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      in Energy

      Using excess heat to improve electrolyzers and fuel cells

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      Reducing the use of fossil fuels will have unintended consequences for the power-generation industry and beyond. For example, many industrial chemical processes use fossil-fuel byproducts as precursors to things like asphalt, glycerine, and other important chemicals. One solution to reduce the impact of the loss of fossil fuels on industrial chemical processes is to store and use the heat that nuclear fission produces. New MIT research has dramatically improved a way to put that heat toward generating chemicals through a process called electrolysis. 

      Electrolyzers are devices that use electricity to split water (H2O) and generate molecules of hydrogen (H2) and oxygen (O2). Hydrogen is used in fuel cells to generate electricity and drive electric cars or drones or in industrial operations like the production of steel, ammonia, and polymers. Electrolyzers can also take in water and carbon dioxide (CO2) and produce oxygen and ethylene (C2H4), a chemical used in polymers and elsewhere.

      There are three main types of electrolyzers. One type works at room temperature, but has downsides; they’re inefficient and require rare metals, such as platinum. A second type is more efficient but runs at high temperatures, above 700 degrees Celsius. But metals corrode at that temperature, and the devices need expensive sealing and insulation. The third type would be a Goldilocks solution for nuclear heat if it were perfected, running at 300-600 C and requiring mostly cheap materials like stainless steel. These cells have never been operated as efficiently as theory says they should. The new work, published this month in Nature, both illuminates the problem and offers a solution.

      A sandwich mystery

      The intermediate-temperature devices use what are called protonic ceramic electrochemical cells. Each cell is a sandwich, with a dense electrolyte layered between two porous electrodes. Water vapor is pumped into the top electrode. A wire on the side connects the two electrodes, and externally generated electricity runs from the top to the bottom. The voltage pulls electrons out of the water, which splits the molecule, releasing oxygen. A hydrogen atom without an electron is just a proton. The protons get pulled through the electrolyte to rejoin with the electrons at the bottom electrode and form H2 molecules, which are then collected.

      On its own, the electrolyte in the middle, made mainly of barium, cerium, and zirconium, conducts protons very well. “But when we put the same material into this three-layer device, the proton conductivity of the full cell is pretty bad,” says Yanhao Dong, a postdoc in MIT’s Department of Nuclear Science and Engineering and a paper co-author. “Its conductivity is only about 50 percent of the bulk form’s. We wondered why there’s an inconsistency here.”

      A couple of clues pointed them in the right direction. First, if they don’t prepare the cell very carefully, the top layer, only about 20 microns (.02 millimeters) thick, doesn’t stay attached. “Sometimes if you use just Scotch tape, it will peel off,” Dong says. Second, when they looked at a cross section of a device using a scanning electron microscope, they saw that the top surface of the electrolyte layer was flat, whereas the bottom surface of the porous electrode sitting on it was bumpy, and the two came into contact in only a few places. They didn’t bond well. That precarious interface leads to both structural de-lamination and poor proton passage from the electrode to the electrolyte.

      Acidic solution

      The solution turned out to be simple: researchers roughed up the top of the electrolyte. Specifically, they applied acid for 10 minutes, which etched grooves into the surface. Ju Li, the Battelle Energy Alliance Professor in Nuclear Engineering and professor of materials science and engineering at MIT, and a paper co-author, likens it to sandblasting a surface before applying paint to increase adhesion. Their acid-treated cells produced about 200 percent more hydrogen per area at 1.5 volts at 600 C than did any previous cell of its type, and worked well down to 350 C with very little performance decay over extended operation. 

      “The authors reported a surprisingly simple yet highly effective surface treatment to dramatically improve the interface,” says Liangbing Hu, the director of the Center for Materials Innovation at the Maryland Energy Innovation Institute, who was not involved in the work. He calls the cell performance “exceptional.”

      “We are excited and surprised” by the results, Dong says. “The engineering solution seems quite simple. And that’s actually good, because it makes it very applicable to real applications.” In a practical product, many such cells would be stacked together to form a module. MIT’s partner in the project, Idaho National Laboratory, is very strong in engineering and prototyping, so Li expects to see electrolyzers based on this technology at scale before too long. “At the materials level, this is a breakthrough that shows that at a real-device scale you can work at this sweet spot of temperature of 350 to 600 degrees Celsius for nuclear fission and fusion reactors,” he says.

      “Reduced operating temperature enables cheaper materials for the large-scale assembly, including the stack,” says Idaho National Laboratory researcher and paper co-author Dong Ding. “The technology operates within the same temperature range as several important, current industrial processes, including ammonia production and CO2 reduction. Matching these temperatures will expedite the technology’s adoption within the existing industry.”

