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      in Energy

      Desalination system could produce freshwater that is cheaper than tap water

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      Engineers at MIT and in China are aiming to turn seawater into drinking water with a completely passive device that is inspired by the ocean, and powered by the sun.

      In a paper appearing today in the journal Joule, the team outlines the design for a new solar desalination system that takes in saltwater and heats it with natural sunlight.

      The configuration of the device allows water to circulate in swirling eddies, in a manner similar to the much larger “thermohaline” circulation of the ocean. This circulation, combined with the sun’s heat, drives water to evaporate, leaving salt behind. The resulting water vapor can then be condensed and collected as pure, drinkable water. In the meantime, the leftover salt continues to circulate through and out of the device, rather than accumulating and clogging the system.

      The new system has a higher water-production rate and a higher salt-rejection rate than all other passive solar desalination concepts currently being tested.

      The researchers estimate that if the system is scaled up to the size of a small suitcase, it could produce about 4 to 6 liters of drinking water per hour and last several years before requiring replacement parts. At this scale and performance, the system could produce drinking water at a rate and price that is cheaper than tap water.

      “For the first time, it is possible for water, produced by sunlight, to be even cheaper than tap water,” says Lenan Zhang, a research scientist in MIT’s Device Research Laboratory.

      The team envisions a scaled-up device could passively produce enough drinking water to meet the daily requirements of a small family. The system could also supply off-grid, coastal communities where seawater is easily accessible.

      Zhang’s study co-authors include MIT graduate student Yang Zhong and Evelyn Wang, the Ford Professor of Engineering, along with Jintong Gao, Jinfang You, Zhanyu Ye, Ruzhu Wang, and Zhenyuan Xu of Shanghai Jiao Tong University in China.

      A powerful convection

      The team’s new system improves on their previous design — a similar concept of multiple layers, called stages. Each stage contained an evaporator and a condenser that used heat from the sun to passively separate salt from incoming water. That design, which the team tested on the roof of an MIT building, efficiently converted the sun’s energy to evaporate water, which was then condensed into drinkable water. But the salt that was left over quickly accumulated as crystals that clogged the system after a few days. In a real-world setting, a user would have to place stages on a frequent basis, which would significantly increase the system’s overall cost.

      In a follow-up effort, they devised a solution with a similar layered configuration, this time with an added feature that helped to circulate the incoming water as well as any leftover salt. While this design prevented salt from settling and accumulating on the device, it desalinated water at a relatively low rate.

      In the latest iteration, the team believes it has landed on a design that achieves both a high water-production rate, and high salt rejection, meaning that the system can quickly and reliably produce drinking water for an extended period. The key to their new design is a combination of their two previous concepts: a multistage system of evaporators and condensers, that is also configured to boost the circulation of water — and salt — within each stage.

      “We introduce now an even more powerful convection, that is similar to what we typically see in the ocean, at kilometer-long scales,” Xu says.

      The small circulations generated in the team’s new system is similar to the “thermohaline” convection in the ocean — a phenomenon that drives the movement of water around the world, based on differences in sea temperature (“thermo”) and salinity (“haline”).

      “When seawater is exposed to air, sunlight drives water to evaporate. Once water leaves the surface, salt remains. And the higher the salt concentration, the denser the liquid, and this heavier water wants to flow downward,” Zhang explains. “By mimicking this kilometer-wide phenomena in small box, we can take advantage of this feature to reject salt.”

      Tapping out

      The heart of the team’s new design is a single stage that resembles a thin box, topped with a dark material that efficiently absorbs the heat of the sun. Inside, the box is separated into a top and bottom section. Water can flow through the top half, where the ceiling is lined with an evaporator layer that uses the sun’s heat to warm up and evaporate any water in direct contact. The water vapor is then funneled to the bottom half of the box, where a condensing layer air-cools the vapor into salt-free, drinkable liquid. The researchers set the entire box at a tilt within a larger, empty vessel, then attached a tube from the top half of the box down through the bottom of the vessel, and floated the vessel in saltwater.

      In this configuration, water can naturally push up through the tube and into the box, where the tilt of the box, combined with the thermal energy from the sun, induces the water to swirl as it flows through. The small eddies help to bring water in contact with the upper evaporating layer while keeping salt circulating, rather than settling and clogging.

      The team built several prototypes, with one, three, and 10 stages, and tested their performance in water of varying salinity, including natural seawater and water that was seven times saltier.

      From these tests, the researchers calculated that if each stage were scaled up to a square meter, it would produce up to 5 liters of drinking water per hour, and that the system could desalinate water without accumulating salt for several years. Given this extended lifetime, and the fact that the system is entirely passive, requiring no electricity to run, the team estimates that the overall cost of running the system would be cheaper than what it costs to produce tap water in the United States.

      “We show that this device is capable of achieving a long lifetime,” Zhong says. “That means that, for the first time, it is possible for drinking water produced by sunlight to be cheaper than tap water. This opens up the possibility for solar desalination to address real-world problems.”

      “This is a very innovative approach that effectively mitigates key challenges in the field of desalination,” says Guihua Yu, who develops sustainable water and energy storage systems at the University of Texas at Austin, and was not involved in the research. “The design is particularly beneficial for regions struggling with high-salinity water. Its modular design makes it highly suitable for household water production, allowing for scalability and adaptability to meet individual needs.”

