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    MIT engineers design tiny batteries for powering cell-sized robots

    A tiny battery designed by MIT engineers could enable the deployment of cell-sized, autonomous robots for drug delivery within in the human body, as well as other applications such as locating leaks in gas pipelines.The new battery, which is 0.1 millimeters long and 0.002 millimeters thick — roughly the thickness of a human hair — can capture oxygen from air and use it to oxidize zinc, creating a current of up to 1 volt. That is enough to power a small circuit, sensor, or actuator, the researchers showed.“We think this is going to be very enabling for robotics,” says Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT and the senior author of the study. “We’re building robotic functions onto the battery and starting to put these components together into devices.”Ge Zhang PhD ’22 and Sungyun Yang, an MIT graduate student, are the lead author of the paper, which appears in Science Robotics.Powered by batteriesFor several years, Strano’s lab has been working on tiny robots that can sense and respond to stimuli in their environment. One of the major challenges in developing such tiny robots is making sure that they have enough power.Other researchers have shown that they can power microscale devices using solar power, but the limitation to that approach is that the robots must have a laser or another light source pointed at them at all times. Such devices are known as “marionettes” because they are controlled by an external power source. Putting a power source such as a battery inside these tiny devices could free them to roam much farther.“The marionette systems don’t really need a battery because they’re getting all the energy they need from outside,” Strano says. “But if you want a small robot to be able to get into spaces that you couldn’t access otherwise, it needs to have a greater level of autonomy. A battery is essential for something that’s not going to be tethered to the outside world.”To create robots that could become more autonomous, Strano’s lab decided to use a type of battery known as a zinc-air battery. These batteries, which have a longer lifespan than many other types of batteries due to their high energy density, are often used in hearing aids.The battery that they designed consists of a zinc electrode connected to a platinum electrode, embedded into a strip of a polymer called SU-8, which is commonly used for microelectronics. When these electrodes interact with oxygen molecules from the air, the zinc becomes oxidized and releases electrons that flow to the platinum electrode, creating a current.In this study, the researchers showed that this battery could provide enough energy to power an actuator — in this case, a robotic arm that can be raised and lowered. The battery could also power a memristor, an electrical component that can store memories of events by changing its electrical resistance, and a clock circuit, which allows robotic devices to keep track of time.The battery also provides enough power to run two different types of sensors that change their electrical resistance when they encounter chemicals in the environment. One of the sensors is made from atomically thin molybdenum disulfide and the other from carbon nanotubes.“We’re making the basic building blocks in order to build up functions at the cellular level,” Strano says.Robotic swarmsIn this study, the researchers used a wire to connect their battery to an external device, but in future work they plan to build robots in which the battery is incorporated into a device.“This is going to form the core of a lot of our robotic efforts,” Strano says. “You can build a robot around an energy source, sort of like you can build an electric car around the battery.”One of those efforts revolves around designing tiny robots that could be injected into the human body, where they could seek out a target site and then release a drug such as insulin. For use in the human body, the researchers envision that the devices would be made of biocompatible materials that would break apart once they were no longer needed.The researchers are also working on increasing the voltage of the battery, which may enable additional applications.The research was funded by the U.S. Army Research Office, the U.S. Department of Energy, the National Science Foundation, and a MathWorks Engineering Fellowship. More

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    MIT announces 2024 Bose Grants

    MIT Provost Cynthia Barnhart announced four Professor Amar G. Bose Research Grants to support bold research projects across diverse areas of study, including a way to generate clean hydrogen from deep in the Earth, build an environmentally friendly house of basalt, design maternity clothing that monitors fetal health, and recruit sharks as ocean oxygen monitors.

    This year’s recipients are Iwnetim Abate, assistant professor of materials science and engineering; Andrew Babbin, the Cecil and Ida Green Associate Professor in Earth, Atmospheric and Planetary Sciences; Yoel Fink, professor of materials science and engineering and of electrical engineering and computer science; and Skylar Tibbits, associate professor of design research in the Department of Architecture.

    The program was named for the visionary founder of the Bose Corporation and MIT alumnus Amar G. Bose ’51, SM ’52, ScD ’56. After gaining admission to MIT, Bose became a top math student and a Fulbright Scholarship recipient. He spent 46 years as a professor at MIT, led innovations in sound design, and founded the Bose Corp. in 1964. MIT launched the Bose grant program 11 years ago to provide funding over a three-year period to MIT faculty who propose original, cross-disciplinary, and often risky research projects that would likely not be funded by conventional sources.

    “The promise of the Bose Fellowship is to help bold, daring ideas become realities, an approach that honors Amar Bose’s legacy,” says Barnhart. “Thanks to support from this program, these talented faculty members have the freedom to explore their bold and innovative ideas.”

    Deep and clean hydrogen futures

    A green energy future will depend on harnessing hydrogen as a clean energy source, sequestering polluting carbon dioxide, and mining the minerals essential to building clean energy technologies such as advanced batteries. Iwnetim Abate thinks he has a solution for all three challenges: an innovative hydrogen reactor.

    He plans to build a reactor that will create natural hydrogen from ultramafic mineral rocks in the crust. “The Earth is literally a giant hydrogen factory waiting to be tapped,” Abate explains. “A back-of-the-envelope calculation for the first seven kilometers of the Earth’s crust estimates that there is enough ultramafic rock to produce hydrogen for 250,000 years.”

    The reactor envisioned by Abate injects water to create a reaction that releases hydrogen, while also supporting the injection of climate-altering carbon dioxide into the rock, providing a global carbon capacity of 100 trillion tons. At the same time, the reactor process could provide essential elements such as lithium, nickel, and cobalt — some of the most important raw materials used in advanced batteries and electronics.

    “Ultimately, our goal is to design and develop a scalable reactor for simultaneously tapping into the trifecta from the Earth’s subsurface,” Abate says.

    Sharks as oceanographers

    If we want to understand more about how oxygen levels in the world’s seas are disturbed by human activities and climate change, we should turn to a sensing platform “that has been honed by 400 million years of evolution to perfectly sample the ocean: sharks,” says Andrew Babbin.

