Tag Archives: Northwestern University

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

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..

Brainlike transistor and human intelligence

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.

Everlasting dirt-powered sensors for agriculture?

Caption: The fuel cell’s 3D printed cap peeks above the ground. The cap keeps debris out of the device while enabling air flow. Credit: Bill Yen/Northwestern University

A January 12, 2024 Northwestern University news release (also received via email and also on EurekAlert both published January 15, 2024) describes this dirt-powered research from the US, Note: Links have been removed,

*New fuel cell harnesses naturally occurring microbes to generate electricity

*Soil-powered sensors to successfully monitor soil moisture and detect touch

*New tech was robust enough to withstand drier soil conditions and flooding

*Fuel cell could replace batteries in sensors used for precision agriculture

EVANSTON, Ill. — A Northwestern University-led team of researchers has developed a new fuel cell that harvests energy from microbes living in dirt. 

About the size of a standard paperback book, the completely soil-powered technology could fuel underground sensors used in precision agriculture and green infrastructure. This potentially could offer a sustainable, renewable alternative to batteries, which hold toxic, flammable chemicals that leach into the ground, are fraught with conflict-filled supply chains and contribute to the ever-growing problem of electronic waste.

To test the new fuel cell, the researchers used it to power sensors measuring soil moisture and detecting touch, a capability that could be valuable for tracking passing animals. To enable wireless communications, the researchers also equipped the soil-powered sensor with a tiny antenna to transmit data to a neighboring base station by reflecting existing radio frequency signals.

Not only did the fuel cell work in both wet and dry conditions, but its power also outlasted similar technologies by 120%.

The research will be published today (Jan. 12 [2024]) in the Proceedings of the Association for Computing Machinery on Interactive, Mobile, Wearable and Ubiquitous Technologies. The study authors also are releasing all designs, tutorials and simulation tools to the public, so others may use and build upon the research.

“The number of devices in the Internet of Things (IoT) is constantly growing,” said Northwestern alumnus Bill Yen, who led the work. “If we imagine a future with trillions of these devices, we cannot build every one of them out of lithium, heavy metals and toxins that are dangerous to the environment. We need to find alternatives that can provide low amounts of energy to power a decentralized network of devices. In a search for solutions, we looked to soil microbial fuel cells, which use special microbes to break down soil and use that low amount of energy to power sensors. As long as there is organic carbon in the soil for the microbes to break down, the fuel cell can potentially last forever.”

“These microbes are ubiquitous; they already live in soil everywhere,” said Northwestern’s George Wells, a senior author on the study. “We can use very simple engineered systems to capture their electricity. We’re not going to power entire cities with this energy. But we can capture minute amounts of energy to fuel practical, low-power applications.”

Wells is an associate professor of civil and environmental engineering at Northwestern’s McCormick School of Engineering. Now a Ph.D. student at Stanford University, Yen started this project when he was an undergraduate researcher in Wells’ laboratory.

Solutions for a dirty job

In recent years, farmers worldwide increasingly have adopted precision agriculture as a strategy to improve crop yields. The tech-driven approach relies on measuring precise levels of moisture, nutrients and contaminants in soil to make decisions that enhance crop health. This requires a widespread, dispersed network of electronic devices to continuously collect environmental data.

“If you want to put a sensor out in the wild, in a farm or in a wetland, you are constrained to putting a battery in it or harvesting solar energy,” Yen said. “Solar panels don’t work well in dirty environments because they get covered with dirt, do not work when the sun isn’t out and take up a lot of space. Batteries also are challenging because they run out of power. Farmers are not going to go around a 100-acre farm to regularly swap out batteries or dust off solar panels.”

To overcome these challenges, Wells, Yen and their collaborators wondered if they could instead harvest energy from the existing environment. “We could harvest energy from the soil that farmers are monitoring anyway,” Yen said.

‘Stymied efforts’

Making their first appearance in 1911, soil-based microbial fuel cells (MFCs) operate like a battery — with an anode, cathode and electrolyte. But instead of using chemicals to generate electricity, MFCs harvest electricity from bacteria that naturally donate electrons to nearby conductors. When these electrons flow from the anode to the cathode, it creates an electric circuit.

But in order for microbial fuel cells to operate without disruption, they need to stay hydrated and oxygenated — which is tricky when buried underground within dry dirt.

“Although MFCs have existed as a concept for more than a century, their unreliable performance and low output power have stymied efforts to make practical use of them, especially in low-moisture conditions,” Yen said.

Winning geometry

With these challenges in mind, Yen and his team embarked on a two-year journey to develop a practical, reliable soil-based MFC. His expedition included creating — and comparing — four different versions. First, the researchers collected a combined nine months of data on the performance of each design. Then, they tested their final version in an outdoor garden.

The best-performing prototype worked well in dry conditions as well as within a water-logged environment. The secret behind its success: Its geometry. Instead of using a traditional design, in which the anode and cathode are parallel to one another, the winning fuel cell leveraged a perpendicular design.

Made of carbon felt (an inexpensive, abundant conductor to capture the microbes’ electrons), the anode is horizontal to the ground’s surface. Made of an inert, conductive metal, the cathode sits vertically atop the anode. 

Although the entire device is buried, the vertical design ensures that the top end is flush with the ground’s surface. A 3D-printed cap rests on top of the device to prevent debris from falling inside. And a hole on top and an empty air chamber running alongside the cathode enable consistent airflow.  

The lower end of the cathode remains nestled deep beneath the surface, ensuring that it stays hydrated from the moist, surrounding soil — even when the surface soil dries out in the sunlight. The researchers also coated part of the cathode with waterproofing material to allow it to breathe during a flood. And, after a potential flood, the vertical design enables the cathode to dry out gradually rather than all at once.

On average, the resulting fuel cell generated 68 times more power than needed to operate its sensors. It also was robust enough to withstand large changes in soil moisture — from somewhat dry (41% water by volume) to completely underwater.

Making computing accessible

The researchers say all components for their soil-based MFC can be purchased at a local hardware store. Next, they plan to develop a soil-based MFC made from fully biodegradable materials. Both designs bypass complicated supply chains and avoid using conflict minerals.

“With the COVID-19 pandemic, we all became familiar with how a crisis can disrupt the global supply chain for electronics,” said study co-author Josiah Hester, a former Northwestern faculty member who is now at the Georgia Institute of Technology. “We want to build devices that use local supply chains and low-cost materials so that computing is accessible for all communities.”

