Monthly Archives: February 2021

Graphene-based material for high-performance supercapacitors

Researchers from Russia and France have developed a new material, based on graphene, that would allow supercapacitors to store more energy according to a January 15, 2021 news item on Nanowerk,

Scientists of Tomsk Polytechnic University jointly with colleagues from the University of Lille (Lille, France) synthetized a new material based on reduced graphene oxide (rGO) for supercapacitors, energy storage devices. The rGO modification method with the use of organic molecules, derivatives of hypervalent iodine, allowed obtaining a material that stores 1.7 times more electrical energy.

Photo: modified rGO supercapacitor electrodes. Courtesy: Tomsk University

A January 15, 2020 Tomsk Polytechnic University press release (also on EurekAlert), which originated the news item, provides more details,

A supercapacitor is an electrochemical device for storage and release of electric charge. Unlike batteries, they store and release energy several times faster and do not contain lithium.

A supercapacitor is an element with two electrodes separated by an organic or inorganic electrolyte. The electrodes are coated with an electric charge accumulating material. The modern trend in science is to use various materials based on graphene, one of the thinnest and most durable materials known to man. The researchers of TPU and the University of Lille used reduced graphene oxide (rGO), a cheap and available material.

“Despite their potential, supercapacitors are not wide-spread yet. For further development of the technology, it is required to enhance the efficiency of supercapacitors. One of the key challenges here is to increase the energy capacity.

It can be achieved by expanding the surface area of an energy storage material, rGO in this particular case. We found a simple and quite fast method. We used exceptionally organic molecules under mild conditions and did not use expensive and toxic metals,” Pavel Postnikov, Associate Professor of TPU Research School of Chemistry and Applied Biomedical Science and the research supervisor says.

Reduced graphene oxide in a powder form is deposited on electrodes. As a result, the electrode becomes coated with hundreds of nanoscale layers of the substance. The layers tend to agglomerate, in other words, to sinter. To expand the surface area of a material, the interlayer spacing should be increased.

“For this purpose, we modified rGO with organic molecules, which resulted in the interlayer spacing increase. Insignificant differences in interlayer spacing allowed increasing energy capacity of the material by 1.7 times. That is, 1 g of the new material can store 1.7 times more energy in comparison with a pristine reduced graphene oxide,” Elizaveta Sviridova, Junior Research Fellow of TPU Research School of Chemistry and Applied Biomedical Sciences and one of the authors of the article explains.

The reaction proceeded through the formation of active arynes from iodonium salts. They kindle scientists` interest due to their property to form a single layer of new organic groups on material surfaces. The TPU researchers have been developing the chemistry of iodonium salts for many years.

“The modification reaction proceeds under mild conditions by simply mixing the solution of iodonium salt with reduced graphene oxide. If we compare it with other methods of reduced graphene oxide functionalization, we have achieved the highest indicators of material energy capacity increase,” Elizaveta Sviridova says.

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

Aryne cycloaddition reaction as a facile and mild modification method for design of electrode materials for high-performance symmetric supercapacitor by Elizaveta Sviridova, Min Li, Alexandre Barras, Ahmed Addad, Mekhman S.Yusubov, Viktor V. Zhdankin, Akira Yoshimura, Sabine Szunerits, Pavel S. Postnikov, Rabah Boukherroub. Electrochimica Acta Volume 369, 10 February 2021, 137667 DOI: https://doi.org/10.1016/j.electacta.2020.137667

This paper is behind a paywall.

CRISPR technology is like a pair of scissors and a dimmer switch?

The ‘pair of scissors’ analogy is probably the most well known of the attempts to describe how the CRISPR (clustered regularly interspaced short palindromic repeats)-Cas9 gene editing system works. It seems a new analogy is about to be added according to a January 19 2021 news item on ScienceDaily (Note: This October 30, 2019 posting features more CRISPR analogies),

In a series of experiments with laboratory-cultured bacteria, Johns Hopkins scientists have found evidence that there is a second role for the widely used gene-cutting system CRISPR-Cas9 — as a genetic dimmer switch for CRISPR-Cas9 genes. Its role of dialing down or dimming CRISPR-Cas9 activity may help scientists develop new ways to genetically engineer cells for research purposes.

Here’s an image illustrating the long form of the tracrRNA or ‘dimmer switch’ alongside the more commonly used short form,

Caption: Left – a schematic of the long form of the tracrRNA used by the CRISPR-Cas9 system in bacteria; Right – the standard guide RNA used by many scientists as part of the gene-cutting CRISPR-Cas9 system. Credit: Joshua Modell, Rachael Workman and Johns Hopkins Medicine

A January 19 ,2021 Johns Hopkins Medicine news release (also on EurekAlert), which originated the news item, explains about CRISPR and what the acronym stands for, as well as, giving more details about the discovery,

First identified in the genome of gut bacteria in 1987, CRISPR-Cas9 is a naturally occurring but unusual group of genes with a potential for cutting DNA sequences in other types of cells that was realized 25 years later. Its value in genetic engineering — programmable gene alteration in living cells, including human cells — was rapidly appreciated, and its widespread use as a genome “editor” in thousands of laboratories worldwide was recognized in the awarding of the Nobel Prize in Chemistry last year to its American and French co-developers.

CRISPR stands for clustered, regularly interspaced short palindromic repeats. Cas9, which refers to CRISPR-associated protein 9, is the name of the enzyme that makes the DNA slice. Bacteria naturally use CRISPR-Cas9 to cut viral or other potentially harmful DNA and disable the threat, says Joshua Modell, Ph.D., assistant professor of molecular biology and genetics at the Johns Hopkins University School of Medicine. In this role, Modell says, “CRISPR is not only an immune system, it’s an adaptive immune system — one that can remember threats it has previously encountered by holding onto a short piece of their DNA, which is akin to a mug shot.” These mug shots are then copied into “guide RNAs” that tell Cas9 what to cut.

Scientists have long worked to unravel the precise steps of CRISPR-Cas9’s mechanism and how its activity in bacteria is dialed up or down. Looking for genes that ignite or inhibit the CRISPR-Cas9 gene-cutting system for the common, strep-throat causing bacterium Streptococcus pyogenes, the Johns Hopkins scientists found a clue regarding how that aspect of the system works.

