Tag Archives: Massachusetts Institute of Technology (MIT)

Super-black wood from the University of British Columbia (UBC)

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The researchers have developed prototype watches and jewelry using the new super-black wood. Photo credit: UBC Forestry/Ally Penders

Generally stories about very black materials will mention carbon nanotubes but not this time. A July 30, 2024 University of British Columbia (UBC) news release (also on EurekAlert and received via email) announces the discovery of a technique for making super-black wood,

Thanks to an accidental discovery, researchers at the University of British Columbia have created a new super-black material that absorbs almost all light, opening potential applications in fine jewelry, solar cells and precision optical devices. 

Professor Philip Evans and PhD student Kenny Cheng were experimenting with high-energy plasma to make wood more water-repellent. However, when they applied the technique to the cut ends of wood cells, the surfaces turned extremely black. 

Measurements by Texas A&M University’s department of physics and astronomy confirmed that the material reflected less than one per cent of visible light, absorbing almost all the light that struck it. 

Instead of discarding this accidental finding, the team decided to shift their focus to designing super-black materials, contributing a new approach to the search for the darkest materials on Earth.

“Ultra-black or super-black material can absorb more than 99 per cent of the light that strikes it – significantly more so than normal black paint, which absorbs about 97.5 per cent of light,” explained Dr. Evans, a professor in the faculty of forestry and BC Leadership Chair in Advanced Forest Products Manufacturing Technology.

Super-black materials are increasingly sought after in astronomy, where ultra-black coatings on devices help reduce stray light and improve image clarity. Super-black coatings can enhance the efficiency of solar cells. They are also used in making art pieces and luxury consumer items like watches.

The researchers have developed prototype commercial products using their super-black wood, initially focusing on watches and jewelry, with plans to explore other commercial applications in the future.

Wonder wood

The team named and trademarked their discovery Nxylon (niks-uh-lon), after Nyx, the Greek goddess of the night, and xylon, the Greek word for wood. 

Most surprisingly, Nxylon remains black even when coated with an alloy, such as the gold coating applied to the wood to make it electrically conductive enough to be viewed and studied using an electron microscope. This is because Nxylon’s structure inherently prevents light from escaping rather than depending on black pigments.

The UBC team have demonstrated that Nxylon can replace expensive and rare black woods like ebony and rosewood for watch faces, and it can be used in jewelry to replace the black gemstone onyx.

“Nxylon’s composition combines the benefits of natural materials with unique structural features, making it lightweight, stiff and easy to cut into intricate shapes,” said Dr. Evans.

Made from basswood, a tree widely found in North America and valued for hand carving, boxes, shutters and musical instruments, Nxylon can also use other types of wood such as European lime wood.

Breathing new life into forestry

Dr. Evans and his colleagues plan to launch a startup, Nxylon Corporation of Canada, to scale up applications of Nxylon in collaboration with jewellers, artists and tech product designers. They also plan to develop a commercial-scale plasma reactor to produce larger super-black wood samples suitable for non-reflective ceiling and wall tiles. 

“Nxylon can be made from sustainable and renewable materials widely found in North America and Europe, leading to new applications for wood. The wood industry in B.C. is often seen as a sunset industry focused on commodity products—our research demonstrates its great untapped potential,” said Dr. Evans.

Other researchers who contributed to this work include Vickie Ma, Dengcheng Feng and Sara Xu (all from UBC’s faculty of forestry); Luke Schmidt (Texas A&M); and Mick Turner (The Australian National University).

Here’s a link to and a citation for the paper (and hat’s off to the writers for an accessible introduction),

Super-Black Material Created by Plasma Etching Wood by Kenneth J. Cheng, Dengcheng Feng, Luke M. Schmidt, Michael Turner, Philip D. Evans. Advanced Sustainable Systems DOI: https://doi.org/10.1002/adsu.202400184 First published: 16 June 2024

This paper is open access.

I can’t resist; this is such a good introduction, keeping in mind it’s written for an academic journal, from Super-Black Material Created by Plasma Etching Wood.

Super-black materials have very low reflectivity due to structural absorption of light.[1] They are attracting considerable scientific and industrial attention because of their important applications in many fields: astronomy,[2, 3] photovoltaics,[4, 5] and optical science,[6] among others. In these applications, super-black materials minimize unwanted reflection of light enabling devices to operate more accurately or efficiently.[6] In other fields, for example art and design, the attraction of super-black materials lies in their ability to create bizarre visual effects because of huge contrast between black and adjacent colored objects or surfaces.[7] This artistic application of super-black materials is analogous to the juxtaposition of super-black and brightly colored courtship display patches in birds and peacock spiders.[8, 9] In birds, super-black patches have been defined as those having less than 2% directional reflectance at normal incidence.[8] Reflectance values of super-black patches in 32 bird species ranged from 0.045 to 1.97% with an average of 0.94% (300–700 nm).[8] Other studies have associated super-blackness with reflectance values of 1%[10] or 0.5%.[3] Far lower reflectance values have been achieved with materials containing aligned carbon nanotubes (CNT), for example a low-density CNT array (0.045%),[11] the coating Vantablack (0.035%)[7] and a CNT-metal foil (0.005%).[12] The current holder of the “record” for a low reflectivity material (<0.0002%) is an ion-track micro-textured polymer with anti-backscatter matrix.[13]

The low reflectivity of materials such as Vantablack is due to the high absorption of light by graphene and the ability of vertical arrays of CNT to lower surface reflection.[6, 7] In the case of a low-density CNT array, its low reflectivity was ascribed to its random surface profile and presence of a loose network of entangled nanotubes, in addition to vertically oriented nanotubes.[11] Other structures can also be used to reduce reflectivity of synthetic materials including nanopores, and microcavities.[6] Even more diverse structures are found in natural super-black materials, including complex barbule microstructures in birds,[1] cuticular micro-lens arrays in peacock spiders,[9] and polydisperse honeycomb configurations in the wings of butterflies.[14] The structural features of butterfly wings have been used as biomimetic models to create super-black polymer films.[4, 10] This biomimetic route to creating super-black materials has the advantages that “the films are thinner than known alternatives and can be fabricated at lower temperatures via plasma-enhanced chemical vapor deposition, instead of being grown from CNT.”[4, 14]

Biomimicry of nature’s structural material par excellence, wood, is being used to create lightweight stiff and tough composites,[15, 16] but wood is not a model for the creation of super-black materials because even the darkest woods such as ebony (Diospyros spp.) or African blackwood (Dalbergia melanoxylon Guill. & Perr.) lack structural features that reduce reflectivity. Nevertheless, there is interest in using wood in applications where blackness is advantageous such as solar steam generation and desalination of water,[17-20] because wood is widely available, inexpensive, sustainable and can be fabricated into panels and objects. In these applications, wood is carbonized and retains its porous microstructure creating a black material with reflectivity of 3%.[18] The creation of additional porosity by micro-drilling the wood prior to carbonization further reduced reflectivity to 2%.[18] We serendipitously created a super-black wood during undirected investigations into the use of plasma etching to “machine” novel microstructures at basswood (Tilia americana L.) surfaces. We called this material Nxylon, a neologism created from Nyx (Greek goddess of the night) and xylon (Greek for wood materials). One of us published the reflectivity data for Nxylon in 2020.[21] Here we report on the structural features responsible for the super-blackness of Nxylon, describe how it is made and discuss its possible practical uses. During the preparation of this manuscript, we became aware of a novel approach to creating super-black wood involving high temperature carbonization of delignified balsa wood (Ochroma pyramidale (Cav. ex Lam.) Urb.).[22] This material is produced using “mature processing technologies” and can be used to create solid wood products with complex geometries. The surface plasma process we describe is liquid free, generates little waste and is more suited for the creation of super-black veneer which can be used on a small scale to manufacture luxury consumer products. Therein lies the novelty and significance of our work.

