Tag Archives: Purdue University

World’s smallest disco party features nanoscale disco ball

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I haven’t featured one of these ‘fun’ (world’s smallest xxx) announcements in a long time. An August 14, 2024 news item on phys.org announces the world’s smallest disco party and a step towards exploring quantum gravity, Note: Links have been removed,

Physicists at Purdue [Purdue University, Indiana, US] are throwing the world’s smallest disco party. The disco ball itself is a fluorescent nanodiamond, which they have levitated and spun at incredibly high speeds. The fluorescent diamond emits and scatters multicolor lights in different directions as it rotates. The party continues as they study the effects of fast rotation on the spin qubits within their system and are able to observe the Berry phase.

The team, led by Tongcang Li, professor of Physics and Astronomy and Electrical and Computer Engineering at Purdue University, published their results in Nature Communications. Reviewers of the publication described this work as “arguably a groundbreaking moment for the study of rotating quantum systems and levitodynamics” and “a new milestone for the levitated optomechanics community.”

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This graph illustrates a diamond particle levitated above a surface ion trap. The fluorescent diamond nanoparticle is driven to rotate at a high speed (up to 1.2 billion rpm) by alternating voltages applied to the four corner electrodes. This rapid rotation induces a phase in the nitrogen-vacancy electron spins inside the diamond. The diagram in the top left corner depicts the atomic structure of a nitrogen-vacancy spin defect inside the diamond. Graphic provided by Kunhong Shen.

An August 13, 2024 Purdue University news release (also on EurekAlert but published August 14, 2024) by Cheryl Pierce, which originated the news item, explains what makes this work so exciting (!), Note: Links have been removed,

“Imagine tiny diamonds floating in an empty space or vacuum. Inside these diamonds, there are spin qubits that scientists can use to make precise measurements and explore the mysterious relationship between quantum mechanics and gravity,” explains Li, who is also a member of the Purdue Quantum Science and Engineering Institute.  “In the past, experiments with these floating diamonds had trouble in preventing their loss in vacuum and reading out the spin qubits. However, in our work, we successfully levitated a diamond in a high vacuum using a special ion trap. For the first time, we could observe and control the behavior of the spin qubits inside the levitated diamond in high vacuum.”

The team made the diamonds rotate incredibly fast—up to 1.2 billion times per minute! By doing this, they were able to observe how the rotation affected the spin qubits in a unique way known as the Berry phase.

“This breakthrough helps us better understand and study the fascinating world of quantum physics,” he says.

The fluorescent nanodiamonds, with an average diameter of about 750 nm, were produced through high-pressure, high-temperature synthesis. These diamonds were irradiated with high-energy electrons to create nitrogen-vacancy color centers, which host electron spin qubits. When illuminated by a green laser, they emitted red light, which was used to read out their electron spin states. An additional infrared laser was shone at the levitated nanodiamond to monitor its rotation. Like a disco ball, as the nanodiamond rotated, the direction of the scattered infrared light changed, carrying the rotation information of the nanodiamond.

The authors of this paper were mostly from Purdue University and are members of Li’s research group: Yuanbin Jin (postdoc), Kunhong Shen (PhD student), Xingyu Gao (PhD student) and Peng Ju (recent PhD graduate). Li, Jin, Shen, and Ju conceived and designed the project and Jin and Shen built the setup. Jin subsequently performed measurements and calculations and the team collectively discussed the results. Two non-Purdue authors are Alejandro Grine, principal member of technical staff at Sandia National Laboratories, and Chong Zu, assistant professor at Washington University in St. Louis. Li’s team discussed the experiment results with Grine and Zu who provided suggestions for improvement of the experiment and manuscript.

“For the design of our integrated surface ion trap,” explains Jin, “we used a commercial software, COMSOL Multiphysics, to perform 3D simulations. We calculate the trapping position and the microwave transmittance using different parameters to optimize the design. We added extra electrodes to conveniently control the motion of a levitated diamond. And for fabrication, the surface ion trap is fabricated on a sapphire wafer using photolithography. A 300-nm-thick gold layer is deposited on the sapphire wafer to create the electrodes of the surface ion trap.”

So which way are the diamonds spinning and can they be speed or direction manipulated? Shen says yes, they can adjust the spin direction and levitation.

“We can adjust the driving voltage to change the spinning direction,” he explains. “The levitated diamond can rotate around the z-axis (which is perpendicular to the surface of the ion trap), shown in the schematic, either clockwise or counterclockwise, depending on our driving signal. If we don’t apply the driving signal, the diamond will spin omnidirectionally, like a ball of yarn.”

Levitated nanodiamonds with embedded spin qubits have been proposed for precision measurements and creating large quantum superpositions to test the limit of quantum mechanics and the quantum nature of gravity.

“General relativity and quantum mechanics are two of the most important scientific breakthroughs in the 20th century. However, we still do not know how gravity might be quantized,” says Li. “Achieving the ability to study quantum gravity experimentally would be a tremendous breakthrough. In addition, rotating diamonds with embedded spin qubits provide a platform to study the coupling between mechanical motion and quantum spins.”

This discovery could have a ripple effect in industrial applications. Li says that levitated micro and nano-scale particles in vacuum can serve as excellent accelerometers and electric field sensors. For example, the US Air Force Research Laboratory (AFRL) are using optically-levitated nanoparticles to develop solutions for critical problems in navigation and communication.

“At Purdue University, we have state-of-the-art facilities for our research in levitated optomechanics,” says Li. “We have two specialized, home-built systems dedicated to this area of study. Additionally, we have access to the shared facilities at the Birck Nanotechnology Center, which enables us to fabricate and characterize the integrated surface ion trap on campus. We are also fortunate to have talented students and postdocs capable of conducting cutting-edge research. Furthermore, my group has been working in this field for ten years, and our extensive experience has allowed us to make rapid progress.”

Quantum research is one of four key pillars of the Purdue Computes initiative, which emphasizes the university’s extensive technological and computational environment.

This research was supported by the National Science Foundation (grant number PHY-2110591), the Office of Naval Research (grant number N00014-18-1-2371), and the Gordon and Betty Moore Foundation (grant DOI 10.37807/gbmf12259). The project is also partially supported by the Laboratory Directed Research and Development program at Sandia National Laboratories.

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

Quantum control and Berry phase of electron spins in rotating levitated diamonds in high vacuum by Yuanbin Jin, Kunhong Shen, Peng Ju, Xingyu Gao, Chong Zu, Alejandro J. Grine & Tongcang Li. Nature Communications volume 15, Article number: 5063 (2024) DOI: https://doi.org/10.1038/s41467-024-49175-3 Published online: 13 June 2024

This paper is open access.

Nano-enabled precision delivery methods for agriculture

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A July 23, 2024 news item on Nanowerk provides an introduction to nanoparticles and their potential use in agriculture, Note: Links have been removed,

Nanoparticles could potentially help address agricultural and environmental sustainability issues on a global scale.

Those issues include rising food demand, increasing greenhouse gas emissions generated by agricultural activities, climbing costs of agrochemicals, reducing crop yields induced by climate change, and degrading soil quality. A class of nanoscale particles called “nanocarriers” could make crop agriculture more sustainable and resilient to climate change, according to a group of specialists that includes Kurt Ristroph, assistant professor of agricultural and biological engineering at Purdue University.

“Saying ‘nanoparticle’ means different things to different people,” Ristroph said. In nanodrug delivery, a nanoparticle usually ranges in size from 60 to 100 nanometers and is made of lipids or polymers. “In the environmental world, a nanoparticle usually means a 3- to 5-nanometer metal oxide colloid. Those are not the same thing, but people use ‘nanoparticle’ for both.”

Ristroph helped organize a 2022 interdisciplinary workshop on nanomethods for drug delivery in plants. Funded by the National Science Foundation and the U.S. Department of Agriculture, the workshop was attended by 30 participants from academia, industry and government laboratories.

Many of the workshop participants, including Ristroph, have now published their conclusions in Nature Nanotechnology (“Towards realizing nano-enabled precision delivery in plants”). Their article reviews the possibility nanocarriers could make crop agriculture more sustainable and resilient to climate change.