Specifically, the scientists found a gene in the CRISPR-Cas9 system that, when deactivated, led to a dramatic increase in the activity of the system in bacteria. The product of this gene appeared to re-program Cas9 to act as a brake, rather than as a “scissor,” to dial down the CRISPR system.

“From an immunity perspective, bacteria need to ramp up CRISPR-Cas9 activity to identify and rid the cell of threats, but they also need to dial it down to avoid autoimmunity — when the immune system mistakenly attacks components of the bacteria themselves,” says graduate student Rachael Workman, a bacteriologist working in Modell’s laboratory.

To further nail down the particulars of the “brake,” the team’s next step was to better understand the product of the deactivated gene (tracrRNA). RNA is a genetic cousin to DNA and is vital to carrying out DNA “instructions” for making proteins. TracrRNAs belong to a unique family of RNAs that do not make proteins. Instead, they act as a kind of scaffold that allows the Cas9 enzyme to carry the guide RNA that contains the mug shot and cut matching DNA sequences in invading viruses.

TracrRNA comes in two sizes: long and short. Most of the modern gene-cutting CRISPR-Cas9 tools use the short form. However, the research team found that the deactivated gene product was the long form of tracrRNA, the function of which has been entirely unknown.

The long and short forms of tracrRNA are similar in structure and have in common the ability to bind to Cas9. The short form tracrRNA also binds to the guide RNA. However, the long form tracrRNA doesn’t need to bind to the guide RNA, because it contains a segment that mimics the guide RNA. “Essentially, long form tracrRNAs have combined the function of the short form tracrRNA and guide RNA,” says Modell.

In addition, the researchers found that while guide RNAs normally seek out viral DNA sequences, long form tracrRNAs target the CRISPR-Cas9 system itself. The long form tracrRNA tends to sit on DNA, rather than cut it. When this happens in a particular area of a gene, it prevents that gene from expressing, — or becoming functional.

To confirm this, the researchers used genetic engineering to alter the length of a certain region in long form tracrRNA to make the tracrRNA appear more like a guide RNA. They found that with the altered long form tracrRNA, Cas9 once again behaved more like a scissor.

Other experiments showed that in lab-grown bacteria with a plentiful amount of long form tracrRNA, levels of all CRISPR-related genes were very low. When the long form tracrRNA was removed from bacteria, however, expression of CRISPR-Cas9 genes increased a hundredfold.

Bacterial cells lacking the long form tracrRNA were cultured in the laboratory for three days and compared with similarly cultured cells containing the long form tracrRNA. By the end of the experiment, bacteria without the long form tracrRNA had completely died off, suggesting that long form tracrRNA normally protects cells from the sickness and death that happen when CRISPR-Cas9 activity is very high.

“We started to get the idea that the long form was repressing but not eliminating its own CRISPR-related activity,” says Workman.

To see if the long form tracrRNA could be re-programmed to repress other bacterial genes, the research team altered the long form tracrRNA’s spacer region to let it sit on a gene that produces green fluorescence. Bacteria with this mutated version of long form tracrRNA glowed less green than bacteria containing the normal long form tracrRNA, suggesting that the long form tracrRNA can be genetically engineered to dial down other bacterial genes.

Another research team, from Emory University, found that in the parasitic bacteria Francisella novicida, Cas9 behaves as a dimmer switch for a gene outside the CRISPR-Cas9 region. The CRISPR-Cas9 system in the Johns Hopkins study is more widely used by scientists as a gene-cutting tool, and the Johns Hopkins team’s findings provide evidence that the dimmer action controls the CRISPR-Cas9 system in addition to other genes.

The researchers also found the genetic components of long form tracrRNA in about 40% of the Streptococcus group of bacteria. Further study of bacterial strains that don’t have the long form tracrRNA, says Workman, will potentially reveal whether their CRISPR-Cas9 systems are intact, and other ways that bacteria may dial back the CRISPR-Cas9 system.

The dimmer capability that the experiments uncovered, says Modell, offers opportunities to design new or better CRISPR-Cas9 tools aimed at regulating gene activity for research purposes. “In a gene editing scenario, a researcher may want to cut a specific gene, in addition to using the long form tracrRNA to inhibit gene activity,” he says.

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

A natural single-guide RNA repurposes Cas9 to autoregulate CRISPR-Cas expression by Rachael E. Workman, Teja Pammi, Binh T.K. Nguyen, Leonardo W. Graeff, Erika Smith, Suzanne M. Sebald, Marie J. Stoltzfus, Chad W. Euler, Joshua W. Modell. Cell DOI:https://doi.org/10.1016/j.cell.2020.12.017 Published Online:J anuary 08, 2021

This paper is behind a paywall.

One-dimensional quantum nanowires and Majorana zero modes

Length but no width or height? That’s a quantum nanowire according to a Jan. 18, 2021 news item on Nanowerk (Note: A link has been removed),

Why is studying spin properties of one-dimensional quantum nanowires important?

Quantum nanowires–which have length but no width or height–provide a unique environment for the formation and detection of a quasiparticle known as a Majorana zero mode.

A new UNSW [University of New South Wales]-led study (Nature Communications, “New signatures of the spin gap in quantum point contacts”) overcomes previous difficulty detecting the Majorana zero mode, and produces a significant improvement in device reproducibility.

Potential applications for Majorana zero modes include fault-resistant topological quantum computers, and topological superconductivity.

A Jan. 19 (?), 2021 ARC (Australian Research Council) Centre of Excellence in Future Low-Energy Electronics Technologies (or FLEET) press release (also on EurekAlert), which originated the news item, provides more detail about the research,

MAJORANA FERMIONS IN 1D WIRES

A Majorana fermion is a composite particle that is its own antiparticle.

Antimatter explainer: Every fundamental particle has a corresponding antimatter particle, with the same mass but opposite electrical charge. For example, the antiparticle of an electron (charge -1) is a positron (charge +1)

Such unusual particle’s interest academically and commercially comes from their potential use in a topological quantum computer, predicted to be immune to the decoherence that randomises the precious quantum information.