The study, “Soil-powered computing: The engineer’s guide to practical soil microbial fuel cell design,” was supported by the National Science Foundation (award number CNS-2038853), the Agricultural and Food Research Initiative (award number 2023-67021-40628) from the USDA National Institute of Food and Agriculture, the Alfred P. Sloan Foundation, VMware Research and 3M.

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

Soil-Powered Computing: The Engineer’s Guide to Practical Soil Microbial Fuel Cell Design by Bill Yen, Laura Jaliff, Louis Gutierrez, Philothei Sahinidis, Sadie Bernstein, John Madden, Stephen Taylor, Colleen Josephson, Pat Pannuto, Weitao Shuai, George Wells, Nivedita Arora, Josiah Hester. Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies Volume 7 Issue 4 Article No.: 196 pp 1–40 DOI: https://doi.org/10.1145/3631410 Published: 12 January 2024

This paper is open access.

Celebrating the 20th Anniversary of the Authorization of the US 21st Century Nanotechnology Research and Development Act

The US National Nanotechnology Initiative (NNI) was signed into existence by then US President Bill Clinton in 2000 (one of his last official acts while still in office) but it was then US President George W. Bush who signed the 21st Century Nanotechnology Research and Development Act in 2003. My understanding is the act gave the NNI a more permanent status.

In any event it’s the 20th anniversary of the 2003 signing of the act as noted in a December 6, 2023 posting by : Lynn L. Bergeson and Carla N. Hutton on the National Law Review blog, Note: A link has been removed,

The White House Office of Science and Technology Policy (OSTP) and the National Nanotechnology Coordination Office (NNCO) announced on December 4, 2023, a series of events to drive U.S. leadership in nanotechnology, in celebration of the 20-year anniversary of the 21st Century Nanotechnology Research and Development Act. The announcement notes that for the past two decades, the National Nanotechnology Initiative (NNI) “has worked with more than 20 departments and agencies to advance a vision to understand and control matter at the nanoscale, for the benefit of society.” …

A December 4, 2023 White House Office of Science and Technology Policy (OSTP) news release announced the 20th anniversary and celebrations, Note: Links have been removed,

In celebration of the 20-year anniversary of the 21st Century Nanotechnology Research and Development Act, the White House Office of Science and Technology Policy (OSTP) and the National Nanotechnology Coordination Office (NNCO) are announcing a series of events to drive U.S. leadership in nanotechnology.

For the past two decades, the National Nanotechnology Initiative (NNI) has worked with more than 20 departments and agencies to advance a vision to understand and control matter at the nanoscale, for the benefit of society. Coordination across the government has allowed Americans to safely enjoy the benefits of nanotechnology, which has led to revolutions in technology and industry, including faster microchips, powerful mRNA vaccines, and clean energy technologies. Meanwhile, carbon nanotubes have improved the power and lifecycle of batteries; quantum dots make flat screen TVs more vibrant; and nanoparticles allow for faster medical diagnostics.

“Over the years, the NNI has dynamically and responsibly responded to the needs of the country,” said Dr. Branden Brough, Director of NNCO, which coordinates the NNI. “The initiative is a model for collaborative and thoughtful technology development, while supporting the rapid development of other emerging fields by creating the infrastructure and workforce development programs that bolster these growing industries.”

The NNI community will host a symposium on March 5, 2024 [emphasis mine] at the National Academies of Sciences, Engineering, and Medicine in Washington, D.C., to recognize the impact of research and development at the nanoscale and plan the NNI’s promising future. The event is open to the public. …

This week, as we celebrate the Act’s signing, the NNCO will release a series of reports and stories that illustrate the impact of the NNI. This includes readouts from the Nano4EARTH roundtable discussions [emphasis mine] about applying nanotechnology solutions to address climate change, such as surface technologies, new batteries and energy storage solutions, and greenhouse gas capture approaches. Also, the NNCO will highlight a new independent study [emphasis mine] about how the U.S. nanotechnology community contributes tens of billions of dollars—and potentially hundreds of billions of dollars—to the economy each year. And, to highlight the importance of this growing field, NNCO will feature the stories of early-career scientists who represent the promising future of nanotechnology.

Additional events will be held during the coming months, including science cafes across the country, activities at local museums, and podcasts and articles in the media. For more information about these activities, visit the NNI website.

The report/study

The independent study (Economic Impact Analysis: 20 Years of Nanotechnology Investments, 2002 – 2022) mentioned in the OSTP news release was launched on December 5, 2023 and highlighted here in a January 2, 2024 posting.

The symposium

Here’s a poster of the March 5, 2024 symposium celebrating the 20th anniversary of the act,

There’s a registration page where you can register for the in-person symposium and find more information about the speakers. I thought introduction and agenda from the registration page might be of interest, Note: A link has been removed,

Scientists and engineers across many fields and disciplines are united by their work at the nanoscale. Their diverse efforts have helped produce everything from faster microchips to powerful mRNA vaccines. The transformative impact of this work has been spurred by the coordination and focus on U.S. nanotechnology established by the 21st Century Nanotechnology Research and Development Act in 2003. Celebrating such a broad impact and envisioning the future can be quite challenging, but this event will bring together voices from across the emerging technology landscape. There will be experts who can speak on the importance of nanotechnology in quantum engineering, optics, EHS, plastics, DEIA, microelectronics, medicine, education, manufacturing, and more. We can’t predict what will emerge from this lively discussion between researchers, policymakers, members of industry, educators, and the public, but the conversation can only benefit from including more diverse perspectives – especially yours.

AGENDA

8:30-9:00   Coffee and refreshments

9:00-9:05   Welcome and Introduction

9:05-9:30   Policy Perspectives #1

9:30-10:15  Morning Keynote

10:15-10:45  Coffee Break

10:45-11:30  Panel: Responsible Development

11:30-12:15  Panel: Fundamental Research

12:15-1:15  Lunch, Poster Session, and Networking

1:15-1:45  Policy Perspectives #2

1:45-2:30  Keynote Panel: The Future of Nanotechnology

2:30-3:15  Panel: Workforce Development

3:15-3:45  Break

3:45-4:30  Panel: Infrastructure

4:30-5:15  Panel: Commercialization

5:15-6:00  Closing Keynote

6:00-7:00  Reception Sponsored by the Kavli Foundation

No details about exactly what is being discussed but it certainly seems like it will be a busy day.