…

The most comprehensive piece I’ve published on the topic of the ‘really, really black’ is in a December 4, 2019 posting, “More of the ‘blackest black’.” At that point, some new work on creating the blackest black (up to 99.99% and 99.995% light absorption, respectively) had come from the US National Institute of Standards and Technology (NIST) and the Massachusetts Institute of Technology (MIT). I also included the latest about an artistic feud over Vantablack (mentioned in the paper’s introduction) and its 99.8% light absorption and provided a link back to my earliest stories on Vantablack.

Sound-suppressing silk

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I keep telling a friend that noise will be the ‘new smoking’; i.e., there will be more rules and people will demand enforcement. She doesn’t agree, vociferously so. With the mounting research into the effects that noise has on health and on longevity, it doesn’t matter if I win the ‘argument’, I’m just happy to see research dedicated to mitigating noise levels. From a May 7, 2024 news item on ScienceDaily,

We are living in a very noisy world. From the hum of traffic outside your window to the next-door neighbor’s blaring TV to sounds from a co-worker’s cubicle, unwanted noise remains a resounding problem. [nice bit of wordplay]

Caption: The fabric can suppress sound by generating sound waves that interfere with an unwanted noise to cancel it out (as seen in figure C) or by being held still to suppress vibrations that are key to the transmission of sound (as seen in figure D). Credit: Courtesy of Yoel Fink and Grace (Noel) Yang and Massachusetts Institute of Technology (MIT)

A May 7, 2024 Massachusetts Institute of Technology (MIT) news release (also on EurekAlert), which originated the news item, describes how a surprising material, silk, can be used for suppressing sound, Note: Links have been removed,

To cut through the din, an interdisciplinary collaboration of researchers from MIT and elsewhere developed a sound-suppressing silk fabric that could be used to create quiet spaces. 

The fabric, which is barely thicker than a human hair, contains a special fiber that vibrates when a voltage is applied to it. The researchers leveraged those vibrations to suppress sound in two different ways.

In one, the vibrating fabric generates sound waves that interfere with an unwanted noise to cancel it out, similar to noise-canceling headphones, which work well in a small space like your ears but do not work in large enclosures like rooms or planes. 

In the other, more surprising technique, the fabric is held still to suppress vibrations that are key to the transmission of sound. This prevents noise from being transmitted through the fabric and quiets the volume beyond. This second approach allows for noise reduction in much larger spaces like rooms or cars.

By using common materials like silk, canvas, and muslin, the researchers created noise-suppressing fabrics which would be practical to implement in real-world spaces. For instance, one could use such a fabric to make dividers in open workspaces or thin fabric walls that prevent sound from getting through. 

“Noise is a lot easier to create than quiet. In fact, to keep noise out we dedicate a lot of space to thick walls. [First author] Grace’s work provides a new mechanism for creating quiet spaces with a thin sheet of fabric,” says Yoel Fink, a professor in the departments of Materials Science and Engineering and Electrical Engineering and Computer Science, a Research Laboratory of Electronics principal investigator, and senior author of a paper on the fabric.

The study’s lead author is Grace (Noel) Yang SM ’21, PhD ’24. Co-authors include MIT graduate students Taigyu Joo, Hyunhee Lee, Henry Cheung, and Yongyi Zhao; Zachary Smith, the Robert N. Noyce Career Development Professor of Chemical Engineering at MIT; graduate student Guanchun Rui and professor Lei Zhu of Case Western [Reserve] University; graduate student Jinuan Lin and Assistant Professor Chu Ma of the University of Wisconsin at Madison; and Latika Balachander, a graduate student at the Rhode Island School of Design. The an open-access paper about the research appeared recently in Advanced Materials.

Silky silence

The sound-suppressing silk builds off the group’s prior work to create fabric microphones.

In that research, they sewed a single strand of piezoelectric fiber into fabric. Piezoelectric materials produce an electrical signal when squeezed or bent. When a nearby noise causes the fabric to vibrate, the piezoelectric fiber converts those vibrations into an electrical signal, which can capture the sound. 

In the new work, the researchers flipped that idea to create a fabric loudspeaker that can be used to cancel out soundwaves. 

“While we can use fabric to create sound, there is already so much noise in our world. We thought creating silence could be even more valuable,” Yang says.

Applying an electrical signal to the piezoelectric fiber causes it to vibrate, which generates sound. The researchers demonstrated this by playing Bach’s “Air” using a 130-micrometer sheet of silk mounted on a circular frame.

To enable direct sound suppression, the researchers use a silk fabric loudspeaker to emit sound waves that destructively interfere with unwanted sound waves. They control the vibrations of the piezoelectric fiber so that sound waves emitted by the fabric are opposite of unwanted sound waves that strike the fabric, which can cancel out the noise.

However, this technique is only effective over a small area. So, the researchers built off this idea to develop a technique that uses fabric vibrations to suppress sound in much larger areas, like a bedroom.

Let’s say your next-door neighbors are playing foosball in the middle of the night. You hear noise in your bedroom because the sound in their apartment causes your shared wall to vibrate, which forms sound waves on your side.

To suppress that sound, the researchers could place the silk fabric onto your side of the shared wall, controlling the vibrations in the fiber to force the fabric to remain still. This vibration-mediated suppression prevents sound from being transmitted through the fabric.

“If we can control those vibrations and stop them from happening, we can stop the noise that is generated, as well,” Yang says.

A mirror for sound

Surprisingly, the researchers found that holding the fabric still causes sound to be reflected by the fabric, resulting in a thin piece of silk that reflects sound like a mirror does with light. 

Their experiments also revealed that both the mechanical properties of a fabric and the size of its pores affect the efficiency of sound generation. While silk and muslin have similar mechanical properties, the smaller pore sizes of silk make it a better fabric loudspeaker. 

But the effective pore size also depends on the frequency of sound waves. If the frequency is low enough, even a fabric with relatively large pores could function effectively, Yang says.

When they tested the silk fabric in direct suppression mode, the researchers found that it could significantly reduce the volume of sounds up to 65 decibels (about as loud as enthusiastic human conversation). In vibration-mediated suppression mode, the fabric could reduce sound transmission up to 75 percent.

These results were only possible due to a robust group of collaborators, Fink says. Graduate students at the Rhode Island School of Design helped the researchers understand the details of constructing fabrics; scientists at the University of Wisconsin at Madison conducted simulations; researchers at Case Western Reserve University characterized materials; and chemical engineers in the Smith Group at MIT used their expertise in gas membrane separation to measure airflow through the fabric.

Moving forward, the researchers want to explore the use of their fabric to block sound of multiple frequencies. This would likely require complex signal processing and additional electronics. 

In addition, they want to further study the architecture of the fabric to see how changing things like the number of piezoelectric fibers, the direction in which they are sewn, or the applied voltages could improve performance.

“There are a lot of knobs we can turn to make this sound-suppressing fabric really effective. We want to get people thinking about controlling structural vibrations to suppress sound. This is just the beginning,” says Yang.

This work is funded, in part, by the National Science Foundation (NSF), the Army Research Office (ARO), the Defense Threat Reduction Agency (DTRA), and the Wisconsin Alumni Research Foundation.