Majorana zero modes can be created in quantum wires made from special materials in which there is a strong coupling between their electrical and magnetic properties.

In particular, Majorana zero modes can be created in one-dimensional semiconductors (such as semiconductor nanowires) when coupled with a superconductor.

In a one-dimensional nanowire, whose dimensions perpendicular to length are small enough not to allow any movement of subatomic particles, quantum effects predominate.

NEW METHOD FOR DETECTING NECESSARY SPIN-ORBIT GAP

Majorana fermions, which are their own antiparticle, have been theorised since 1937, but have only been experimentally observed in the last decade. The Majorana fermion’s ‘immunity’ to decoherence provides potential use for fault-tolerant quantum computing.

One-dimensional semiconductor systems with strong spin-orbit interaction are attracting great attention due to potential applications in topological quantum computing.

The magnetic ‘spin’ of an electron is like a little bar magnet, whose orientation can be set with an applied magnetic field.

In materials with a ‘spin-orbit interaction’ the spin of an electron is determined by the direction of motion, even at zero magnetic field. This allows for all electrical manipulation of magnetic quantum properties.

Applying a magnetic field to such a system can open an energy gap such that forward -moving electrons all have the same spin polarisation, and backward-moving electrons have the opposite polarisation. This ‘spin-gap’ is a pre-requisite for the formation of Majorana zero modes.

Despite intense experimental work, it has proven extremely difficult to unambiguously detect this spin-gap in semiconductor nanowires, since the spin-gap’s characteristic signature (a dip in its conductance plateau when a magnetic field is applied) is very hard to distinguish from unavoidable the background disorder in nanowires.

The new study finds a new, unambiguous signature for the spin-orbit gap that is impervious to the disorder effects plaguing previous studies.

“This signature will become the de-facto standard for detecting spin-gaps in the future,” says lead author Dr Karina Hudson.

REPRODUCIBILITY

The use of Majorana zero modes in a scalable quantum computer faces an additional challenge due to the random disorder and imperfections in the self-assembled nanowires that host the MZM.

It has previously been almost impossible to fabricate reproducible devices, with only about 10% of devices functioning within desired parameters.

The latest UNSW results show a significant improvement, with reproducible results across six devices based on three different starting wafers.

“This work opens a new route to making completely reproducible devices,” says corresponding author Prof Alex Hamilton UNSW).

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

New signatures of the spin gap in quantum point contacts by K. L. Hudson, A. Srinivasan, O. Goulko, J. Adam, Q. Wang, L. A. Yeoh, O. Klochan, I. Farrer, D. A. Ritchie, A. Ludwig, A. D. Wieck, J. von Delft & A. R. Hamilton. Nature Communications volume 12, Article number: 5 (2021) DOI: https://doi.org/10.1038/s41467-020-19895-3 Published: 04 January 2021

This paper is open access.

For anyone who might find references to UNSW and ARC/FLEET confusing, I found this in the ARC Centre of Excellence in Future Low-Energy Electronics Technologies Wikipedia entry,

The ARC Centre of Excellence in Future Low-Energy Electronics Technologies (or FLEET) is a collaboration …

FLEET is an Australian initiative, headquartered at Monash University, and in conjunction with the Australian National University, the University of New South Wales, the University of Queensland, RMIT University, the University of Wollongong and Swinburne University of Technology, complemented by a group of Australian and international partners. It is funded by the Australian Research Council [ARC] and by the member universities. [emphases as seen here are mine]

‘Greener’ lithium mining in Canada

A February 19, 2021 article by Pamela Fieber for CBC (Canadian Broadcasting Corporation) news online features news of a Calgary (Alberta) company, Summit Nanotech, and a greener way to mine lithium (Note: A link has been removed),

Amanda Hall was on top of a mountain in Tibet when inspiration struck. 

“I saw a Tibetan monk reach into his robe and pull out an iPhone,” Hall told the Calgary Eyeopener [CBC radio programme].

“If there’s an iPhone at the top of a mountain in Tibet, where isn’t there an iPhone on this planet? And then it just got me thinking about batteries and battery technology and energy and how we store that energy.”

On her return to Calgary, the accomplished geophysicist began looking into a better, greener way to mine lithium — the essential ingredient in lithium-ion batteries, which power electric cars and smartphones.

This led to her founding the company, Summit Nanotech in 2018 and developing nanotechnology, which works with materials at the molecular or atomic level to selectively filter lithium out of the wasted saltwater brine used in oil wells.

It’s completely different from the way lithium is traditionally mined.

Sarah Offin’s November 12, 2020 article for Global TV News offers insight into the technology developed by Hall’s company (Note: Links have been removed),

Since the downturn in the oil and gas industry, there have been repeated calls for Alberta to diversify its economy. The province invests hundreds of millions of dollars every year to help grow both the tech and green energy sectors, industries that could have a bright future in a province rich with talent.

Amanda Hall is a prime example of that. She was able to draw on her experience in resource extraction with Alberta’s oil and gas industry, developing green technology to be used in energy storage.

Hall developed the only female-led mining technology company in the world: Summit Nanotech Corp. Using nanotechnology, Hall and her team say they have created an improved method of lithium-ion resource extraction from produced brine water.

“We’ve come up with a much more elegant approach — I say, feminine, approach — at bringing a resource out of the ground, and then giving it to the electric vehicle sector,” Hall said.

Using sponges developed through nanoscience, Hall and her team have created technology that will allow producers to extract lithium directly from the wellhead without the need for expansive ponds and toxic chemicals. The process is expected to reduce costs and decrease chemical waste by 90 per cent.

The firm’s website touts that its process is the most “green lithium extraction in the world.”

“The sponge has lithium selective cavities in it, just the exact size of a lithium-ion. And so, as if you put a fluid in against this sponge, it will only suck up lithium, nothing else, and it holds on to it. And then when you wash it, you wash the lithium off the sponge just by changing the environment it’s in. So we don’t have to use any acids,” Hall said.