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A July 23, 2024 Purdue University news release (also on EurekAlert but published July 19, 2024) by Steve Koppes, which originated the news item, delves further into the topic of how agriculture could be made more sustainable with nanotechnology-enabled delivery methods, Note: Links have been removed,

“Nano-enabled precision delivery of active agents in plants will transform agriculture, but there are critical technical challenges that we must first overcome to realize the full range of its benefits,” said the article’s co-lead author Greg Lowry, the Walter J. Blenko, Sr. Professor of Civil and Environmental Engineering at Carnegie Mellon University. “I’m optimistic about the future of plant nanobiotechnology approaches and the beneficial impacts it will have on our ability to sustainably produce food.”

Plant cells and human cells have major physiological differences. Plant cells have a cell wall while human cells don’t, for example. But certain tools can be transferred from nanomedicine to plant applications.

“People have developed tools for studying the bio-corona formation around nanoparticles in an animal. We could think about bringing some of those tools to bear on nanoparticles in plants,” Ristroph said. 

When nanoparticles are injected into the bloodstream, many components of the blood stick onto the surface of the nanoparticles. The various proteins sticking to a nanoparticle’s surface make it look different.

The task then becomes figuring out what proteins or other molecules will stick to the surface and where the particle will go as a result. A nanoparticle designed to move toward a certain organ may have its destination altered by white blood cells that detect the particle’s surface proteins and send it to a different organ.

“Broadly speaking, that’s the idea of bio-corona formation and trafficking,” Ristroph said. “People in drug delivery nanomedicine have been thinking about and developing tools for studying that kind of thing. Some of those thoughts and some of those tools could be applied to plants.” 

Researchers already have developed many different architectures and chemistries for making nanoscale delivery vehicles for nanomedicine. “Some of the particle types are transferable,” he said. “You can take a nanoparticle that was optimized for movement in humans and put it in a plant, and you’ll probably find that it needs to be redesigned at least somewhat.”

Ristroph focuses on organic (carbon-based) nanocarriers that have a core-shell structure. The core contains a payload, while the shell forms a protective outer layer. Researchers have used many different types of nanomaterial in plants. The most popular materials are metallic nanoparticles because they are somewhat easier to make, handle and track where they go in a plant than organic nanoparticles.

“One of the first questions that you want to figure out is where these nanoparticles go in a plant,” Ristroph said. “It’s a lot easier to detect a metal inside of a plant that’s made of carbon than it is to detect a carbon-based nanoparticle in a plant that’s made of carbon.”

Last March, Ristroph and Purdue PhD student Luiza Stolte Bezerra Lisboa Oliveira published a critical review of the research literature on the Uptake and Translocation of Organic Nanodelivery Vehicles in Plants in Environmental Science and Technology.

“Not a lot is understood about transformations after these things go into a plant, how they’re getting metabolized,” Ristroph said. His team is interested in studying that, along with ways to help ensure that the nanoparticles are delivered to their proper destinations, and in corona formation. Coronas are biomolecular coatings that affect nanoparticle functions. 

The manufacturability of nanocarriers is another interest area that could be transferred to agriculture from nanomedicine.

“I care a lot about manufacturability and making sure that whatever techniques we’re using to make the nanoparticles are scalable and economically feasible,” Ristroph said.

The manufacturability of nanocarriers is another interest area that could be transferred to agriculture from nanomedicine.

“I care a lot about manufacturability and making sure that whatever techniques we’re using to make the nanoparticles are scalable and economically feasible,” Ristroph said.

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

Towards realizing nano-enabled precision delivery in plants by Gregory V. Lowry, Juan Pablo Giraldo, Nicole F. Steinmetz, Astrid Avellan, Gozde S. Demirer, Kurt D. Ristroph, Gerald J. Wang, Christine O. Hendren, Christopher A. Alabi, Adam Caparco, Washington da Silva, Ivonne González-Gamboa, Khara D. Grieger, Su-Ji Jeon, Mariya V. Khodakovskaya, Hagay Kohay, Vivek Kumar, Raja Muthuramalingam, Hanna Poffenbarger, Swadeshmukul Santra, Robert D. Tilton & Jason C. White. Nature Nanotechnology (2024) DOI: https://doi.org/10.1038/s41565-024-01667-5 Published: 06 June 2024

This paper is behind a paywall.

Fullertubes, at last!

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A theoretical possibility has been proven by an international team including researchers from the Université de Montréal (University of Montreal) according to a March 27, 2024 news item on phys.org,

For years, C130 fullertubes—molecules made up of 130 carbon atoms—have existed only in theory. Now, leading an international team of scientists, a UdeM doctoral student in physics has successfully shown them in real life—and even managed to capture some in a photograph.

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Illustration of the discovery of the C130-D5h molecule, published on the cover page of the prestigious “Journal of the American Chemical Society” last December. Credit: JACS

A March 27, 2024 Université de Montréal (UdeM) nouvelles (news release), which originated the news item, provides more detail, Note: Links have been removed,

This feat in the realm of basic research has led Emmanuel Bourret to have a cover-page illustration of his discovery in a prestigious scientific journal, the Journal of the American Chemical Society.

First published online last October [2023], the discovery was made by Bourret as lead scientist of an inter-university team that also included researchers from Purdue University, Virginia Tech and the Oak Ridge National Laboratory, in Tennessee.

A fullertube is basically an assembly of carbon atoms arranged to form a closed tubular cage. It is related to fullerenes, molecules that are represented as cages of interconnected hexagons and pentagons, and come in a wide variety of sizes and shapes.

For example, a C60 fullerene is made up of 60 carbon atoms and is shaped like a soccer ball. It is relatively small, spherical and very abundant. C120 fullerenes are less common. They are longer and shaped like a tube capped at either ends with the two halves of a C60 fullerene.

Found in soot

The C130 fullertube (or C130-D5h, its full scientific name) is more elongated than the C120 and even rarer. To isolate it, Bourret and his team generated an electric arc between two graphite electrodes to produce soot containing fullerene and fullertube molecules. The electronic structure of these molecules was then calculated using density functional theory (DFT).

“Drawing on principles of quantum mechanics, DFT enables us to calculate electronic structures and predict the properties of a molecule using the fundamental rules of physics,” explained Bourret’s thesis supervisor, UdeM physics professor Michel Côté, a researcher at the university’s Institut Courtois.

Using special software, Bourret was able to describe the structure of the C130 molecule: it is a tube with two hemispheres at the ends, making it look like a microscopic capsule. It measures just under 2 nanometres long by 1 nm wide (a nanometre is one billionth of a metre).

“The structure of the tube is basically made up of atoms arranged in hexagons,” said Bourret. “At the two ends, these hexagons are linked by pentagons, giving them their rounded shape.”

Bourret began doing theoretical work on fullertubes in 2014 under his then-supervisor Jiri Patera, an UdeM mathematics professor. After Patera passed away in January 2022, Bourret then approached Côté, who became his new supervisor.

Existence shown in 2020

Two years before that, Bourret had read an article by Purdue University at Fort Wayne professor Steven Stevenson, who described the experimental isolation of certain fullertubes, demonstrating their existence but not identifying all of them.

Under Côté’s guidance, Bourret set to work advancing knowledge on the topic.

“Emmanuel had a strong background in abstract mathematics,” Bourret recalled, “and he added an interesting dimension to my research group, which focuses on more computational approaches.”

Are any possible future applications in the offing?

“It’s hard to say at this stage, but one possibility might be the production of hydrogen,” said Côté. “Currently, what’s used is a catalyst made of platinum and rubidium, both of which are rare and expensive. Replacing them with carbon structures such as C130 would make it possible to produce hydrogen in a ‘greener’ way.”

Last year, Bourret’s groundbreaking work earned him an invitation to deliver a paper at the annual meeting of the U.S. Electrochemical Society (ECS), in Boston. This May [2024], he’ll chair a panel on fullerenes and fullertubes at the ECS annual meeting in San Francisco.