      “This is very significant for both Idaho National Lab and us,” Li adds, “because it bridges nuclear energy and renewable electricity.” He notes that the technology could also help fuel cells, which are basically electrolyzers run in reverse, using green hydrogen or hydrocarbons to generate electricity. According to Wei Wu, a materials scientist at Idaho National Laboratory and a paper co-author, “this technique is quite universal and compatible with other solid electrochemical devices.”

      Dong says it’s rare for a paper to advance both science and engineering to such a degree. “We are happy to combine those together and get both very good scientific understanding and also very good real-world performance.”

      This work, done in collaboration with Idaho National Laboratory, New Mexico State University, and the University of Nebraska–Lincoln, was funded, in part, by the U.S. Department of Energy. More

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      in Environment

      Five MIT PhD students awarded 2022 J-WAFS fellowships for water and food solutions

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      The Abdul Latif Jameel Water and Food Systems Lab (J-WAFS) recently announced the selection of its 2022-23 cohort of graduate fellows. Two students were named Rasikbhai L. Meswani Fellows for Water Solutions and three students were named J-WAFS Graduate Student Fellows. All five fellows will receive full tuition and a stipend for one semester, and J-WAFS will support the students throughout the 2022-23 academic year by providing networking, mentorship, and opportunities to showcase their research.

      New this year, fellowship nominations were open not only to students pursuing water research, but food-related research as well. The five students selected were chosen for their commitment to solutions-based research that aims to alleviate problems such as water supply or purification, food security, or agriculture. Their projects exemplify the wide range of research that J-WAFS supports, from enhancing nutrition through improved methods to deliver micronutrients to developing high-performance drip irrigation technology. The strong applicant pool reflects the passion MIT students have to address the water and food crises currently facing the planet.

      “This year’s fellows are drawn from a dynamic and engaged community across the Institute whose creativity and ingenuity are pushing forward transformational water and food solutions,” says J-WAFS executive director Renee J. Robins. “We congratulate these students as we recognize their outstanding achievements and their promise as up-and-coming leaders in global water and food sectors.”

      2022-23 Rasikbhai L. Meswani Fellows for Water SolutionsThe Rasikbhai L. Meswani Fellowship for Water Solutions is a fellowship for students pursuing water-related research at MIT. The Rasikbhai L. Meswani Fellowship for Water Solutions was made possible by a generous gift from Elina and Nikhil Meswani and family.

      Aditya Ghodgaonkar is a PhD candidate in the Department of Mechanical Engineering at MIT, where he works in the Global Engineering and Research (GEAR) Lab under Professor Amos Winter. Ghodgaonkar received a bachelor’s degree in mechanical engineering from the RV College of Engineering in India. He then moved to the United States and received a master’s degree in mechanical engineering from Purdue University.Ghodgaonkar is currently designing hydraulic components for drip irrigation that could support the development of water-efficient irrigation systems that are off-grid, inexpensive, and low-maintenance. He has focused on designing drip irrigation emitters that are resistant to clogging, seeking inspiration about flow regulation from marine fauna such as manta rays, as well as turbomachinery concepts. Ghodgaonkar notes that clogging is currently an expensive technical challenge to diagnose, mitigate, and resolve. With an eye on hundreds of millions of farms in developing countries, he aims to bring the benefits of irrigation technology to even the poorest farmers.Outside of his research, Ghodgaonkar is a mentor in MIT Makerworks and has been a teaching assistant for classes such as 2.007 (Design and Manufacturing I). He also helped organize the annual MIT Water Summit last fall.

      Devashish Gokhale is a PhD candidate advised by Professor Patrick Doyle in the Department of Chemical Engineering. He received a bachelor’s degree in chemical engineering from the Indian Institute of Technology Madras, where he researched fluid flow in energy-efficient pumps. Gokhale’s commitment to global water security stemmed from his experience growing up in India, where water sources are threatened by population growth, industrialization, and climate change.As a researcher in the Doyle group, Devashish is developing sustainable and reusable materials for water treatment, with a focus on the elimination of emerging contaminants and other micropollutants from water through cost-effective processes. Many of these contaminants are carcinogens or endocrine disruptors, posing significant threats to both humans and animals. His advisor notes that Devashish was the first researcher in the Doyle group to work on water purification, bringing his passion for the topic to the lab.Gokhale’s research won an award for potential scalability in last year’s J-WAFS World Water Day competition. He also serves as the lecture series chair in the MIT Water Club.

      2022-23 J-WAFS Graduate Student FellowsThe J-WAFS Fellowship for Water and Food Solutions is funded by the J-WAFS Research Affiliate Program, which offers companies the opportunity to collaborate with MIT on water and food research. A portion of each research affiliate’s fees supports this fellowship. The program is central to J-WAFS’ efforts to engage across sector and disciplinary boundaries in solving real-world problems. Currently, there are two J-WAFS Research Affiliates: Xylem, Inc., a water technology company, and GoAigua, a company leading the digital transformation of the water industry.