Hall and her team have spent the last two-and-a-half years in the lab perfecting their design and are now building the company’s first full-scale 12-metre tall unit. “It’s our baby, but it’s huge,” Hall said. “It’s a mini-refinery, essentially.”

That “mini-refinery” will then be sent via shipping container to the first of the company’s three pilot partners: Lithium Chile.

The other two partners are Saskatchewan-based Prairie Lithium and 3 Proton Lithium (3PL) Operating Inc. in Nevada.

For anyone interested in the business and investment aspects (there’s mention of Elon Musk in both stories) check out Fieber’s February 19, 2021 article and Offin’s November 12, 2020 article.

You can find Summit Nanotech here. I found a little more information about the company’s technology on the Lithium webpage,

denaLi 1.0
Direct Lithium Extraction
(DLE) Process

Summit Nanotech has designed an innovative new method to generate battery grade lithium compounds from brine fluids, named denaLi. This process is the most green lithium extraction technology in the world. Lithium carbonate and lithium hydroxide can be sold at market value to supply the growing demand from electric vehicle battery manufacturers. 

Interconnected modules using nanoporous membranes in a unique arrangement are synthesized with specific filtration functions. Carbon dioxide is used to initiate end product precipitation. Discrete power generation modules are selected to work together to harvest and store available geothermal, solar, wind, and hydroelectric power from the system’s environment.

Prairie Lithium, the Saskatchewan-based company mentioned in Offin’s article, co-founded a joint venture specifically dedicated to lithium extraction from brine (to begin with) in 2020 according to Jonathan Guignard in a June 3, 2020 article for Global TV news (Note: Links have been removed),

Saskatchewan will soon be home to a new lithium production project.

The Prairie-LiEP Critical Mineral (PLCM) joint venture is being undertaken by Prairie Lithium Corp. and LiEP Energy Ltd [headquarted in Calgary, Alberta].

Their two-stage pilot project will produce lithium hydroxide from some of the province’s oilfield brines.

The first stage of the project is based in Regina and is set to being in July. The second stage is set for the second half of 2021, with field operations in southern parts of the province.

“PLCM Joint Venture is excited to begin Stage 1 of the pilot operation in Saskatchewan this summer,” said Prairie president and CEO Zach Maurer and LiEP president and CEO Haafiz Hasham.

I can’t find any mention of the PLCM joint venture on the Prairie Lithium website but there is what appears to be a June 3, 2020 news release announcing the venture on the LiEP Energy website but there is no further information on that website.

On another front, Lithium Chile, which seems to be headquartered in Calgary with extensive lithium mining projects in Chile, has a brief mention of their partnership with Summit Nanotech in a December 24, 2020 posting (on the News webpage) by Steve (Cochrane; president and chief executive officer),

Lastly our partnership with Summit continues to move forward and we are very happy to be working with them. I have attached our recently negotiated LOI [letter of intent] for our JV [joint venture] pilot project in Chile. We should have the definitive agreement signed early in the new year. They plan to have their pilot unit completed and shipped by July of 2021 so a planned test is scheduled for late summer next year. This gives us the time to get back on one or more of our lithium prospects to prepare for our pilot project. They continue to see great results in the lab and hope this is the breakthrough we all want to see for an efficient cost and environmentally effective method of producing lithium from brines.

I cannot find any further mention on the Lithium Chile website about their joint venture with Summit Nanotech.

The big question is whether or not this technology can be scaled for industrial use. I wish them good luck with the effort.

All this talk about lithium extraction and other natural resource extraction brought to mind Harold Innis and his staples theory of Canadian history, culture, and economy. From the Harold Innis Wikipedia entry (Note: Links have been removed),

Harold Adams Innis FRSC (1894 – 1952) was a Canadian professor of political economy at the University of Toronto and the author of seminal works on media, communication theory, and Canadian economic history. He helped develop the staples thesis, [emphasis mine] which holds that Canada’s culture, political history, and economy have been decisively influenced by the exploitation and export of a series of “staples” such as fur, fishing, lumber, wheat, mined metals [emphasis mine], and coal. The staple thesis dominated economic history in Canada from the 1930s to 1960s, and continues to be a fundamental part of the Canadian political economic tradition.[8]

There you have it.

Girls Day (Feb. 25.21) during (US) Discover Engineers Week 2021

Discover Engineers Week is being held from February 21 -27, 2021 by the (US) National Society of Professional Engineers (NSPE). Included in the schedule of events is a special day, February 25, 2021, dedicated to introducing engineering to girls.

There is a poster celebrating 10 female engineers on a February 18, 2021 blog posting at wetheparents.org. I’ve excerpted a few of the images and biographies,

#5 Henrietta Vansittart

Born Henrietta Lowe, a young Vansittart was raised in poverty. Her father, a machinist, studied ship propulsion and made efforts to obtain patents using connections and income from his wife’s wealthier family. His repeated failures to succeed at profiting from his patents nearly drove the family to bankruptcy, leading to a young Lowe’s marriage to Lieutenant Frederick Vansittart in 1855.

A self-taught engineer, Vansittart began the study of her father’s work shortly after marriage. The Lowe Propeller, her father’s most noteworthy invention, never successfully created income for the family due to infringement issues; after his death in 1866, Vansittart’s focus became perfecting the propeller. The Lowe-Vansittart propeller allowed ships to move faster while utilizing less fuel, earning her a patent in 1868; it was later used on many ships, including the S.S. Lusitania.

Both the inventor and her patent were awarded a number of awards for her engineering prowess, and Vansittart’s name was mentioned in The Times and other key newspapers of the era. She was the first female to read, write, and illustrate her diagrams for a scientific article, and is considered to be one of the first female engineers.

#7 Kimberly Bryant

A native of Memphis, Tennessee, electrical engineer Kimberly Bryant earned her EE degree with a minor in Computer Science at Nashville’s Vanderbilt University. There, Bryant’s studies focused on high-voltage electronics, informing her early career with Westinghouse Electric and DuPont, two leading innovators in the industry. Bryant’s focus later shifted to biotech and pharmaceutical engineering, where she worked for Genentech, Merck, Novartis, and Pfizer.