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

Colossal C130 Fullertubes: Soluble [5,5] C130-D5h(1) Pristine Molecules with 70 Nanotube Carbons and Two 30-Atom Hemifullerene End-caps by Emmanuel Bourret, Xiaoyang Liu, Cora A. Noble, Kevin Cover, Tanisha P. Davidson, Rong Huang, Ryan M. Koenig, K. Shawn Reeves, Ivan V. Vlassiouk, Michel Côté, Jefferey S. Baxter, Andrew R. Lupini, David B. Geohegan, Harry C. Dorn, and Steven Stevenson. J. Am. Chem. Soc. 2023, 145, 48, 25942–25947 DOI: https://doi.org/10.1021/jacs.3c09082 Publication Date: October 27, 2023 Copyright © 2023 American Chemical Society

This paper is behind a paywall.

Your gas stove may be emitting more polluting nanoparticles than your car exhaust

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A February 27, 2024 news item on ScienceDaily describes the startling research results to anyone who’s listened to countless rhapsodize about the superiority of gas stoves over any other,

Cooking on your gas stove can emit more nano-sized particles into the air than vehicles that run on gas or diesel, possibly increasing your risk of developing asthma or other respiratory illnesses, a new Purdue University study has found.

“Combustion remains a source of air pollution across the world, both indoors and outdoors. We found that cooking on your gas stove produces large amounts of small nanoparticles that get into your respiratory system and deposit efficiently,” said Brandon Boor, an associate professor in Purdue’s Lyles School of Civil Engineering, who led this research.

Based on these findings, the researchers would encourage turning on a kitchen exhaust fan while cooking on a gas stove.

The study, published in the journal PNAS [Proceedngs of the National Academy of Sciences] Nexus, focused on tiny airborne nanoparticles that are only 1-3 nanometers in diameter, which is just the right size for reaching certain parts of the respiratory system and spreading to other organs.

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A February 27, 2024 Purdue University news release by Kayla Albert (also on EurekAlert), which originated the news item, provides more detail about the research, Note: Links have been removed,

Recent studies have found that children who live in homes with gas stoves are more likely to develop asthma. But not much is known about how particles smaller than 3 nanometers, called nanocluster aerosol, grow and spread indoors because they’re very difficult to measure.

“These super tiny nanoparticles are so small that you’re not able to see them. They’re not like dust particles that you would see floating in the air,” Boor said. “After observing such high concentrations of nanocluster aerosol during gas cooking, we can’t ignore these nano-sized particles anymore.”

Using state-of-the-art air quality instrumentation provided by the German company GRIMM AEROSOL TECHNIK, a member of the DURAG GROUP, Purdue researchers were able to measure these tiny particles down to a single nanometer while cooking on a gas stove in a “tiny house” lab. They collaborated with Gerhard Steiner, a senior scientist and product manager for nano measurement at GRIMM AEROSOL. 

Called the Purdue zero Energy Design Guidance for Engineers (zEDGE) lab, the tiny house has all the features of a typical home but is equipped with sensors for closely monitoring the impact of everyday activities on a home’s air quality. With this testing environment and the instrument from GRIMM AEROSOL, a high-resolution particle size magnifier—scanning mobility particle sizer (PSMPS), the team collected extensive data on indoor nanocluster aerosol particles during realistic cooking experiments.

This magnitude of high-quality data allowed the researchers to compare their findings with known outdoor air pollution levels, which are more regulated and understood than indoor air pollution. They found that as many as 10 quadrillion nanocluster aerosol particles could be emitted per kilogram of cooking fuel — matching or exceeding those produced from vehicles with internal combustion engines. 

This would mean that adults and children could be breathing in 10-100 times more nanocluster aerosol from cooking on a gas stove indoors than they would from car exhaust while standing on a busy street.

“You would not use a diesel engine exhaust pipe as an air supply to your kitchen,” said Nusrat Jung, a Purdue assistant professor of civil engineering who designed the tiny house lab with her students and co-led this study.

Purdue civil engineering PhD student Satya Patra made these findings by looking at data collected in the tiny house lab and modeling the various ways that nanocluster aerosol could transform indoors and deposit into a person’s respiratory system.

The models showed that nanocluster aerosol particles are very persistent in their journey from the gas stove to the rest of the house. Trillions of these particles were emitted within just 20 minutes of boiling water or making grilled cheese sandwiches or buttermilk pancakes on a gas stove.

Even though many particles rapidly diffused to other surfaces, the models indicated that approximately 10 billion to 1 trillion particles could deposit into an adult’s head airways and tracheobronchial region of the lungs. These doses would be even higher for children — the smaller the human, the more concentrated the dose.

The nanocluster aerosol coming from the gas combustion also could easily mix with larger particles entering the air from butter, oil or whatever else is cooking on the gas stove, resulting in new particles with their own unique behaviors.

A gas stove’s exhaust fan would likely redirect these nanoparticles away from your respiratory system, but that remains to be tested.

“Since most people don’t turn on their exhaust fan while cooking, having kitchen hoods that activate automatically would be a logical solution,” Boor said. “Moving forward, we need to think about how to reduce our exposure to all types of indoor air pollutants. Based on our new data, we’d advise that nanocluster aerosol be considered as a distinct air pollutant category.”

This study was supported by a National Science Foundation CAREER award to Boor. Additional financial support was provided by the Alfred P. Sloan Foundation’s Chemistry of Indoor Environments program through an interdisciplinary collaboration with Philip Stevens, a professor in Indiana University’s Paul H. O’Neill School of Public and Environmental Affairs in Bloomington.

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

Dynamics of nanocluster aerosol in the indoor atmosphere during gas cooking by Satya S Patra, Jinglin Jiang, Xiaosu Ding, Chunxu Huang, Emily K Reidy, Vinay Kumar, Paige Price, Connor Keech, Gerhard Steiner, Philip Stevens, Nusrat Jung, Brandon E Boor. PNAS Nexus, Volume 3, Issue 2, February 2024, pgae044, DOI: https://doi.org/10.1093/pnasnexus/pgae044 Published: 27 February 2024

This paper is open access.

A hardware (neuromorphic and quantum) proposal for handling increased AI workload

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It’s been a while since I’ve featured anything from Purdue University (Indiana, US). From a November 7, 2023 news item on Nanowerk, Note Links have been removed,

Technology is edging closer and closer to the super-speed world of computing with artificial intelligence. But is the world equipped with the proper hardware to be able to handle the workload of new AI technological breakthroughs?

Key Takeaways
Current AI technologies are strained by the limitations of silicon-based computing hardware, necessitating new solutions.

Research led by Erica Carlson [Purdue University] suggests that neuromorphic [brainlike] architectures, which replicate the brain’s neurons and synapses, could revolutionize computing efficiency and power.

Vanadium oxides have been identified as a promising material for creating artificial neurons and synapses, crucial for neuromorphic computing.

Innovative non-volatile memory, observed in vanadium oxides, could be the key to more energy-efficient and capable AI hardware.

Future research will explore how to optimize the synaptic behavior of neuromorphic materials by controlling their memory properties.

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The colored landscape above shows a transition temperature map of VO2 (pink surface) as measured by optical microscopy. This reveals the unique way that this neuromorphic quantum material [emphasis mine] stores memory like a synapse. Image credit: Erica Carlson, Alexandre Zimmers, and Adobe Stock

An October 13, 2023 Purdue University news release (also on EurekAlert but published November 6, 2023) by Cheryl Pierce, which originated the news item, provides more detail about the work, Note: A link has been removed,

“The brain-inspired codes of the AI revolution are largely being run on conventional silicon computer architectures which were not designed for it,” explains Erica Carlson, 150th Anniversary Professor of Physics and Astronomy at Purdue University.

A joint effort between Physicists from Purdue University, University of California San Diego (USCD) and École Supérieure de Physique et de Chimie Industrielles (ESPCI) in Paris, France, believe they may have discovered a way to rework the hardware…. [sic] By mimicking the synapses of the human brain.  They published their findings, “Spatially Distributed Ramp Reversal Memory in VO2” in Advanced Electronic Materials which is featured on the back cover of the October 2023 edition.