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

Single Layer Silk and Cotton Woven Fabrics for Acoustic Emission and Active Sound Suppression by Grace H. Yang, Jinuan Lin, Henry Cheung, Guanchun Rui, Yongyi Zhao, Latika Balachander, Taigyu Joo, Hyunhee Lee, Zachary P. Smith, Lei Zhu, Chu Ma, Yoel Fink. Advanced Materials DOI: https://doi.org/10.1002/adma.202313328 First published: 01 April 2024

This paper is open access.

2024 Kavli Prize Laureates: in the fields of astrophysics, nanoscience and neuroscience

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The Kavli Prize has yet to acquire the lustre of a Nobel Prize (first awarded in 1901 as per its Wikipedia entry). By comparison the Kavli Prize is relatively new (established in 2005 as per its Wikipedia entry) but it appears to be achieving big deal status in the US.

This year’s crop of prize winners was listed in a June 12, 2024 Kavli Foundation news release on EurekAlert,

Eight scientists from three countries are honored for their research that has broadened our understanding of the big, the small and the complex.

June 12, 2024 (Oslo, Norway) — The Norwegian Academy of Science and Letters today announced the 2024 Kavli Prize Laureates in the fields of astrophysics, nanoscience and neuroscience. Eight scientists from three countries are honored for their research that has broadened our understanding of the big, the small and the complex. The laureates in each field will share $1 million USD. 

The 2024 Kavli Prizes recognize groundbreaking science for the discovery and characterization of extra-solar planets and their atmospheres; foundational research integrating synthetic nanoscale materials for biomedical use; and the localization of areas in the brain specialized for face recognition and processing.  

The 2024 Kavli Prize Laureates are:  

  • Kavli Prize in Astrophysics: David Charbonneau (Canada/USA) and Sara Seager (Canada/USA) 
  • Kavli Prize in Nanoscience: Robert S. Langer (USA), Armand Paul Alivisatos (USA) and Chad A. Mirkin (USA) 
  • Kavli Prize in Neuroscience: Nancy Kanwisher (USA), Winrich Freiwald (Germany), and Doris Tsao (USA) 

“The Kavli Prize 2024 honors outstanding researchers doing fundamental science that moves the world forward. They are exploring planets outside our solar system; they have broadened the scientific field of nanoscience towards biomedicine; and they are adding to our understanding of the neurological basis of face recognition,” said Lise Øvreås, president at The Norwegian Academy of Science and Letters.  

Astrophysics: Searching for life beyond Earth  

The 2024 Kavli Prize in Astrophysics honors Sara Seager and David Charbonneau for discoveries of exoplanets and the characterization of their atmospheres. They pioneered methods for the detection of atomic species in planetary atmospheres and the measurement of their thermal infrared emission, setting the stage for finding the molecular fingerprints of atmospheres around both giant and rocky planets. Their contributions have been key to the enormous progress seen in the last 20 years in the exploration of myriad exo-planets.  

“Humans have always looked towards the stars for discoveries. The pivotal research conducted by Seager and Charbonneau has been an important first step towards finding new planets and strong evidence of life elsewhere in the universe,” remarked Viggo Hansteen, Chair of the Astrophysics Committee.  

David Charbonneau led the team that used the transit method to discover a giant exoplanet (HD 209458b). He pioneered the application of space-based observatories to perform the first studies of the atmosphere of giant extrasolar planets. This new method measures the tiny amount of light blocked by such a planet as it passes in front of its host star. Charbonneau has also used the transit method to study exoplanetary atmospheres, measuring molecular spectra using both filtered starlight and infrared emission from the planets themselves. He demonstrated these two approaches with observations from the Hubble Space Telescope in 2002 and the Spitzer Space Telescope three years later.  

Sara Seager pioneered the theoretical study of planetary atmospheres and predicted the presence of atomic and molecular species detectable by transit spectroscopy, most notably the alkali gases. She predicted how transits could be used to measure atomic and molecular characteristics in exoplanetary atmospheres, which is crucial for identifying biomarkers – signs of life. Seager made outstanding contributions to the understanding of planets with masses below that of Neptune. She also carried out extensive research on starshades – enormous petal-like structures designed to shield space observatories from the glare of a faraway Sun-like star – and was among the first to recognize their importance in detecting and characterizing the faint light from any Earth-like planet orbiting the star. 

Nanoscience: Integrating nanomaterials for biomedical advances 

The 2024 Kavli Prize in Nanoscience honors Robert S. Langer, Armand Paul Alivisatos and Chad A. Mirkin who each revolutionized the field of nanomedicine by demonstrating how engineering nanoscale materials can advance biomedical research and application. Their discoveries contributed foundationally to the development of therapeutics, vaccines, bioimaging and diagnostics.   

“The three scientists, Langer, Alivisatos and Mirkin, have broadened the scientific field of nanoscience, building from fundamental research. By scientific curiosity they have become inventors for the future of nanoscience and biomedicine,” stated Bodil Holst, Chair of the Nanoscience Committee.  

Robert S. Langer was the first to develop nano-engineered materials that enabled the controlled release, or regular flow, of drug molecules. This capability has had an immense impact for the treatment of a range of diseases, such as aggressive brain cancer, prostate cancer and schizophrenia. His work also showed that tiny particles, containing protein antigens, can be used in vaccination, and was instrumental in the development of the delivery of mRNA vaccines. 

Armand Paul Alivisatos demonstrated that semiconductor nanocrystals, or quantum dots (nanoparticles that possess bright, size-dependent light-emitting properties), can be used as multicolor probes in bioimaging. Essential to this achievement was the synthesis of biocompatible nanocrystals. Semiconductor nanocrystals became the basis for the widely used research and diagnostic tools such as live cell tracking, labelling and in vivo imaging. 

Chad A. Mirkin engineered spherical nucleic acids (SNA) using a gold nanoparticle as the core, and a cloud of radially distributed DNA or RNA strands as the shell. He was then able to show how SNAs can be combined to create larger structures and how they can be used in biodiagnostics. His discovery led to the development of fast, automated point-of-care medical diagnostic systems.  

Neuroscience: Understanding recognition of faces 

The 2024 Kavli Prize in Neuroscience honors Nancy Kanwisher, Doris Tsao and Winrich Freiwald for the discovery of a specialized system within the brain to recognize faces. Their discoveries have provided basic principles of neural organization and made the starting point for further research on how the processing of visual information is integrated with other cognitive functions.  

“Kanwisher, Freiwald and Tsao together discovered a localized and specialized neocortical system for face recognition. Their outstanding research will ultimately further our understanding of recognition not only of faces, but objects and scenes,” commented Kristine Walhovd, Chair of the Neuroscience Committee.  

Nancy Kanwisher was the first to prove that a specific area in the human neocortex is dedicated to recognizing faces, now called the fusiform face area. Using functional magnetic resonance imaging (fMRI) she found individual differences in the location of this area and devised an analysis technique to effectively localize specialized functional regions in the brain. This technique is now widely used and applied to domains beyond the face recognition system.  

Elaborating on Kanwisher’s findings, Winrich Freiwald and Doris Tsao studied macaques and mapped out six distinct brain regions, known as the face patch system, including these regions’ functional specialization and how they are connected. By recording the activity of individual brain cells, they revealed how cells in some face patches specialize in faces with particular views.  

Tsao proceeded to identify how the face patches work together to identify a face, through a specific code that enables single cells to identify faces by assembling information of facial features. For example, some cells respond to the presence of hair, others to the distance between the eyes. 

Freiwald uncovered that a separate brain region, called the temporal pole, accelerates our recognition of familiar faces, and that some cells are selectively responsive to familiar faces. 