Bryant’s most recognizable achievement is the founding of the not-for-profit organization Black Girls Code. She created BGC after her daughter attended a tech summer camp, finding herself disappointed to be the only African American girl in the small handful of female attendees. Seeing a lack of coding and computing camps for underrepresented communities, Bryant encouraged Genentech colleagues to join her in the creation of a coding initiative for young girls of color.

As of late 2019, BGC has 15 chapters and is an internationally recognized not-for-profit organization. Bryant has been named a White House Champion of Change for Tech Inclusion, was the recipient of Smithsonian Magazine’s American Ingenuity Award for Social Projects, and was named one of 2013’s 25 Most Influential African-Americans in Technology by Business Insider.

#9 Judith Resnik

The daughter of Ukranian Jewish immigrants, Judy Resnik’s talents quickly became clear during childhood. Recognized for “intellectual brilliance” in kindergarten, Resnik entered elementary school a year early, remaining an outstanding student throughout high school. She graduated as high school valedictorian, and was one of only 16 women to have ever received a perfect store on the SAT at the time.

Resnik received a B.S. in electrical engineering from Carnegie Mellon, and a Ph.D. in electrical engineering with honors from the University of Maryland. She worked as a design engineer on RCA’s missile and radar projects, built custom integrated circuitry for the Navy’s radar control systems, and developed software and electronics for NASA. She qualified as a professional aircraft pilot during the completion of her Ph.D. and was ultimately recruited into NASA’s Astronaut Corps at age 28.

Resnik’s first space flight was as a mission specialist on the maiden voyage of the Space Shuttle Discovery. There, she became the first Jewish woman, second Jewish person, and second American woman in space. While Resnik enjoyed a successful first mission, she tragically lost her life in the 1986 Challenger explosion. Her life and accomplishments have been posthumously recognized by Carnegie Mellon, the University of Maryland, the Institute of Electrical and Electronics Engineering, and the Society of Women Engineers, among many others.

While I encourage you to go see the other seven in the February 18, 2021 blog posting, I suggest you also double-check the information you find there and, for that matter, here on this blog, too, with other sources.

Finally, there’s an event being hosted by Westcoast Women in Engineering, Science and Technology (WWEST), which is the operating name for the 2015-2020 NSERC (Natural Sciences and Engineering Research Council of Canada) Chair for Women in Science and Engineering (CWSE), BC and Yukon Region. Complicated, yes? Thankfully the event description is much simpler from the What’s Happening webpage (on the WWest at Simon Fraser University webspace),

The Future of Tech (All Girls) – Grade 11

February 25, 2021

As technology continues to evolve in our daily lives, we are able to leverage new technologies for new applications. The Future of Tech creates the bridge and identifies the differences between electrical and computer engineering through hands-on workshops. Engineering students [from the University of British Columbia] share ideas and perceptions bringing you closer to this exciting domain.

This event is open to all girls in grade 11. We have an inclusive view of the word ‘girl’ and we welcome trans*, genderqueer and non-binary folks interested in these workshops.

Date: Thursday, February 25
Cost: Free
Location: Online
Register: Here

Fungal wearable tech and building materials

This is the first time I’ve seen wearable tech based on biological material, in this case, fungi. In diving further into this material (wordplay intended), I discovered some previous work on using fungi for building materials, which you’ll find later in this posting.

Wearable tech and more

A January 18, 2021 news item on phys.org provides some illumination on the matter,

Fungi are among the world’s oldest and most tenacious organisms. They are now showing great promise to become one of the most useful materials for producing textiles, gadgets and other construction materials. The joint research venture undertaken by the University of the West of England, Bristol, the U.K. (UWE Bristol) and collaborators from Mogu S.r.l., Italy, Istituto Italiano di Tecnologia, Torino, Italy and the Faculty of Computer Science, Multimedia and Telecommunications of the Universitat Oberta de Catalunya (UOC) has demonstrated that fungi possess incredible properties that allow them to sense and process a range of external stimuli, such as light, stretching, temperature, the presence of chemical substances and even electrical signals. [emphasis mine]

This could help pave the way for the emergence of new fungal materials with a host of interesting traits, including sustainability, durability, repairability and adaptability. Through exploring the potential of fungi as components in wearable devices, the study has verified the possibility of using these biomaterials as efficient sensors with endless possible applications.

A January 18, 2021 Universitat Oberta de Catalunya (UOC) press release (also on EurekAlert), which originated the news item, describes this vision for future wearable tech based on fungi,

Fungi to make smart wearables even smarter

People are unlikely to think of fungi as a suitable material for producing gadgets, especially smart devices such as pedometers or mobile phones. Wearable devices require sophisticated circuits that connect to sensors and have at least some computing power, which is accomplished through complex procedures and special materials. This, roughly speaking, is what makes them “smart”. The collaboration of Prof. Andrew Adamatzky and Dr. Anna Nikolaidou from UWE Bristol’s Unconventional Computing Laboratory, Antoni Gandia, Chief Technology Officer at Mogu S.r.l., Prof. Alessandro Chiolerio from Istituto Italiano di Tecnologia, Torino, Italy and Dr. Mohammad Mahdi Dehshibi, researcher with the UOC’s Scene Understanding and Artificial Intelligence Lab (SUNAI) have demonstrated that fungi can be added to the list of these materials.

Indeed, the recent study, entitled “Reactive fungal wearable” and featured in Biosystems, analyses the ability of oyster fungus Pleurotus ostreatus to sense environmental stimuli that could come, for example, from the human body. In order to test the fungus’s response capabilities as a biomaterial, the study analyses and describes its role as a biosensor with the ability to discern between chemical, mechanical and electrical stimuli.

“Fungi make up the largest, most widely distributed and oldest group of living organisms on the planet,” said Dehshibi, who added, “They grow extremely fast and bind to the substrate you combine them with”. According to the UOC researcher, fungi are even able to process information in a way that resembles computers.