    As the planet warms, oceans are projected to contain less dissolved oxygen, with impacts on the productivity of global fisheries, natural carbon sequestration, and the flux of climate-altering greenhouse gasses from the ocean to the air. While scientists know dissolved oxygen is important, it has proved difficult to track over seasons, decades, and underexplored regions both shallow and deep.

    Babbin’s goal is to develop a low-cost sensor for dissolved oxygen that can be integrated with preexisting electronic shark tags used by marine biologists. “This fleet of sharks … will finally enable us to measure the extent of the low-oxygen zones of the ocean, how they change seasonally and with El Niño/La Niña oscillation, and how they expand or contract into the future.”

    The partnership with sharks will also spotlight the importance of these often-maligned animals for global marine and fisheries health, Babbin says. “We hope in pursuing this work marrying microscopic and macroscopic life we will inspire future oceanographers and conservationists, and lead to a better appreciation for the chemistry that underlies global habitability.”

    Maternity wear that monitors fetal health

    There are 2 million stillbirths around the world each year, and in the United States alone, 21,000 families suffer this terrible loss. In many cases, mothers and their doctors had no warning of any abnormalities or changes in fetal health leading up to these deaths. Yoel Fink and colleagues are looking for a better way to monitor fetal health and provide proactive treatment.

    Fink is building on years of research on acoustic fabrics to design an affordable shirt for mothers that would monitor and communicate important details of fetal health. His team’s original research drew inspiration from the function of the eardrum, designing a fiber that could be woven into other fabrics to create a kind of fabric microphone.

    “Given the sensitivity of the acoustic fabrics in sensing these nanometer-scale vibrations, could a mother’s clothing transcend its conventional role and become a health monitor, picking up on the acoustic signals and subsequent vibrations that arise from her unborn baby’s heartbeat and motion?” Fink says. “Could a simple and affordable worn fabric allow an expecting mom to sleep better, knowing that her fetus is being listened to continuously?”

    The proposed maternity shirt could measure fetal heart and breathing rate, and might be able to give an indication of the fetal body position, he says. In the final stages of development, he and his colleagues hope to develop machine learning approaches that would identify abnormal fetal heart rate and motion and deliver real-time alerts.

    A basalt house in Iceland

    In the land of volcanoes, Skylar Tibbits wants to build a case-study home almost entirely from the basalt rock that makes up the Icelandic landscape.

    Architects are increasingly interested in building using one natural material — creating a monomaterial structure — that can be easily recycled. At the moment, the building industry represents 40 percent of carbon emissions worldwide, and consists of many materials and structures, from metal to plastics to concrete, that can’t be easily disassembled or reused.

    The proposed basalt house in Iceland, a project co-led by J. Jih, associate professor of the practice in the Department of Architecture, is “an architecture that would be fully composed of the surrounding earth, that melts back into that surrounding earth at the end of its lifespan, and that can be recycled infinitely,” Tibbits explains.

    Basalt, the most common rock form in the Earth’s crust, can be spun into fibers for insulation and rebar. Basalt fiber performs as well as glass and carbon fibers at a lower cost in some applications, although it is not widely used in architecture. In cast form, it can make corrosion- and heat-resistant plumbing, cladding and flooring.

    “A monomaterial architecture is both a simple and radical proposal that unfortunately falls outside of traditional funding avenues,” says Tibbits. “The Bose grant is the perfect and perhaps the only option for our research, which we see as a uniquely achievable moonshot with transformative potential for the entire built environment.” More

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    Power when the sun doesn’t shine

    In 2016, at the huge Houston energy conference CERAWeek, MIT materials scientist Yet-Ming Chiang found himself talking to a Tesla executive about a thorny problem: how to store the output of solar panels and wind turbines for long durations.        

    Chiang, the Kyocera Professor of Materials Science and Engineering, and Mateo Jaramillo, a vice president at Tesla, knew that utilities lacked a cost-effective way to store renewable energy to cover peak levels of demand and to bridge the gaps during windless and cloudy days. They also knew that the scarcity of raw materials used in conventional energy storage devices needed to be addressed if renewables were ever going to displace fossil fuels on the grid at scale.

    Energy storage technologies can facilitate access to renewable energy sources, boost the stability and reliability of power grids, and ultimately accelerate grid decarbonization. The global market for these systems — essentially large batteries — is expected to grow tremendously in the coming years. A study by the nonprofit LDES (Long Duration Energy Storage) Council pegs the long-duration energy storage market at between 80 and 140 terawatt-hours by 2040. “That’s a really big number,” Chiang notes. “Every 10 people on the planet will need access to the equivalent of one EV [electric vehicle] battery to support their energy needs.”

    In 2017, one year after they met in Houston, Chiang and Jaramillo joined forces to co-found Form Energy in Somerville, Massachusetts, with MIT graduates Marco Ferrara SM ’06, PhD ’08 and William Woodford PhD ’13, and energy storage veteran Ted Wiley.

    “There is a burgeoning market for electrical energy storage because we want to achieve decarbonization as fast and as cost-effectively as possible,” says Ferrara, Form’s senior vice president in charge of software and analytics.

    Investors agreed. Over the next six years, Form Energy would raise more than $800 million in venture capital.

    Bridging gaps

    The simplest battery consists of an anode, a cathode, and an electrolyte. During discharge, with the help of the electrolyte, electrons flow from the negative anode to the positive cathode. During charge, external voltage reverses the process. The anode becomes the positive terminal, the cathode becomes the negative terminal, and electrons move back to where they started. Materials used for the anode, cathode, and electrolyte determine the battery’s weight, power, and cost “entitlement,” which is the total cost at the component level.

    During the 1980s and 1990s, the use of lithium revolutionized batteries, making them smaller, lighter, and able to hold a charge for longer. The storage devices Form Energy has devised are rechargeable batteries based on iron, which has several advantages over lithium. A big one is cost.

    Chiang once declared to the MIT Club of Northern California, “I love lithium-ion.” Two of the four MIT spinoffs Chiang founded center on innovative lithium-ion batteries. But at hundreds of dollars a kilowatt-hour (kWh) and with a storage capacity typically measured in hours, lithium-ion was ill-suited for the use he now had in mind.