…

There’s a video of the official 2024 Kavli Prize announcement which despite the Kavli Foundation being headquartered in California, US, was held (as noted in the news release) at the Norwegian Academy of Science and Letters where the organization’s president, Lise Øvreås, revealed the 2024 Kavli Prize laureates..(I’ll get back to that choice of location.)

The 2024 Kavli Prize in Nanoscience

There are many posts here featuring work from Robert S. Langer (or Robert Langer), Armand Paul Alivisatos (or Paul Alivisatos or A. Paul Alivisatos) and Chad A. Mirkin (or Chad Mirkin).

Northwestern University (Chicago, Illinois) issued a June 12, 2024 news release (also received via email) by Maria Paul that provides a few more details about the nanoscience winners (main focus: Chad Mirkin), the prize, and the Kavli Foundation. Note: A link has been removed,

Northwestern University nanoscientist Chad Mirkin has been awarded The 2024 Kavli Prize in Nanoscience by The Norwegian Academy of Science and Letters. Mirkin is the first Northwestern scientist to receive the prestigious award.

Mirkin is recognized for his discovery of spherical nucleic acids (SNAs), nanostructures comprised of a nanoparticle core and a shell of radially distributed DNA or RNA strands. These globular forms of nucleic acids have become the cornerstones of the burgeoning fields of nanomedicine and colloidal crystal engineering with DNA. They allow scientists to construct new forms of matter using particle “atoms” as the basic building blocks and DNA “bonds” as particle interconnects, and they are the basis for powerful tools that allow researchers and clinicians to track and treat disease in new ways. In particular, SNAs have led to the development of fast, automated point-of-care medical diagnostic systems and new experimental drugs for treating many forms of cancer, neurological disorders, and diseases of the skin.

Mirkin is one of three laureates in nanoscience recognized by The Norwegian Academy for revolutionizing the field of nanomedicine by demonstrating how engineering nanoscale structures can advance biomedical research and application. The other two are Robert Langer of the Massachusetts Institute of Technology and Paul Alivisatos of the University of Chicago [emphasis mine]. The scientists’ discoveries “contributed foundationally to the development of therapeutics, vaccines, bioimaging and diagnostics,” The Norwegian Academy said in a release. They will share the $1 million award.

“When I first found out I won The Kavli Prize, there was both excitement but also relief, because I consider Northwestern to be the ultimate center for nanotechnology research,” Mirkin said. “To be recognized with this award, along with my incredible co-awardees, was great validation of what we’ve been trying to do at Northwestern. While I’m proud of what we’ve accomplished, the best is yet to come.”

The laureates will be awarded the prize on Sept. 3 during a ceremony in Oslo, Norway, presided over the by The Royal Family. The Kavli Prizes thus far have honored 65 scientists from 13 countries. Ten laureates received the Nobel Prize after receiving The Kavli Prize. [emphasis mine]

“I am thrilled for Chad, for the International Institute for Nanotechnology and for Northwestern,” Northwestern President Michael Schill said. “Chad has earned this prestigious and influential award in a pathbreaking area of science that is aligned with two of the University’s key priorities — to lead in decarbonization, renewable energy and sustainability, and innovating in the biosciences to help prolong lives and make the world a healthier place.

“Through groundbreaking research and hard work, Chad and his team have made Northwestern a leading center for nanotechnology research and investment. The fact that he is sharing this award with President Alivisatos at U of C further emphasizes how the Chicago area has become an international hub for nano research.”

The vision for The Kavli Prize comes from Fred Kavli, a Norwegian-American entrepreneur and philanthropist [emphasis mine] who turned his lifelong fascination with science into a lasting legacy for recognizing scientific breakthroughs and supporting basic research.

Since the first awards in 2008, The Kavli Prize has recognized innovative scientific research — from the discovery of CRISPR-Cas9 to the detection of gravitational waves — transforming our understanding of the big, the small and the complex.

Mirkin’s discovery of SNAs has far-reaching implications for biology and medicine. SNAs, which have no known natural equivalents, interact uniquely with living systems compared to nucleic acids of other forms. Mirkin was the first to synthesize SNAs and elucidate the distinctive chemical and physical properties that underpin their use in transformative techniques and technologies in medicine and the life sciences. This work has led to the development of the first commercialized molecular medical diagnostic systems of the modern nanotechnology era, such as the Food and Drug Administration-cleared Verigene System, used in over half of the world’s top hospitals to detect diseases with high sensitivity and selectivity.

Illinois Gov. JB Pritzker praised Mirkin for his extraordinary contributions to the field of nanotechnology and how his innovations have helped find solutions to some of society’s biggest challenges.

“Academic institutions in Chicago and across Illinois have become the biggest drivers in nanoscience and technology over the last three decades,” Pritzker said. “Chad Mirkin and his Northwestern colleagues have made outstanding scientific discoveries that change how we view the world around us.”

In 1996, Mirkin created the first SNAs with DNA shells on gold nanoparticle cores. Over the years, he has developed numerous other types of SNAs with other shells and cores, including proteins, liposomes and FDA-approved materials, as well as core-less, hollow structures composed entirely of nucleic acids. These cores impart unique properties to the SNAs, such as optical and magnetic characteristics, while also serving as scaffolds to densely arrange the oligonucleotides, which participate in binding. This dense arrangement gives rise to the novel functional properties that differentiate SNAs from the natural linear and two-dimensional nucleic acids and make them particularly effective in interacting with certain biological structures within cells and tissues. SNAs, unlike conventional DNA and RNA, are naturally taken up by cells without the need for toxic, positively charged co-carriers, making them highly effective in RNA interference (RNAi), antisense gene regulation, and gene editing pathways.

Mirkin’s pioneering work on SNAs has also advanced the development of immunotherapeutics, structures capable of stimulating a patient’s immune response to fight both infectious diseases and certain forms of cancer. Using SNAs, Mirkin has pioneered the concept of rational vaccinology, where he demonstrated that the structure of a vaccine, rather than the components alone, is crucial for dictating its therapeutic effectiveness. This insight and these “structural nanomedicines” have opened new possibilities for developing curative treatments by rearranging known components into more effective structures at the nanoscale. Mirkin founded Flashpoint Therapeutics to commercialize these innovations, focusing on nucleic acid-based nanostructure cancer vaccines. Mirkin also invented the first SNA-based antiviral vaccine, using COVID-19 as a model. These SNAs, featuring the spike protein’s RBD subunit in the core, achieved a 100% survival rate in humanized mice challenged with the live virus. These structures and concepts for designing such vaccines are poised to move vaccine development beyond the current mRNA vaccines.

In addition, Mirkin invented dip-pen nanolithography, initially a technique for molecular writing with nanometer-scale precision that has evolved into a powerful platform for tip-based materials synthesis that, when combined with artificial intelligence, is revolutionizing how materials important for many sectors, especially clean energy, are discovered. Dip-pen nanolithography, which has spurred subsequent techniques that now use tens of millions of tiny tips to rapidly synthesize materials to be explored for such purposes, was recognized by National Geographic as one of the “top 100 scientific discoveries that changed the world.” These innovations are being commercialized by Mattiq, Inc., another venture-backed company Mirkin cofounded. Mirkin and his students also invented high-area rapid printing, an additive manufacturing technology, that is being commercialized by Azul 3D and being used to disrupt the microelectronics and optical lens industries.

Mirkin’s research has progressed SNA drugs through seven human clinical trials so far for treating various cancers, including glioblastoma multiforme and Merkel cell carcinoma. One SNA drug has shown remarkable potential in stimulating the immune system, proving effective in models of breast, colorectal and bladder cancers, lymphoma and melanoma. This drug has achieved complete tumor elimination in a subset of patients with Merkel cell carcinoma during Phase 1b/2 clinical trials, earning FDA fast-track and orphan drug status. It was recently licensed to Bluejay Therapeutics to treat hepatitis.