“We can reprogramme a geometry and graph-theoretical structure of the mycelium networks and then use the fungi’s electrical activity to realize computing circuits,” said Dehshibi, adding that, “Fungi do not only respond to stimuli and trigger signals accordingly, but also allow us to manipulate them to carry out computational tasks, in other words, to process information”. As a result, the possibility of creating real computer components with fungal material is no longer pure science fiction. In fact, these components would be capable of capturing and reacting to external signals in a way that has never been seen before.

Why use fungi?

These fungi have less to do with diseases and other issues caused by their kin when grown indoors. What’s more, according to Dehshibi, mycelium-based products are already used commercially in construction. He said: “You can mould them into different shapes like you would with cement, but to develop a geometric space you only need between five days and two weeks. They also have a small ecological footprint. In fact, given that they feed on waste to grow, they can be considered environmentally friendly”.

The world is no stranger to so-called “fungal architectures” [emphasis mine], built using biomaterials made from fungi. Existing strategies in this field involve growing the organism into the desired shape using small modules such as bricks, blocks or sheets. These are then dried to kill off the organism, leaving behind a sustainable and odourless compound.

But this can be taken one step further, said the expert, if the mycelia are kept alive and integrated into nanoparticles and polymers to develop electronic components. He said: “This computer substrate is grown in a textile mould to give it shape and provide additional structure. Over the last decade, Professor Adamatzky has produced several prototypes of sensing and computing devices using the slime mould Physarum polycephalum, including various computational geometry processors and hybrid electronic devices.”

The upcoming stretch

Although Professor Adamatzky found that this slime mould is a convenient substrate for unconventional computing, the fact that it is continuously changing prevents the manufacture of long-living devices, and slime mould computing devices are thus confined to experimental laboratory set-ups.

However, according to Dehshibi, thanks to their development and behaviour, basidiomycetes are more readily available, less susceptible to infections, larger in size and more convenient to manipulate than slime mould. In addition, Pleurotus ostreatus, as verified in their most recent paper, can be easily experimented on outdoors, thus opening up the possibility for new applications. This makes fungi an ideal target for the creation of future living computer devices.

The UOC researcher said: “In my opinion, we still have to address two major challenges. The first consists in really implementing [fungal system] computation with a purpose; in other words, computation that makes sense. The second would be to characterize the properties of the fungal substrates via Boolean mapping, in order to uncover the true computing potential of the mycelium networks.” To word it another way, although we know that there is potential for this type of application, we still have to figure out how far this potential goes and how we can tap into it for practical purposes.

We may not have to wait too long for the answers, though. The initial prototype developed by the team, which forms part of the study, will streamline the future design and construction of buildings with unique capabilities, thanks to their fungal biomaterials. The researcher said: “This innovative approach promotes the use of a living organism as a building material that is also fashioned to compute.” When the project wraps up in December 2022, the FUNGAR project will construct a large-scale fungal building in Denmark and Italy, as well as a smaller version on UWE Bristol’s Frenchay Campus.

Dehshibi said: “To date, only small modules such as bricks and sheets have been manufactured. However, NASA [US National Aeronautics Space Administration] is also interested in the idea and is looking for ways to build bases on the Moon and Mars to send inactive spores to other planets.” To conclude, he said: “Living inside a fungus may strike you as odd, but why is it so strange to think that we could live inside something living? It would mark a very interesting ecological shift that would allow us to do away with concrete, glass and wood. Just imagine schools, offices and hospitals that continuously grow, regenerate and die; it’s the pinnacle of sustainable life.”

For the Authors of the paper, the point of fungal computers is not to replace silicon chips. Fungal reactions are too slow for that. Rather, they think humans could use mycelium growing in an ecosystem as a “large-scale environmental sensor.” Fungal networks, they reason, are monitoring a large number of data streams as part of their everyday existence. If we could plug into mycelial networks and interpret the signals, they use to process information, we could learn more about what was happening in an ecosystem.

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

Reactive fungal wearable by Andrew Adamatzky, Anna Nikolaidou, Antoni Gandia, Alessandro Chiolerio, Mohammad Mahdi Dehshibi. Biosystems Volume 199, January 2021, 104304 DOI: https://doi.org/10.1016/j.biosystems.2020.104304

This paper is behind a paywall.

Fungal architecture and building materials

Here’s a video, which shows the work which inspired the fungal architecture that Dr. Dehshibi mentioned in the press release about wearable tech,

The video shows a 2014 Hy-Fi installation by The Living for MoMA (Museum of Modern Art) PS1 in New York City. Here’s more about HyFi and what it inspired from a January 15, 2021 article by Caleb Davies for the EU (European Union) Research and Innovation Magazine and republished on phys.org (Note: Links have been removed),

In the summer of 2014 a strange building began to take shape just outside MoMA PS1, a contemporary art centre in New York City. It looked like someone had started building an igloo and then got carried away, so that the ice-white bricks rose into huge towers. It was a captivating sight, but the truly impressive thing about this building was not so much its looks but the fact that it had been grown.

The installation, called Hy-Fi, was designed and created by The Living, an architectural design studio in New York. Each of the 10,000 bricks had been made by packing agricultural waste and mycelium, the fungus that makes mushrooms, into a mould and letting them grow into a solid mass.

This mushroom monument gave architectural researcher Phil Ayres an idea. “It was impressive,” said Ayres, who is based at the Centre for Information Technology and Architecture in Copenhagen, Denmark. But this project and others like it were using fungus as a component in buildings such as bricks without necessarily thinking about what new types of building we could make from fungi.

That’s why he and three colleagues have begun the FUNGAR project—to explore what kinds of new buildings we might construct out of mushrooms.

FUNGAR (Fungal Architectures) can be found here, Mogu can be found here, and The Living can be found here.

Put a ring on it: preventing clumps of gold nanoparticles

Caption: A comparison of how linear PEG (left) and cyclic PEG (right) attach to a gold nanoparticle Credit: Yubo Wang, Takuya Yamamoto

A January 20, 2021 news item on phys.org focuses on work designed to stop gold nanoparticles from clumping together (Note: A link has been removed),

Hokkaido University scientists have found a way to prevent gold nanoparticles from clumping, which could help towards their use as an anti-cancer therapy.