      James Zhang is a PhD candidate in the Department of Mechanical Engineering at MIT, where he has worked in the NanoEngineering Laboratory with Professor Gang Chen since 2019. As an undergraduate at Carnegie Mellon University, he double majored in mechanical engineering and engineering public policy. He then received a master’s degree in mechanical engineering from MIT. In addition to working in the NanoEngineering Laboratory, James has also worked in the Zhao Laboratory and in the Boriskina Research Group at MIT.Zhang is developing a technology that uses light-induced evaporation to clean water. He is currently investigating the fundamental properties of how light interacts with brackish water surfaces. With strong theoretical as well as experimental components, his research could lead to innovations in desalinating brackish water at high energy efficiencies. Outside of his research, Zhang has served as a student moderator for the MIT International Colloquia on Thermal Innovations.

      Katharina Fransen is a PhD candidate advised by Professor Bradley Olsen in the Department of Chemical Engineering at MIT. She received a bachelor’s degree in chemical engineering from the University of Minnesota, where she was involved in the Society of Women Engineers. Fransen is motivated by the challenge of protecting the most vulnerable global communities from the large quantities of plastic waste associated with traditional food packaging materials. As a researcher in the Olsen Lab, Fransen is developing new plastics that are biologically-based and biodegradable, so they can degrade in the environment instead of polluting communities with plastic waste. These polymers are also optimized for food packaging applications to keep food fresher for longer, preventing food waste.Outside of her research, Fransen is involved in Diversity in Chemical Engineering as the coordinator for the graduate application mentorship program for underrepresented groups. She is also an active member of Graduate Womxn in ChemE and mentors an Undergraduate Research Opportunities Program student.

      Linzixuan (Rhoda) Zhang is a PhD candidate advised by Professor Robert Langer and Ana Jaklenec in the Department of Chemical Engineering at MIT. She received a bachelor’s degree in chemical engineering from the University of Illinois at Urbana-Champaign, where she researched how to genetically engineer microorganisms for the efficient production of advanced biofuels and chemicals.Zhang is currently developing a micronutrient delivery platform that fortifies foods with essential vitamins and nutrients. She has helped develop a group of biodegradable polymers that can stabilize micronutrients under harsh conditions, enabling local food companies to fortify food with essential vitamins. This work aims to tackle a hidden crisis in low- and middle-income countries, where a chronic lack of essential micronutrients affects an estimated 2 billion people.Zhang is also working on the development of self-boosting vaccines to promote more widespread vaccine access and serves as a research mentor in the Langer Lab. More

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      in Energy

      At Climate Grand Challenges showcase event, an exploration of how to accelerate breakthrough solutions

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      On the eve of Earth Day, more than 300 faculty, researchers, students, government officials, and industry leaders gathered in the Samberg Conference Center, along with thousands more who tuned in online, to celebrate MIT’s first-ever Climate Grand Challenges and the five most promising concepts to emerge from the two-year competition.

      The event began with a climate policy conversation between MIT President L. Rafael Reif and Special Presidential Envoy for Climate John Kerry, followed by presentations from each of the winning flagship teams, and concluded with an expert panel that explored pathways for moving from ideas to impact at scale as quickly as possible.

      “In 2020, when we launched the Climate Grand Challenges, we wanted to focus the daring creativity and pioneering expertise of the MIT community on the urgent problem of climate change,” said President Reif in kicking off the event. “Together these flagship projects will define a transformative new research agenda at MIT, one that has the potential to make meaningful contributions to the global climate response.”

      Reif and Kerry discussed multiple aspects of the climate crisis, including mitigation, adaptation, and the policies and strategies that can help the world avert the worst consequences of climate change and make the United States a leader again in bringing technology into commercial use. Referring to the accelerated wartime research effort that helped turn the tide in World War II, which included work conducted at MIT, Kerry said, “We need about five Manhattan Projects, frankly.”

      “People are now sensing a much greater urgency to finding solutions — new technology — and taking to scale some of the old technologies,” Kerry said. “There are things that are happening that I think are exciting, but the problem is it’s not happening fast enough.”

      Strategies for taking technology from the lab to the marketplace were the basis for the final portion of the event. The panel was moderated by Alicia Barton, president and CEO of FirstLight Power, and included Manish Bapna, president and CEO of the Natural Resources Defense Council; Jack Little, CEO and co-founder of MathWorks; Arati Prabhakar, president of Actuate and former head of the Defense Advanced Research Projects Agency; and Katie Rae, president and managing director of The Engine. The discussion touched upon the importance of marshaling the necessary resources and building the cross-sector partnerships required to scale the technologies being developed by the flagship teams and to deliver them to the world in time to make a difference. 