In 2000, Mirkin founded the International Institute for Nanotechnology (IIN) at Northwestern University, which he also directs. Research at the IIN has led to over 2,000 new commercial products sold globally and the creation of more than 40 startup companies. The IIN has collectively brought together over $1.2 billion to support research, education and infrastructure at Northwestern since its inception.

Mirkin is the George B. Rathmann Professor of Chemistry and a professor of medicine, chemical and biological engineering, biomedical engineering, and materials science and engineering at Northwestern. He is among an elite group of scientists elected to all three branches of the U.S. National Academies — the National Academy of Sciences, the National Academy of Engineering and the National Academy of Medicine. He is a member of the American Academy of Arts and Sciences. Mirkin served on President Obama’s Council of Advisors on Science and Technology for eight years.

Congratulations to all of the winners in all of the categories!

As for the Norway announcement, it makes a bit of sense given that Fred Kavli was a Norwegian American. However, it’s a little hard to avoid the suspicion that there might be some regional and prize rivalry between Norway with its Kavli and Sweden its Nobel..

A graphene joke (of sorts): What did the electron ‘say’ to the phonon in the graphene sandwich?

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Unfortunately, there isn’t a punch line but I appreciate the effort to inject a little lightness into the description of a fairly technical achievement, from a February 12, 2024 news item on Nanowerk, Note: A link has been removed,

Electrons carry electrical energy, while vibrational energy is carried by phonons. Understanding how they interact with each other in certain materials, like in a sandwich of two graphene layers, will have implications for future optoelectronic devices.

Key Takeaways

Twisted graphene layers exhibit unique electrical properties.

Electron-phonon interactions crucial for energy loss in graphene.

Discovery of a new physical process involving electron-phonon Umklapp scattering.

Potential implications for ultrafast optoelectronics and quantum applications.

…

A February 9, 2024 Eindhoven University of Technology (TU/e; Netherlands) press release, which originated the news item, is reproduced here in its entirety, Note: Links have been removed,

Electrons carry electrical energy, while vibrational energy is carried by phonons. Understanding how they interact with each other in certain materials, like in a sandwich of two graphene layers, will have implications for future optoelectronic devices. Recent work has revealed that graphene layers twisted relative to each other by a small ‘magic angle’ can act as perfect insulator or superconductor. But the physics of the electron-phonon interactions are a mystery. As part of a worldwide international collaboration, TU/e researcher Klaas-Jan Tielrooij has led a study on electron-phonon interactions in graphene layers. And they have made a startling discovery.

What did the electron say to the phonon between two layers of graphene?

This might sound like the start of a physics meme with a hilarious punchline to follow. But that’s not the case according to Klaas-Jan Tielrooij. He’s an associate professor at the Department of Applied Physics and Science Education at TU/e and the research lead of the new work published in Science Advances.

“We sought to understand how electrons and phonons ‘talk’ to each other within two twisted graphene layers,” says Tielrooij.

Electrons are the well-known charge and energy carriers associated with electricity, while a phonon is linked to the emergence of vibrations between atoms in an atomic crystal.

“Phonons aren’t particles like electrons though, they’re a quasiparticle. Yet, their interaction with electrons in certain materials and how they affect energy loss in electrons has been a mystery for some time,” notes Tielrooij.

But why would it be interesting to learn more about electron-phonon interactions? “These interactions can have a major effect on the electronic and optoelectronic properties of devices, made from materials like graphene, which we are going to see more of in the future.”

Twistronics: Breakthrough of the Year 2018

Tielrooij and his collaborators, who are based around the world in Spain, Germany, Japan, and the US, decided to study electron-phonon interactions in a very particular case – within two layers of graphene where the layers are ever-so-slightly misaligned.

Graphene is a two-dimensional layer of carbon atoms arranged in a honeycomb lattice that has several impressive properties such as high electrical conductivity, high flexibility, and high thermal conductivity, and it is also nearly transparent.

Back in 2018, the Physics World Breakthrough of the Year award went to Pablo Jarillo-Herrero and colleagues at MIT [Massachusetts Institute of Technology] for their pioneering work on twistronics, where adjacent layers of graphene are rotated very slightly relative to each other to change the electronic properties of the graphene.

Twist and astound!

“Depending on how the layers of graphene are rotated and doped with electrons, contrasting outcomes are possible. For certain dopings, the layers act as an insulator, which prevents the movement of electrons. For other doping, the material behaves as a superconductor – a material with zero resistance that allows the dissipation-less movement of electrons,” says Tielrooij.

Better known as twisted bilayer graphene, these outcomes occur at the so-called magic angle of misalignment, which is just over one degree of rotation. “The misalignment between the layers is tiny, but the possibility for a superconductor or an insulator is an astounding result.”

How electrons lose energy

For their study, Tielrooij and the team wanted to learn more about how electrons lose energy in magic-angle twisted bilayer graphene, or MATBG for short.

To achieve this, they used a material consisting of two sheets of monolayer graphene (each 0.3 nanometers thick), placed on top of each other, and misaligned relative to each other by about one degree.

Then using two optoelectronic measurement techniques, the researchers were able to probe the electron-phonon interactions in detail, and they made some staggering discoveries.

“We observed that the energy vanishes very quickly in the MATBG – it occurs on the picosecond timescale, which is one-millionth of one-millionth of a second!” says Tielrooij.

This observation is much faster than for the case of a single layer of graphene, especially at ultracold temperatures (specifically below -73 degrees Celsius). “At these temperatures, it’s very difficult for electrons to lose energy to phonons, yet it happens in the MATBG.”

Why electrons lose energy

So, why are the electrons losing the energy so quickly through interaction with the phonons? Well, it turns out the researchers have uncovered a whole new physical process.

“The strong electron-phonon interaction is a completely new physical process and involves so-called electron-phonon Umklapp scattering,” adds Hiroaki Ishizuka from Tokyo Institute of Technology in Japan, who developed the theoretical understanding of this process together with Leonid Levitov from Massachusetts Institute of Technology in the US.

Umklapp scattering between phonons is a process that often affects heat transfer in materials, because it enables relatively large amounts of momentum to be transferred between phonons.

“We see the effects of phonon-phonon Umklapp scattering all the time as it affects the ability for (non-metallic) materials at room temperature to conduct heat. Just think of an insulating material on the handle of a pot for example,” says Ishizuka. “However, electron-phonon Umklapp scattering is rare. Here though we have observed for the first time how electrons and phonons interact via Umklapp scattering to dissipate electron energy.”

Challenges solved together

Tielrooij and collaborators may have completed most of the work while he was based in Spain at the Catalan Institute of Nanoscience and Nanotechnology (ICN2), but as Tielrooij notes. “The international collaboration proved pivotal to making this discovery.”

So, how did all the collaborators contribute to the research? Tielrooij: “First, we needed advanced fabrication techniques to make the MATBG samples. But we also needed a deep theoretical understanding of what’s happening in the samples. Added to that, ultrafast optoelectronic measurement setups were required to measure what’s happening in the samples too.”

Tielrooij and the team received the magic-angle twisted samples from Dmitri Efetov’s group at Ludwig-Maximilians-Universität in Munich, who were the first group in Europe able to make such samples and who also performed photomixing measurements, while theoretical work at MIT in the US and at Tokyo Institute of Technology in Japan proved crucial to the success of the research.

At ICN2, Tielrooij and his team members Jake Mehew and Alexander Block used cutting-edge equipment particularly time-resolved photovoltage microscopy to perform their measurements of electron-phonon dynamics in the samples.