Attaching ring-shaped synthetic compounds to gold nanoparticles helps them retain their essential light-absorbing properties, Hokkaido University researchers report in the journal Nature Communications.

A January 20, 2021 Hokkaido University press release (also on EurekAlert but published Jan. 21, 2020), which originated the news item, elaborates on the work,

Metal nanoparticles have unique light-absorbing properties, making them interesting for a wide range of optical, electronic and biomedical applications. For example, if delivered to a tumour, they could react with applied light to kill cancerous tissue. A problem with this approach, though, is that they easily clump together in solution, losing their ability to absorb light. This clumping happens in response to a variety of factors, including temperature, salt concentration and acidity.

Scientists have been trying to find ways to ensure nanoparticles stay dispersed in their target environments. Covering them with polyethylene glycol, otherwise known as PEG, has been relatively successful at this in the case of gold nanoparticles. PEG is biocompatible and can prevent gold surfaces from clumping together in the laboratory and in living organisms, but improvements are still needed.

Applied chemist Takuya Yamamoto and colleagues at Hokkaido University, The University of Tokyo, and Tokyo Institute of Technology found that mixing gold nanoparticles with ring-shaped PEG, rather than the normally linear PEG, significantly improved dispersion. The ‘cyclic-PEG’ (c-PEG) attaches to the surfaces of the nanoparticles without forming chemical bonds with them, a process called physisorption. The coated nanoparticles remained dispersed when frozen, freeze-dried and heated.

The team tested the c-PEG-covered gold nanoparticles in mice and found that they cleared slowly from the blood and accumulated better in tumours compared to gold nanoparticles coated with linear PEG. However, accumulation was lower than desired levels, so the researchers recommend further investigations to fine-tune the nanoparticles for this purpose.

Associate Professor Takuya Yamamoto is part of the Laboratory of Chemistry of Molecular Assemblies at Hokkaido University, where he studies the properties and applications of various cyclic chemical compounds.

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

Enhanced dispersion stability of gold nanoparticles by the physisorption of cyclic poly(ethylene glycol) by Yubo Wang, Jose Enrico Q. Quinsaat, Tomoko Ono, Masatoshi Maeki, Manabu Tokeshi, Takuya Isono, Kenji Tajima, Toshifumi Satoh, Shin-ichiro Sato, Yutaka Miura & Takuya Yamamoto. Nature Communications volume 11, Article number: 6089 (2020) DOI: https://doi.org/10.1038/s41467-020-19947-8 Published: 30 November 2020

This paper is open access.

Nuclear power plants take a cue from Roman concrete

Every once in a while I delve into concrete, especially Roman concrete, and cement. The most recent of these postings (until now) was a June 3, 2016 post titled, Making better concrete by looking to nature for inspiration.

A January 8, 2021 Nagoya University press release (also on EurekAlert but published Jan. 13, 2021) describes how nuclear power plants could lead the way to an eco-friendly modern concrete as durable as that the ancient Romans developed,

A rare mineral that has allowed Roman concrete marine barriers to survive for more than 2,000 years has been found in the thick concrete walls of a decommissioned nuclear power plant in Japan. The formation of aluminous tobermorite increased the strength of the walls more than three times their design strength, Nagoya University researchers and colleagues report in the journal Materials and Design. The finding could help scientists develop stronger and more eco-friendly concrete.

“We found that cement hydrates and rock-forming minerals reacted in a way similar to what happens in Roman concrete, significantly increasing the strength of the nuclear plant walls,” says Nagoya University environmental engineer Ippei Maruyama.

Research has shown that Roman concrete used in the construction of marine barriers has managed to survive for more than two millennia because seawater dissolves volcanic ash in the mixture, leading to the formation of aluminous tobermorite. Since aluminous tobermorite is a crystal, it makes the concrete more chemically stable and stronger. It is very difficult to incorporate aluminous tobermorite directly into modern-day concrete. Scientists have generated the mineral in the lab, but it requires very high temperatures above 70°C. On the other hand, laboratory experiments have shown that hot environments are detrimental to concrete strength, which has led to regulations that limit its use to temperatures below 65°C.

Maruyama and his colleagues found that aluminous tobermorite formed in a nuclear reactor’s concrete walls when temperatures of 40-55°C were maintained for 16.5 years.

The samples were taken from the Hamaoka Nuclear Power Plant in Japan, which operated from 1976 to 2009.

In-depth analyses showed that the reactor’s very thick walls were able to retain moisture. Minerals used to make the concrete reacted in the presence of this water, increasing availability of silicon and aluminium ions and the alkali content of the wall. This ultimately led to the formation of aluminous tobermorite.

“Our understanding of concrete is based on short-term experiments conducted at lab time scales,” says Maruyama. “But real concrete structures give us more insights for long-term use.”

Maruyama and his colleagues are searching for ways to make concrete more durable and environmentally friendly. Cement used in concrete manufacturing produces nearly 10% of human-made carbon dioxide emissions, so the team is looking to produce more eco-friendly mixtures that still meet standardized requirements for strong concrete structures.

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

Long-term use of modern Portland cement concrete: The impact of Al-tobermorite formation by Ippei Maruyama, Jiří Rymeš, Abudushalamu Aili, Shohei Sawada, Osamu Kontani, Shinya Ueda, Ryu Shimamoto. Materials & Design
Volume 198, 15 January 2021, 109297 DOI: https://doi.org/10.1016/j.matdes.2020.109297

This paper appears to be open access.

A lotus root-inspired hydrogel fiber for surgical sutures

By FotoosRobin – originally posted to Flickr as Lotus root, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=4826529

The lotus (Nelumbo nucifera) rhizome (mass of roots) is not the prettiest part of the lotus but its fibers (and presumably fiber from other parts of the lotus plant) served as inspiration for a hydrogel that might be used as a surgical suture according to a Jan. 14, 2021 news item on phys.org (Note: Links have been removed),

“The lotus roots may break, but the fiber remains joined”—an old Chinese saying that reflects the unique structure and mechanical properties of the lotus fiber. The outstanding mechanical properties of lotus fibers can be attributed to their unique spiral structure, which provides an attractive model for biomimetic design of artificial fibers.