New paradigms in hardware will be necessary to handle the complexity of tomorrow’s computational advances. According to Carlson, lead theoretical scientist of this research, “neuromorphic architectures hold promise for lower energy consumption processors, enhanced computation, fundamentally different computational modes, native learning and enhanced pattern recognition.”

Neuromorphic architecture basically boils down to computer chips mimicking brain behavior.  Neurons are cells in the brain that transmit information. Neurons have small gaps at their ends that allow signals to pass from one neuron to the next which are called synapses. In biological brains, these synapses encode memory. This team of scientists concludes that vanadium oxides show tremendous promise for neuromorphic computing because they can be used to make both artificial neurons and synapses.

“The dissonance between hardware and software is the origin of the enormously high energy cost of training, for example, large language models like ChatGPT,” explains Carlson. “By contrast, neuromorphic architectures hold promise for lower energy consumption by mimicking the basic components of a brain: neurons and synapses. Whereas silicon is good at memory storage, the material does not easily lend itself to neuron-like behavior. Ultimately, to provide efficient, feasible neuromorphic hardware solutions requires research into materials with radically different behavior from silicon – ones that can naturally mimic synapses and neurons. Unfortunately, the competing design needs of artificial synapses and neurons mean that most materials that make good synaptors fail as neuristors, and vice versa. Only a handful of materials, most of them quantum materials, have the demonstrated ability to do both.”

The team relied on a recently discovered type of non-volatile memory which is driven by repeated partial temperature cycling through the insulator-to-metal transition. This memory was discovered in vanadium oxides.

Alexandre Zimmers, lead experimental scientist from Sorbonne University and École Supérieure de Physique et de Chimie Industrielles, Paris, explains, “Only a few quantum materials are good candidates for future neuromorphic devices, i.e., mimicking artificial synapses and neurons. For the first time, in one of them, vanadium dioxide, we can see optically what is changing in the material as it operates as an artificial synapse. We find that memory accumulates throughout the entirety of the sample, opening new opportunities on how and where to control this property.”

“The microscopic videos show that, surprisingly, the repeated advance and retreat of metal and insulator domains causes memory to be accumulated throughout the entirety of the sample, rather than only at the boundaries of domains,” explains Carlson. “The memory appears as shifts in the local temperature at which the material transitions from insulator to metal upon heating, or from metal to insulator upon cooling. We propose that these changes in the local transition temperature accumulate due to the preferential diffusion of point defects into the metallic domains that are interwoven through the insulator as the material is cycled partway through the transition.”

Now that the team has established that vanadium oxides are possible candidates for future neuromorphic devices, they plan to move forward in the next phase of their research.

“Now that we have established a way to see inside this neuromorphic material, we can locally tweak and observe the effects of, for example, ion bombardment on the material’s surface,” explains Zimmers. “This could allow us to guide the electrical current through specific regions in the sample where the memory effect is at its maximum. This has the potential to significantly enhance the synaptic behavior of this neuromorphic material.”

There’s a very interesting 16 mins. 52 secs. video embedded in the October 13, 2023 Purdue University news release. In an interview with Dr. Erica Carlson who hosts The Quantum Age website and video interviews on its YouTube Channel, Alexandre Zimmers takes you from an amusing phenomenon observed by 19th century scientists through the 20th century where it becomes of more interest as the nanscale phenonenon can be exploited (sonar, scanning tunneling microscopes, singing birthday cards, etc.) to the 21st century where we are integrating this new information into a quantum* material for neuromorphic hardware.

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

Spatially Distributed Ramp Reversal Memory in VO2 by Sayan Basak, Yuxin Sun, Melissa Alzate Banguero, Pavel Salev, Ivan K. Schuller, Lionel Aigouy, Erica W. Carlson, Alexandre Zimmers. Advanced Electronic Materials Volume 9, Issue 10 October 2023 2300085 DOI: https://doi.org/10.1002/aelm.202300085 First published: 10 July 2023

This paper is open access.

There’s a lot of research into neuromorphic hardware, here’s a sampling of some of my most recent posts on the topic,

There’s more, just use ‘neuromorphic hardware’ for your search term.

*’meta’ changed to ‘quantum’ on January 8, 2024.

Building Transdisciplinary Research Paths [for a] Sustainable & Inclusive Future, a December 14, 2022 science policy event

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I received (via email) a December 8, 2022 Canadian Science Policy Centre (CSPC) announcement about their various doings when this event, which seems a little short on information, caught my attention,

[Building Transdisciplinary Research Paths towards a more Sustainable and Inclusive Future]

Upcoming Virtual Event

With this workshop, Belmont Forum and IAI aim to open a collective reflection on the ideas and practices around ‘Transdisciplinarity’ (TD) to foster participatory knowledge production. Our goal is to create a safe environment for people to share their impressions about TD, as a form of experimental lab based on a culture of collaboration.

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This CSPC event page cleared up a few questions,

Building Transdisciplinary Research Paths towards a more Sustainable and Inclusive Future

Global environmental change and sustainability require engagement with civil society and wide participation to gain social legitimacy, also, it is necessary to open cooperation among different scientific disciplines, borderless collaboration, and collaborative learning processes, among other crucial issues.

Those efforts have been recurrently encompassed by the idea of ‘Transdisciplinarity’ (TD), which is a fairly new word and evolving concept. Several of those characteristics are daily practices in academic and non-academic communities, sometimes under different words or conceptions.

With this workshop, Belmont Forum and IAI [Inter-American Institute for Global Change Research?] aim to open a collective reflection on the ideas and practices around ‘Transdisciplinarity’ (TD) to foster participatory knowledge production. Our goal is to create a safe environment for people to share their impressions about TD, as a form of experimental lab based on a culture of collaboration.

Date: Dec 14 [2022]

Time: 3:00 pm – 4:00 pm EST

Website [Register here]: https://us02web.zoom.us/meeting/register/tZArcOCupj4rHdBbwhSUpVhpvPuou5kNlZId

For the curious, here’s more about the Belmont Forum from their About page, Note: Links have been removed,

Established in 2009, the Belmont Forum is a partnership of funding organizations, international science councils, and regional consortia committed to the advancement of transdisciplinary science. Forum operations are guided by the Belmont Challenge, a vision document that encourages:

International transdisciplinary research providing knowledge for understanding, mitigating and adapting to global environmental change.

Forum members and partner organizations work collaboratively to meet this Challenge by issuing international calls for proposals, committing to best practices for open data access, and providing transdisciplinary training.  To that end, the Belmont Forum is also working to enhance the broader capacity to conduct transnational environmental change research through its e-Infrastructure and Data Management initiative.

Since its establishment, the Forum has successfully led 19 calls for proposals, supporting 134 projects and more than 1,000 scientists and stakeholders, representing over 90 countries.  Themes addressed by CRAs have included Freshwater Security, Coastal Vulnerability, Food Security and Land Use Change, Climate Predictability and Inter-Regional Linkages, Biodiversity and Ecosystem Services, Arctic Observing and Science for Sustainability, and Mountains as Sentinels of Change.  New themes are developed through a scoping process and made available for proposals through the Belmont Forum website and its BF Grant Operations site.

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If you keep scrolling down the Bellmont Forum’s About page, you’ll find an impressive list of partners including the Natural Sciences and Engineering Research Council of Canada (NSERC).

I’m pretty sure IAI is Inter-American Institute for Global Change Research, given that two of the panelists come from that organization. Here’s more about the IAI from their About Us page, Note: Links have been removed,

Humans have affected practically all ecosystems on earth. Over the past 200 years, mankind’s emissions of greenhouse gases into the Earth’s atmosphere have changed its radiative properties and are causing a rise in global temperatures which is now modifying Earth system functions globally. As a result, the 21st-century is faced with environmental changes from local to global scales that require large efforts of mitigation and adaptation by societies and ecosystems. The causes and effects, problems and solutions of global change interlink biogeochemistry, Earth system functions and socio-economic conditions in increasingly complex ways. To guide efforts of mitigation and adaptation to global change and aid policy decisions, scientific knowledge now needs to be generated in broad transdisciplinary ways that address the needs of knowledge users and also provide profound understanding of complex socio-environmental systems.