      “MIT doesn’t sit on its hands ever, and innovation is central to its founding,” said Rae. “The students coming out of MIT at every level, along with the professors, have been committed to these challenges for a long time and therefore will have a big impact. These flagships have always been in process, but now we have an extraordinary moment to commercialize these projects.”

      The panelists weighed in on how to change the mindset around finance, policy, business, and community adoption to scale massive shifts in energy generation, transportation, and other major carbon-emitting industries. They stressed the importance of policies that address the economic, equity, and public health impacts of climate change and of reimagining supply chains and manufacturing to grow and distribute these technologies quickly and affordably. 

      “We are embarking on five adventures, but we do not know yet, cannot know yet, where these projects will take us,” said Maria Zuber, MIT’s vice president for research. “These are powerful and promising ideas. But each one will require focused effort, creative and interdisciplinary teamwork, and sustained commitment and support if they are to become part of the climate and energy revolution that the world urgently needs. This work begins now.” 

      Zuber called for investment from philanthropists and financiers, and urged companies, governments, and others to join this all-of-humanity effort. Associate Provost for International Activities Richard Lester echoed this message in closing the event. 

      “Every one of us needs to put our shoulder to the wheel at the points where our leverage is maximized — where we can do what we’re best at,” Lester said. “For MIT, Climate Grand Challenges is one of those maximum leverage points.” More

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      in Environment

      A community approach to improving the health of the planet

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      Earlier this month, MIT’s Department of Mechanical Engineering (MechE) hosted a Health of the Planet Showcase. The event was the culmination of a four-year long community initiative to focus on what the mechanical engineering community at MIT can do to solve some of the biggest challenges the planet faces on a local and global scale. Structured like an informal poster session, the event marked the first time that administrative staff joined students, researchers, and postdocs in sharing their own research.

      When Evelyn Wang started her tenure as mechanical engineering department head in July 2018, she and associate department heads Pierre Lermusiaux and Rohit Karnik made the health of the planet a top priority for the department. Their goal was to bring students, faculty, and staff together to develop solutions that address the many problems related to the health of the planet.

      “As a field, mechanical engineering is unique in its diversity,” says Wang, the Ford Professor of Engineering. “We have researchers who are world-leading experts on desalination, ocean engineering, energy storage, and photovoltaics, just to name a few. One of our driving motivations has been getting those experts to collaborate and work on new health of the planet research projects together.”

      Wang also saw an opportunity to tap into the passions of the department’s students and staff, many of whom devote their extracurricular and personal time to environmental causes. She enlisted the help of a team of faculty and staff to launch what has become known as the MechE Health of the Planet Initiative.

      The initiative, which capitalizes on the diverse range of research fields in mechanical engineering, encouraged both grand research ideas that could have impact on a global scale, and smaller personal habits that could help on a smaller scale.

      “We wanted to encourage everyone in our community to think about their daily routine and make small changes that really add up over time,” says Dorothy Hanna, program administrator at MIT and one of the staff members leading the initiative.

      The Health of the Planet team started small. They hosted an office supply swap day to encourage recycling and reuse of everyday office products. This idea expanded to include the launch of “Lab Reuse Days.” Members of the Rohsenow Kendall Lab, including members of the research groups of professors Gang Chen, John Lienhard, and Evelyn Wang, gathered extra materials for reuse. Researchers from other labs picked up Arduino kits, tubing, and electrical wiring to use for their own projects.

      While individuals were encouraged to adopt small habits at home and at work to help the health of the planet, research teams were encouraged to work together on solutions on a larger scale.

      Seed funding for collaborative research

      In early 2020, the MIT Department of Mechanical Engineering launched a new collaborative seed research program based on funding from MathWorks, the computing software company that developed MATLAB. The first seed funding supported health of the planet research projects led by two or more mechanical engineering faculty members.

      “One of the driving goals of MechE has been fostering collaborations and supporting interdisciplinary research on the grand challenges our world faces,” says Pierre Lermusiaux, the Nam P. Suh Professor and associate department head for operations. “The seed funding from MathWorks was a great opportunity to build upon the diverse expertise and creativity our researchers have to address health of the planet related issues.” 

      The research projects supported by the seed funding ranged from lithium-ion batteries for electric vehicles to high-performance household energy products for low- and middle-income countries. Each project differs in scope and application, and draws upon the expertise of at least two different research groups at MIT.

      Throughout the past two years, faculty presented about these research projects in several community seminars. They also participated in a full-day faculty research retreat focused on health of the planet research that included presentations from local Cambridge and Boston city leaders, as well as experts from other MIT departments and Harvard University.

      These projects have helped break down barriers and increased collaboration among research groups that focus on different areas. The third round of seed funding for collaborative research projects was recently announced and new projects will be chosen in the coming weeks.

      A community showcase

      Upon returning to the campus last fall, the Health of the Planet team began planning an event to bring the community together and celebrate the department’s research efforts. The Health of the Planet Showcase, which took place on April 4, featured 26 presenters from across the mechanical engineering community at MIT.