The future

So, what does the future look like for these materials then? According to Tielrooij, don’t expect anything too soon.

“As the material is only being studied for a few years, we’re still some way from seeing magic-angle twisted bilayer graphene having an impact on society.”

But there is a great deal to be explored about energy loss in the material.

“Future discoveries could have implications for charge transport dynamics, which could have implications for future ultrafast optoelectronics devices,” says Tielrooij. “In particular, they would be very useful at low temperatures, so that makes the material suitable for space and quantum applications.”

The research from Tielrooij and the international team is a real breakthrough when it comes to how electrons and phonons interact with each other.

But we’ll have to wait a little longer to fully understand the consequences of what the electron said to the phonon in the graphene sandwich.

Illustration showing the control of energy relaxation with twist angle. Image: Authors

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

Ultrafast Umklapp-assisted electron-phonon cooling in magic-angle twisted bilayer graphene by Jake Dudley Mehew, Rafael Luque Merino, Hiroaki Ishizuka, Alexander Block, Jaime Díez Mérida, Andrés Díez Carlón, Kenji Watanabe, Takashi Taniguchi, Leonid S. Levitov, Dmitri K. Efetov, and Klaas-Jan Tielrooij. Science Advances 9 Feb 2024 Vol 10, Issue 6 DOI: 10.1126/sciadv.adj1361

This paper is open access.

Detect lung cancer early by inhaling a nanosensor

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The technology described in a January 5, 2024 news item on Nanowerk has not been tried in human clinical trials but early pre-clinical trial testing offers promise,

Using a new technology developed at MIT, diagnosing lung cancer could become as easy as inhaling nanoparticle sensors and then taking a urine test that reveals whether a tumor is present.

Key Takeaways

*This non-invasive approach may serve as an alternative or supplement to traditional CT scans, particularly beneficial in areas with limited access to advanced medical equipment.

*The technology focuses on detecting cancer-linked proteins in the lungs, with results obtainable through a simple paper test strip.

*Designed for early-stage lung cancer detection, the method has shown promise in animal models and may soon advance to human clinical trials.

*This innovation holds potential for significantly improving lung cancer screening and early detection, especially in low-resource settings.

…

A January 5, 2024 Massachusetts Institute of Technology (MIT) news release (also on EurkeAlert), which originated the news item, goes on to provide some technical details,

The new diagnostic is based on nanosensors that can be delivered by an inhaler or a nebulizer. If the sensors encounter cancer-linked proteins in the lungs, they produce a signal that accumulates in the urine, where it can be detected with a simple paper test strip.

This approach could potentially replace or supplement the current gold standard for diagnosing lung cancer, low-dose computed tomography (CT). It could have an especially significant impact in low- and middle-income countries that don’t have widespread availability of CT scanners, the researchers say.

“Around the world, cancer is going to become more and more prevalent in low- and middle-income countries. The epidemiology of lung cancer globally is that it’s driven by pollution and smoking, so we know that those are settings where accessibility to this kind of technology could have a big impact,” says Sangeeta Bhatia, the John and Dorothy Wilson Professor of Health Sciences and Technology and of Electrical Engineering and Computer Science at MIT, and a member of MIT’s Koch Institute for Integrative Cancer Research and the Institute for Medical Engineering and Science.

Bhatia is the senior author of the paper, which appears today [January 5, 2024] in Science Advances. Qian Zhong, an MIT research scientist, and Edward Tan, a former MIT postdoc, are the lead authors of the study.

Inhalable particles

To help diagnose lung cancer as early as possible, the U.S. Preventive Services Task Force recommends that heavy smokers over the age of 50 undergo annual CT scans. However, not everyone in this target group receives these scans, and the high false-positive rate of the scans can lead to unnecessary, invasive tests.

Bhatia has spent the last decade developing nanosensors for use in diagnosing cancer and other diseases, and in this study, she and her colleagues explored the possibility of using them as a more accessible alternative to CT screening for lung cancer.

These sensors consist of polymer nanoparticles coated with a reporter, such as a DNA barcode, that is cleaved from the particle when the sensor encounters enzymes called proteases, which are often overactive in tumors. Those reporters eventually accumulate in the urine and are excreted from the body.

Previous versions of the sensors, which targeted other cancer sites such as the liver and ovaries, were designed to be given intravenously. For lung cancer diagnosis, the researchers wanted to create a version that could be inhaled, which could make it easier to deploy in lower resource settings.

“When we developed this technology, our goal was to provide a method that can detect cancer with high specificity and sensitivity, and also lower the threshold for accessibility, so that hopefully we can improve the resource disparity and inequity in early detection of lung cancer,” Zhong says.

To achieve that, the researchers created two formulations of their particles: a solution that can be aerosolized and delivered with a nebulizer, and a dry powder that can be delivered using an inhaler.

Once the particles reach the lungs, they are absorbed into the tissue, where they encounter any proteases that may be present. Human cells can express hundreds of different proteases, and some of them are overactive in tumors, where they help cancer cells to escape their original locations by cutting through proteins of the extracellular matrix. These cancerous proteases cleave DNA barcodes from the sensors, allowing the barcodes to circulate in the bloodstream until they are excreted in the urine.

In the earlier versions of this technology, the researchers used mass spectrometry to analyze the urine sample and detect DNA barcodes. However, mass spectrometry requires equipment that might not be available in low-resource areas, so for this version, the researchers created a lateral flow assay, which allows the barcodes to be detected using a paper test strip.

The researchers designed the strip to detect up to four different DNA barcodes, each of which indicates the presence of a different protease. No pre-treatment or processing of the urine sample is required, and the results can be read about 20 minutes after the sample is obtained.

“We were really pushing this assay to be point-of-care available in a low-resource setting, so the idea was to not do any sample processing, not do any amplification, just to be able to put the sample right on the paper and read it out in 20 minutes,” Bhatia says.

Accurate diagnosis

The researchers tested their diagnostic system in mice that are genetically engineered to develop lung tumors similar to those seen in humans. The sensors were administered 7.5 weeks after the tumors started to form, a time point that would likely correlate with stage 1 or 2 cancer in humans.

In their first set of experiments in the mice, the researchers measured the levels of 20 different sensors designed to detect different proteases. Using a machine learning algorithm to analyze those results, the researchers identified a combination of just four sensors that was predicted to give accurate diagnostic results. They then tested that combination in the mouse model and found that it could accurately detect early-stage lung tumors.

For use in humans, it’s possible that more sensors might be needed to make an accurate diagnosis, but that could be achieved by using multiple paper strips, each of which detects four different DNA barcodes, the researchers say.

The researchers now plan to analyze human biopsy samples to see if the sensor panels they are using would also work to detect human cancers. In the longer term, they hope to perform clinical trials in human patients. A company called Sunbird Bio has already run phase 1 trials on a similar sensor developed by Bhatia’s lab, for use in diagnosing liver cancer and a form of hepatitis known as nonalcoholic steatohepatitis (NASH).

In parts of the world where there is limited access to CT scanning, this technology could offer a dramatic improvement in lung cancer screening, especially since the results can be obtained during a single visit.

“The idea would be you come in and then you get an answer about whether you need a follow-up test or not, and we could get patients who have early lesions into the system so that they could get curative surgery or lifesaving medicines,” Bhatia says.

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

Inhalable point-of-care urinary diagnostic platform by Qian Zhong, Edward K. W. Tan, Carmen Martin-Alonso, Tiziana Parisi, Liangliang Hao, Jesse D. Kirkpatrick, Tarek Fadel, Heather E. Fleming, Tyler Jacks, and Sangeeta N. Bhatia. Science Advances 5 Jan 2024 Vol 10, Issue 1 DOI: 10.1126/sciadv.adj9591

This paper is open access.