      Funding for the research at Shanghai Jiao Tong University was supported by the Natural Science Foundation of China. More

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      in Energy

      Study suggests energy-efficient route to capturing and converting CO2

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      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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      in Security

      Tiny magnetic beads produce an optical signal that could be used to quickly detect pathogens

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      Getting results from a blood test can take anywhere from one day to a week, depending on what a test is targeting. The same goes for tests of water pollution and food contamination. And in most cases, the wait time has to do with time-consuming steps in sample processing and analysis.

      Now, MIT engineers have identified a new optical signature in a widely used class of magnetic beads, which could be used to quickly detect contaminants in a variety of diagnostic tests. For example, the team showed the signature could be used to detect signs of the food contaminant Salmonella.

      The so-called Dynabeads are microscopic magnetic beads that can be coated with antibodies that bind to target molecules, such as a specific pathogen. Dynabeads are typically used in experiments in which they are mixed into solutions to capture molecules of interest. But from there, scientists have to take additional, time-consuming steps to confirm that the molecules are indeed present and bound to the beads.

      The MIT team found a faster way to confirm the presence of Dynabead-bound pathogens, using optics, specifically, Raman spectroscopy. This optical technique identifies specific molecules based on their “Raman signature,” or the unique way in which a molecule scatters light.

      The researchers found that Dynabeads have an unusually strong Raman signature that can be easily detected, much like a fluorescent tag. This signature, they found, can act as a “reporter.” If detected, the signal can serve as a quick confirmation, within less than one second, that a target pathogen is indeed present in a given sample. The team is currently working to develop a portable device for quickly detecting a range of bacterial pathogens, and their results will appear in an Emerging Investigators special issue of the Journal of Raman Spectroscopy.

      “This technique would be useful in a situation where a doctor is trying to narrow down the source of an infection in order to better inform antibiotic prescription, as well as for the detection of known pathogens in food and water,” says study co-author Marissa McDonald, a graduate student in the Harvard-MIT Program in Health Sciences and Technology. “Additionally, we hope this approach will eventually lead to expanded access to advanced diagnostics in resource-limited environments.”

      Study co-authors at MIT include Postdoctoral Associate Jongwan Lee; Visiting Scholar Nikiwe Mhlanga; Research Scientist Jeon Woong Kang; Tata Professor Rohit Karnik, who is also the associate director of the Abdul Latif Jameel Water and Food Systems Lab; and Assistant Professor Loza Tadesse of the Department of Mechanical Engineering.

      Oil and water

      Looking for diseased cells and pathogens in fluid samples is an exercise in patience.

      “It’s kind of a needle-in-a-haystack problem,” Tadesse says.

      The numbers present are so small that they must be grown in controlled environments to sufficient numbers, and their cultures stained, then studied under a microscope. The entire process can take several days to a week to yield a confident positive or negative result.

      Both Karnik and Tadesse’s labs have independently been developing techniques to speed up various parts of the pathogen testing process and make the process portable, using Dynabeads.

      Dynabeads are commercially available microscopic beads made from a magnetic iron core and a polymer shell that can be coated with antibodies. The surface antibodies act as hooks to bind specific target molecules. When mixed with a fluid, such as a vial of blood or water, any molecules present will glom onto the Dynabeads. Using a magnet, scientists can gently coax the beads to the bottom of a vial and filter them out of a solution. Karnik’s lab is investigating ways to then further separate the beads into those that are bound to a target molecule, and those that are not. “Still, the challenge is, how do we know that we have what we’re looking for?” Tadesse says.

      The beads themselves are not visible by eye. That’s where Tadesse’s work comes in. Her lab uses Raman spectroscopy as a way to “fingerprint” pathogens. She has found that different cell types scatter light in unique ways that can be used as a signature to identify them.

      In the team’s new work, she and her colleagues found that Dynabeads also have a unique and strong Raman signature that can act as a surprisingly clear beacon.

      “We were initially seeking to identify the signatures of bacteria, but the signature of the Dynabeads was actually very strong,” Tadesse says. “We realized this signal could be a means of reporting to you whether you have that bacteria or not.”

      Testing beacon

      As a practical demonstration, the researchers mixed Dynabeads into vials of water contaminated with Salmonella. They then magnetically isolated these beads onto microscope slides and measured the way light scattered through the fluid when exposed to laser light. Within half a second, they quickly detected the Dynabeads’ Raman signature — a confirmation that bound Dynabeads, and by inference, Salmonella, were present in the fluid.

      “This is something that can be used to rapidly give a positive or negative answer: Is there a contaminant or not?” Tadesse says. “Because even a handful of pathogens can cause clinical symptoms.”

      The team’s new technique is significantly faster than conventional methods and uses elements that could be adapted into smaller, more portable forms — a goal that the researchers are currently working toward. The approach is also highly versatile.

      “Salmonella is the proof of concept,” Tadesse says. “You could purchase Dynabeads with E.coli antibodies, and the same thing would happen: It would bind to the bacteria, and we’d be able to detect the Dynabead signature because the signal is super strong.”

      The team is particularly keen to apply the test to conditions such as sepsis, where time is of the essence, and where pathogens that trigger the condition are not rapidly detected using conventional lab tests.

      “There are a lot cases, like in sepsis, where pathogenic cells cannot always be grown on a plate,” says Lee, a member of Karnik’s lab. “In that case, our technique could rapidly detect these pathogens.”

      This research was supported, in part, by the MIT Laser Biomedical Research Center, the National Cancer Institute, and the Abdul Latif Jameel Water and Food Systems Lab at MIT. More

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      in Energy

      Supporting sustainability, digital health, and the future of work

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      The MIT and Accenture Convergence Initiative for Industry and Technology has selected three new research projects that will receive support from the initiative. The research projects aim to accelerate progress in meeting complex societal needs through new business convergence insights in technology and innovation.