      Projects included a marine coastal monitoring robot, solar hydrogen production with thermochemical cycles, and a portable atmospheric water extractor for dry climates. Among the presenters was Administrative Assistant Tony Pulsone, who presented on how honeybees navigate their surroundings, as well as program manager Theresa Werth and program administrator Dorothy Hanna, who presented on reducing bottled water use and practical strategies developed by staff to overcome functional barriers on campus.

      The event concluded with the announcement of the Fay and Alfred D. Chandler Jr. Research Fellowship, awarded to a MechE student-led effort to propose a new paradigm to improve the health of our planet. Graduate student Charlene Xia won for her work developing a real-time opto-fluidics system for monitoring the soil microbiome.

      “The soil microbiome governs the biogeochemical cycling of macronutrients, micronutrients, and other elements vital for the growth of plants and animal life,” Xia said. “Understanding and predicting the impact of climate change on soil microbiomes and the ecosystem services they provide present a grand challenge and major opportunity.”

      The Chandler Fellowship will continue during the 2022-23 academic year, when another student-led project will be chosen. The department also hopes to make the Health of the Planet Showcase an annual gathering.

      “The showcase was such a vibrant event,” adds Wang. “It really energized the department and renewed our commitment to growing community efforts and continuing to advance research to help improve and protect the health of our planet.” More

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      in Environment

      Strengthening students’ knowledge and experience in climate and sustainability

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      Tackling the climate crisis is central to MIT. Critical to this mission is harnessing the innovation, passion, and expertise of MIT’s talented students, from a variety of disciplines and backgrounds. To help raise this student involvement to the next level, the MIT Climate and Sustainability Consortium (MCSC) recently launched a program that will engage MIT undergraduates in a unique, year-long, interdisciplinary experience both developing and implementing climate and sustainability research projects.

      The MCSC Climate and Sustainability Scholars Program is a way for students to dive deeply and directly into climate and sustainability research, strengthen their skill sets in a variety of climate and sustainability-related areas, build their networks, and continue to embrace and grow their passion.The MCSC Climate and Sustainability Scholars Program is representative of MIT’s ambitious and bold initiatives on climate and sustainability — bringing together faculty and students across MIT to collaborate with industry on developing climate and sustainability solutions in the context of undergraduate education and research.

      The program, open to rising juniors and seniors from all majors and departments, is inspired by MIT’s SuperUROP program. Students will enroll in a year-long class while simultaneously engaging in research. Research projects will be climate- and sustainability-focused and can be on or off campus. The course will be initially facilitated by Desiree Plata, the Gilbert W. Winslow Career Development Professor in Civil and Environmental Engineering, and Elsa Olivetti, the Esther and Harold E. Edgerton Associate Professor in Materials Science and Engineering and MCSC co-director.“Climate and sustainability challenges face real barriers in science, technology, policy, and beyond,” says Plata, who also serves on the MCSC’s Faculty Steering Committee. “We need to motivate an all-hands effort to bring MIT talent to bear on these challenges, and we need to give our students the tools to make tangible benefits within and between their disciplines. This was our goal in designing the MCSC Scholars Program, and it’s what I’m most excited about.”

      The Climate and Sustainability Scholars Program has relevance across all five schools, and the number of places the course is cross-listed continues to grow. As is the broader goal of the MCSC, the Climate and Sustainability Scholars Program aims to amplify and extend MIT’s expertise — through engaging students of all backgrounds and majors, bringing in faculty mentors and instructors from around the Institute, and identifying research opportunities and principal investigators that span disciplines. The student cohort model will also build off of the successful community-building endeavors by the MIT Energy Initiative and Environmental Solutions Initiative, among others, to bring students with similar interests together into an interdisciplinary, problem-solving space.The program’s fall semester will focus on key climate and sustainability topics, such as decarbonization strategies, policy, environmental justice, and quantitative methods for evaluating social and environmental impacts, and humanities-based communication of climate topics, all while students engage in research. Students will simultaneously develop project proposals, participate in a project through MIT’s Undergraduate Research Opportunities Program, and communicate their work using written and oral media. The spring semester’s course will focus on research and experiential activities, and help students communicate their outputs in entrepreneurial or policy activities that would enable the research outcomes to be rapidly scaled for impact.Throughout the program, students will engage with their research mentors, additional mentors drawn from MCSC-affiliated faculty, postdoctoral Impact Fellows, and graduate students — and there will also be opportunities for interaction with representatives of MCSC member companies.“Providing opportunities for students to sharpen the skills and knowledge needed to pioneer solutions for climate change mitigation and adaptation is critical,” says Olivetti. “We are excited that the Climate and Sustainability Scholars Program can contribute to that important mission.” More

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      in Environment

      Using plant biology to address climate change

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      On April 11, MIT announced five multiyear flagship projects in the first-ever Climate Grand Challenges, a new initiative to tackle complex climate problems and deliver breakthrough solutions to the world as quickly as possible. This article is the fourth in a five-part series highlighting the most promising concepts to emerge from the competition and the interdisciplinary research teams behind them.