Sunbird Bio (the company mentioned in the news release) can be found here.

Brainlike transistor and human intelligence

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This brainlike transistor (not a memristor) is important because it functions at room temperature as opposed to others, which require cryogenic temperatures.

A December 20, 2023 Northwestern University news release (received via email; also on EurekAlert) fills in the details,

  • Researchers develop transistor that simultaneously processes and stores information like the human brain
  • Transistor goes beyond categorization tasks to perform associative learning
  • Transistor identified similar patterns, even when given imperfect input
  • Previous similar devices could only operate at cryogenic temperatures; new transistor operates at room temperature, making it more practical

EVANSTON, Ill. — Taking inspiration from the human brain, researchers have developed a new synaptic transistor capable of higher-level thinking.

Designed by researchers at Northwestern University, Boston College and the Massachusetts Institute of Technology (MIT), the device simultaneously processes and stores information just like the human brain. In new experiments, the researchers demonstrated that the transistor goes beyond simple machine-learning tasks to categorize data and is capable of performing associative learning.

Although previous studies have leveraged similar strategies to develop brain-like computing devices, those transistors cannot function outside cryogenic temperatures. The new device, by contrast, is stable at room temperatures. It also operates at fast speeds, consumes very little energy and retains stored information even when power is removed, making it ideal for real-world applications.

The study was published today (Dec. 20 [2023]) in the journal Nature.

“The brain has a fundamentally different architecture than a digital computer,” said Northwestern’s Mark C. Hersam, who co-led the research. “In a digital computer, data move back and forth between a microprocessor and memory, which consumes a lot of energy and creates a bottleneck when attempting to perform multiple tasks at the same time. On the other hand, in the brain, memory and information processing are co-located and fully integrated, resulting in orders of magnitude higher energy efficiency. Our synaptic transistor similarly achieves concurrent memory and information processing functionality to more faithfully mimic the brain.”

Hersam is the Walter P. Murphy Professor of Materials Science and Engineering at Northwestern’s McCormick School of Engineering. He also is chair of the department of materials science and engineering, director of the Materials Research Science and Engineering Center and member of the International Institute for Nanotechnology. Hersam co-led the research with Qiong Ma of Boston College and Pablo Jarillo-Herrero of MIT.

Recent advances in artificial intelligence (AI) have motivated researchers to develop computers that operate more like the human brain. Conventional, digital computing systems have separate processing and storage units, causing data-intensive tasks to devour large amounts of energy. With smart devices continuously collecting vast quantities of data, researchers are scrambling to uncover new ways to process it all without consuming an increasing amount of power. Currently, the memory resistor, or “memristor,” is the most well-developed technology that can perform combined processing and memory function. But memristors still suffer from energy costly switching.

“For several decades, the paradigm in electronics has been to build everything out of transistors and use the same silicon architecture,” Hersam said. “Significant progress has been made by simply packing more and more transistors into integrated circuits. You cannot deny the success of that strategy, but it comes at the cost of high power consumption, especially in the current era of big data where digital computing is on track to overwhelm the grid. We have to rethink computing hardware, especially for AI and machine-learning tasks.”

To rethink this paradigm, Hersam and his team explored new advances in the physics of moiré patterns, a type of geometrical design that arises when two patterns are layered on top of one another. When two-dimensional materials are stacked, new properties emerge that do not exist in one layer alone. And when those layers are twisted to form a moiré pattern, unprecedented tunability of electronic properties becomes possible.

For the new device, the researchers combined two different types of atomically thin materials: bilayer graphene and hexagonal boron nitride. When stacked and purposefully twisted, the materials formed a moiré pattern. By rotating one layer relative to the other, the researchers could achieve different electronic properties in each graphene layer even though they are separated by only atomic-scale dimensions. With the right choice of twist, researchers harnessed moiré physics for neuromorphic functionality at room temperature.

“With twist as a new design parameter, the number of permutations is vast,” Hersam said. “Graphene and hexagonal boron nitride are very similar structurally but just different enough that you get exceptionally strong moiré effects.”

To test the transistor, Hersam and his team trained it to recognize similar — but not identical — patterns. Just earlier this month, Hersam introduced a new nanoelectronic device capable of analyzing and categorizing data in an energy-efficient manner, but his new synaptic transistor takes machine learning and AI one leap further.

“If AI is meant to mimic human thought, one of the lowest-level tasks would be to classify data, which is simply sorting into bins,” Hersam said. “Our goal is to advance AI technology in the direction of higher-level thinking. Real-world conditions are often more complicated than current AI algorithms can handle, so we tested our new devices under more complicated conditions to verify their advanced capabilities.”

First the researchers showed the device one pattern: 000 (three zeros in a row). Then, they asked the AI to identify similar patterns, such as 111 or 101. “If we trained it to detect 000 and then gave it 111 and 101, it knows 111 is more similar to 000 than 101,” Hersam explained. “000 and 111 are not exactly the same, but both are three digits in a row. Recognizing that similarity is a higher-level form of cognition known as associative learning.”

In experiments, the new synaptic transistor successfully recognized similar patterns, displaying its associative memory. Even when the researchers threw curveballs — like giving it incomplete patterns — it still successfully demonstrated associative learning.

“Current AI can be easy to confuse, which can cause major problems in certain contexts,” Hersam said. “Imagine if you are using a self-driving vehicle, and the weather conditions deteriorate. The vehicle might not be able to interpret the more complicated sensor data as well as a human driver could. But even when we gave our transistor imperfect input, it could still identify the correct response.”

The study, “Moiré synaptic transistor with room-temperature neuromorphic functionality,” was primarily supported by the National Science Foundation.

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

Moiré synaptic transistor with room-temperature neuromorphic functionality by Xiaodong Yan, Zhiren Zheng, Vinod K. Sangwan, Justin H. Qian, Xueqiao Wang, Stephanie E. Liu, Kenji Watanabe, Takashi Taniguchi, Su-Yang Xu, Pablo Jarillo-Herrero, Qiong Ma & Mark C. Hersam. Nature volume 624, pages 551–556 (2023) DOI: https://doi.org/10.1038/s41586-023-06791-1 Published online: 20 December 2023 Issue Date: 21 December 2023

This paper is behind a paywall.

Health/science journalists/editors: deadline is March 22, 2024 for media boot camp in Boston, Massachusetts

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A February 14, 2023 Broad Institute news release presents an exciting opportunity for health/science journalists and editors,

The Broad Institute of MIT [Massachusetts Institute of Technology] and Harvard is now accepting applications for its 2024 Media Boot Camp.

This annual program connects health/science journalists and editors with faculty from the Broad Institute, Massachusetts Institute of Technology, Harvard University, and Harvard’s teaching hospitals for a two-day event exploring the latest advances in genomics and biomedicine. Journalists will explore possible future storylines, gain fundamental background knowledge, and build relationships with researchers. The program format includes presentations, discussions, and lab tours.

The 2024 Media Boot Camp will take place in person at the Broad Institute in Cambridge, MA on Thursday, May 16 and Friday, May 17 (with an evening welcome reception on Wednesday, May 15).

APPLICATION DEADLINE IS FRIDAY, MARCH 22 (5:00 PM US EASTERN TIME).