Nano4EARTH

I found the OSTP news release a little confusing with regard to the “readouts from the Nano4EARTH roundtable discussions” but here’s how the Nano4EARTH (Climate Change National Nanotechnology Challenge) webpage describes its upcoming workshop and roundtables,

Nano4EARTH Kick-off Workshop

Click here for information about the Nano4EARTH Kick-off hybrid workshop, to be held in Washington, DC and online on Jan. 24–25, 2023.

Nano4EARTH Roundtable Discussions

The Nano4EARTH roundtable discussions aim to identify fundamental knowledge gaps, needs, and opportunities to advance current energy efficiency, sustainable development, and climate change goals. By convening stakeholders from different sectors, backgrounds, and expertise, the goals of these roundtables are to identify applicable lessons across the spectrum of technologies, discuss system-specific needs, scalability and commercialization challenges, and potential paths forward.

The topics of the roundtables were identified at the Nano4EARTH Kick-off Workshop as particularly promising areas that could have an impact in a short time frame (four years or less). 

Roundtables:

Coatings, Lubricants, Membranes, and Other Interface Technologies

Roundtable Information, Discussion Summary

Batteries and Energy Storage

Roundtable Information, Discussion Summary

Capture, Storage, and Use of Greenhouse Gases

Roundtable Information, Discussion Summary

Nano4EARTH Roundtable Discussion on Catalysts (January 24, 2024)

Roundtable Information

Other celebrations around the country

There’s this December 11, 2023 notice from the “Celebrating nanotechnology around the country” webpage on the NNI website,

In celebration of the 20-year anniversary of the signing of the 21st Century Nanotechnology Research and Development Act, which codified the National Nanotechnology Initiative, the National Nanotechnology Coordination Office is showing its appreciation for the many organizations across the country that have put together engagement events with the general public to raise awareness about nanotechnology.

Such events (compiled by the National Informal STEM Education (NISE) Network) include:

Nanotechnology Day Activities in Arizona

Family Science Nights in Greensboro, NC

Celebrating 45 Years of Nanoscale Research at the Cornell Nanoscale Science and Technology Facility

Twenty Years of Nanotechnology! Opportunity to engage your community with NanoDays activities

The end

Chad Mirkin at Northwestern University (Chicago, Illinois, US) who’s a pretty big deal in the nanomedicine field wrote an October 29, 2021 introductory essay for Scientific American,

A Big Bet on Nanotechnology Has Paid Off

The National Nanotechnology Initiative promised a lot. It has delivered more

We’re now more than two decades out from the initial announcement of the National Nanotechnology Initiative (NNI), a federal program from President Bill Clinton founded in 2000 to support nanotechnology research and development in universities, government agencies and industry laboratories across the United States. It was a significant financial bet on a field that was better known among the general public for science fiction than scientific achievement. Today it’s clear that the NNI did more than influence the direction of research in the U.S. It catalyzed a worldwide effort and spurred an explosion of creativity in the scientific community. And we’re reaping the rewards not just in medicine, but also clean energy, environmental remediation and beyond.

Before the NNI, there were people who thought nanotechnology was a gimmick. I began my research career in chemistry, but it seemed to me that nanotechnology was a once-in-a-lifetime opportunity: the opening of a new field that crossed scientific disciplines. In the wake of the NNI, my university, Northwestern University, made the strategic decision to establish the International Institute for Nanotechnology, which now represents more than $1 billion in pure nanotechnology research, educational programs and supporting infrastructure. Other universities across the U.S. made similar investments, creating new institutes and interdisciplinary partnerships.

He’s a little euphoric but his perspective and the information he offers is worth knowing about.

Nanoscientists speculate that artificial life forms could be medicine of the future

Even after all these years, my jaw is still capable of dropping but then I read the details. This looks a lot like ‘medical nanobots’ which researchers have been talking about for a long time. Nice twist on a familiar theme. From an October 5, 2023 news item on ScienceDaily,

Imagine a life form that doesn’t resemble any of the organisms found on the tree of life. One that has its own unique control system, and that a doctor would want to send into your body. It sounds like a science fiction movie, but according to nanoscientists, it can—and should—happen in the future.

Creating artificial life is a recurring theme in both science and popular literature, where it conjures images of creeping slime creatures with malevolent intentions or super-cute designer pets. At the same time, the question arises: What role should artificial life play in our environment here on Earth, where all life forms are created by nature and have their own place and purpose?

Associate professor Chenguang Lou from the Department of Physics, Chemistry, and Pharmacy, University of Southern Denmark, together with Professor Hanbin Mao from Kent State University, is the parent of a special artificial hybrid molecule that could lead to the creation of artificial life forms. They have now published a review in the journal Cell Reports Physical Science on the state of research in the field behind their creation. The field is called “hybrid peptide-DNA nanostructures,” and it is an emerging field, less than ten years old.

An October 5, 2023 University of Southern Denmark press release (also on EurekAlert) by Birgitte Svennevig, which originated the news item, shares the researcher’s (Chenguang Lou) vision for the research and more technical details about “hybrid peptide-DNA nanostructures” along with other international research efforts,

Lou’s vision is to create viral vaccines (modified and weakened versions of a virus) and artificial life forms that can be used for diagnosing and treating diseases.

“In nature, most organisms have natural enemies, but some do not. For example, some disease-causing viruses have no natural enemy. It would be a logical step to create an artificial life form that could become an enemy to them,” he says.

Similarly, he envisions such artificial life forms can act as vaccines against viral infection and can be used as nanorobots [also known as nanobots] or nanomachines loaded with medication or diagnostic elements and sent into a patient’s body.

“An artificial viral vaccine may be about 10 years away. An artificial cell, on the other hand, is on the horizon because it consists of many elements that need to be controlled before we can start building with them. But with the knowledge we have, there is, in principle, no hindrance to produce artificial cellular organisms in the future,” he says.

What are the building blocks that Lou and his colleagues in this field will use to create viral vaccines and artificial life? DNA and peptides are some of the most important biomolecules in nature, making DNA technology and peptide technology the two most powerful molecular tools in the nanotechnological toolkit today. DNA technology provides precise control over programming, from the atomic level to the macro level, but it can only provide limited chemical functions since it only has four bases: A, C, G, and T. Peptide technology, on the other hand, can provide sufficient chemical functions on a large scale, as there are 20 amino acids to work with. Nature uses both DNA and peptides to build various protein factories found in cells, allowing them to evolve into organisms.

