Even a small “detuning” of energy levels is enough to interrupt the subtle process of quantum mechanical tunneling. Similarly, a small voltage at the control gate is able to “connect” the levels and initiate the tunneling current

“The idea of ??a strong reaction of a tunneling transistor to low voltages is known for about fifteen years,” says Dr. Dmitry Svintsov, one of the authors of the study, head of the laboratory for optoelectronics of two-dimensional materials at the MIPT center for photonics and 2D materials. “But it’s been known only in the community of low-power electronics. No one realized before us that the same property of a tunneling transistor can be applied in the technology of terahertz detectors. Georgy Alymov (co-author of the study) and I were lucky to work in both areas. We realized then: if the transistor is opened and closed at a low power of the control signal, then it should also be good in picking up weak signals from the ambient surrounding. “

The created device is based on bilayer graphene, a unique material in which the position of energy levels (more strictly, the band structure) can be controlled using an electric voltage. This allowed the authors to switch between classical transport and quantum tunneling transport within a single device, with just a change in the polarities of the voltage at the control contacts. This possibility is of extreme importance for an accurate comparison of the detecting ability of a classical and quantum tunneling transistor.

The experiment showed that the sensitivity of the device in the tunnelling mode is few orders of magnitude higher than that in the classical transport mode. The minimum signal distinguishable by the detector against the noisy background already competes with that of commercially available superconducting and semiconductor bolometers. However, this is not the limit – the sensitivity of the detector can be further increased in “cleaner” devices with a low concentration of residual impurities. The developed detection theory, tested by the experiment, shows that the sensitivity of the “optimal” detector can be a hundred times higher.

“The current characteristics give rise to great hopes for the creation of fast and sensitive detectors for wireless communications,” says the author of the work, Dr. Denis Bandurin. And this area is not limited to graphene and is not limited to tunnel transistors. We expect that, with the same success, a remarkable detector can be created, for example, based on an electrically controlled phase transition. Graphene turned out to be just a good launching pad here, just a door, behind which is a whole world of exciting new research.”

The results presented in this paper are an example of a successful collaboration between several research groups. The authors note that it is this format of work that allows them to obtain world-class scientific results. For example, earlier, the same team of scientists demonstrated how waves in the electron sea of ??graphene can contribute to the development of terahertz technology. “In an era of rapidly evolving technology, it is becoming increasingly difficult to achieve competitive results.” – comments Dr. Georgy Fedorov, deputy head of the nanocarbon materials laboratory, MIPT, – “Only by combining the efforts and expertise of several groups can we successfully realize the most difficult tasks and achieve the most ambitious goals, which we will continue to do.”

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

Tunnel field-effect transistors for sensitive terahertz detection by I. Gayduchenko, S. G. Xu, G. Alymov, M. Moskotin, I. Tretyakov, T. Taniguchi, K. Watanabe, G. Goltsman, A. K. Geim, G. Fedorov, D. Svintsov & D. A. Bandurin. Nature Communications volume 12, Article number: 543 (2021) DOI: https://doi.org/10.1038/s41467-020-20721-z Published: 22 January 2021

This paper is open access.

One last comment, I’m assuming since the University of Manchester is mentioned that A. K. Geim is Sir Andre K. Geim (you can look him up here is you’re not familiar with his role in the graphene research community).

Sunlight makes transparent wood even lighter and stronger

Researchers at the University of Maryland (US) have found a way to make their wood transparent by using sunlight. From a February 2, 2021 news article by Bob Yirka on phys.org (Note: Links have been removed),

A team of researchers at the University of Maryland, has found a new way to make wood transparent. In their paper published in the journal Science Advances, the group describes their process and why they believe it is better than the old process.

The conventional method for making wood transparent involves using chemicals to remove the lignin—a process that takes a long time, produces a lot of liquid waste and results in weaker wood. In this new effort, the researchers have found a way to make wood transparent without having to remove the lignin.

The process involved changing the lignin rather than removing it. The researchers removed lignin molecules that are involved in producing wood color. First, they applied hydrogen peroxide to the wood surface and then exposed the treated wood to UV light (or natural sunlight). The wood was then soaked in ethanol to further clean it. Next, they filled in the pores with clear epoxy to make the wood smooth.