    The approach Chiang envisioned had to be cost-effective enough to boost the attractiveness of renewables. Making solar and wind energy reliable enough for millions of customers meant storing it long enough to fill the gaps created by extreme weather conditions, grid outages, and when there is a lull in the wind or a few days of clouds.

    To be competitive with legacy power plants, Chiang’s method had to come in at around $20 per kilowatt-hour of stored energy — one-tenth the cost of lithium-ion battery storage.

    But how to transition from expensive batteries that store and discharge over a couple of hours to some as-yet-undefined, cheap, longer-duration technology?

    “One big ball of iron”

    That’s where Ferrara comes in. Ferrara has a PhD in nuclear engineering from MIT and a PhD in electrical engineering and computer science from the University of L’Aquila in his native Italy. In 2017, as a research affiliate at the MIT Department of Materials Science and Engineering, he worked with Chiang to model the grid’s need to manage renewables’ intermittency.

    How intermittent depends on where you are. In the United States, for instance, there’s the windy Great Plains; the sun-drenched, relatively low-wind deserts of Arizona, New Mexico, and Nevada; and the often-cloudy Pacific Northwest.

    Ferrara, in collaboration with Professor Jessika Trancik of MIT’s Institute for Data, Systems, and Society and her MIT team, modeled four representative locations in the United States and concluded that energy storage with capacity costs below roughly $20/kWh and discharge durations of multiple days would allow a wind-solar mix to provide cost-competitive, firm electricity in resource-abundant locations.

    Now that they had a time frame, they turned their attention to materials. At the price point Form Energy was aiming for, lithium was out of the question. Chiang looked at plentiful and cheap sulfur. But a sulfur, sodium, water, and air battery had technical challenges.

    Thomas Edison once used iron as an electrode, and iron-air batteries were first studied in the 1960s. They were too heavy to make good transportation batteries. But this time, Chiang and team were looking at a battery that sat on the ground, so weight didn’t matter. Their priorities were cost and availability.

    “Iron is produced, mined, and processed on every continent,” Chiang says. “The Earth is one big ball of iron. We wouldn’t ever have to worry about even the most ambitious projections of how much storage that the world might use by mid-century.” If Form ever moves into the residential market, “it’ll be the safest battery you’ve ever parked at your house,” Chiang laughs. “Just iron, air, and water.”

    Scientists call it reversible rusting. While discharging, the battery takes in oxygen and converts iron to rust. Applying an electrical current converts the rusty pellets back to iron, and the battery “breathes out” oxygen as it charges. “In chemical terms, you have iron, and it becomes iron hydroxide,” Chiang says. “That means electrons were extracted. You get those electrons to go through the external circuit, and now you have a battery.”

    Form Energy’s battery modules are approximately the size of a washer-and-dryer unit. They are stacked in 40-foot containers, and several containers are electrically connected with power conversion systems to build storage plants that can cover several acres.

    The right place at the right time

    The modules don’t look or act like anything utilities have contracted for before.

    That’s one of Form’s key challenges. “There is not widespread knowledge of needing these new tools for decarbonized grids,” Ferrara says. “That’s not the way utilities have typically planned. They’re looking at all the tools in the toolkit that exist today, which may not contemplate a multi-day energy storage asset.”

    Form Energy’s customers are largely traditional power companies seeking to expand their portfolios of renewable electricity. Some are in the process of decommissioning coal plants and shifting to renewables.

    Ferrara’s research pinpointing the need for very low-cost multi-day storage provides key data for power suppliers seeking to determine the most cost-effective way to integrate more renewable energy.

    Using the same modeling techniques, Ferrara and team show potential customers how the technology fits in with their existing system, how it competes with other technologies, and how, in some cases, it can operate synergistically with other storage technologies.

    “They may need a portfolio of storage technologies to fully balance renewables on different timescales of intermittency,” he says. But other than the technology developed at Form, “there isn’t much out there, certainly not within the cost entitlement of what we’re bringing to market.”  Thanks to Chiang and Jaramillo’s chance encounter in Houston, Form has a several-year lead on other companies working to address this challenge. 

    In June 2023, Form Energy closed its biggest deal to date for a single project: Georgia Power’s order for a 15-megawatt/1,500-megawatt-hour system. That order brings Form’s total amount of energy storage under contracts with utility customers to 40 megawatts/4 gigawatt-hours. To meet the demand, Form is building a new commercial-scale battery manufacturing facility in West Virginia.

    The fact that Form Energy is creating jobs in an area that lost more than 10,000 steel jobs over the past decade is not lost on Chiang. “And these new jobs are in clean tech. It’s super exciting to me personally to be doing something that benefits communities outside of our traditional technology centers.

    “This is the right time for so many reasons,” Chiang says. He says he and his Form Energy co-founders feel “tremendous urgency to get these batteries out into the world.”

    This article appears in the Winter 2024 issue of Energy Futures, the magazine of the MIT Energy Initiative. More

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    Cobalt-free batteries could power cars of the future

    Many electric vehicles are powered by batteries that contain cobalt — a metal that carries high financial, environmental, and social costs.

    MIT researchers have now designed a battery material that could offer a more sustainable way to power electric cars. The new lithium-ion battery includes a cathode based on organic materials, instead of cobalt or nickel (another metal often used in lithium-ion batteries).

    In a new study, the researchers showed that this material, which could be produced at much lower cost than cobalt-containing batteries, can conduct electricity at similar rates as cobalt batteries. The new battery also has comparable storage capacity and can be charged up faster than cobalt batteries, the researchers report.

    “I think this material could have a big impact because it works really well,” says Mircea Dincă, the W.M. Keck Professor of Energy at MIT. “It is already competitive with incumbent technologies, and it can save a lot of the cost and pain and environmental issues related to mining the metals that currently go into batteries.”

    Dincă is the senior author of the study, which appears today in the journal ACS Central Science. Tianyang Chen PhD ’23 and Harish Banda, a former MIT postdoc, are the lead authors of the paper. Other authors include Jiande Wang, an MIT postdoc; Julius Oppenheim, an MIT graduate student; and Alessandro Franceschi, a research fellow at the University of Bologna.