      Established in MIT’s School of Engineering and now in its third year, the MIT and Accenture Convergence Initiative is furthering its mission to bring together technological experts from across business and academia to share insights and learn from one another. Recently, Thomas W. Malone, the Patrick J. McGovern (1959) Professor of Management, joined the initiative as its first-ever faculty lead. The research projects relate to three of the initiative’s key focus areas: sustainability, digital health, and the future of work.

      “The solutions these research teams are developing have the potential to have tremendous impact,” says Anantha Chandrakasan, dean of the School of Engineering and the Vannevar Bush Professor of Electrical Engineering and Computer Science. “They embody the initiative’s focus on advancing data-driven research that addresses technology and industry convergence.”

      “The convergence of science and technology driven by advancements in generative AI, digital twins, quantum computing, and other technologies makes this an especially exciting time for Accenture and MIT to be undertaking this joint research,” says Kenneth Munie, senior managing director at Accenture Strategy, Life Sciences. “Our three new research projects focusing on sustainability, digital health, and the future of work have the potential to help guide and shape future innovations that will benefit the way we work and live.”

      The MIT and Accenture Convergence Initiative charter project researchers are described below.

      Accelerating the journey to net zero with industrial clusters

      Jessika Trancik is a professor at the Institute for Data, Systems, and Society (IDSS). Trancik’s research examines the dynamic costs, performance, and environmental impacts of energy systems to inform climate policy and accelerate beneficial and equitable technology innovation. Trancik’s project aims to identify how industrial clusters can enable companies to derive greater value from decarbonization, potentially making companies more willing to invest in the clean energy transition.

      To meet the ambitious climate goals that have been set by countries around the world, rising greenhouse gas emissions trends must be rapidly reversed. Industrial clusters — geographically co-located or otherwise-aligned groups of companies representing one or more industries — account for a significant portion of greenhouse gas emissions globally. With major energy consumers “clustered” in proximity, industrial clusters provide a potential platform to scale low-carbon solutions by enabling the aggregation of demand and the coordinated investment in physical energy supply infrastructure.

      In addition to Trancik, the research team working on this project will include Aliza Khurram, a postdoc in IDSS; Micah Ziegler, an IDSS research scientist; Melissa Stark, global energy transition services lead at Accenture; Laura Sanderfer, strategy consulting manager at Accenture; and Maria De Miguel, strategy senior analyst at Accenture.

      Eliminating childhood obesity

      Anette “Peko” Hosoi is the Neil and Jane Pappalardo Professor of Mechanical Engineering. A common theme in her work is the fundamental study of shape, kinematic, and rheological optimization of biological systems with applications to the emergent field of soft robotics. Her project will use both data from existing studies and synthetic data to create a return-on-investment (ROI) calculator for childhood obesity interventions so that companies can identify earlier returns on their investment beyond reduced health-care costs.

      Childhood obesity is too prevalent to be solved by a single company, industry, drug, application, or program. In addition to the physical and emotional impact on children, society bears a cost through excess health care spending, lost workforce productivity, poor school performance, and increased family trauma. Meaningful solutions require multiple organizations, representing different parts of society, working together with a common understanding of the problem, the economic benefits, and the return on investment. ROI is particularly difficult to defend for any single organization because investment and return can be separated by many years and involve asymmetric investments, returns, and allocation of risk. Hosoi’s project will consider the incentives for a particular entity to invest in programs in order to reduce childhood obesity.

      Hosoi will be joined by graduate students Pragya Neupane and Rachael Kha, both of IDSS, as well a team from Accenture that includes Kenneth Munie, senior managing director at Accenture Strategy, Life Sciences; Kaveh Safavi, senior managing director in Accenture Health Industry; and Elizabeth Naik, global health and public service research lead.

      Generating innovative organizational configurations and algorithms for dealing with the problem of post-pandemic employment

      Thomas Malone is the Patrick J. McGovern (1959) Professor of Management at the MIT Sloan School of Management and the founding director of the MIT Center for Collective Intelligence. His research focuses on how new organizations can be designed to take advantage of the possibilities provided by information technology. Malone will be joined in this project by John Horton, the Richard S. Leghorn (1939) Career Development Professor at the MIT Sloan School of Management, whose research focuses on the intersection of labor economics, market design, and information systems. Malone and Horton’s project will look to reshape the future of work with the help of lessons learned in the wake of the pandemic.

      The Covid-19 pandemic has been a major disrupter of work and employment, and it is not at all obvious how governments, businesses, and other organizations should manage the transition to a desirable state of employment as the pandemic recedes. Using natural language processing algorithms such as GPT-4, this project will look to identify new ways that companies can use AI to better match applicants to necessary jobs, create new types of jobs, assess skill training needed, and identify interventions to help include women and other groups whose employment was disproportionately affected by the pandemic.

      In addition to Malone and Horton, the research team will include Rob Laubacher, associate director and research scientist at the MIT Center for Collective Intelligence, and Kathleen Kennedy, executive director at the MIT Center for Collective Intelligence and senior director at MIT Horizon. The team will also include Nitu Nivedita, managing director of artificial intelligence at Accenture, and Thomas Hancock, data science senior manager at Accenture. More

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      in Energy

      Alumnus’ thermal battery helps industry eliminate fossil fuels

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      The explosion of renewable energy projects around the globe is leading to a saturation problem. As more renewable power contributes to the grid, the value of electricity is plummeting during the times of day when wind and solar hit peak productivity. The problem is limiting renewable energy investments in some of the sunniest and windiest places in the world.