Caption: Solar-assisted large-scale fabrication of transparent wood. (A) Schematic showing the potential large-scale fabrication of transparent wood based on the rotary wood cutting method and the solar-assisted chemical brushing process. (B) The outdoor fabrication of lignin-modified wood with a length of 1 m [9 August 2019 (the summer months) at 13:00 p.m. (solar noon), the Global Solar UV Index (UVI): 7 to 8]. (C) Digital photo of a piece of large transparent wood (400 mm by 110 mm by 1 mm). (D) The energy consumption, chemical cost, and waste emission for the solar-assisted chemical brushing process and NaClO2 solution–based delignification process. (E) A radar plot showing a comparison of the fabrication process for transparent wood. Photo credit: Qinqin Xia, University of Maryland, College Park. [downloaded from https://advances.sciencemag.org/content/7/5/eabd7342]

Bob McDonald in a February 5, 2021 posting on his Canadian Broadcasting Corporation (CBC) Quirks & Quarks blog provides a more detailed description of the new ‘solar-based transparency process’,

Early attempts to make transparent wood involved removing the lignin, but this involved hazardous chemicals, high temperatures and a lot of time, making the product expensive and somewhat brittle. The new technique is so cheap and easy it could literally be done in a backyard.

Starting with planks of wood a metre long and one millimetre thick, the scientists simply brushed on a solution of hydrogen peroxide using an ordinary paint brush. When left in the sun, or under a UV lamp for an hour or so, the peroxide bleached out the brown chromophores but left the lignin intact, so the wood turned white.

Next, they infused the wood with a tough transparent epoxy designed for marine use, which filled in the spaces and pores in the wood and then hardened. This made the white wood transparent.

As window material, it would be much more resistant to accidental breakage. The clear wood is lighter than glass, with better insulating properties, which is important because windows are a major source of heat loss in buildings. It also might take less energy to manufacture clear wood because there are no high temperatures involved.

Many different types of wood, from balsa to oak, can be made transparent, and it doesn’t matter if it is cut along the grain or against it. If the transparent wood is made a little thicker, it would be strong enough to become part of the structure of a building, so there could be entire transparent wooden walls.

Adele Peters in her February 2, 2021 article for Fast Company describes the work in Maryland and includes some information about other innovative and possibly sustainable uses of wood (Note: Links have been removed),

It’s [transparent wood] just one of a number of ways scientists and engineers are rethinking how we can use this renewable resource in construction. Skyscrapers made entirely out of wood are gaining popularity in cities around the world. And scientists recently discovered a technique to grow wood in a lab, opening up the possibility of using wood without having to chop down a forest.

There were three previous posts here about this work at the University of Maryland,

University of Maryland looks into transparent wood May 11, 2016 posting

Transparent wood more efficient than glass in windows? Sept, 8, 2016 posting

Glass-like wood windows protect against UV rays and insulate heat October 21, 2020 posting

I have this posting, which is also from 2016 but features work in Sweden,

Transparent wood instead of glass for window panes? April 1, 2016 posting

Getting back to the latest work from the University of Maryland, here’s a link to and a citation for the paper,

Solar-assisted fabrication of large-scale, patternable transparent wood by Qinqin Xia, Chaoji Chen, Tian Li, Shuaiming He, Jinlong Gao, Xizheng Wang and Liangbing Hu. Science Advances Vol. 7, no. 5, eabd7342 DOI: 10.1126/sciadv.abd7342 Published: 27 Jan 2021

This paper is open access.

One last item, Liangbing Hu has founded a company InventWood for commercializing the work he and his colleagues have done at the University of Maryland.

“Wolves, Livestock, and the Physical and Social Environments,” an April 14, 2021 event in celebration of Italian Research in the World Day

ARPICO (Society of Italian Researchers & Professionals in Western Canada) is presenting a pre-celebration event to honour Italian Research in the World Day (April 15, 2021). Take special note: the event is being held the day before.

Before launching into the announcement, bravo to the organizers! ARPICO consistently offers the most comprehensive details about their events of any group that contacts me. One more thing, to date, they are the only group that have described which technology they’re using for the webcast and explicitly address any concerns about downloading software (you don’t have to) or about personal information. (Check out Technical Instruction here.)

Here are the details from ARPICO’s April 4, 2021 announcement (received via email),

We hope everyone is doing well and being safe while we attempt to outlast this pandemic. In the meanwhile, from the comfort of our homes, we hope to be able to continue to share with you informative lectures to entertain and stimulate thought.

It is our pleasure, in collaboration with the Consulate General of Italy in Vancouver, to announce that ARPICO’s next public event will be held on April 14th, 2021 at 7:00 PM, in celebration of Italian Research in the World Day. Italian Research in the World Day was instituted starting in 2018 as part of the Piano Straordinario “Vivere all’Italiana” – Giornata della ricerca Italiana nel mondo. The celebration day was chosen by government decree to be every year on April 15 on the anniversary of the birth of Leonardo da Vinci.