    Alternatives to cobalt

    Most electric cars are powered by lithium-ion batteries, a type of battery that is recharged when lithium ions flow from a positively charged electrode, called a cathode, to a negatively electrode, called an anode. In most lithium-ion batteries, the cathode contains cobalt, a metal that offers high stability and energy density.

    However, cobalt has significant downsides. A scarce metal, its price can fluctuate dramatically, and much of the world’s cobalt deposits are located in politically unstable countries. Cobalt extraction creates hazardous working conditions and generates toxic waste that contaminates land, air, and water surrounding the mines.

    “Cobalt batteries can store a lot of energy, and they have all of features that people care about in terms of performance, but they have the issue of not being widely available, and the cost fluctuates broadly with commodity prices. And, as you transition to a much higher proportion of electrified vehicles in the consumer market, it’s certainly going to get more expensive,” Dincă says.

    Because of the many drawbacks to cobalt, a great deal of research has gone into trying to develop alternative battery materials. One such material is lithium-iron-phosphate (LFP), which some car manufacturers are beginning to use in electric vehicles. Although still practically useful, LFP has only about half the energy density of cobalt and nickel batteries.

    Another appealing option are organic materials, but so far most of these materials have not been able to match the conductivity, storage capacity, and lifetime of cobalt-containing batteries. Because of their low conductivity, such materials typically need to be mixed with binders such as polymers, which help them maintain a conductive network. These binders, which make up at least 50 percent of the overall material, bring down the battery’s storage capacity.

    About six years ago, Dincă’s lab began working on a project, funded by Lamborghini, to develop an organic battery that could be used to power electric cars. While working on porous materials that were partly organic and partly inorganic, Dincă and his students realized that a fully organic material they had made appeared that it might be a strong conductor.

    This material consists of many layers of TAQ (bis-tetraaminobenzoquinone), an organic small molecule that contains three fused hexagonal rings. These layers can extend outward in every direction, forming a structure similar to graphite. Within the molecules are chemical groups called quinones, which are the electron reservoirs, and amines, which help the material to form strong hydrogen bonds.

    Those hydrogen bonds make the material highly stable and also very insoluble. That insolubility is important because it prevents the material from dissolving into the battery electrolyte, as some organic battery materials do, thereby extending its lifetime.

    “One of the main methods of degradation for organic materials is that they simply dissolve into the battery electrolyte and cross over to the other side of the battery, essentially creating a short circuit. If you make the material completely insoluble, that process doesn’t happen, so we can go to over 2,000 charge cycles with minimal degradation,” Dincă says.

    Strong performance

    Tests of this material showed that its conductivity and storage capacity were comparable to that of traditional cobalt-containing batteries. Also, batteries with a TAQ cathode can be charged and discharged faster than existing batteries, which could speed up the charging rate for electric vehicles.

    To stabilize the organic material and increase its ability to adhere to the battery’s current collector, which is made of copper or aluminum, the researchers added filler materials such as cellulose and rubber. These fillers make up less than one-tenth of the overall cathode composite, so they don’t significantly reduce the battery’s storage capacity.

    These fillers also extend the lifetime of the battery cathode by preventing it from cracking when lithium ions flow into the cathode as the battery charges.

    The primary materials needed to manufacture this type of cathode are a quinone precursor and an amine precursor, which are already commercially available and produced in large quantities as commodity chemicals. The researchers estimate that the material cost of assembling these organic batteries could be about one-third to one-half the cost of cobalt batteries.

    Lamborghini has licensed the patent on the technology. Dincă’s lab plans to continue developing alternative battery materials and is exploring possible replacement of lithium with sodium or magnesium, which are cheaper and more abundant than lithium. More

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    Angela Belcher delivers 2023 Dresselhaus Lecture on evolving organisms for new nanomaterials

    “How do we get to making nanomaterials that haven’t been evolved before?” asked Angela Belcher at the 2023 Mildred S. Dresselhaus Lecture at MIT on Nov. 20. “We can use elements that biology has already given us.”

    The combined in-person and virtual audience of over 300 was treated to a light-up, 3D model of M13 bacteriophage, a virus that only infects bacteria, complete with a pull-out strand of DNA. Belcher used the feather-boa-like model to show how her research group modifies the M13’s genes to add new DNA and peptide sequences to template inorganic materials.

    “I love controlling materials at the nanoscale using biology,” said Belcher, the James Mason Crafts Professor of Biological Engineering, materials science professor, and of the Koch Institute of Integrative Cancer Research at MIT. “We all know if you control materials at the nanoscale and you can start to tune them, then you can have all kinds of different applications.” And the opportunities are indeed vast — from building batteries, fuel cells, and solar cells to carbon sequestration and storage, environmental remediation, catalysis, and medical diagnostics and imaging.

    Belcher sprinkled her talk with models and props, lined up on a table at the front of the 10-250 lecture hall, to demonstrate a wide variety of concepts and projects made possible by the intersection of biology and nanotechnology.

    Play video

    2023 Mildred S. Dresselhaus Lecture: Angela BelcherVideo: MIT.nano

    Energy storage and environment

    “How do you go from a DNA sequence to a functioning battery?” posed Belcher. Grabbing a model of a large carbon nanotube, she explained how her group engineered a phage to pick up carbon nanotubes that would wind all the way around the virus and then fill in with different cathode or anode materials to make nanowires for battery electrodes.

    How about using the M13 bacteriophage to improve the environment? Belcher referred to a project by former student Geran Zhang PhD ’19 that proved the virus can be modified for this context, too. He used the phage to template high-surface-area, carbon-based materials that can grab small molecules and break them down, Belcher said, opening a realm of possibilities from cleaning up rivers to developing chemical warfare agents to combating smog.

    Belcher’s lab worked with the U.S. Army to produce protective clothing and masks made of these carbon-based virus nanofibers. “We went from five liters in our lab to a thousand liters, then 10,000 liters in the army labs where we’re able to make kilograms of the material,” Belcher said, stressing the importance of being able to test and prototype at scale.