      The impact of our changing climate on agriculture and food security — and how contemporary agriculture contributes to climate change — is at the forefront of MIT’s multidisciplinary project “Revolutionizing agriculture with low-emissions, resilient crops.” The project The project is one of five flagship winners in the Climate Grand Challenges competition, and brings together researchers from the departments of Biology, Biological Engineering, Chemical Engineering, and Civil and Environmental Engineering.

      “Our team’s research seeks to address two connected challenges: first, the need to reduce the greenhouse gas emissions produced by agricultural fertilizer; second, the fact that the yields of many current agricultural crops will decrease, due to the effects of climate change on plant metabolism,” says the project’s faculty lead, Christopher Voigt, the Daniel I.C. Wang Professor in MIT’s Department of Biological Engineering. “We are pursuing six interdisciplinary projects that are each key to our overall goal of developing low-emissions methods for fertilizing plants that are bioengineered to be more resilient and productive in a changing climate.”

      Whitehead Institute members Mary Gehring and Jing-Ke Weng, plant biologists who are also associate professors in MIT’s Department of Biology, will lead two of those projects.

      Promoting crop resilience

      For most of human history, climate change occurred gradually, over hundreds or thousands of years. That pace allowed plants to adapt to variations in temperature, precipitation, and atmospheric composition. However, human-driven climate change has occurred much more quickly, and crop plants have suffered: Crop yields are down in many regions, as is seed protein content in cereal crops.

      “If we want to ensure an abundant supply of nutritious food for the world, we need to develop fundamental mechanisms for bioengineering a wide variety of crop plants that will be both hearty and nutritious in the face of our changing climate,” says Gehring. In her previous work, she has shown that many aspects of plant reproduction and seed development are controlled by epigenetics — that is, by information outside of the DNA sequence. She has been using that knowledge and the research methods she has developed to identify ways to create varieties of seed-producing plants that are more productive and resilient than current food crops.

      But plant biology is complex, and while it is possible to develop plants that integrate robustness-enhancing traits by combining dissimilar parental strains, scientists are still learning how to ensure that the new traits are carried forward from one generation to the next. “Plants that carry the robustness-enhancing traits have ‘hybrid vigor,’ and we believe that the perpetuation of those traits is controlled by epigenetics,” Gehring explains. “Right now, some food crops, like corn, can be engineered to benefit from hybrid vigor, but those traits are not inherited. That’s why farmers growing many of today’s most productive varieties of corn must purchase and plant new batches of seeds each year. Moreover, many important food crops have not yet realized the benefits of hybrid vigor.”

      The project Gehring leads, “Developing Clonal Seed Production to Fix Hybrid Vigor,” aims to enable food crop plants to create seeds that are both more robust and genetically identical to the parent — and thereby able to pass beneficial traits from generation to generation.

      The process of clonal (or asexual) production of seeds that are genetically identical to the maternal parent is called apomixis. Gehring says, “Because apomixis is present in 400 flowering plant species — about 1 percent of flowering plant species — it is probable that genes and signaling pathways necessary for apomixis are already present within crop plants. Our challenge is to tweak those genes and pathways so that the plant switches reproduction from sexual to asexual.”

      The project will leverage the fact that genes and pathways related to autonomous asexual development of the endosperm — a seed’s nutritive tissue — exist in the model plant Arabidopsis thaliana. In previous work on Arabidopsis, Gehring’s lab researched a specific gene that, when misregulated, drives development of an asexual endosperm-like material. “Normally, that seed would not be viable,” she notes. “But we believe that by epigenetic tuning of the expression of additional relevant genes, we will enable the plant to retain that material — and help achieve apomixis.”

      If Gehring and her colleagues succeed in creating a gene-expression “formula” for introducing endosperm apomixis into a wide range of crop plants, they will have made a fundamental and important achievement. Such a method could be applied throughout agriculture to create and perpetuate new crop breeds able to withstand their changing environments while requiring less fertilizer and fewer pesticides.

      Creating “self-fertilizing” crops

      Roughly a quarter of greenhouse gas (GHG) emissions in the United States are a product of agriculture. Fertilizer production and use accounts for one third of those emissions and includes nitrous oxide, which has heat-trapping capacity 298-fold stronger than carbon dioxide, according to a 2018 Frontiers in Plant Science study. Most artificial fertilizer production also consumes huge quantities of natural gas and uses minerals mined from nonrenewable resources. After all that, much of the nitrogen fertilizer becomes runoff that pollutes local waterways. For those reasons, this Climate Grand Challenges flagship project aims to greatly reduce use of human-made fertilizers.