To address these knowledge needs, 12 nations of the American continent came together in Montevideo, Uruguay, in 1992 to establish the Inter-American Institute for Global Change Research (IAI). The 12 governments, in the Declaration of Montevideo, called for the Institute to develop the best possible international coordination of scientific and economic research on the extent, causes, and consequences of global change in the Americas.

Sixteen governments signed the resulting Agreement Establishing the IAI which laid the  foundation for the IAI’s function as a regional intergovernmental organization that promotes interdisciplinary scientific research and capacity building to inform decision-makers on the continent and beyond. Since the establishment of the Agreement in 1992, 3 additional nations have acceded the treaty, and the IAI has now 19 Parties in the Americas, which come together once every year in the Conference of the Parties to monitor and direct the IAI’s activities.

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Now onto the best part, reading about the panelists (from CSPC event page, scroll down and click on the See bio button), Note: I have made some rough changes to the formatting so that the bios match each other more closely,

Dr. Lily House-Peters is Associate Professor in the Department of Geography at California State University, Long Beach. Dr. House-Peters is a broadly trained human-environment geographer with experience in qualitative and quantitative approaches to human dimensions of environmental change, water security, mining and extraction, and natural resource conservation policy. She has a decade of experience and expertise in transdisciplinary research for action-oriented solutions to global environmental change. She is currently part of a team creating a curriculum for global change researchers in the Americas focused on the drivers and barriers of effective transdisciplinary collaboration and processes of integration and convergence in diverse teams.

Dr. Gabriela Alonso Yanez, Associate Professor, Werklund School of Education University of Calgary. Learning and education in the context of sustainability and global change are the focus of my work. Over the last ten years, I have participated in several collaborative research projects with multiple aims, including building researchers’ and organizations’ capacity for collaboration and engaging networks that include knowledge keepers, local community members and academics in co-designing and co-producing solutions-oriented knowledge.

Marshalee Valentine, MSc, BTech. Marshalee Valentine is Co-founder and Vice President of the International Women’s Coffee Alliance Jamaica (IWCA), a charitable organization responsible for the development and implementation of social impact and community development projects geared towards improving the livelihoods of women along the coffee value chain in Jamaica. In addition, she also owns and operates a Quality, Food Safety and Environmental Management Systems Consultancy. Her areas of expertise include; Process improvement, technology and Innovation transfer methods, capacity building and community-based research.

With a background in Agriculture, she holds a Bachelor of Technology in Environmental Sciences and a Master’s Degree in Environmental Management. Marshalee offers a unique perspective for regional authenticity bringing deep sensibility to issues of gender, equity and inclusion, in particular related to GEC issues in small countries.

Fany Ramos Quispe, Science Technology and Policy Fellow, Inter-American Institute for Global Change Research. Fany Ramos Quispe holds a B.S. in Environmental Engineering from the Polytechnic Institute of Mexico, and an MSc. in Environmental Change and International Development from the University of Sheffield in the United Kingdom. She worked with a variety of private and public organizations at the national and international levels. She has experience on projects related to renewable energies, waste and water management, environmental education, climate change, and inter and transdisciplinary research, among others. After her postgraduate studies, she joined the Bolivian government mainly to support international affairs related to climate change at the Plurinational Authority of Mother Earth, afterwards, she joined the Centre for Social Research of the Vicepresidency as a Climate Change Specialist.

For several years now she combined academic and professional activities with side projects and activism for environmental and educational issues. She is a founder and former chair (2019-2020) of the environmental engineers’ society of La Paz and collaborates with different grassroots organizations.

Fany is a member of OWSD Bolivia [Organization for Women in Science for the Developing World {OWSD}] and current IAI Science, Technology and Policy fellow at the Belmont Forum.

Dr. Laila Sandroni, Science Technology and Policy Fellow, InterAmerican Institute for Global Change Research. Laila Sandroni is an Anthropologist and Geographer with experience in transdisciplinary research in social sciences. Her research interests lie in the field of transformations to sustainability and the role of different kinds of knowledge in defining the best paths to achieve biodiversity conservation and forest management. She has particular expertise in epistemology, power-knowledge relations, and evidence-based policy in environmental issues.

Laila has a longstanding involvement with stakeholders working on different paths towards biodiversity conservation. She has experience in transdisciplinary science and participatory methodologies to encompass plural knowledge on the management of protected areas in tropical rainforests in Brazil.

This event seems to be free and it looks like an exciting panel.

Unexpectedly, they don’t have a male participant amongst the panelists. Outside of groups that are explicitly exploring women’s issues in the sciences, I’ve never before seen a science panel composed entirely of women. As well, the organizers seem to have broadened the range of geographies represented at a Canadian event with a researcher who has experience in Brazil, another with experience in Bolivia, a panelist who works in Jamaica, and two academics who focus on the Americas (South, Central, and North).

Transdisciplinarity and other disciplinarities

There are so many: crossdisciplinarity, multidisciplinarity, interdisciplinarity, and transdisciplinarity, that the whole subject gets a little confusing. Jeffrey Evans’ July 29, 2014 post on the Purdue University (Indiana, US) Polytechnic Institute blog answers questions about three (trans-, multi-, and inter-) of the disciplinarities,

Learners entering the Polytechnic Incubator’s new program will no doubt hear the terms “multidisciplinary (arity)” and “interdisciplinary (arity)” thrown about somewhat indiscriminately. Interestingly, we administrators, faculty, and staff also use these terms rather loosely and too often without carefully considering their underlying meaning.

Recently I gave a talk about yet another disciplinarity: “transdisciplinarity.” The purpose of the talk was to share with colleagues from around the country the opportunities and challenges associated with developing a truly transdisciplinary environment in an institution of higher education. During a meeting after I returned, the terms “multi”, “inter”, and “trans” disciplinary(arity) were being thrown around, and it was clear that the meanings of the terms were not clearly understood. Hopefully this blog entry will help shed some light on the subject. …

First, I am not an expert in the various “disciplinarities.” The ideas and descriptions that follow are not mine and have been around for decades, with many books and articles written on the subject. Yet my Polytechnic Incubator colleagues and I believe in these ideas and in their advantages and constraints, and they serve to motivate the design of the Incubator’s transdisciplinary environment.

In 1992, Hugh G. Petrie wrote a seminal article1 for the American Educational Research Association that articulates the meaning of these ideas. Later, in 2007, A. Wendy Russell, Fern Wickson, and Anna L. Carew contributed an article2 discussing the context of transdisciplinarity, prescriptions for transdisciplinary knowledge production and the contradictions that arise, and suggestions for universities to develop capacity for transdisciplinarity, rather than simply investing in knowledge “products.” …

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Multidisciplinarity

Petrie1 discusses multidisciplinarity as “the idea of a number of disciplines working together on a problem, an educational program, or a research study. The effect is additive rather than integrative. The project is usually short-lived, and there is seldom any long-term change in the ways in which the disciplinary participants in a multidisciplinary project view their own work.”

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Interdisciplinarity

Moving to extend the idea of multidisciplinarity to include more integration, rather than just addition, Petrie writes about interdisciplinarity in this way:

“Interdisciplinary research or education typically refers to those situations in which the integration of the work goes beyond the mere concatenation of disciplinary contributions. Some key elements of disciplinarians’ use of their concepts and tools change. There is a level of integration. Interdisciplinary subjects in university curricula such as physical chemistry or social psychology, which by now have, perhaps,themselves become disciplines, are good examples. A newer one might be the field of immunopharmocology, which combines the work of bacteriology, chemistry, physiology, and immunology. Another instance of interdisciplinarity might be the emerging notion of a core curriculum that goes considerably beyond simple distribution requirements in undergraduate programs of general education.”