    Imaging tools and therapeutics in cancer

    In the area of biomedical imaging, Belcher explained, a lot less is known in near-infrared imaging — imaging in wavelengths above 1,000 nanometers — than other imaging techniques, yet with near-infrared scientists can see much deeper inside the body. Belcher’s lab built their own systems to image at these wavelengths. The third generation of this system provides real-time, sub-millimeter optical imaging for guided surgery.

    Working with Sangeeta Bhatia, the John J. and Dorothy Wilson Professor of Engineering, Belcher used carbon nanotubes to build imaging tools that find tiny tumors during surgery that doctors otherwise would not be able to see. The tool is actually a virus engineered to carry with it a fluorescent, single-walled carbon nanotube as it seeks out the tumors.

    Nearing the end of her talk, Belcher presented a goal: to develop an accessible detection and diagnostic technology for ovarian cancer in five to 10 years.

    “We think that we can do it,” Belcher said. She described her students’ work developing a way to scan an entire fallopian tube, as opposed to just one small portion, to find pre-cancer lesions, and talked about the team of MIT faculty, doctors, and researchers working collectively toward this goal.

    “Part of the secret of life and the meaning of life is helping other people enjoy the passage of time,” said Belcher in her closing remarks. “I think that we can all do that by working to solve some of the biggest issues on the planet, including helping to diagnose and treat ovarian cancer early so people have more time to spend with their family.”

    Honoring Mildred S. Dresselhaus

    Belcher was the fifth speaker to deliver the Dresselhaus Lecture, an annual event organized by MIT.nano to honor the late MIT physics and electrical engineering Institute Professor Mildred Dresselhaus. The lecture features a speaker from anywhere in the world whose leadership and impact echo Dresselhaus’s life, accomplishments, and values.

    “Millie was and is a huge hero of mine,” said Belcher. “Giving a lecture in Millie’s name is just the greatest honor.”

    Belcher dedicated the talk to Dresselhaus, whom she described with an array of accolades — a trailblazer, a genius, an amazing mentor, teacher, and inventor. “Just knowing her was such a privilege,” she said.

    Belcher also dedicated her talk to her own grandmother and mother, both of whom passed away from cancer, as well as late MIT professors Susan Lindquist and Angelika Amon, who both died of ovarian cancer.

    “I’ve been so fortunate to work with just the most talented and dedicated graduate students, undergraduate students, postdocs, and researchers,” concluded Belcher. “It has been a pure joy to be in partnership with all of you to solve these very daunting problems.” More

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    Pixel-by-pixel analysis yields insights into lithium-ion batteries

    By mining data from X-ray images, researchers at MIT, Stanford University, SLAC National Accelerator, and the Toyota Research Institute have made significant new discoveries about the reactivity of lithium iron phosphate, a material used in batteries for electric cars and in other rechargeable batteries.

    The new technique has revealed several phenomena that were previously impossible to see, including variations in the rate of lithium intercalation reactions in different regions of a lithium iron phosphate nanoparticle.

    The paper’s most significant practical finding — that these variations in reaction rate are correlated with differences in the thickness of the carbon coating on the surface of the particles — could lead to improvements in the efficiency of charging and discharging such batteries.

    “What we learned from this study is that it’s the interfaces that really control the dynamics of the battery, especially in today’s modern batteries made from nanoparticles of the active material. That means that our focus should really be on engineering that interface,” says Martin Bazant, the E.G. Roos Professor of Chemical Engineering and a professor of mathematics at MIT, who is the senior author of the study.

    This approach to discovering the physics behind complex patterns in images could also be used to gain insights into many other materials, not only other types of batteries but also biological systems, such as dividing cells in a developing embryo.

    “What I find most exciting about this work is the ability to take images of a system that’s undergoing the formation of some pattern, and learning the principles that govern that,” Bazant says.

    Hongbo Zhao PhD ’21, a former MIT graduate student who is now a postdoc at Princeton University, is the lead author of the new study, which appears today in Nature. Other authors include Richard Bratz, the Edwin R. Gilliland Professor of Chemical Engineering at MIT; William Chueh, an associate professor of materials science and engineering at Stanford and director of the SLAC-Stanford Battery Center; and Brian Storey, senior director of Energy and Materials at the Toyota Research Institute.

    “Until now, we could make these beautiful X-ray movies of battery nanoparticles at work, but it was challenging to measure and understand subtle details of how they function because the movies were so information-rich,” Chueh says. “By applying image learning to these nanoscale movies, we can extract insights that were not previously possible.”

    Modeling reaction rates

    Lithium iron phosphate battery electrodes are made of many tiny particles of lithium iron phosphate, surrounded by an electrolyte solution. A typical particle is about 1 micron in diameter and about 100 nanometers thick. When the battery discharges, lithium ions flow from the electrolyte solution into the material by an electrochemical reaction known as ion intercalation. When the battery charges, the intercalation reaction is reversed, and ions flow in the opposite direction.

    “Lithium iron phosphate (LFP) is an important battery material due to low cost, a good safety record, and its use of abundant elements,” Storey says. “We are seeing an increased use of LFP in the EV market, so the timing of this study could not be better.”

    Before the current study, Bazant had done a great deal of theoretical modeling of patterns formed by lithium-ion intercalation. Lithium iron phosphate prefers to exist in one of two stable phases: either full of lithium ions or empty. Since 2005, Bazant has been working on mathematical models of this phenomenon, known as phase separation, which generates distinctive patterns of lithium-ion flow driven by intercalation reactions. In 2015, while on sabbatical at Stanford, he began working with Chueh to try to interpret images of lithium iron phosphate particles from scanning tunneling X-ray microscopy.

    Using this type of microscopy, the researchers can obtain images that reveal the concentration of lithium ions, pixel-by-pixel, at every point in the particle. They can scan the particles several times as the particles charge or discharge, allowing them to create movies of how lithium ions flow in and out of the particles.

    In 2017, Bazant and his colleagues at SLAC received funding from the Toyota Research Institute to pursue further studies using this approach, along with other battery-related research projects.