      Now Antora Energy, co-founded by David Bierman SM ’14, PhD ’17, is addressing the intermittent nature of wind and solar with a low-cost, highly efficient thermal battery that stores electricity as heat to allow manufacturers and other energy-hungry businesses to eliminate their use of fossil fuels.

      “We take electricity when it’s cheapest, meaning when wind gusts are strongest and the sun is shining brightest,” Bierman explains. “We run that electricity through a resistive heater to drive up the temperature of a very inexpensive material — we use carbon blocks, which are extremely stable, produced at incredible scales, and are some of the cheapest materials on Earth. When you need to pull energy from the battery, you open a large shutter to extract thermal radiation, which is used to generate process heat or power using our thermophotovoltaic, or TPV, technology. The end result is a zero-carbon, flexible, combined heat and power system for industry.”

      Antora’s battery could dramatically expand the application of renewable energy by enabling its use in industry, a sector of the U.S. economy that accounted for nearly a quarter of all greenhouse gas emissions in 2021.

      Antora says it is able to deliver on the long-sought promise of heat-to-power TPV technology because it has achieved new levels of efficiency and scalability with its cells. Earlier this year, Antora opened a new manufacturing facility that will be capable of producing 2 megawatts of its TPV cells each year — which the company says makes it the largest TPV production facility in the world.

      Antora’s thermal battery manufacturing facilities and demonstration unit are located in sun-soaked California, where renewables make up close to a third of all electricity. But Antora’s team says its technology holds promise in other regions as increasingly large renewable projects connect to grids across the globe.

      “We see places today [with high renewables] as a sign of where things are going,” Bierman says. “If you look at the tailwinds we have in the renewable industry, there’s a sense of inevitability about solar and wind, which will need to be deployed at incredible scales to avoid a climate catastrophe. We’ll see terawatts and terawatts of new additions of these renewables, so what you see today in California or Texas or Kansas, with significant periods of renewable overproduction, is just the tip of the iceberg.”

      Bierman has been working on thermal energy storage and thermophotovoltaics since his time at MIT, and Antora’s ties to MIT are especially strong because its progress is the result of two MIT startups becoming one.

      Alumni join forces

      Bierman did his masters and doctoral work in MIT’s Department of Mechanical Engineering, where he worked on solid-state solar thermal energy conversion systems. In 2016, while taking course 15.366 (Climate and Energy Ventures), he met Jordan Kearns SM ’17, then a graduate student in the Technology and Policy Program and the Department of Nuclear Science and Engineering. The two were studying renewable energy when they began to think about the intermittent nature of wind and solar as an opportunity rather than a problem.

      “There are already places in the U.S. where we have more wind and solar at times than we know what to do with,” Kearns says. “That is an opportunity for not only emissions reductions but also for reducing energy costs. What’s the application? I don’t think the overproduction of energy was being talked about as much as the intermittency problem.”

      Kearns did research through the MIT Energy Initiative and the researchers received support from MIT’s Venture Mentoring Service and the MIT Sandbox Innovation Fund to further explore ways to capitalize on fluctuating power prices.

      Kearns officially founded a company called Medley Thermal in 2017 to help companies that use natural gas switch to energy produced by renewables when the price was right. To accomplish that, he combined an off-the-shelf electric boiler with novel control software so the companies could switch energy sources seamlessly from fossil fuel to electricity at especially windy or sunny times. Medley went on to become a finalist for the MIT Clean Energy Prize, and Kearns wanted Bierman to join him as a co-founder, but Bierman had received a fellowship to commercialize a thermal energy storage solution and decided to pursue that after graduation.

      The split ended up working out for both alumni. In the ensuing years, Kearns led Medley Thermal through a number of projects in which gradually larger companies switched from relying on natural gas or propane sources to renewable electricity from the grid. The work culminated in an installment at the Jay Peak resort in Vermont that Kearns says is one of the largest projects in the U.S. using renewable energy to produce heat. The project is expected to reduce about 2,500 tons of carbon dioxide per year.

      Bierman, meanwhile, further developed a thermal energy storage solution for industrial decarbonization, which works by using renewable electricity to heat blocks of carbon, which are stored in insulation to retain energy for long periods of time. The heat from those blocks can then be used to deliver electricity or heat to customers, at temperatures that can exceed 1,500 C. When Antora raised a $50 million Series A funding round last year, Bierman asked Kearns if he could buy out Medley’s team, and the researchers finally became co-workers.

      “Antora and Medley Thermal have a similar value prop: There’s low-cost electricity, and we want to connect that to the industrial sector,” Kearns explains. “But whereas Medley used renewables on an as-available basis, and then when the winds stop we went back to burning fossil fuel with a boiler, Antora has a thermal battery that takes in the electricity, converts it to heat, but also stores it as heat so even when the wind stops blowing we have a reservoir of heat that we can continue to pull from to make steam or power or whatever the facility needs. So, we can now further reduce energy costs by offsetting more fuel and offer a 100 percent clean energy solution.”

      United we scale

      Today, Kearns runs the project development arm of Antora.

      “There are other, much larger projects in the pipeline,” Kearns says. “The Jay Peak project is about 3 megawatts of power, but some of the ones we’re working on now are 30, 60 megawatt projects. Those are more industrial focused, and they’re located in places where we have a strong industrial base and an abundance of renewables, everywhere from Texas to Kansas to the Dakotas — that heart of the country that our team lovingly calls the Wind Belt.”