      One tantalizing approach is to cultivate cereal crop plants — which account for about 75 percent of global food production — capable of drawing nitrogen from metabolic interactions with bacteria in the soil. Whitehead Institute’s Weng leads an effort to do just that: genetically bioengineer crops such as corn, rice, and wheat to, essentially, create their own fertilizer through a symbiotic relationship with nitrogen-fixing microbes.

      “Legumes such as bean and pea plants can form root nodules through which they receive nitrogen from rhizobia bacteria in exchange for carbon,” Weng explains. “This metabolic exchange means that legumes release far less greenhouse gas — and require far less investment of fossil energy — than do cereal crops, which use a huge portion of the artificially produced nitrogen fertilizers employed today.

      “Our goal is to develop methods for transferring legumes’ ‘self-fertilizing’ capacity to cereal crops,” Weng says. “If we can, we will revolutionize the sustainability of food production.”

      The project — formally entitled “Mimicking legume-rhizobia symbiosis for fertilizer production in cereals” — will be a multistage, five-year effort. It draws on Weng’s extensive studies of metabolic evolution in plants and his identification of molecules involved in formation of the root nodules that permit exchanges between legumes and nitrogen-fixing bacteria. It also leverages his expertise in reconstituting specific signaling and metabolic pathways in plants.

      Weng and his colleagues will begin by deciphering the full spectrum of small-molecule signaling processes that occur between legumes and rhizobium bacteria. Then they will genetically engineer an analogous system in nonlegume crop plants. Next, using state-of-the-art metabolomic methods, they will identify which small molecules excreted from legume roots prompt a nitrogen/carbon exchange from rhizobium bacteria. Finally, the researchers will genetically engineer the biosynthesis of those molecules in the roots of nonlegume plants and observe their effect on the rhizobium bacteria surrounding the roots.

      While the project is complex and technically challenging, its potential is staggering. “Focusing on corn alone, this could reduce the production and use of nitrogen fertilizer by 160,000 tons,” Weng notes. “And it could halve the related emissions of nitrous oxide gas.” More

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      in Environment

      Empowering people to adapt on the frontlines of climate change

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      On April 11, MIT announced five multiyear flagship projects in the first-ever Climate Grand Challenges, a new initiative to tackle complex climate problems and deliver breakthrough solutions to the world as quickly as possible. This article is the fifth in a five-part series highlighting the most promising concepts to emerge from the competition and the interdisciplinary research teams behind them.

      In the coastal south of Bangladesh, rice paddies that farmers could once harvest three times a year lie barren. Sea-level rise brings saltwater to the soil, ruining the staple crop. It’s one of many impacts, and inequities, of climate change. Despite producing less than 1 percent of global carbon emissions, Bangladesh is suffering more than most countries. Rising seas, heat waves, flooding, and cyclones threaten 90 million people.

      A platform being developed in a collaboration between MIT and BRAC, a Bangladesh-based global development organization, aims to inform and empower climate-threatened communities to proactively adapt to a changing future. Selected as one of five MIT Climate Grand Challenges flagship projects, the Climate Resilience Early Warning System (CREWSnet) will forecast the local impacts of climate change on people’s lives, homes, and livelihoods. These forecasts will guide BRAC’s development of climate-resiliency programs to help residents prepare for and adapt to life-altering conditions.

      “The communities that CREWSnet will focus on have done little to contribute to the problem of climate change in the first place. However, because of socioeconomic situations, they may be among the most vulnerable. We hope that by providing state-of-the-art projections and sharing them broadly with communities, and working through partners like BRAC, we can help improve the capacity of local communities to adapt to climate change, significantly,” says Elfatih Eltahir, the H.M. King Bhumibol Professor in the Department of Civil and Environmental Engineering.

      Eltahir leads the project with John Aldridge and Deborah Campbell in the Humanitarian Assistance and Disaster Relief Systems Group at Lincoln Laboratory. Additional partners across MIT include the Center for Global Change Science; the Department of Earth, Atmospheric and Planetary Sciences; the Joint Program on the Science and Policy of Global Change; and the Abdul Latif Jameel Poverty Action Lab. 

      Predicting local risks

      CREWSnet’s forecasts rely upon a sophisticated model, developed in Eltahir’s research group over the past 25 years, called the MIT Regional Climate Model. This model zooms in on climate processes at local scales, at a resolution as granular as 6 miles. In Bangladesh’s population-dense cities, a 6-mile area could encompass tens, or even hundreds, of thousands of people. The model takes into account the details of a region’s topography, land use, and coastline to predict changes in local conditions.

      When applying this model over Bangladesh, researchers found that heat waves will get more severe and more frequent over the next 30 years. In particular, wet-bulb temperatures, which indicate the ability for humans to cool down by sweating, will rise to dangerous levels rarely observed today, particularly in western, inland cities.