    By analyzing X-ray images of 63 lithium iron phosphate particles as they charged and discharged, the researchers found that the movement of lithium ions within the material could be nearly identical to the computer simulations that Bazant had created earlier. Using all 180,000 pixels as measurements, the researchers trained the computational model to produce equations that accurately describe the nonequilibrium thermodynamics and reaction kinetics of the battery material.
    By analyzing X-ray images of lithium iron phosphate particles as they charged and discharged, researchers have shown that the movement of lithium ions within the material was nearly identical to computer simulations they had created earlier.  In each pair, the actual particles are on the left and the simulations are on the right.Courtesy of the researchers

    “Every little pixel in there is jumping from full to empty, full to empty. And we’re mapping that whole process, using our equations to understand how that’s happening,” Bazant says.

    The researchers also found that the patterns of lithium-ion flow that they observed could reveal spatial variations in the rate at which lithium ions are absorbed at each location on the particle surface.

    “It was a real surprise to us that we could learn the heterogeneities in the system — in this case, the variations in surface reaction rate — simply by looking at the images,” Bazant says. “There are regions that seem to be fast and others that seem to be slow.”

    Furthermore, the researchers showed that these differences in reaction rate were correlated with the thickness of the carbon coating on the surface of the lithium iron phosphate particles. That carbon coating is applied to lithium iron phosphate to help it conduct electricity — otherwise the material would conduct too slowly to be useful as a battery.

    “We discovered at the nano scale that variation of the carbon coating thickness directly controls the rate, which is something you could never figure out if you didn’t have all of this modeling and image analysis,” Bazant says.

    The findings also offer quantitative support for a hypothesis Bazant formulated several years ago: that the performance of lithium iron phosphate electrodes is limited primarily by the rate of coupled ion-electron transfer at the interface between the solid particle and the carbon coating, rather than the rate of lithium-ion diffusion in the solid.

    Optimized materials

    The results from this study suggest that optimizing the thickness of the carbon layer on the electrode surface could help researchers to design batteries that would work more efficiently, the researchers say.

    “This is the first study that’s been able to directly attribute a property of the battery material with a physical property of the coating,” Bazant says. “The focus for optimizing and designing batteries should be on controlling reaction kinetics at the interface of the electrolyte and electrode.”

    “This publication is the culmination of six years of dedication and collaboration,” Storey says. “This technique allows us to unlock the inner workings of the battery in a way not previously possible. Our next goal is to improve battery design by applying this new understanding.”  

    In addition to using this type of analysis on other battery materials, Bazant anticipates that it could be useful for studying pattern formation in other chemical and biological systems.

    This work was supported by the Toyota Research Institute through the Accelerated Materials Design and Discovery program. More

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    Study suggests energy-efficient route to capturing and converting CO2

    In the race to draw down greenhouse gas emissions around the world, scientists at MIT are looking to carbon-capture technologies to decarbonize the most stubborn industrial emitters.

    Steel, cement, and chemical manufacturing are especially difficult industries to decarbonize, as carbon and fossil fuels are inherent ingredients in their production. Technologies that can capture carbon emissions and convert them into forms that feed back into the production process could help to reduce the overall emissions from these “hard-to-abate” sectors.

    But thus far, experimental technologies that capture and convert carbon dioxide do so as two separate processes, that themselves require a huge amount of energy to run. The MIT team is looking to combine the two processes into one integrated and far more energy-efficient system that could potentially run on renewable energy to both capture and convert carbon dioxide from concentrated, industrial sources.

    In a study appearing today in ACS Catalysis, the researchers reveal the hidden functioning of how carbon dioxide can be both captured and converted through a single electrochemical process. The process involves using an electrode to attract carbon dioxide released from a sorbent, and to convert it into a reduced, reusable form.

    Others have reported similar demonstrations, but the mechanisms driving the electrochemical reaction have remained unclear. The MIT team carried out extensive experiments to determine that driver, and found that, in the end, it came down to the partial pressure of carbon dioxide. In other words, the more pure carbon dioxide that makes contact with the electrode, the more efficiently the electrode can capture and convert the molecule.

    Knowledge of this main driver, or “active species,” can help scientists tune and optimize similar electrochemical systems to efficiently capture and convert carbon dioxide in an integrated process.

    The study’s results imply that, while these electrochemical systems would probably not work for very dilute environments (for instance, to capture and convert carbon emissions directly from the air), they would be well-suited to the highly concentrated emissions generated by industrial processes, particularly those that have no obvious renewable alternative.

    “We can and should switch to renewables for electricity production. But deeply decarbonizing industries like cement or steel production is challenging and will take a longer time,” says study author Betar Gallant, the Class of 1922 Career Development Associate Professor at MIT. “Even if we get rid of all our power plants, we need some solutions to deal with the emissions from other industries in the shorter term, before we can fully decarbonize them. That’s where we see a sweet spot, where something like this system could fit.”

    The study’s MIT co-authors are lead author and postdoc Graham Leverick and graduate student Elizabeth Bernhardt, along with Aisyah Illyani Ismail, Jun Hui Law, Arif Arifutzzaman, and Mohamed Kheireddine Aroua of Sunway University in Malaysia.

    Breaking bonds

    Carbon-capture technologies are designed to capture emissions, or “flue gas,” from the smokestacks of power plants and manufacturing facilities. This is done primarily using large retrofits to funnel emissions into chambers filled with a “capture” solution — a mix of amines, or ammonia-based compounds, that chemically bind with carbon dioxide, producing a stable form that can be separated out from the rest of the flue gas.

    High temperatures are then applied, typically in the form of fossil-fuel-generated steam, to release the captured carbon dioxide from its amine bond. In its pure form, the gas can then be pumped into storage tanks or underground, mineralized, or further converted into chemicals or fuels.

    “Carbon capture is a mature technology, in that the chemistry has been known for about 100 years, but it requires really large installations, and is quite expensive and energy-intensive to run,” Gallant notes. “What we want are technologies that are more modular and flexible and can be adapted to more diverse sources of carbon dioxide. Electrochemical systems can help to address that.”

    Her group at MIT is developing an electrochemical system that both recovers the captured carbon dioxide and converts it into a reduced, usable product. Such an integrated system, rather than a decoupled one, she says, could be entirely powered with renewable electricity rather than fossil-fuel-derived steam.