The main objective of the Italian Research Day in the World is to value the quality and competencies of Italian researchers abroad, but also to promote concrete actions and investments to allow Italian researchers to continue pursuing their careers in their homeland. Italy wishes to enable Italian talents to return from abroad as well as to become an attractive environment for foreign researchers.

This year we are pleased to have Professor Marco Musiani, an academic in biological sciences, share with us a lecture titled “Wolves, Livestock, and the Physical and Social Environments.” An abstract and short professional biography are provided below.

We have chosen BlueJeans as the videoconferencing platform, for which you will only require a web browser (Chrome, Firefox, Edge, Safari, Opera are all supported). Full detailed instructions on how the virtual event will unfold are available on the EventBrite listing here in the Technical Instruction section.

If participants wish to donate to ARPICO, this can be done within EventBrite; this would be greatly appreciated in order to help us continue to build upon our scholarship fund, and to defray the cost of the videoconferencing license.

We look forward to seeing everyone there.

The evening agenda is as follows:

  • 6:45PM – BlueJeans Presentation link becomes active and registrants may join.
    • If you experience any technical details please email us at info@arpico.ca and we will attempt to assist you as best we can.
  • 7:00pm – Start of the evening Event with introductions & lecture by Prof. Marco Musiani
  • ~8:00 pm – Q & A Period via BlueJeans Chat Interface

If you have not already done so, please register for the event by visiting the EventBrite link or RSVPing to info@arpico.ca.

Further details are also available at arpico.ca and Eventbrite.

Wolves, Livestock, and the Physical and Social Environments

Due primarily to wolf predation on livestock (depredation), some groups oppose wolf (Canis lupus) conservation, which is an objective for large sectors of the public. Prof. Musiani’s talk will compare wolf depredation of sheep in Southern Europe to wolf depredation of beef cattle in the US and Canada, taking into account the differences in social and economic contexts. It will detail where and when wolf attacks happen, and what environmental factors promote such attacks. Livestock depredation by wolves is a cost of wolf conservation borne by livestock producers, which creates conflict between producers, wolves and organizations involved in wolf conservation and management. Compensation is the main tool used to mitigate the costs of depredation, but this tool may be limited at improving tolerance for wolves. In poorer countries compensation funds might not be available. Other lethal and nonlethal tools used to manage the problem will also be analysed. Wolf depredation may be a small economic cost to the industry, although it may be a significant cost to affected producers as these costs are not equitably distributed across the industry. Prof. Musiani maintains that conservation groups should consider the potential consequences of all of these ecological and economic trends. Specifically, declining sheep or cattle price and the steady increase in land price might induce conversion of agricultural land to rural-residential developments, which could negatively impact the whole environment via large scale habitat change and increased human presence.

Marco Musiani is a Professor in the Dept. of Biological Sciences, Faculty of Science, University of Calgary. He also has a Joint Appointment with the Faculty of Veterinary Medicine in Calgary. His lab has a strong focus on landscape ecology, molecular ecology, and wildlife conservation.

Marco is Principal Investigator on projects on caribou, elk, moose, wolves, grizzlies and other wildlife species throughout the Rocky Mountains and Foothills regions of Canada. All such projects are run together with graduate students and have applications towards impact assessment, mainly of human infrastructure.

His focus is on academic matters. However, he also serves as reviewer for research and management projects, and acted as a consultant for the Food and Agriculture Organisation of the United Nations (working on conflicts with wolves).

WHEN (EVENT): Wed, April 14th, 2021 at 7:00PM (BlueJeans link active at 6:45PM)

WHERE: Online using the BlueJeans Conferencing platform.

RSVP: Please register for tickets at EventBrite

Tickets are Needed

Tickets for this event are FREE. Due to limited seating at the venue, we ask that each household register once and watch the presentation together on a single device.       You will receive the event videoconferencing invite link via email in your registration confirmation.

FAQs

  • Where can I contact the organizer with any questions? info@arpico.ca
  • Can I update my registration information? Yes. If you have any questions, contact us at info@arpico.ca
  • I am having trouble using EventBrite and cannot reserve my ticket(s). Can someone at ARPICO help me with my ticket reservation? Of course, simply send your ticket request to us at info@arpico.ca so we help you.

You can find the programme announcement on this ARPICO event page.