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Transdisciplinarity

Petrie1 writes about transdisciplinarity in this way: “The notion of transdisciplinarity exemplifies one of the historically important driving forces in the area of interdisciplinarity, namely, the idea of the desirability of the integration of knowledge into some meaningful whole. The best example, perhaps, of the drive to transdisciplinarity might be the early discussions of general systems theory when it was being held forward as a grand synthesis of knowledge. Marxism, structuralism, and feminist theory are sometimes cited as examples of a transdisciplinary approach. Essentially, this kind of interdisciplinarity represents the impetus to integrate knowledge, and, hence, is often characterized by a denigration and repudiation of the disciplines and disciplinary work as essentially fragmented and incomplete.

…

It seems multidisciplinarity could be viewed as an ad hoc approach whereas interdsciplinarity and transdisciplinarity are intimately related with ‘inter-‘ being a subset of ‘trans-‘.

I think that’s enough for now. Should I ever stumble across a definition for crossdisciplinarity, I will endeavour to add it here.

An ‘artificial brain’ and life-long learning

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Talk of artificial brains (also known as, brainlike computing or neuromorphic computing) usually turns to memory fairly quickly. This February 3, 2022 news item on ScienceDaily does too although the focus is on how memory and forgetting affect the ability to learn,

When the human brain learns something new, it adapts. But when artificial intelligence learns something new, it tends to forget information it already learned.

As companies use more and more data to improve how AI recognizes images, learns languages and carries out other complex tasks, a paper publishing in Science this week shows a way that computer chips could dynamically rewire themselves to take in new data like the brain does, helping AI to keep learning over time.

“The brains of living beings can continuously learn throughout their lifespan. We have now created an artificial platform for machines to learn throughout their lifespan,” said Shriram Ramanathan, a professor in Purdue University’s [Indiana, US] School of Materials Engineering who specializes in discovering how materials could mimic the brain to improve computing.

Unlike the brain, which constantly forms new connections between neurons to enable learning, the circuits on a computer chip don’t change. A circuit that a machine has been using for years isn’t any different than the circuit that was originally built for the machine in a factory.

This is a problem for making AI more portable, such as for autonomous vehicles or robots in space that would have to make decisions on their own in isolated environments. If AI could be embedded directly into hardware rather than just running on software as AI typically does, these machines would be able to operate more efficiently.

A February 3, 2022 Purdue University news release (also on EurekAlert), which originated the news item, provides more technical detail about the work (Note: Links have been removed),

In this study, Ramanathan and his team built a new piece of hardware that can be reprogrammed on demand through electrical pulses. Ramanathan believes that this adaptability would allow the device to take on all of the functions that are necessary to build a brain-inspired computer.

“If we want to build a computer or a machine that is inspired by the brain, then correspondingly, we want to have the ability to continuously program, reprogram and change the chip,” Ramanathan said.

Toward building a brain in chip form

The hardware is a small, rectangular device made of a material called perovskite nickelate,  which is very sensitive to hydrogen. Applying electrical pulses at different voltages allows the device to shuffle a concentration of hydrogen ions in a matter of nanoseconds, creating states that the researchers found could be mapped out to corresponding functions in the brain.

When the device has more hydrogen near its center, for example, it can act as a neuron, a single nerve cell. With less hydrogen at that location, the device serves as a synapse, a connection between neurons, which is what the brain uses to store memory in complex neural circuits.

Through simulations of the experimental data, the Purdue team’s collaborators at Santa Clara University and Portland State University showed that the internal physics of this device creates a dynamic structure for an artificial neural network that is able to more efficiently recognize electrocardiogram patterns and digits compared to static networks. This neural network uses “reservoir computing,” which explains how different parts of a brain communicate and transfer information.

Researchers from The Pennsylvania State University also demonstrated in this study that as new problems are presented, a dynamic network can “pick and choose” which circuits are the best fit for addressing those problems.

Since the team was able to build the device using standard semiconductor-compatible fabrication techniques and operate the device at room temperature, Ramanathan believes that this technique can be readily adopted by the semiconductor industry.

“We demonstrated that this device is very robust,” said Michael Park, a Purdue Ph.D. student in materials engineering. “After programming the device over a million cycles, the reconfiguration of all functions is remarkably reproducible.”

The researchers are working to demonstrate these concepts on large-scale test chips that would be used to build a brain-inspired computer.

Experiments at Purdue were conducted at the FLEX Lab and Birck Nanotechnology Center of Purdue’s Discovery Park. The team’s collaborators at Argonne National Laboratory, the University of Illinois, Brookhaven National Laboratory and the University of Georgia conducted measurements of the device’s properties.

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

Reconfigurable perovskite nickelate electronics for artificial intelligence by Hai-Tian Zhang, Tae Joon Park, A. N. M. Nafiul Islam, Dat S. J. Tran, Sukriti Manna, Qi Wang, Sandip Mondal, Haoming Yu, Suvo Banik, Shaobo Cheng, Hua Zhou, Sampath Gamage, Sayantan Mahapatra, Yimei Zhu, Yohannes Abate, Nan Jiang, Subramanian K. R. S. Sankaranarayanan, Abhronil Sengupta, Christof Teuscher, Shriram Ramanathan. Science • 3 Feb 2022 • Vol 375, Issue 6580 • pp. 533-539 • DOI: 10.1126/science.abj7943

This paper is behind a paywall.

Neuromorphic (brainlike) computing inspired by sea slugs

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The sea slug has taught neuroscientists the intelligence features that any creature in the animal kingdom needs to survive. Now, the sea slug is teaching artificial intelligence how to use those strategies. Pictured: Aplysia californica. (Image by NOAA Monterey Bay National Marine Sanctuary/Chad King.)

I don’t think I’ve ever seen a picture of a sea slug before. Its appearance reminds me of its terrestrial cousin.

As for some of the latest news on brainlike computing, a December 7, 2021 news item on Nanowerk makes an announcement from the Argonne National Laboratory (a US Department of Energy laboratory; Note: Links have been removed),

A team of scientists has discovered a new material that points the way toward more efficient artificial intelligence hardware for everything from self-driving cars to surgical robots.

For artificial intelligence (AI) to get any smarter, it needs first to be as intelligent as one of the simplest creatures in the animal kingdom: the sea slug.

A new study has found that a material can mimic the sea slug’s most essential intelligence features. The discovery is a step toward building hardware that could help make AI more efficient and reliable for technology ranging from self-driving cars and surgical robots to social media algorithms.

The study, published in the Proceedings of the National Academy of Sciences [PNAS] (“Neuromorphic learning with Mott insulator NiO”), was conducted by a team of researchers from Purdue University, Rutgers University, the University of Georgia and the U.S. Department of Energy’s (DOE) Argonne National Laboratory. The team used the resources of the Advanced Photon Source (APS), a DOE Office of Science user facility at Argonne.

A December 6, 2021 Argonne National Laboratory news release (also on EurekAlert) by Kayla Wiles and Andre Salles, which originated the news item, provides more detail,

“Through studying sea slugs, neuroscientists discovered the hallmarks of intelligence that are fundamental to any organism’s survival,” said Shriram Ramanathan, a Purdue professor of Materials Engineering. ​“We want to take advantage of that mature intelligence in animals to accelerate the development of AI.”

Two main signs of intelligence that neuroscientists have learned from sea slugs are habituation and sensitization. Habituation is getting used to a stimulus over time, such as tuning out noises when driving the same route to work every day. Sensitization is the opposite — it’s reacting strongly to a new stimulus, like avoiding bad food from a restaurant.

AI has a really hard time learning and storing new information without overwriting information it has already learned and stored, a problem that researchers studying brain-inspired computing call the ​“stability-plasticity dilemma.” Habituation would allow AI to ​“forget” unneeded information (achieving more stability) while sensitization could help with retaining new and important information (enabling plasticity).

In this study, the researchers found a way to demonstrate both habituation and sensitization in nickel oxide, a quantum material. Quantum materials are engineered to take advantage of features available only at nature’s smallest scales, and useful for information processing. If a quantum material could reliably mimic these forms of learning, then it may be possible to build AI directly into hardware. And if AI could operate both through hardware and software, it might be able to perform more complex tasks using less energy.

“We basically emulated experiments done on sea slugs in quantum materials toward understanding how these materials can be of interest for AI,” Ramanathan said.