Recently, Hanbin Mao and Chenguang Lou have succeeded in linking designed three-stranded DNA structures with three-stranded peptide structures, thus creating an artificial hybrid molecule that combines the strengths of both. This work was published in Nature Communications in 2022. (read the article here “Chirality transmission in macromolecular domains” and the press release at https://www.sdu.dk/en/om_sdu/fakulteterne/naturvidenskab/nyheder-2022/supermolekyle)

Elsewhere in the world, other researchers are also working on connecting DNA and peptides because this connection forms a strong foundation for the development of more advanced biological entities and life forms.

At Oxford University, researchers have succeeded in building a nanomachine made of DNA and peptides that can drill through a cell membrane, creating an artificial membrane channel through which small molecules can pass. (Spruijt et al., Nat. Nanotechnol. 2018, 13, 739-745)

At Arizona State University, Nicholas Stephanopoulos and colleagues have enabled DNA and peptides to self-assemble into 2D and 3D structures. (Buchberger et al., J. Am. Chem. Soc. 2020, 142, 1406-1416)

At Northwest University [Northwestern University?], researchers have shown that microfibers can form in conjunction with DNA and peptides self-assembling. DNA and peptides operate at the nano level, so when considering the size differences, microfibers are huge. (Freeman et al., Science, 2018, 362, 808-813)

At Ben-Gurion University of the Negev, scientists have used hybrid molecules to create an onion-like spherical structure containing cancer medication, which holds promise to be used in the body to target cancerous tumors. (Chotera et al., Chem. Eur. J., 2018, 24, 10128-10135)

“In my view, the overall value of all these efforts is that they can be used to improve society’s ability to diagnose and treat sick people. Looking forward, I will not be surprised that one day we can arbitrarily create hybrid nanomachines, viral vaccines and even artificial life forms from these building blocks to help the society to combat those difficult-to-cure diseases. It would be a revolution in healthcare,” says Chenguang Lou.

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

Peptide-DNA conjugates as building blocks for de novo design of hybrid nanostructures by Mathias Bogetoft Danielsen, Hanbin Mao, Chenguang Lou. Cell Reports Physical Science Volume 4, Issue 10, 18 October 2023, 101620 DOI: https://doi.org/10.1016/j.xcrp.2023.101620

This paper is open access.

The sounds of recent (December 2023) seismic activity in Iceland

On the heels of yesterday’s When the rocks sing “I got rhythm” (my December 18, 2023 posting), I received (via email) a media notice/reminder/update about a Northwestern University (Chicago, Illinois, US) app that allows you to listen,

From the original November 16, 2023 Northwestern University news release by Amanda Morris (also published as a November 16, 2023 news item on phys.org),

As seismic activity intensifies ahead of an impending eruption of a fissure near Iceland’s Fagradalsfjall volcano, the island’s Reykjanes Peninsula is experiencing hundreds of earthquakes per day.

Now, listeners can follow along through Northwestern University’s Earthtunes app. Developed in 2019, the app transforms seismic frequencies into audible pitches. Whereas a classic seismometer records motions in the Earth’s surface as squiggly lines scratched across a page, Earthtunes enables users to hear, rather than see, activity.

So far, Iceland’s recent, ongoing seismic activity sounds like a jarring symphony of doors slamming, hail pelting against a tin roof or window and people cracking trays of ice cubes.

By listening to activities recorded by the Global Seismographic Network station (named BORG), located to the north-northeast of Reykjavik, people can hear how the seismic activity has changed around the Fagradalsfjall area.

In this audio clip, listeners can hear 24 hours of activity recorded from Friday, Nov. 10, into Saturday, Nov. 11. Peppered with a cacophony of sharp knocking noises, it sounds like someone is insistently banging on a door.

“The activity is formidable, exciting and scary,” said Northwestern seismologist Suzan van der Lee, who co-developed Earthtunes. “Iceland did the right thing by evacuating residents in nearby Grindavik and the nearby Svartsengi geothermal power plant, one of the world’s oldest geothermal power plants, which was the first to combine electricity generation with hot water for heating in the region.”

Van der Lee is the Sarah Rebecca Roland Professor of Earth and Planetary Sciences at Northwestern’s Weinberg College of Arts and Sciences. In her research, she applies data science to millions of records of seismic waves in order to decode seismic signals, which harbor valuable information about the Earth’s interior dynamics.

As hundreds of earthquakes shake the ground, Van der Lee says the impending eruption is reminiscent of the 1973 eruption of Heimaey on Iceland’s Vestmannaeyjar archipelago.

“This level of danger is unprecedented for this area of Iceland, but not for Iceland as a whole,” said van der Lee, who hiked Fagradalsfjall in June. “While most Icelandic volcanoes erupt away from towns and other infrastructure, Icelanders share the terrible memory of an eruption 50 years ago on the island Vestmannaeyjar, during which lava covered part of that island’s town, Heimaey. The residents felt very vulnerable, as the evacuated people of Grindavik feel now. In a few days or weeks, they might no longer have their jobs, homes and most possessions, while still having to feed their families and pay their mortgages. However, partially resulting from that eruption on Vestmannaeyjar, Icelanders are well prepared for the current situation in the Fagradallsfjall-Svartsengi-Grindavik area.” 

Accelerated audio

This audio clip presents the same data, with the pitch increased by 10 octaves. Listeners will hear a long, low rumbling sound, punctuated by an occasional slamming door.

“What you’re hearing is 24 hours of seismic data — filled with earthquake signals,” van der Lee said. “The vast majority of these quakes are associated with the magma intrusion into the crust of the Fagradallsfjall-Svartsengi-Grindavik area of the Reykjanes Peninsula. Seismic data are not audible; their frequencies are too low. So, the 24 hours of data are compressed into approximately 1.5 minutes of audio data. You can hear an unprecedented intensity of earthquakes during the night from last Friday into Saturday and related to a new magma intrusion into the crust area.”

In a third audio clip, the same data is less compressed, with the pitch increased by just seven octaves

“One can hear frequent earthquakes happening at this point,” van der Lee said. “Icelandic seismologists have been monitoring these quakes and their increasing vigor and changing patterns. They recognized similar patterns to earthquake swarms that preceded the 2021-2023 eruptions of the adjacent Fagradallsfjall volcano.”

Earthtunes is supported by the American Geophysical Union and Northwestern’s department of Earth and planetary sciences. Seismic data is obtained from the Earthscope Consortium. The app was designed and developed by van der Lee, Helio Tejedor, Melanie Marzen, Igor Eufrasio, Josephine Anderson, Liam Toney, Cooper Barth, Michael Ji and Leonicio Cabrera.