2024 Boot Camp topics include:

  • Gene editing
  • New approaches for therapeutic delivery  
  • Cancer biology, drug development
  • Data sciences, machine learning
  • Neurobiology (stem cell models of psychiatric disorders)
  • Antibiotic resistance, microbial biology
  • Medical and population genetics, genomic medicine

Current speakers include: Mimi Bandopadhayay, Clare Bernard,Roby Bhattacharyya, Todd Golub, Laura Kiessling, Eric Lander,David Liu, Ralda Nehme,Heidi Rehm, William Sellers, Feng Zhang, with potentially more to come.

This Media Boot Camp is an educational offering. All presentations are on-background.

Hotel accommodations and meals during the program will be provided by the Broad Institute. Attendees must cover travel costs to and from Boston.

Application Process

By Friday, March 22 [2024] (5:00 PM US Eastern time [2 pm PT]), please send at least one paragraph describing your interest in the program and how you hope it will benefit your reporting, as well as three recent news clips, to David Cameron, Director of External Communications, dcameron@broadinstitute.org

Please contact David at dcameron@broadinstitute.org, or 617-714-7184 with any questions.

I couldn’t find details about eligibility, that said, I wish you good luck with your ‘paragraph and three recent clips’ submission.

When the rocks sing “I got rhythm”

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George Gershwin, along with his brother Ira, wrote jazz standards such as “I got rhythm” in 1930 and, before that, “Fascinating rhythm” in 1924 and both seem à propos in relation to this October 9, 2023 news item on phys.org,

f you could sink through the Earth’s crust, you might hear, with a carefully tuned ear, a cacophany of booms and crackles along the way. The fissures, pores, and defects running through rocks are like strings that resonate when pressed and stressed. And as a team of MIT geologists has found, the rhythm and pace of these sounds can tell you something about the depth and strength of the rocks around you.

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The fissures and pores running through rocks, from the Earth’s crust to the liquid mantle, are like channels and cavities through which sound can resonate. Credit: iStock [downloaded from https://news.mit.edu/2023/boom-crackle-pop-earth-crust-sounds-1009]

An October 9, 2023 Massachusetts Institute of Technology news release (also on EurekAlert) by Jennifer Chu, which originated the news item, (word play alert) delves down into the material, Note: A link has been removed,

“If you were listening to the rocks, they would be singing at higher and higher pitches, the deeper you go,” says MIT geologist Matěj Peč. 

Peč and his colleagues are listening to rocks, to see whether any acoustic patterns, or “fingerprints” emerge when subjected to various pressures. In lab studies, they have now shown that samples of marble, when subjected to low pressures, emit low-pitched “booms,” while at higher pressures, the rocks generate an ‘avalanche’ of higher-pitched crackles. 

Peč says these acoustic patterns in rocks can help scientists estimate the types of cracks, fissures, and other defects that the Earth’s crust experiences with depth, which they can then use to identify unstable regions below the surface, where there is potential for earthquakes or eruptions. The team’s results, published in the Proceedings of the National Academy of Sciences, could also help inform surveyors’ efforts to drill for renewable, geothermal energy. 

“If we want to tap these very hot geothermal sources, we will have to learn how to drill into rocks that are in this mixed-mode condition, where they are not purely brittle, but also flow a bit,” says Peč, who is an assistant professor in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS). “But overall, this is fundamental science that can help us understand where the lithosphere is strongest.” 

Peč’s collaborators at MIT are lead author and research scientist Hoagy O. Ghaffari, technical associate Ulrich Mok, graduate student Hilary Chang, and professor emeritus of geophysics Brian Evans. Tushar Mittal, co-author and former EAPS postdoc, is now an assistant professor at Penn State University.

Fracture and flow

The Earth’s crust is often compared to the skin of an apple. At its thickest, the crust can be 70 kilometers deep — a tiny fraction of the globe’s total, 12,700-kilometer diameter. And yet, the rocks that make up the planet’s thin peel vary greatly in their strength and stability. Geologists infer that rocks near the surface are brittle and fracture easily, compared to rocks at greater depths, where immense pressures, and heat from the core, can make rocks flow. 

The fact that rocks are brittle at the surface and more ductile at depth implies there must be an in-between — a phase in which rocks transition from one to the other, and may have properties of both, able to fracture like granite, and flow like honey. This “brittle-to-ductile transition” is not well understood, though geologists believe it may be where rocks are at their strongest within the crust. 

“This transition state of partly flowing, partly fracturing, is really important, because that’s where we think the peak of the lithosphere’s strength is and where the largest earthquakes nucleate,” Peč says. “But we don’t have a good handle on this type of mixed-mode behavior.”

He and his colleagues are studying how the strength and stability of rocks — whether brittle, ductile, or somewhere in between — varies, based on a rock’s microscopic defects. The size, density, and distribution of defects such as microscopic cracks, fissures, and pores can shape how brittle or ductile a rock can be. 

But measuring the microscopic defects in rocks, under conditions that simulate the Earth’s various pressures and depths, is no trivial task. There is, for instance, no visual-imaging technique that allows scientists to see inside rocks to map their microscopic imperfections. So the team turned to ultrasound, and the idea that, any sound wave traveling through a rock should bounce, vibrate, and reflect off any microscopic cracks and crevices, in specific ways that should reveal something about the pattern of those defects. 

All these defects will also generate their own sounds when they move under stress and therefore both actively sounding through the rock as well as listening to it should give them a great deal of information. They found that the idea should work with ultrasound waves, at megahertz frequencies.

“This kind of ultrasound method is analogous to what seismologists do in nature, but at much higher frequencies,” Peč explains. “This helps us to understand the physics that occur at microscopic scales, during the deformation of these rocks.” 

A rock in a hard place

In their experiments, the team tested cylinders of Carrara marble. 

“It’s the same material as what Michaelangelo’s David is made from,” Peč notes. “It’s a very well-characterized material, and we know exactly what it should be doing.”

The team placed each marble cylinder in a a vice-like apparatus made from pistons of aluminum, zirconium, and steel, which together can generate extreme stresses. They placed the vice in a pressurized chamber, then subjected each cylinder to pressures similar to what rocks experience throughout the Earth’s crust.  

As they slowly crushed each rock, the team sent pulses of ultrasound through the top of the sample, and recorded the acoustic pattern that exited through the bottom. When the sensors were not pulsing, they were listening to any naturally occurring acoustic emissions.

They found that at the lower end of the pressure range, where rocks are brittle, the marble indeed formed sudden fractures in response, and the sound waves resembled large, low-frequency booms. At the highest pressures, where rocks are more ductile, the acoustic waves resembled a higher-pitched crackling. The team believes this crackling was produced by microscopic defects called dislocations that then spread and flow like an avalanche. 

“For the first time, we have recorded the ‘noises’ that rocks make when they are deformed across this brittle-to-ductile transition, and we link these noises to the individual microscopic defects that cause them,” Peč says. “We found that these defects massively change their size and propagation velocity as they cross this transition. It’s more complicated than people had thought.”

The team’s characterizations of rocks and their defects at various pressures can help scientists estimate how the Earth’s crust will behave at various depths, such as how rocks might fracture in an earthquake, or flow in an eruption.    

“When rocks are partly fracturing and partly flowing, how does that feed back into the earthquake cycle? And how does that affect the movement of magma through a network of rocks?” Peč says. “Those are larger scale questions that can be tackled with research like this.”

This research was supported, in part, by the National Science Foundation.

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

Microscopic defect dynamics during a brittle-to-ductile transition by Hoagy O’Ghaffari, Matěj Peč, Tushar Mittal, Ulrich Mok, Hilary Chang, and Brian Evans. Proceedings of the National Academy of Sciences 120 (42) e2305667120 DOI: https://doi.org/10.1073/pnas.2305667120 October 9, 2023

This paper is behind a paywall.