In a new study published in Nano Letters, a team led by Prof. Yu Shuhong from the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS) reported a bio-inspired lotus-fiber-mimetic spiral structure bacterial cellulose (BC) hydrogel fiber with high strength, high toughness, excellent biocompatibility, good stretchability, and high energy dissipation.

A Jan. 14, 2021 University of Science and Technology of China press release on the Chinese Academy of Sciences website (also on EurekAlert), which originated the news item, describes the new hydrogel in more detail,

Unlike polymer-based hydrogel, the newly designed biomimetic hydrogel fiber (BHF) is based on the BC hydrogel with 3D cellulose nanofiber networks produced by bacteria. The cellulose nanofibers provide the reversible hydrogen bonding network that results in unique mechanical properties.

The researchers applied a constant tangential force to the pretreated BC hydrogel along the cross-sectional direction. Then, the two sides of the hydrogel were subjected to opposite tangential forces, and local plastic deformation occurred.

The hydrogen bonds in the 3D network of cellulose nanofibers were broken by the tangential force, causing the hydrogel strip to twist spirally and the network to slip and deform. When the tangential force was removed, the hydrogen bonds reformed between the nanofibers, and the spiral structure of the fiber was fixed.

Benefited from lotus-fiber-mimetic spiral structure, the toughness of BHF can reach ?116.3 MJ m-3, which is more than nine times higher than those of non-spiralized BC hydrogel fiber. Besides, once the BHF is stretched, it is nearly non-resilient.

Combining outstanding mechanical properties with excellent biocompatibility derived from BC, BHF is a promising hydrogel fiber for biomedical material, especially for surgical suture, a commonly used structural biomedical material for wound repair.

Compared with commercial surgical suture with higher modulus, the BHF has similar modulus and strength to soft tissue, like skin. The outstanding stretchability and energy dissipation of BHF allow it to absorb energy from the tissue deformation around a wound and effectively protect the wound from rupture, which makes BHF an ideal surgical suture.

What’s more, the porous structure of BHF also allows it to adsorb functional small molecules, such as antibiotics or anti-inflammatory compounds, and sustainably release them on wounds. With an appropriate design, BHF would be a powerful platform for many medical applications.

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

Bio-Inspired Lotus-Fiber-like Spiral Hydrogel Bacterial Cellulose Fibers by Qing-Fang Guan, Zi-Meng Han, YinBo Zhu, Wen-Long Xu, Huai-Bin Yang, Zhang-Chi Ling, Bei-Bei Yan, Kun-Peng Yang, Chong-Han Yin, HengAn Wu, and Shu-Hong Yu. Nano Lett. 2021, XXXX, XXX, XXX-XXX DOI: https://doi.org/10.1021/acs.nanolett.0c03707 Publication Date:January 5, 2021 Copyright © 2021 American Chemical Society

This paper is behind a paywall.

A quantum phenomenon (Kondo effect) and nanomaterials

This is a little outside my comfort zone but here goes anyway. From a December 23, 2020 news item on phys.org (Note: Links have been removed),

Osaka City University scientists have developed mathematical formulas to describe the current and fluctuations of strongly correlated electrons in quantum dots. Their theoretical predictions could soon be tested experimentally.

Theoretical physicists Yoshimichi Teratani and Akira Oguri of Osaka City University, and Rui Sakano of the University of Tokyo have developed mathematical formulas that describe a physical phenomenon happening within quantum dots and other nanosized materials. The formulas, published in the journal Physical Review Letters, could be applied to further theoretical research about the physics of quantum dots, ultra-cold atomic gasses, and quarks.

At issue is the Kondo effect. This effect was first described in 1964 by Japanese theoretical physicist Jun Kondo in some magnetic materials, but now appears to happen in many other systems, including quantum dots and other nanoscale materials.

A December 23, 2020 Osaka City University press release (also on EurekAlert), which originated the news item, provides more detail,

Normally, electrical resistance drops in metals as the temperature drops. But in metals containing magnetic impurities, this only happens down to a critical temperature, beyond which resistance rises with dropping temperatures.

Scientists were eventually able to show that, at very low temperatures near absolute zero, electron spins become entangled with the magnetic impurities, forming a cloud that screens their magnetism. The cloud’s shape changes with further temperature drops, leading to a rise in resistance. This same effect happens when other external ‘perturbations’, such as a voltage or magnetic field, are applied to the metal. 

Teratani, Sakano and Oguri wanted to develop mathematical formulas to describe the evolution of this cloud in quantum dots and other nanoscale materials, which is not an easy task. 

To describe such a complex quantum system, they started with a system at absolute zero where a well-established theoretical model, namely Fermi liquid theory, for interacting electrons is applicable. They then added a ‘correction’ that describes another aspect of the system against external perturbations. Using this technique, they wrote formulas describing electrical current and its fluctuation through quantum dots. 

Their formulas indicate electrons interact within these systems in two different ways that contribute to the Kondo effect. First, two electrons collide with each other, forming well-defined quasiparticles that propagate within the Kondo cloud. More significantly, an interaction called a three-body contribution occurs. This is when two electrons combine in the presence of a third electron, causing an energy shift of quasiparticles. 

“The formulas’ predictions could soon be investigated experimentally”, Oguri says. “Studies along the lines of this research have only just begun,” he adds. 

The formulas could also be extended to understand other quantum phenomena, such as quantum particle movement through quantum dots connected to superconductors. Quantum dots could be a key for realizing quantum information technologies, such as quantum computers and quantum communication.

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

Fermi Liquid Theory for Nonlinear Transport through a Multilevel Anderson Impurity by Yoshimichi Teratani, Rui Sakano, and Akira Oguri. Phys. Rev. Lett. 125, 216801 (Issue Vol. 125, Iss. 21 — 20 November 2020) DOI: https://doi.org/10.1103/PhysRevLett.125.216801 Published Online: 17 November 2020

This paper is behind a paywall.