Jennifer Ouellette’s November 16, 2023 article for Ars Tecnica draws heavily from the news release while delving into the topic of data sonification (making sounds from data), Note: Links have been removed,

….

Sonification of scientific data is an area of growing interest in many different fields. For instance, several years ago, a project called LHCSound built a library of the “sounds” of a top quark jet and the Higgs boson, among others. The project hoped to develop sonification as a technique for analyzing the data from particle collisions so that physicists could “detect” subatomic particles by ear. Other scientists have mapped the molecular structure of proteins in spider silk threads onto musical theory to produce the “sound” of silk in hopes of establishing a radical new way to create designer proteins. And there’s a free app for Android called the Amino Acid Synthesizer that enables users to create their own protein “compositions” from the sounds of amino acids.

The December 19, 2023 Northwestern University media update points to the latest audio file of the eruption of the svartsengi-grindavik fissure in Iceland: 24 hours as of Monday, December 18, 2023 14:00:00 UTC.

Enjoy!

One last thing, there are a number of postings about data sonification here; many but not all scientists and/or communication practitioners think to include audio files.

100-fold increase in AI energy efficiency

Most people don’t realize how much energy computing, streaming video, and other technologies consume and AI (artificial intelligence) consumes a lot. (For more about work being done in this area, there’s my October 13, 2023 posting about an upcoming ArtSci Salon event in Toronto featuring Laura U. Marks’s recent work ‘Streaming Carbon Footprint’ and my October 16, 2023 posting about how much water is used for AI.)

So this news is welcome, from an October 12, 2023 Northwestern University news release (also received via email and on EurekAlert), Note: Links have been removed,

AI just got 100-fold more energy efficient

Nanoelectronic device performs real-time AI classification without relying on the cloud

– AI is so energy hungry that most data analysis must be performed in the cloud
– New energy-efficient device enables AI tasks to be performed within wearables
– This allows real-time analysis and diagnostics for faster medical interventions
– Researchers tested the device by classifying 10,000 electrocardiogram samples
– The device successfully identified six types of heart beats with 95% accuracy

Northwestern University engineers have developed a new nanoelectronic device that can perform accurate machine-learning classification tasks in the most energy-efficient manner yet. Using 100-fold less energy than current technologies, the device can crunch large amounts of data and perform artificial intelligence (AI) tasks in real time without beaming data to the cloud for analysis.

With its tiny footprint, ultra-low power consumption and lack of lag time to receive analyses, the device is ideal for direct incorporation into wearable electronics (like smart watches and fitness trackers) for real-time data processing and near-instant diagnostics.

To test the concept, engineers used the device to classify large amounts of information from publicly available electrocardiogram (ECG) datasets. Not only could the device efficiently and correctly identify an irregular heartbeat, it also was able to determine the arrhythmia subtype from among six different categories with near 95% accuracy.

The research was published today (Oct. 12 [2023]) in the journal Nature Electronics.

“Today, most sensors collect data and then send it to the cloud, where the analysis occurs on energy-hungry servers before the results are finally sent back to the user,” said Northwestern’s Mark C. Hersam, the study’s senior author. “This approach is incredibly expensive, consumes significant energy and adds a time delay. Our device is so energy efficient that it can be deployed directly in wearable electronics for real-time detection and data processing, enabling more rapid intervention for health emergencies.”

A nanotechnology expert, Hersam is 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 of Nanotechnology. Hersam co-led the research with Han Wang, a professor at the University of Southern California, and Vinod Sangwan, a research assistant professor at Northwestern.

Before machine-learning tools can analyze new data, these tools must first accurately and reliably sort training data into various categories. For example, if a tool is sorting photos by color, then it needs to recognize which photos are red, yellow or blue in order to accurately classify them. An easy chore for a human, yes, but a complicated — and energy-hungry — job for a machine.

For current silicon-based technologies to categorize data from large sets like ECGs, it takes more than 100 transistors — each requiring its own energy to run. But Northwestern’s nanoelectronic device can perform the same machine-learning classification with just two devices. By reducing the number of devices, the researchers drastically reduced power consumption and developed a much smaller device that can be integrated into a standard wearable gadget.

The secret behind the novel device is its unprecedented tunability, which arises from a mix of materials. While traditional technologies use silicon, the researchers constructed the miniaturized transistors from two-dimensional molybdenum disulfide and one-dimensional carbon nanotubes. So instead of needing many silicon transistors — one for each step of data processing — the reconfigurable transistors are dynamic enough to switch among various steps.

“The integration of two disparate materials into one device allows us to strongly modulate the current flow with applied voltages, enabling dynamic reconfigurability,” Hersam said. “Having a high degree of tunability in a single device allows us to perform sophisticated classification algorithms with a small footprint and low energy consumption.”

To test the device, the researchers looked to publicly available medical datasets. They first trained the device to interpret data from ECGs, a task that typically requires significant time from trained health care workers. Then, they asked the device to classify six types of heart beats: normal, atrial premature beat, premature ventricular contraction, paced beat, left bundle branch block beat and right bundle branch block beat.

The nanoelectronic device was able to identify accurately each arrhythmia type out of 10,000 ECG samples. By bypassing the need to send data to the cloud, the device not only saves critical time for a patient but also protects privacy.

“Every time data are passed around, it increases the likelihood of the data being stolen,” Hersam said. “If personal health data is processed locally — such as on your wrist in your watch — that presents a much lower security risk. In this manner, our device improves privacy and reduces the risk of a breach.”

Hersam imagines that, eventually, these nanoelectronic devices could be incorporated into everyday wearables, personalized to each user’s health profile for real-time applications. They would enable people to make the most of the data they already collect without sapping power.

“Artificial intelligence tools are consuming an increasing fraction of the power grid,” Hersam said. “It is an unsustainable path if we continue relying on conventional computer hardware.”

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

Reconfigurable mixed-kernel heterojunction transistors for personalized support vector machine classification by Xiaodong Yan, Justin H. Qian, Jiahui Ma, Aoyang Zhang, Stephanie E. Liu, Matthew P. Bland, Kevin J. Liu, Xuechun Wang, Vinod K. Sangwan, Han Wang & Mark C. Hersam. Nature Electronics (2023) DOI: https://doi.org/10.1038/s41928-023-01042-7 Published: 12 October 2023

This paper is behind a paywall.