    Their concept centers on an electrode that would fit into existing chambers of carbon-capture solutions. When a voltage is applied to the electrode, electrons flow onto the reactive form of carbon dioxide and convert it to a product using protons supplied from water. This makes the sorbent available to bind more carbon dioxide, rather than using steam to do the same.

    Gallant previously demonstrated this electrochemical process could work to capture and convert carbon dioxide into a solid carbonate form.

    “We showed that this electrochemical process was feasible in very early concepts,” she says. “Since then, there have been other studies focused on using this process to attempt to produce useful chemicals and fuels. But there’s been inconsistent explanations of how these reactions work, under the hood.”

    Solo CO2

    In the new study, the MIT team took a magnifying glass under the hood to tease out the specific reactions driving the electrochemical process. In the lab, they generated amine solutions that resemble the industrial capture solutions used to extract carbon dioxide from flue gas. They methodically altered various properties of each solution, such as the pH, concentration, and type of amine, then ran each solution past an electrode made from silver — a metal that is widely used in electrolysis studies and known to efficiently convert carbon dioxide to carbon monoxide. They then measured the concentration of carbon monoxide that was converted at the end of the reaction, and compared this number against that of every other solution they tested, to see which parameter had the most influence on how much carbon monoxide was produced.

    In the end, they found that what mattered most was not the type of amine used to initially capture carbon dioxide, as many have suspected. Instead, it was the concentration of solo, free-floating carbon dioxide molecules, which avoided bonding with amines but were nevertheless present in the solution. This “solo-CO2” determined the concentration of carbon monoxide that was ultimately produced.

    “We found that it’s easier to react this ‘solo’ CO2, as compared to CO2 that has been captured by the amine,” Leverick offers. “This tells future researchers that this process could be feasible for industrial streams, where high concentrations of carbon dioxide could efficiently be captured and converted into useful chemicals and fuels.”

    “This is not a removal technology, and it’s important to state that,” Gallant stresses. “The value that it does bring is that it allows us to recycle carbon dioxide some number of times while sustaining existing industrial processes, for fewer associated emissions. Ultimately, my dream is that electrochemical systems can be used to facilitate mineralization, and permanent storage of CO2 — a true removal technology. That’s a longer-term vision. And a lot of the science we’re starting to understand is a first step toward designing those processes.”

    This research is supported by Sunway University in Malaysia. More

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    Q&A: Three Tata Fellows on the program’s impact on themselves and the world

    The Tata Fellowship at MIT gives graduate students the opportunity to pursue interdisciplinary research and work with real-world applications in developing countries. Part of the MIT Tata Center for Technology and Design, this fellowship contributes to the center’s goal of designing appropriate, practical solutions for resource-constrained communities. Three Tata Fellows — Serena Patel, Rameen Hayat Malik, and Ethan Harrison — discuss the impact of this program on their research, perspectives, and time at MIT.

    Serena Patel

    Serena Patel graduated from the University of California at Berkeley with a degree in energy engineering and a minor in energy and resources. She is currently pursuing her SM in technology and policy at MIT and is a Tata Fellow focusing on decarbonization in India using techno-economic modeling. Her interest in the intersection of technology, policy, economics, and social justice led her to attend COP27, where she experienced decision-maker and activist interactions firsthand.

    Q: How did you become interested in the Tata Fellowship, and how has it influenced your time at MIT?

    A: The Tata Center appealed to my interest in searching for creative, sustainable energy technologies that center collaboration with local-leading organizations. It has also shaped my understanding of the role of technology in sustainable development planning. Our current energy system disproportionately impacts marginalized communities, and new energy systems have the potential to perpetuate and/or create inequities. I am broadly interested in how we can put people at the core of our technological solutions and support equitable energy transitions. I specifically work on techno-economic modeling to analyze the potential for an early retirement of India’s large coal fleet and conversion to long-duration thermal energy storage. This could mitigate job losses from rapid transitions, support India’s energy system decarbonization plan, and provide a cost-effective way to retire stranded assets.

    Q: Why is interdisciplinary study important to real-world solutions for global communities, and how has working at the intersection of technology and policy influenced your research?

    A: Technology and policy work together in mediating and regulating the world around us. Technological solutions can be disruptive in all the good ways, but they can also do a lot of harm and perpetuate existing inequities. Interdisciplinary studies are important to mitigate these interrelated issues so innovative ideas in the ivory towers of Western academia do not negatively impact marginalized communities. For real-world solutions to positively impact individuals, marginalized communities need to be centered within the research design process. I think the research community’s perspective on real-world, global solutions is shifting to achieve these goals, but much work remains for resources to reach the right communities.

    The energy space is especially fascinating because it impacts everyone’s quality of life in overt or nuanced ways. I’ve had the privilege of taking classes that sit at the intersection of energy technology and policy, involving land-use law, geographic representation, energy regulation, and technology policy. In general, working at the intersection of technology and policy has shaped my perspective on how regulation influences widespread technology adoption and the overall research directions and assumptions in our energy models.

    Q: How has your experience at COP27 influenced your approach to your research?

    A: Attending COP27 at Sharm El-Sheikh, Egypt, last November influenced my understanding of the role of science, research, and activism in climate negotiations and action. Science and research are often promoted as necessary for sharing knowledge at the higher levels, but they were also used as a delay tactic by negotiators. I heard how institutional bodies meant to support fair science and research often did not reach intended stakeholders. Lofty goals or financial commitments to ensure global climate stability and resilience still lacked implementation and coordination with deep technology transfer and support. On the face of it, these agreements have impact and influence, but I heard many frustrations over the lack of tangible, local support. This has driven my research to be as context-specific as possible, to provide actionable insights and leverage different disciplines.

    I also observed the role of activism in the negotiations. Decision-makers are accountable to their country, and activists are spreading awareness and bringing transparency to the COP process. As a U.S. citizen, I suddenly became more aware of how political engagement and awareness in the country could push the boundaries of international climate agreements if the government were more aligned on climate action.