Neuroscience studies have shown that the sea slug demonstrates habituation when it stops withdrawing its gill as much in response to tapping. But an electric shock to its tail causes its gill to withdraw much more dramatically, showing sensitization.

For nickel oxide, the equivalent of a ​“gill withdrawal” is an increased change in electrical resistance. The researchers found that repeatedly exposing the material to hydrogen gas causes nickel oxide’s change in electrical resistance to decrease over time, but introducing a new stimulus like ozone greatly increases the change in electrical resistance.

Ramanathan and his colleagues used two experimental stations at the APS to test this theory, using X-ray absorption spectroscopy. A sample of nickel oxide was exposed to hydrogen and oxygen, and the ultrabright X-rays of the APS were used to see changes in the material at the atomic level over time.

“Nickel oxide is a relatively simple material,” said Argonne physicist Hua Zhou, a co-author on the paper who worked with the team at beamline 33-ID. ​“The goal was to use something easy to manufacture, and see if it would mimic this behavior. We looked at whether the material gained or lost a single electron after exposure to the gas.”

The research team also conducted scans at beamline 29-ID, which uses softer X-rays to probe different energy ranges. While the harder X-rays of 33-ID are more sensitive to the ​“core” electrons, those closer to the nucleus of the nickel oxide’s atoms, the softer X-rays can more readily observe the electrons on the outer shell. These are the electrons that define whether a material is conductive or resistive to electricity.

“We’re very sensitive to the change of resistivity in these samples,” said Argonne physicist Fanny Rodolakis, a co-author on the paper who led the work at beamline 29-ID. ​“We can directly probe how the electronic states of oxygen and nickel evolve under different treatments.”

Physicist Zhan Zhang and postdoctoral researcher Hui Cao, both of Argonne, contributed to the work, and are listed as co-authors on the paper. Zhang said the APS is well suited for research like this, due to its bright beam that can be tuned over different energy ranges.

For practical use of quantum materials as AI hardware, researchers will need to figure out how to apply habituation and sensitization in large-scale systems. They also would have to determine how a material could respond to stimuli while integrated into a computer chip.

This study is a starting place for guiding those next steps, the researchers said. Meanwhile, the APS is undergoing a massive upgrade that will not only increase the brightness of its beams by up to 500 times, but will allow for those beams to be focused much smaller than they are today. And this, Zhou said, will prove useful once this technology does find its way into electronic devices.

“If we want to test the properties of microelectronics,” he said, ​“the smaller beam that the upgraded APS will give us will be essential.”

In addition to the experiments performed at Purdue and Argonne, a team at Rutgers University performed detailed theory calculations to understand what was happening within nickel oxide at a microscopic level to mimic the sea slug’s intelligence features. The University of Georgia measured conductivity to further analyze the material’s behavior.

A version of this story was originally published by Purdue University

About the Advanced Photon Source

The U. S. Department of Energy Office of Science’s Advanced Photon Source (APS) at Argonne National Laboratory is one of the world’s most productive X-ray light source facilities. The APS provides high-brightness X-ray beams to a diverse community of researchers in materials science, chemistry, condensed matter physics, the life and environmental sciences, and applied research. These X-rays are ideally suited for explorations of materials and biological structures; elemental distribution; chemical, magnetic, electronic states; and a wide range of technologically important engineering systems from batteries to fuel injector sprays, all of which are the foundations of our nation’s economic, technological, and physical well-being. Each year, more than 5,000 researchers use the APS to produce over 2,000 publications detailing impactful discoveries, and solve more vital biological protein structures than users of any other X-ray light source research facility. APS scientists and engineers innovate technology that is at the heart of advancing accelerator and light-source operations. This includes the insertion devices that produce extreme-brightness X-rays prized by researchers, lenses that focus the X-rays down to a few nanometers, instrumentation that maximizes the way the X-rays interact with samples being studied, and software that gathers and manages the massive quantity of data resulting from discovery research at the APS.

This research used resources of the Advanced Photon Source, a U.S. DOE Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.

Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation’s first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America’s scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science.

The U.S. Department of Energy’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit https://​ener​gy​.gov/​s​c​ience.

You can find the September 24, 2021 Purdue University story, Taking lessons from a sea slug, study points to better hardware for artificial intelligence here.

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

Neuromorphic learning with Mott insulator NiO by Zhen Zhang, Sandip Mondal, Subhasish Mandal, Jason M. Allred, Neda Alsadat Aghamiri, Alireza Fali, Zhan Zhang, Hua Zhou, Hui Cao, Fanny Rodolakis, Jessica L. McChesney, Qi Wang, Yifei Sun, Yohannes Abate, Kaushik Roy, Karin M. Rabe, and Shriram Ramanathan. PNAS September 28, 2021 118 (39) e2017239118 DOI: https://doi.org/10.1073/pnas.2017239118

This paper is behind a paywall.

Pandemic science breakthroughs: combining supercomputing materials with specialized oxides to mimic brain function

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This breakthrough in neuromorphic (brainlike) computing is being attributed to the pandemic (COVID-19) according to a September 3, 2021 news item on phys.org,

Isaac Newton’s groundbreaking scientific productivity while isolated from the spread of bubonic plague is legendary. University of California San Diego physicists can now claim a stake in the annals of pandemic-driven science.

A team of UC San Diego [University of California San Diego] researchers and colleagues at Purdue University have now simulated the foundation of new types of artificial intelligence computing devices that mimic brain functions, an achievement that resulted from the COVID-19 pandemic lockdown. By combining new supercomputing materials with specialized oxides, the researchers successfully demonstrated the backbone of networks of circuits and devices that mirror the connectivity of neurons and synapses in biologically based neural networks.

A September 3, 2021 UC San Diego news release by Mario Aguilera, which originated the news item, delves further into the topic of neuromorphic computing,

As bandwidth demands on today’s computers and other devices reach their technological limit, scientists are working towards a future in which new materials can be orchestrated to mimic the speed and precision of animal-like nervous systems. Neuromorphic computing based on quantum materials, which display quantum-mechanics-based properties, allow scientists the ability to move beyond the limits of traditional semiconductor materials. This advanced versatility opens the door to new-age devices that are far more flexible with lower energy demands than today’s devices. Some of these efforts are being led by Department of Physics Assistant Professor Alex Frañó and other researchers in UC San Diego’s Quantum Materials for Energy Efficient Neuromorphic Computing (Q-MEEN-C), a Department of Energy-supported Energy Frontier Research Center.

“In the past 50 years we’ve seen incredible technological achievements that resulted in computers that were progressively smaller and faster—but even these devices have limits for data storage and energy consumption,” said Frañó, who served as one of the PNAS paper’s authors, along with former UC San Diego chancellor, UC president and physicist Robert Dynes. “Neuromorphic computing is inspired by the emergent processes of the millions of neurons, axons and dendrites that are connected all over our body in an extremely complex nervous system.”

As experimental physicists, Frañó and Dynes are typically busy in their laboratories using state-of-the-art instruments to explore new materials. But with the onset of the pandemic, Frañó and his colleagues were forced into isolation with concerns about how they would keep their research moving forward. They eventually came to the realization that they could advance their science from the perspective of simulations of quantum materials.

“This is a pandemic paper,” said Frañó. “My co-authors and I decided to study this issue from a more theoretical perspective so we sat down and started having weekly (Zoom-based) meetings. Eventually the idea developed and took off.”

The researchers’ innovation was based on joining two types of quantum substances—superconducting materials based on copper oxide and metal insulator transition materials that are based on nickel oxide. They created basic “loop devices” that could be precisely controlled at the nano-scale with helium and hydrogen, reflecting the way neurons and synapses are connected. Adding more of these devices that link and exchange information with each other, the simulations showed that eventually they would allow the creation of an array of networked devices that display emergent properties like an animal’s brain.

Like the brain, neuromorphic devices are being designed to enhance connections that are more important than others, similar to the way synapses weigh more important messages than others.

“It’s surprising that when you start to put in more loops, you start to see behavior that you did not expect,” said Frañó. “From this paper we can imagine doing this with six, 20 or a hundred of these devices—then it gets exponentially rich from there. Ultimately the goal is to create a very large and complex network of these devices that will have the ability to learn and adapt.”