Sponge coated with nanoparticles removes lead from water

It doesn’t look like much but who cares when it does the job and is being made available commercially,

Caption: Commercially available cellulose sponge coated in manganese-doped goethite nanoparticles. Credit: Caroline Harms/Northwestern University

A May 11, 2023 news item on Nanowerk announces the research,

Northwestern University engineers have developed a new sponge that can remove metals — including toxic heavy metals like lead and critical metals like cobalt — from contaminated water, leaving safe, drinkable water behind.

In proof-of-concept experiments, the researchers tested their new sponge on a highly contaminated sample of tap water, containing more than 1 part per million of lead. With one use, the sponge filtered lead to below detectable levels.

After using the sponge, researchers also were able to successfully recover metals and reuse the sponge for multiple cycles. The new sponge shows promise for future use as an inexpensive, easy-to-use tool in home water filters or large-scale environmental remediation efforts.

A May 10, 2023 Northwestern University news release on EurekAlert (also received via email) provides more detail, Note: Links have been removed,

The study was published late yesterday (May 10 [2023]) in the journal ACS ES&T Water. The paper outlines the new research and sets design rules for optimizing similar platforms for removing — and recovering — other heavy-metal toxins, including cadmium, arsenic, cobalt and chromium.

“The presence of heavy metals in the water supply is an enormous public health challenge for the entire globe,” said Northwestern’s Vinayak Dravid, senior author of the study. “It is a gigaton problem that requires solutions that can be deployed easily, effectively and inexpensively. That’s where our sponge comes in. It can remove the pollution and then be used again and again.”

Dravid is the Abraham Harris Professor of Materials Science and Engineering at Northwestern’s McCormick School of Engineering and director of global initiatives at the International Institute for Nanotechnology.

Sopping up spills

The project builds on Dravid’s previous work to develop highly porous sponges for various aspects of environmental remediation. In May 2020, his team unveiled a new sponge designed to clean up oil spills. [Note: My June 25, 2020 posting highlights the work and includes an embedded video demonstration of the technology.] The nanoparticle-coated sponge, which is now being commercialized by Northwestern spinoff MFNS Tech, offers a more efficient, economic, ecofriendly and reusable alternative to current approaches to oil spills.

But Dravid knew it wasn’t enough.

“When there is an oil spill, you can remove the oil,” he said. “But there also are toxic heavy metals — like mercury, cadmium, sulfur and lead — in those spills. So, even when you remove the oil, some of the other toxins might remain.

Rinse and repeat

To tackle this aspect of the issue, Dravid’s team, again, turned to sponges coated with an ultrathin layer of nanoparticles. After testing many different types of nanoparticles, the team found that a manganese-doped goethite coating worked best. Not only are manganese-doped goethite nanoparticles inexpensive to make, easily available and nontoxic to human, they also have the properties necessary to selectively remediate heavy metals.

“You want a material with a high surface area, so there’s more room for the lead ions to stick to it,” said Benjamin Shindel, a Ph.D. student in Dravid’s lab and the paper’s first author. “These nanoparticles have high-surface areas and abundant reactive surface sites for adsorption and are stable, so they can be reused many times.”

The team synthesized slurries of manganese-doped goethite nanoparticles, as well as several other compositions of nanoparticles, and coated commercially available cellulose sponges with these slurries. Then, they rinsed the coated sponges with water in order to wash away any loose particles. The final coatings measured just tens of nanometers in thickness.

When submerged into contaminated water, the nanoparticle-coated sponge effectively sequested lead ions. The U.S. Food and Drug Administration requires that bottled drinking water is below 5 parts per billion of lead. In filtration trials, the sponge lowered the amount of lead to approximately 2 parts per billion, making it safe to drink.

“We’re really happy with that,” Shindel said. “Of course, this performance can vary based on several factors. For instance, if you have a large sponge in a tiny volume of water, it will perform better than a tiny sponge in a huge lake.”

Recovery bypasses mining

From there, the team rinsed the sponge with mildly acidified water, which Shindel likened to “having the same acidity of lemonade.” The acidic solution caused the sponge to release the lead ions and be ready for another use. Although the sponge’s performance declined after the first use, it still recovered more than 90% of the ions during subsequent use cycles.

This ability to gather and then recover heavy metals is particularly valuable for removing rare, critical metals, such as cobalt, from water sources. A common ingredient in lithium-ion batteries, cobalt is energetically expensive to mine and accompanied by a laundry list of environmental and human costs.

If researchers could develop a sponge that selectively removes rare metals, including cobalt, from water, then those metals could be recycled into products like batteries.

“For renewable energy technologies, like batteries and fuel cells, there is a need for metal recovery,” Dravid said. “Otherwise, there is not enough cobalt in the world for the growing number of batteries. We must find ways to recover metals from very dilute solutions. Otherwise, it becomes poisonous and toxic, just sitting there in the water. We might as well make something valuable with it.”

Standardized scale

As a part of the study, Dravid and his team set new design rules to help others develop tools to target particular metals, including cobalt. Specifically, they pinpointed which low-cost and nontoxic nanoparticles also have high-surface areas and affinities for sticking to metal ions. They studied the performance of coatings of manganese, iron, aluminum and zinc oxides on lead adsorption. Then, they established relationships between the structures of these nanoparticles and their adsorptive properties.

Called Nanomaterial Sponge Coatings for Heavy Metals (or “Nano-SCHeMe”), the environmental remediation platform can help other researchers differentiate which nanomaterials are best suited for particular applications.

“I’ve read a lot of literature that compares different coatings and adsorbents,” said Caroline Harms, an undergraduate student in Dravid’s lab and paper co-author. “There really is a lack of standardization in the field. By analyzing different types of nanoparticles, we developed a comparative scale that actually works for all of them. It could have a lot of implications in moving the field forward.”

Dravid and his team imagine that their sponge could be used in commercial water filters, for environmental clean-up or as an added step in water reclamation and treatment facilities.

“This work may be pertinent to water quality issues both locally and globally,” Shindel said. “We want to see this out in the world, where it can make a real impact.”

The study, “Nano-SCHeME: Nanomaterial Sponge Coatings for Heavy Metals, an environmental remediation platform,” was supported by the National Science Foundation and U.S. Department of Energy.

Editor’s note: Dravid and Northwestern have financial interests (equities, royalties) in MFNS Tech.

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

Nano-SCHeme: Nanomaterial Sponge Coatings for Heavy Metals, an Environmental Remediation Platform by Benjamin Shindel, Stephanie M. Ribet, Caroline Harms, Vikas Nandwana, and Vinayak P. Dravid. ACS EST Water 2023, XXXX, XXX, XXX-XXX DOI: https://doi.org/10.1021/acsestwater.2c00646 Publication Date:May 10, 2023 © 2023 American Chemical Society

This paper is behind a paywall.