      Antora’s future projects will be with companies in the chemicals, mining, food and beverage, and oil and gas industries. Some of those projects are expected to come online as early as 2025.          

      The company’s scaling strategy is centered on the inexpensive production process for its batteries.

      “We constantly ask ourselves, ‘What is the best product we can make here?’” Bierman says. “We landed on a compact, containerized, modular system that gets shipped to sites and is easily integrated into industrial processes. It means we don’t have huge construction projects, timelines, and budget overruns. Instead, it’s all about scaling up the factory that builds these thermal batteries and just churning them out.”

      It was a winding journey for Kearns and Bierman, but they now believe they’re positioned to help huge companies become carbon-free while promoting the growth of the solar and wind industries.

      “The more I dig into this, the more shocked I am at how important a piece of the decarbonization puzzle this is today,” Bierman says. “The need has become super real since we first started talking about this in 2016. The economic opportunity has grown, but more importantly the awareness from industries that they need to decarbonize is totally different. Antora can help with that, so we’re scaling up as rapidly as possible to meet the demand we see in the market.” More

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      in Energy

      MIT engineers create an energy-storing supercapacitor from ancient materials

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      Two of humanity’s most ubiquitous historical materials, cement and carbon black (which resembles very fine charcoal), may form the basis for a novel, low-cost energy storage system, according to a new study. The technology could facilitate the use of renewable energy sources such as solar, wind, and tidal power by allowing energy networks to remain stable despite fluctuations in renewable energy supply.

      The two materials, the researchers found, can be combined with water to make a supercapacitor — an alternative to batteries — that could provide storage of electrical energy. As an example, the MIT researchers who developed the system say that their supercapacitor could eventually be incorporated into the concrete foundation of a house, where it could store a full day’s worth of energy while adding little (or no) to the cost of the foundation and still providing the needed structural strength. The researchers also envision a concrete roadway that could provide contactless recharging for electric cars as they travel over that road.

      The simple but innovative technology is described this week in the journal PNAS, in a paper by MIT professors Franz-Josef Ulm, Admir Masic, and Yang-Shao Horn, and four others at MIT and at the Wyss Institute for Biologically Inspired Engineering.

      Capacitors are in principle very simple devices, consisting of two electrically conductive plates immersed in an electrolyte and separated by a membrane. When a voltage is applied across the capacitor, positively charged ions from the electrolyte accumulate on the negatively charged plate, while the positively charged plate accumulates negatively charged ions. Since the membrane in between the plates blocks charged ions from migrating across, this separation of charges creates an electric field between the plates, and the capacitor becomes charged. The two plates can maintain this pair of charges for a long time and then deliver them very quickly when needed. Supercapacitors are simply capacitors that can store exceptionally large charges.

      The amount of power a capacitor can store depends on the total surface area of its conductive plates. The key to the new supercapacitors developed by this team comes from a method of producing a cement-based material with an extremely high internal surface area due to a dense, interconnected network of conductive material within its bulk volume. The researchers achieved this by introducing carbon black — which is highly conductive — into a concrete mixture along with cement powder and water, and letting it cure. The water naturally forms a branching network of openings within the structure as it reacts with cement, and the carbon migrates into these spaces to make wire-like structures within the hardened cement. These structures have a fractal-like structure, with larger branches sprouting smaller branches, and those sprouting even smaller branchlets, and so on, ending up with an extremely large surface area within the confines of a relatively small volume. The material is then soaked in a standard electrolyte material, such as potassium chloride, a kind of salt, which provides the charged particles that accumulate on the carbon structures. Two electrodes made of this material, separated by a thin space or an insulating layer, form a very powerful supercapacitor, the researchers found.

      The two plates of the capacitor function just like the two poles of a rechargeable battery of equivalent voltage: When connected to a source of electricity, as with a battery, energy gets stored in the plates, and then when connected to a load, the electrical current flows back out to provide power.

      “The material is fascinating,” Masic says, “because you have the most-used manmade material in the world, cement, that is combined with carbon black, that is a well-known historical material — the Dead Sea Scrolls were written with it. You have these at least two-millennia-old materials that when you combine them in a specific manner you come up with a conductive nanocomposite, and that’s when things get really interesting.”

      As the mixture sets and cures, he says, “The water is systematically consumed through cement hydration reactions, and this hydration fundamentally affects nanoparticles of carbon because they are hydrophobic (water repelling).” As the mixture evolves, “the carbon black is self-assembling into a connected conductive wire,” he says. The process is easily reproducible, with materials that are inexpensive and readily available anywhere in the world. And the amount of carbon needed is very small — as little as 3 percent by volume of the mix — to achieve a percolated carbon network, Masic says.

      Supercapacitors made of this material have great potential to aid in the world’s transition to renewable energy, Ulm says. The principal sources of emissions-free energy, wind, solar, and tidal power, all produce their output at variable times that often do not correspond to the peaks in electricity usage, so ways of storing that power are essential. “There is a huge need for big energy storage,” he says, and existing batteries are too expensive and mostly rely on materials such as lithium, whose supply is limited, so cheaper alternatives are badly needed. “That’s where our technology is extremely promising, because cement is ubiquitous,” Ulm says.