With eased pandemic restrictions, Frañó and his colleagues are back in the laboratory, testing the theoretical simulations described in the PNAS [Proceedings of the National Academy of Sciences] paper with real-world instruments.

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

Low-temperature emergent neuromorphic networks with correlated oxide devices by Uday S. Goteti, Ivan A. Zaluzhnyy, Shriram Ramanathan, Robert C. Dynes, and Alex Frano. PNAS August 31, 2021 118 (35) e2103934118; DOI: https://doi.org/10.1073/pnas.2103934118

This paper is open access.

The coolest paint

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It’s the ‘est’ of it all. The coolest, the whitest, the blackest … Scientists and artists are both pursuing the ‘est’. (More about the pursuit later in this posting.)

In this case, scientists have developed the coolest, whitest paint yet. From an April 16, 2021 news item on Nanowerk,

In an effort to curb global warming, Purdue University engineers have created the whitest paint yet. Coating buildings with this paint may one day cool them off enough to reduce the need for air conditioning, the researchers say.

In October [2020], the team created an ultra-white paint that pushed limits on how white paint can be. Now they’ve outdone that. The newer paint not only is whiter but also can keep surfaces cooler than the formulation that the researchers had previously demonstrated.

“If you were to use this paint to cover a roof area of about 1,000 square feet, we estimate that you could get a cooling power of 10 kilowatts. That’s more powerful than the central air conditioners used by most houses,” said Xiulin Ruan, a Purdue professor of mechanical engineering.

…

Caption: Xiulin Ruan, a Purdue University professor of mechanical engineering, holds up his lab’s sample of the whitest paint on record. Credit: Purdue University/Jared Pike

This is nicely done. Researcher Xiulin Ruan is standing close to a structure that could be said to resemble the sun while in shirtsleeves and sunglasses and holding up a sample of his whitest paint in April (not usually a warm month in Indiana).

An April 15, 2021 Purdue University news release (also on EurkeAlert), which originated the news item, provides more detail about the work and hints about its commercial applications both civilian and military,

The researchers believe that this white may be the closest equivalent of the blackest black, “Vantablack,” [emphasis mine; see comments later in this post] which absorbs up to 99.9% of visible light. The new whitest paint formulation reflects up to 98.1% of sunlight – compared with the 95.5% of sunlight reflected by the researchers’ previous ultra-white paint – and sends infrared heat away from a surface at the same time.

Typical commercial white paint gets warmer rather than cooler. Paints on the market that are designed to reject heat reflect only 80%-90% of sunlight and can’t make surfaces cooler than their surroundings.

The team’s research paper showing how the paint works publishes Thursday (April 15 [2021]) as the cover of the journal ACS Applied Materials & Interfaces.

What makes the whitest paint so white

Two features give the paint its extreme whiteness. One is the paint’s very high concentration of a chemical compound called barium sulfate [emphasis mine] which is also used to make photo paper and cosmetics white.

“We looked at various commercial products, basically anything that’s white,” said Xiangyu Li, a postdoctoral researcher at the Massachusetts Institute of Technology who worked on this project as a Purdue Ph.D. student in Ruan’s lab. “We found that using barium sulfate, you can theoretically make things really, really reflective, which means that they’re really, really white.”

The second feature is that the barium sulfate particles are all different sizes in the paint. How much each particle scatters light depends on its size, so a wider range of particle sizes allows the paint to scatter more of the light spectrum from the sun.

“A high concentration of particles that are also different sizes gives the paint the broadest spectral scattering, which contributes to the highest reflectance,” said Joseph Peoples, a Purdue Ph.D. student in mechanical engineering.

There is a little bit of room to make the paint whiter, but not much without compromising the paint.”Although a higher particle concentration is better for making something white, you can’t increase the concentration too much. The higher the concentration, the easier it is for the paint to break or peel off,” Li said.

How the whitest paint is also the coolest

The paint’s whiteness also means that the paint is the coolest on record. Using high-accuracy temperature reading equipment called thermocouples, the researchers demonstrated outdoors that the paint can keep surfaces 19 degrees Fahrenheit cooler than their ambient surroundings at night. It can also cool surfaces 8 degrees Fahrenheit below their surroundings under strong sunlight during noon hours.

The paint’s solar reflectance is so effective, it even worked in the middle of winter. During an outdoor test with an ambient temperature of 43 degrees Fahrenheit, the paint still managed to lower the sample temperature by 18 degrees Fahrenheit.

This white paint is the result of six years of research building on attempts going back to the 1970s to develop radiative cooling paint as a feasible alternative to traditional air conditioners.

Ruan’s lab had considered over 100 different materials, narrowed them down to 10 and tested about 50 different formulations for each material. Their previous whitest paint was a formulation made of calcium carbonate, an earth-abundant compound commonly found in rocks and seashells.

The researchers showed in their study that like commercial paint, their barium sulfate-based paint can potentially handle outdoor conditions. The technique that the researchers used to create the paint also is compatible with the commercial paint fabrication process.

Patent applications for this paint formulation have been filed through the Purdue Research Foundation Office of Technology Commercialization. This research was supported by the Cooling Technologies Research Center at Purdue University and the Air Force Office of Scientific Research [emphasis mine] through the Defense University Research Instrumentation Program (Grant No.427 FA9550-17-1-0368). The research was performed at Purdue’s FLEX Lab and Ray W. Herrick Laboratories and the Birck Nanotechnology Center of Purdue’s Discovery Park.

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

Ultrawhite BaSO4 Paints and Films for Remarkable Daytime Subambient Radiative Cooling by Xiangyu Li, Joseph Peoples, Peiyan Yao, and Xiulin Ruan. ACS Appl. Mater. Interfaces 2021, XXXX, XXX, XXX-XXX DOI: https://doi.org/10.1021/acsami.1c02368 Publication Date:April 15, 2021 © 2021 American Chemical Society

This paper is behind a paywall.

Vantablack and the ongoing ‘est’ of blackest

Vantablack’s 99.9% light absorption no longer qualifies it for the ‘blackest black’. A newer standard for the ‘blackest black’ was set by the US National Institute of Standards and Technology at 99.99% light absorption with its N.I.S.T. ultra-black in 2019, although that too seems to have been bested.

I have three postings covering the Vantablack and blackest black story,

The third posting (December 2019) provides a brief summary of the story along with what was the latest from the US National Institute of Standards and Technology. There’s also a little bit about the ‘The Redemption of Vanity’ an art piece demonstrating the blackest black material from the Massachusetts Institute of Technology, which they state has 99.995% (at least) absorption of light.

From a science perspective, the blackest black would be useful for space exploration.

I am surprised there doesn’t seem to have been an artistic rush to work with the whitest white. That impression may be due to the fact that the feuds get more attention than quiet work.

Dark side to the whitest white?

Andrew Parnell, research fellow in physics and astronomy at the University of Sheffield (UK), mentions a downside to obtaining the material needed to produce this cooling white paint in a June 10, 2021 essay on The Conversation (h/t Fast Company), Note: Links have been removed,

… this whiter-than-white paint has a darker side. The energy required to dig up raw barite ore to produce and process the barium sulphite that makes up nearly 60% of the paint means it has a huge carbon footprint. And using the paint widely would mean a dramatic increase in the mining of barium.

Parnell ends his essay with this (Note: Links have been removed),

Barium sulphite-based paint is just one way to improve the reflectivity of buildings. I’ve spent the last few years researching the colour white in the natural world, from white surfaces to white animals. Animal hairs, feathers and butterfly wings provide different examples of how nature regulates temperature within a structure. Mimicking these natural techniques could help to keep our cities cooler with less cost to the environment.

The wings of one intensely white beetle species called Lepidiota stigma appear a strikingly bright white thanks to nanostructures in their scales, which are very good at scattering incoming light. This natural light-scattering property can be used to design even better paints: for example, by using recycled plastic to create white paint containing similar nanostructures with a far lower carbon footprint. When it comes to taking inspiration from nature, the sky’s the limit.