You can find the MFNS Tech website here.

Treating cardiac arrhythmia with light: a graphene tattoo

An April 17, 2023 news item on Nanowerk announced research into a graphene cardiac implant/tattoo,

Researchers led by Northwestern University and the University of Texas at Austin (UT) have developed the first cardiac implant made from graphene, a two-dimensional super material with ultra-strong, lightweight and conductive properties.

Similar in appearance to a child’s temporary tattoo, the new graphene “tattoo” implant is thinner than a single strand of hair yet still functions like a classical pacemaker. But unlike current pacemakers and implanted defibrillators, which require hard, rigid materials that are mechanically incompatible with the body, the new device softly melds to the heart to simultaneously sense and treat irregular heartbeats. The implant is thin and flexible enough to conform to the heart’s delicate contours as well as stretchy and strong enough to withstand the dynamic motions of a beating heart.

Caption: Graphene implant on tattoo paper. Credit: Ning Liu/University of Texas at Austin

An April 17, 2023 Northwestern University news release (also on EurekAlert), which originated the news item, provides more detail about the research, graphene, and the difficulties of monitoring a beating heart, Note: Links have been removed,

After implanting the device into a rat model, the researchers demonstrated that the graphene tattoo could successfully sense irregular heart rhythms and then deliver electrical stimulation through a series of pulses without constraining or altering the heart’s natural motions. Even better: The technology also is optically transparent, allowing the researchers to use an external source of optical light to record and stimulate the heart through the device.

The study will be published on Thursday (April 20 [2023]) in the journal Advanced Materials. It marks the thinnest known cardiac implant to date.

“One of the challenges for current pacemakers and defibrillators is that they are difficult to affix onto the surface of the heart,” said Northwestern’s Igor Efimov, the study’s senior author. “Defibrillator electrodes, for example, are essentially coils made of very thick wires. These wires are not flexible, and they break. Rigid interfaces with soft tissues, like the heart, can cause various complications. By contrast, our soft, flexible device is not only unobtrusive but also intimately and seamlessly conforms directly onto the heart to deliver more precise measurements.”

An experimental cardiologist, Efimov is a professor of biomedical engineering at Northwestern’s McCormick School of Engineering and professor of medicine at Northwestern University Feinberg School of Medicine. He co-led the study with Dmitry Kireev, a research associate at UT. Zexu Lin, a Ph.D. candidate in Efimov’s laboratory, is the paper’s first author.

Miracle material

Known as cardiac arrhythmias, heart rhythm disorders occur when the heart beats either too quickly or too slowly. While some cases of arrhythmia are not serious, many cases can lead to heart failure, stroke and even sudden death. In fact, complications related to arrythmia claim about 300,000 lives annually in the United States. Physicians commonly treat arrhythmia with implantable pacemakers and defibrillators that detect abnormal heartbeats and then correct rhythm with electrical stimulation. While these devices are lifesaving, their rigid nature may constrain the heart’s natural motions, injure soft tissues, cause temporary discomfort and induce complications, such as painful swelling, perforations, blood clots, infection and more.

With these challenges in mind, Efimov and his team sought to develop a bio-compatible device ideal for conforming to soft, dynamic tissues. After reviewing multiple materials, the researchers settled on graphene, an atomically thin form of carbon. With its ultra-strong, lightweight structure and superior conductivity, graphene has potential for many applications in high-performance electronics, high-strength materials and energy devices.

“For bio-compatibility reasons, graphene is particularly attractive,” Efimov said. “Carbon is the basis of life, so it’s a safe material that is already used in different clinical applications. It also is flexible and soft, which works well as an interface between electronics and a soft, mechanically active organ.”

Hitting a beating target

At UT, study co-authors Dimitry Kireev and Deji Akinwande were already developing graphene electronic tattoos (GETs) with sensing capabilities. Flexible and weightless, their team’s e-tattoos adhere to the skin to continuously monitor the body’s vital signs, including blood pressure and the electrical activity of the brain, heart and muscles.

But, while the e-tattoos work well on the skin’s surface, Efimov’s team needed to investigate new methods to use these devices inside the body — directly onto the surface of the heart.

“It’s a completely different application scheme,” Efimov said. “Skin is relatively dry and easily accessible. Obviously, the heart is inside the chest, so it’s difficult to access and in a wet environment.”

The researchers developed an entirely new technique to encase the graphene tattoo and adhere it to the surface of a beating heart. First, they encapsulated the graphene inside a flexible, elastic silicone membrane — with a hole punched in it to give access to the interior graphene electrode. Then, they gently placed gold tape (with a thickness of 10 microns) onto the encapsulating layer to serve as an electrical interconnect between the graphene and the external electronics used to measure and stimulate the heart. Finally, they placed it onto the heart. The entire thickness of all layers together measures about 100 microns in total.

The resulting device was stable for 60 days on an actively beating heart at body temperature, which is comparable to the duration of temporary pacemakers used as bridges to permanent pacemakers or rhythm management after surgery or other therapies.

Optical opportunities

Leveraging the device’s transparent nature, Efimov and his team performed optocardiography — using light to track and modulate heart rhythm — in the animal study. Not only does this offer a new way to diagnose and treat heart ailments, the approach also opens new possibilities for optogenetics, a method to control and monitor single cells with light. 

While electrical stimulation can correct a heart’s abnormal rhythm, optical stimulation is more precise. With light, researchers can track specific enzymes as well as interrogate specific heart, muscle or nerve cells.

“We can essentially combine electrical and optical functions into one biointerface,” Efimov said. “Because graphene is optically transparent, we can actually read through it, which gives us a much higher density of readout.”

The University of Texas at Austin issued an April 18, 2023 news release and as you would expect the focus is on their researchers, Note 1: I’ve removed many but not all of the redundancies between the two news releases; Note 2: A link has been removed,

A new cardiac implant made from graphene, a two-dimensional super material with ultra-strong, lightweight and conductive properties, functions like a classic pacemaker with some major improvements.

A team led by researchers from The University of Texas at Austin and Northwestern University developed the implantable derivative from wearable graphene-based electronic tattoo, or e-tattoo – graphene biointerface. The device, detailed in the journal Advanced Materials, marks the thinnest known cardiac implant to date.