      The team calculated that a block of nanocarbon-black-doped concrete that is 45 cubic meters (or yards) in size — equivalent to a cube about 3.5 meters across — would have enough capacity to store about 10 kilowatt-hours of energy, which is considered the average daily electricity usage for a household. Since the concrete would retain its strength, a house with a foundation made of this material could store a day’s worth of energy produced by solar panels or windmills and allow it to be used whenever it’s needed. And, supercapacitors can be charged and discharged much more rapidly than batteries.

      After a series of tests used to determine the most effective ratios of cement, carbon black, and water, the team demonstrated the process by making small supercapacitors, about the size of some button-cell batteries, about 1 centimeter across and 1 millimeter thick, that could each be charged to 1 volt, comparable to a 1-volt battery. They then connected three of these to demonstrate their ability to light up a 3-volt light-emitting diode (LED). Having proved the principle, they now plan to build a series of larger versions, starting with ones about the size of a typical 12-volt car battery, then working up to a 45-cubic-meter version to demonstrate its ability to store a house-worth of power.

      There is a tradeoff between the storage capacity of the material and its structural strength, they found. By adding more carbon black, the resulting supercapacitor can store more energy, but the concrete is slightly weaker, and this could be useful for applications where the concrete is not playing a structural role or where the full strength-potential of concrete is not required. For applications such as a foundation, or structural elements of the base of a wind turbine, the “sweet spot” is around 10 percent carbon black in the mix, they found.

      Another potential application for carbon-cement supercapacitors is for building concrete roadways that could store energy produced by solar panels alongside the road and then deliver that energy to electric vehicles traveling along the road using the same kind of technology used for wirelessly rechargeable phones. A related type of car-recharging system is already being developed by companies in Germany and the Netherlands, but using standard batteries for storage.

      Initial uses of the technology might be for isolated homes or buildings or shelters far from grid power, which could be powered by solar panels attached to the cement supercapacitors, the researchers say.

      Ulm says that the system is very scalable, as the energy-storage capacity is a direct function of the volume of the electrodes. “You can go from 1-millimeter-thick electrodes to 1-meter-thick electrodes, and by doing so basically you can scale the energy storage capacity from lighting an LED for a few seconds, to powering a whole house,” he says.

      Depending on the properties desired for a given application, the system could be tuned by adjusting the mixture. For a vehicle-charging road, very fast charging and discharging rates would be needed, while for powering a home “you have the whole day to charge it up,” so slower-charging material could be used, Ulm says.

      “So, it’s really a multifunctional material,” he adds. Besides its ability to store energy in the form of supercapacitors, the same kind of concrete mixture can be used as a heating system, by simply applying electricity to the carbon-laced concrete.

      Ulm sees this as “a new way of looking toward the future of concrete as part of the energy transition.”

      The research team also included postdocs Nicolas Chanut and Damian Stefaniuk at MIT’s Department of Civil and Environmental Engineering, James Weaver at the Wyss Institute, and Yunguang Zhu in MIT’s Department of Mechanical Engineering. The work was supported by the MIT Concrete Sustainability Hub, with sponsorship by the Concrete Advancement Foundation. More

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      in Environment

      Transatlantic connections make the difference for MIT Portugal

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      Successful relationships take time to develop, with both parties investing energy and resources and fostering mutual trust and understanding. The MIT Portugal Program (MPP), a strategic partnership between MIT, Portuguese universities and research institutions, and the Portuguese government, is a case in point.

      Portugal’s inaugural partnership with a U.S. university, MPP was established in 2006 as a collaboration between MIT and the Portuguese Science and Technology Foundation (Fundação para a Ciência e Tecnologia, or FCT). Since then, the program has developed research platforms in areas such as bioengineering, sustainable energy, transportation systems, engineering design, and advanced manufacturing. Now halfway through its third phase (MPP2030, begun in 2018), the program owes much of its success to the bonds connecting institutions and people across the Atlantic over the past 17 years.

      “When you look at the successes and the impact, these things don’t happen overnight,” says John Hansman, the T. Wilson Professor of Aeronautics and Astronautics at MIT and co-director of MPP, noting, in particular, MPP’s achievements in the areas of energy and ocean research, as well as bioengineering. “This has been a longstanding relationship that we have and want to continue. I think it’s been beneficial to Portugal and to MIT. I think you can argue it has made substantial contributions to the success that Portugal is currently experiencing both in its technical capabilities and also its energy policy.”

      With research often aimed at climate and sustainability solutions, one of MPP’s key strengths is its education of future leaders in science, technology, and entrepreneurship. And the program’s impacts carry forward, as several former MPP students are now on the faculty at participating Portuguese universities.

      “The original intent of working together with Portugal was to try to establish collaboration between universities and to instill some of the MIT culture with the culture in Portugal, and I think that’s been hugely successful,” says Douglas Hart, MPP co-director and professor of mechanical engineering at MIT. “It has had a lot of impacts in terms of the research, but also the people.”

      One of those people is André Pina, associate director of H2 strategy and origination at the company EDP, who was in residence at MIT in 2014 as part of the MPP Sustainable Energy Systems Doctoral Program. He says the competencies and experiences he acquired have been critical to his professional development in energy system planning, have influenced his approach to problem solving, and have allowed him to bring “holistic thinking” to business endeavors.

      “The MIT Portugal Program has created a collaborative ecosystem between Portuguese universities, companies, and MIT that enabled the training of highly qualified professionals, while contributing to the positioning of Portuguese companies in new cutting-edge fields,” he says.