    Rameen Hayat Malik

    Rameen Hayat Malik graduated from the University of Sydney with a bachelor’s degree in chemical and biomolecular engineering and a Bachelor of Laws. She is currently pursuing her SM in technology and policy and is a Tata Fellow researching the impacts of electric vehicle (EV) battery production in Indonesia. Originally from Australia, she first became interested in the geopolitical landscape of resources trade and its implications for the clean energy transition while working in her native country’s Department of Climate Change, Energy, the Environment and Water.

    Q: How did you become interested in the Tata Fellowship, and how has it influenced your time at MIT?

    A: I came across the Tata Fellowship while looking for research opportunities that aligned with my interest in understanding how a just energy transition will occur in a global context, with a particular focus on emerging economies. My research explores the techno-economic, social, and environmental impacts of nickel mining in Indonesia as it seeks to establish itself as a major producer of EV batteries. The fellowship’s focus on community-driven research has given me the freedom to guide the scope of my research. It has allowed me to integrate a community voice into my work that seeks to understand the impact of this mining on forest-dependent communities, Indigenous communities, and workforce development.

    Q: Battery technology and production are highly discussed in the energy sector. How does your research on Indonesia’s battery production contribute to the current discussion around batteries, and what drew you to this topic?

    A: Indonesia is one of the world’s largest exporters of coal, while also having one of the largest nickel reserves in the world — a key mineral for EV battery production. This presents an exciting opportunity for Indonesia to be a leader in the energy transition, as it both seeks to phase out coal production and establish itself as a key supplier of critical minerals. It is also an opportunity to actually apply principles of a just transition to the region, which seeks to repurpose and re-skill existing coal workforces, to bring Indigenous communities into the conversation around the future of their lands, and to explore whether it is actually possible to sustainably and ethically produce nickel for EV battery production.

    I’ve always seen battery technologies and EVs as products that, at least today, are accessible to a small, privileged customer base that can afford such technologies. I’m interested in understanding how we can make such products more widely affordable and provide our lowest-income communities with the opportunities to actively participate in the transition — especially since access to transportation is a key driver of social mobility. With nickel prices impacting EV prices in such a dramatic way, unlocking more nickel supply chains presents an opportunity to make EV batteries more accessible and affordable.

    Q: What advice would you give to new students who want to be a part of real-world solutions to the climate crisis?

    A: Bring your whole self with you when engaging these issues. Quite often we get caught up with the technology or modeling aspect of addressing the climate crisis and forget to bring people and their experiences into our work. Think about your positionality: Who is your community, what are the avenues you have to bring that community along, and what privileges do you hold to empower and amplify voices that need to be heard? Find a piece of this complex puzzle that excites you, and find opportunities to talk and listen to people who are directly impacted by the solutions you are looking to explore. It can get quite overwhelming working in this space, which carries a sense of urgency, politicization, and polarization with it. Stay optimistic, keep advocating, and remember to take care of yourself while doing this important work.

    Ethan Harrison

    After earning his degree in economics and applied science from the College of William and Mary, Ethan Harrison worked at the United Nations Development Program in its Crisis Bureau as a research officer focused on conflict prevention and predictive analysis. He is currently pursuing his SM in technology and policy at MIT. In his Tata Fellowship, he focuses on the impacts of the Ukraine-Russia conflict on global vulnerability and the global energy market.

    Q: How did you become interested in the Tata Fellowship, and how has it influenced your time at MIT?

    A: Coming to MIT, one of my chief interests was figuring out how we can leverage gains from technology to improve outcomes and build pro-poor solutions in developing and crisis contexts. The Tata Fellowship aligned with many of the conclusions I drew while working in crisis contexts and some of the outstanding questions that I was hoping to answer during my time at MIT, specifically: How can we leverage technology to build sustainable, participatory, and ethically grounded interventions in these contexts?

    My research currently examines the secondary impacts of the Ukraine-Russia conflict on low- and middle-income countries — especially fragile states — with a focus on shocks in the global energy market. This includes the development of a novel framework that systematically identifies factors of vulnerability — such as in energy, food systems, and trade dependence — and quantitatively ranks countries by their level of vulnerability. By identifying the specific mechanisms by which these countries are vulnerable, we can develop a map of global vulnerability and identify key policy solutions that can insulate countries from current and future shocks.

    Q: I understand that your research deals with the relationship between oil and gas price fluctuation and political stability. What has been the most surprising aspect of this relationship, and what are its implications for global decarbonization?

    A: One surprising aspect is the degree to which citizen grievances regarding price fluctuations can quickly expand to broader democratic demands and destabilization. In Sri Lanka last year and in Egypt during the Arab spring, initial protests around fuel prices and power outages eventually led to broader demands and the loss of power by heads of state. Another surprising aspect is the popularity of fuel subsidies despite the fact that they are economically regressive: They often comprise a large proportion of GDP in poor countries, disproportionately benefit higher-income populations, and leave countries vulnerable to fiscal stress during price spikes.

    Regarding implications for global decarbonization, one project we are pursuing examines the implications of directing financing from fuel subsidies toward investments in renewable energy. Countries that rely on fossil fuels for electricity have been hit especially hard 
by price spikes from the Ukraine-Russia conflict, especially since many were carrying costly fuel subsidies to keep the price of fuel and energy artificially low. Much of the international community is advocating for low-income countries to invest in renewables and reduce their fossil fuel burden, but it’s important to explore how global decarbonization can align with efforts to end energy poverty and other Sustainable Development Goals.

    Q: How does your research impact the Tata Center’s goal of transforming policy research into real-world solutions, and why is this important?

    A: The crisis in Ukraine has shifted the international community’s focus away from other countries in crisis, such as Yemen and Lebanon. By developing a global map of vulnerability, we’re building a large evidence base on which countries have been most impacted by this crisis. Most importantly, by identifying individual channels of vulnerability for each country, we can also identify the most effective policy solutions to insulate vulnerable populations from shocks. Whether that’s advocating for short-term social protection programs or identifying more medium-term policy solutions — like fuel banks or investment in renewables — we hope providing a detailed map of sources of vulnerability can help inform the global response to shocks imposed by the Russia-Ukraine conflict and post-Covid recovery. More