“It’s very exciting to take our e-tattoo technology and use it as an implantable device inside the body,” said Dmitry Kireev, a postdoctoral research associate in the lab of professor Deji Akinwande’s lab at UT Austin who co-led the research. “The fact that is much more compatible with the human body, lightweight, and transparent, makes this a more natural solution for people dealing with heart problems.”

Hitting a beating target

At UT Austin, Akinwande and his team had been developing e-tattoos using graphene for several years, with a variety of functions, including monitoring body signals. Flexible and weightless, their team’s e-tattoos adhere to the skin to continuously monitor the body’s vital signs, including blood pressure and the electrical activity of the brain, heart and muscles.

But, while the e-tattoos work well on the skin’s surface, the researchers needed to find new ways to deploy these devices inside the body — directly onto the surface of the heart.

“The conditions inside the body are very different compared to affixing a device to the skin, so we had to re-imagine how we package our e-tattoo technology,” said Akinwande, a professor in the Chandra Family Department of Electrical and Computer Engineering.  

The researchers developed an entirely new technique to encase the graphene tattoo and adhere it to the surface of a beating heart. …

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

Graphene Biointerface for Cardiac Arrhythmia Diagnosis and Treatment by Zexu Lin, Dmitry Kireev, Ning Liu, Shubham Gupta, Jessica LaPiano, Sofian N. Obaid, Zhiyuan Chen, Deji Akinwande, Igor R. Efimov. Advanced Materials Volume 35, Issue 22 June 1, 2023 2212190 DOI: https://doi.org/10.1002/adma.202212190 First published online: 25 March 2023

This paper is open access.

Powered by light: a battery-free pacemaker

I think it looks more like a potato than a heart but it does illustrate how this new battery-free pacemaker would wrap around a heart,

Caption: An artist’s rendering shows how a new pacemaker, designed by a UArizona-led team of researchers, is able to envelop the heart. The wireless, battery-free pacemaker could be implanted with a less invasive procedure than currently possible and would cause patients less pain. Credit: Philipp Gutruff

An October 27, 2022 news item on ScienceDaily announces a technology that could make life much easier for people with pacemakers (Comment: In the image, that looks more like a potato than a heart, to me),

University of Arizona engineers lead a research team that is developing a new kind of pacemaker, which envelops the heart and uses precise targeting capabilities to bypass pain receptors and reduce patient discomfort.

An October 27, 2022 University of Arizona news release (also on EurekAlert) by Emily Dieckman, which originated the news item, explains the reasons for the research and provides some technical details (Note: Links have been removed),

Pacemakers are lifesaving devices that regulate the heartbeats of people with chronic heart diseases like atrial fibrillation and other forms of arrhythmia. However, pacemaker implantation is an invasive procedure, and the lifesaving pacing the devices provide can be extremely painful. Additionally, pacemakers can only be used to treat a few specific types of disease.

In a paper published Wednesday [October 26, 2022] in Science Advances, a University of Arizona-led team of researchers detail the workings of a wireless, battery-free pacemaker they designed that could be implanted with a less invasive procedure than currently possible and would cause patients less pain. The study was helmed by researchers in the Gutruf Lab, led by biomedical engineering assistant professor and Craig M. Berge Faculty Fellow Philipp Gutruf.

Currently available pacemakers work by implanting one or two leads, or points of contact, into the heart with hooks or screws. If the sensors on these leads detect a dangerous irregularity, they send an electrical shock through the heart to reset the beat.

“All of the cells inside the heart get hit at one time, including the pain receptors, and that’s what makes pacing or defibrillation painful,” Gutruf said. “It affects the heart muscle as a whole.”

The device Gutruf’s team has developed, which has not yet been tested in humans, would allow pacemakers to send much more targeted signals using a new digitally manufactured mesh design that encompasses the entire heart. The device uses light and a technique called optogenetics.

Optogenetics modifies cells, usually neurons, sensitive to light, then uses light to affect the behavior of those cells. This technique only targets cardiomyocytes, the cells of the muscle that trigger contraction and make up the beat of the heart. This precision will not only reduce pain for pacemaker patients by bypassing the heart’s pain receptors, it will also allow the pacemaker to respond to different kinds of irregularities in more appropriate ways. For example, during atrial fibrillation, the upper and lower chambers of the heart beat asynchronously, and a pacemaker’s role is to get the two parts back in line.

“Whereas right now, we have to shock the whole heart to do this, these new devices can do much more precise targeting, making defibrillation both more effective and less painful,” said Igor Efimov, professor of biomedical engineering and medicine at Northwestern University, where the devices were lab-tested. “This technology could make life easier for patients all over the world, while also helping scientists and physicians learn more about how to monitor and treat the disease.”

Flexible mesh encompasses the heart

To ensure the light signals can reach many different parts of the heart, the team created a design that involves encompassing the organ, rather than implanting leads that provide limited points of contact.

The new pacemaker model consists of four petallike structures made of thin, flexible film, which contain light sources and a recording electrode. The petals, specially designed to accommodate the way the heart changes shape as it beats, fold up around the sides of the organ to envelop it, like a flower closing up at night.

“Current pacemakers record basically a simple threshold, and they will tell you, ‘This is going into arrhythmia, now shock!'” Gutruf said. “But this device has a computer on board where you can input different algorithms that allow you to pace in a more sophisticated way. It’s made for research.”

Because the system uses light to affect the heart, rather than electrical signals, the device can continue recording information even when the pacemaker needs to defibrillate. In current pacemakers, the electrical signal from the defibrillation can interfere with recording capabilities, leaving physicians with an incomplete picture of cardiac episodes. Additionally, the device does not require a battery, which could save pacemaker patients from needing to replace the battery in their device every five to seven years, as is currently the norm.

Gutruf’s team collaborated with researchers at Northwestern University on the project. While the current version of the device has been successfully demonstrated in animal models, the researchers look forward to furthering their work, which could improve the quality of life for millions of people.

The prototype looks like this,

Caption: The device uses light and a technique called optogenetics, which modifies cells that are sensitive to light, then uses light to affect the behavior of those cells.. Credit: Philipp Gutruff

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

Wireless, fully implantable cardiac stimulation and recording with on-device computation for closed-loop pacing and defibrillation by Jokubas Ausra, Micah Madrid, Rose T. Yin, Jessica Hanna, Suzanne Arnott, Jaclyn A. Brennan, Roberto Peralta, David Clausen, Jakob A. Bakall, Igor R. Efimov, and Philipp Gutruf. Science Advances 26 Oct 2022 Vol 8, Issue 43 DOI: 10.1126/sciadv.abq7469

This paper is open access.