      Building on MPP’s previous successes, MPP2030 focuses on advancing research in four strategic areas: climate science and climate change; earth systems from oceans to near space; digital transformation in manufacturing; and sustainable cities — all involving data science-intensive approaches and methodologies. Within these broad scientific areas, FCT funding has enabled seven collaborative large-scale “flagship” projects between Portuguese and MIT researchers during the current phase, as well as dozens of smaller projects.

      Flagship projects currently underway include:

      ·   AEROS Constellation

      ·   C-Tech: Climate Driven Technologies for Low Carbon Cities

      ·   K2D: Knowledge and Data from the Deep to Space

      ·   NEWSAT

      ·   Operator: Digital Transformation in Industry with a Focus on the Operator 4.0

      ·   SNOB-5G: Scalable Network Backhauling for 5G

      ·   Transformer 4.0: Digital Revolution of Power Transformers

      Sustainability plays a significant role in MPP — reflective of the value both Portugal and MIT place on environmental, energy, and climate solutions. Projects under the Sustainable Cities strategic area, for example, are “helping cities in Portugal to become more efficient and more sustainable,” Hansman says, noting that MPP’s influence is being felt in cities across the country and it is “having a big impact in terms of local city planning activities.”

      Regarding energy, Hansman points to a previous MPP phase that focused on the Azores as an isolated energy ecosystem and investigated its ability to minimize energy use and become energy independent.

      “That view of system-level energy use helped to stimulate activity on the mainland in Portugal, which has helped Portugal become a leader in various energy sources and made them less vulnerable in the last year or two,” Hansman says.

      In the Oceans to Near Space strategic area, the K2D flagship project also emphasizes research into sustainability solutions, as well as resilience to environmental change. Over the past few years, K2D researchers in Portugal and MIT have worked together to develop components that permit cost-effective gathering of chemical, physical, biological, and environmental data from the ocean depths. One current project investigates the integration of autonomous underwater vehicles with subsea cables to enhance both environmental monitoring and hazard warning systems.

      “The program has been very successful,” Hart says. “They are now deploying a 2-kilometer cable just south of Lisbon, which will be in place in another month or so. Portugal has been hit with tsunamis that caused tremendous devastation, and one of the objectives of these cables is to sense tsunamis. So, it’s an early warning system.”

      As a leader in ocean technology with a long history of maritime discovery, Portugal provides many opportunities for MIT’s ocean researchers. Hart notes that the Portuguese military invites international researchers on board its ships, providing MIT with research opportunities that would be financially difficult otherwise.

      Hansman adds that partnering with researchers in the Azores provides MIT with unique access to facilities and labs in the middle of the Atlantic Ocean. For example, Hart will be teaching at a marine robotics summer school in the Azores this July.

      Cadence Payne, an MIT PhD candidate, is among those planning to attend. Through MPP’s AEROS project, Payne has helped develop a modular “cubesat” that will orbit over Portugal’s Exclusive Economic Zone collecting images and radio data to help define the ecological health of the country’s coastal waters. The nanosatellite is expected to launch in late 2023 or early 2024, says Payne, adding that it will be Portugal’s first cubesat mission.

      “In monitoring the ocean, you’re monitoring the climate,” Payne says. “If you want to do work on detecting climate change and developing methods of mitigating climate change … it helps to integrate international collaboration,” she says, adding that, for students, “it’s been a really beautiful opportunity for us to see the benefits of collaboration.”

      “I would say one of the main benefits of working with Portugal is that we share many interests in research in the sense that they’re very interested in climate change, sustainability, environmental impacts and those kinds of things,” says Hart. “They have turned out to be a very good strategic partner for MIT, and, hopefully, MIT for them.” More

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      in Energy

      Panel addresses technologies needed for a net-zero future

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      Five speakers at a recent public panel discussion hosted by the MIT Energy Initiative (MITEI) and introduced by Deputy Director for Science and Technology Robert Stoner tackled one of the thorniest, yet most critical, questions facing the world today: How can we achieve the ambitious goals set by governments around the globe, including the United States, to reach net zero emissions of greenhouse gases by mid-century?

      While the challenges are great, the panelists agreed, there is reason for optimism that these technological challenges can be solved. More uncertain, some suggested, are the social, economic, and political hurdles to bringing about the needed innovations.

      The speakers addressed areas where new or improved technologies or systems are needed if these ambitious goals are to be achieved. Anne White, aassociate provost and associate vice president for research administration and a professor of nuclear science and engineering at MIT, moderated the panel discussion. She said that achieving the ambitious net-zero goal “has to be accomplished by filling some gaps, and going after some opportunities.” In addressing some of these needs, she said the five topics chosen for the panel discussion were “places where MIT has significant expertise, and progress is already ongoing.”

      First of these was the heating and cooling of buildings. Christoph Reinhart, a professor of architecture and director of the Building Technology Program, said that currently about 1 percent of existing buildings are being retrofitted each year for energy efficiency and conversion from fossil-fuel heating systems to efficient electric ones — but that is not nearly enough to meet the 2050 net-zero target. “It’s an enormous task,” he said. To meet the goals, he said, would require increasing the retrofitting rate to 5 percent per year, and to require all new construction to be carbon neutral as well.

      Reinhart then showed a series of examples of how such conversions could take place using existing solar and heat pump technology, and depending on the configuration, how they could provide a payback to the homeowner within 10 years or less. However, without strong policy incentives the initial cost outlay for such a system, on the order of $50,000, is likely to put conversions out of reach of many people. Still, a recent survey found that 30 percent of homeowners polled said they would accept installation at current costs. While there is government money available for incentives for others, “we have to be very clever on how we spend all this money … and make sure that everybody is basically benefiting.”

      William Green, a professor of chemical engineering, spoke about the daunting challenge of bringing aviation to net zero. “More and more people like to travel,” he said, but that travel comes with carbon emissions that affect the climate, as well as air pollution that affects human health. The economic costs associated with these emissions, he said, are estimated at $860 per ton of jet fuel used — which is very close to the cost of the fuel itself. So the price paid by the airlines, and ultimately by the passengers, “is only about half of the true cost to society, and the other half is being borne by all of us, by the fact that it’s affecting the climate and it’s causing medical problems for people.”

      Eliminating those emissions is a major challenge, he said. Virtually all jet fuel today is fossil fuel, but airlines are starting to incorporate some biomass-based fuel, derived mostly from food waste. But even these fuels are not carbon-neutral, he said. “They actually have pretty significant carbon intensity.”

      But there are possible alternatives, he said, mostly based on using hydrogen produced by clean electricity, and making fuels out of that hydrogen by reacting it, for example, with carbon dioxide. This could indeed produce a carbon-neutral fuel that existing aircraft could use, but the process is costly, requiring a great deal of hydrogen, and ways of concentrating carbon dioxide. Other viable options also exist, but all would add significant expense, at least with present technology. “It’s going to cost a lot more for the passengers on the plane,” Green said, “But the society will benefit from that.”

      Increased electrification of heating and transportation in order to avoid the use of fossil fuels will place major demands on the existing electric grid systems, which have to perform a constant delicate balancing of production with demand. Anuradha Annaswamy, a senior research scientist in MIT’s mechanical engineering department, said “the electric grid is an engineering marvel.” In the United States it consists of 300,000 miles of transmission lines capable of carrying 470,000 megawatts of power.

      But with a projected doubling of energy from renewable sources entering the grid by 2030, and with a push to electrify everything possible — from transportation to buildings to industry — the load is not only increasing, but the patterns of both energy use and production are changing. Annaswamy said that “with all these new assets and decision-makers entering the picture, the question is how you can use a more sophisticated information layer that coordinates how all these assets are either consuming or producing or storing energy, and have that information layer coexist with the physical layer to make and deliver electricity in all these ways. It’s really not a simple problem.”

      But there are ways of addressing these complexities. “Certainly, emerging technologies in power electronics and control and communication can be leveraged,” she said. But she added that “This is not just a technology problem, really, it is something that requires technologists, economists, and policymakers to all come together.”

      As for industrial processes, Bilge Yildiz, a professor of nuclear science and engineering and materials science and engineering, said that “the synthesis of industrial chemicals and materials constitutes about 33 percent of global CO2 emissions at present, and so our goal is to decarbonize this difficult sector.” About half of all these industrial emissions come from the production of just four materials: steel, cement, ammonia, and ethylene, so there is a major focus of research on ways to reduce their emissions.

      Most of the processes to make these materials have changed little for more than a century, she said, and they are mostly heat-based processes that involve burning a lot of fossil fuel. But the heat can instead be provided from renewable electricity, which can also be used to drive electrochemical reactions in some cases as a substitute for the thermal reactions. Already, there are processes for making cement and steel that produce only about half the present carbon dioxide (CO2) emissions.

      The production of ammonia, which is widely used in fertilizer and other bulk chemicals, accounts for more greenhouse gas emissions than any other industrial source. The present thermochemical process could be replaced by an electrochemical process, she said. Similarly, the production of ethylene, as a feedstock for plastics and other materials, is the second-highest emissions producer, with three tons of carbon dioxide released for every ton of ethylene produced. Again, an electrochemical alternative method exists, but needs to be improved to be cost competitive.

      As the world moves toward electrification of industrial processes to eliminate fossil fuels, the need for emissions-free sources of electricity will continue to increase. One very promising potential addition to the range of carbon-free generation sources is fusion, a field in which MIT is a leader in developing a particularly promising technology that takes advantage of the unique properties of high-temperature superconducting (HTS) materials.

      Dennis Whyte, the director of MIT’s Plasma Science and Fusion Center, pointed out that despite global efforts to reduce CO2 emissions, “we use exactly the same percentage of carbon-based products to generate energy as 10 years ago, or 20 years ago.” To make a real difference in global emissions, “we need to make really massive amounts of carbon-free energy.”

      Fusion, the process that powers the sun, is a particularly promising pathway, because the fuel, derived from water, is virtually inexhaustible. By using recently developed HTS material to generate the powerful magnetic fields needed to produce a sustained fusion reaction, the MIT-led project, which led to a spinoff company called Commonwealth Fusion Systems, was able to radically reduce the required size of a fusion reactor, Whyte explained. Using this approach, the company, in collaboration with MIT, expects to have a fusion system that produces net energy by the middle of this decade, and be ready to build a commercial plant to produce power for the grid early in the next. Meanwhile, at least 25 other private companies are also attempting to commercialize fusion technology. “I think we can take some credit for helping to spawn what is essentially now a new industry in the United States,” Whyte said.

      Fusion offers the potential, along with existing solar and wind technologies, to provide the emissions-free power the world needs, Whyte says, but that’s only half the problem, the other part being how to get that power to where it’s needed, when it’s needed. “How do we adapt these new energy sources to be as compatible as possible with everything that we have already in terms of energy delivery?”

      Part of the way to find answers to that, he suggested, is more collaborative work on these issues that cut across disciplines, as well as more of the kinds of cross-cutting conversations and interactions that took place in this panel discussion. More