      Such hot spots exacerbate other challenges predicted to worsen near Bangladesh’s coast. Rising sea levels and powerful cyclones are eroding and flooding coastal communities, causing saltwater to surge into land and freshwater. This salinity intrusion is detrimental to human health, ruins drinking water supplies, and harms crops, livestock, and aquatic life that farmers and fishermen depend on for food and income.

      CREWSnet will fuse climate science with forecasting tools that predict the social and economic impacts to villages and cities. These forecasts — such as how often a crop season may fail, or how far floodwaters will reach — can steer decision-making.

      “What people need to know, whether they’re a governor or head of a household, is ‘What is going to happen in my area, and what decisions should I make for the people I’m responsible for?’ Our role is to integrate this science and technology together into a decision support system,” says Aldridge, whose group at Lincoln Laboratory specializes in this area. Most recently, they transitioned a hurricane-evacuation planning system to the U.S. government. “We know that making decisions based on climate change requires a deep level of trust. That’s why having a powerful partner like BRAC is so important,” he says.

      Testing interventions

      Established 50 years ago, just after Bangladesh’s independence, BRAC works in every district of the nation to provide social services that help people rise from extreme poverty. Today, it is one of the world’s largest nongovernmental organizations, serving 110 million people across 11 countries in Asia and Africa, but its success is cultivated locally.

      “BRAC is thrilled to partner with leading researchers at MIT to increase climate resilience in Bangladesh and provide a model that can be scaled around the globe,” says Donella Rapier, president and CEO of BRAC USA. “Locally led climate adaptation solutions that are developed in partnership with communities are urgently needed, particularly in the most vulnerable regions that are on the frontlines of climate change.”

      CREWSnet will help BRAC identify communities most vulnerable to forecasted impacts. In these areas, they will share knowledge and innovate or bolster programs to improve households’ capacity to adapt.

      Many climate initiatives are already underway. One program equips homes to filter and store rainwater, as salinity intrusion makes safe drinking water hard to access. Another program is building resilient housing, able to withstand 120-mile-per-hour winds, that can double as local shelters during cyclones and flooding. Other services are helping farmers switch to different livestock or crops better suited for wetter or saltier conditions (e.g., ducks instead of chickens, or salt-tolerant rice), providing interest-free loans to enable this change.

      But adapting in place will not always be possible, for example in areas predicted to be submerged or unbearably hot by midcentury. “Bangladesh is working on identifying and developing climate-resilient cities and towns across the country, as closer-by alternative destinations as compared to moving to Dhaka, the overcrowded capital of Bangladesh,” says Campbell. “CREWSnet can help identify regions better suited for migration, and climate-resilient adaptation strategies for those regions.” At the same time, BRAC’s Climate Bridge Fund is helping to prepare cities for climate-induced migration, building up infrastructure and financial services for people who have been displaced.

      Evaluating impact

      While CREWSnet’s goal is to enable action, it can’t quite measure the impact of those actions. The Abdul Latif Jameel Poverty Action Lab (J-PAL), a development economics program in the MIT School of Humanities, Arts, and Social Sciences, will help evaluate the effectiveness of the climate-adaptation programs.

      “We conduct randomized controlled trials, similar to medical trials, that help us understand if a program improved people’s lives,” says Claire Walsh, the project director of the King Climate Action Initiative at J-PAL. “Once CREWSnet helps BRAC implement adaptation programs, we will generate scientific evidence on their impacts, so that BRAC and CREWSnet can make a case to funders and governments to expand effective programs.”

      The team aspires to bring CREWSnet to other nations disproportionately impacted by climate change. “Our vision is to have this be a globally extensible capability,” says Campbell. CREWSnet’s name evokes another early-warning decision-support system, FEWSnet, that helped organizations address famine in eastern Africa in the 1980s. Today it is a pillar of food-security planning around the world.

      CREWSnet hopes for a similar impact in climate change planning. Its selection as an MIT Climate Grand Challenges flagship project will inject the project with more funding and resources, momentum that will also help BRAC’s fundraising. The team plans to deploy CREWSnet to southwestern Bangladesh within five years.

      “The communities that we are aspiring to reach with CREWSnet are deeply aware that their lives are changing — they have been looking climate change in the eye for many years. They are incredibly resilient, creative, and talented,” says Ashley Toombs, the external affairs director for BRAC USA. “As a team, we are excited to bring this system to Bangladesh. And what we learn together, we will apply at potentially even larger scales.” More

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      in Security

      MIT engineers introduce the Oreometer

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      When you twist open an Oreo cookie to get to the creamy center, you’re mimicking a standard test in rheology — the study of how a non-Newtonian material flows when twisted, pressed, or otherwise stressed. MIT engineers have now subjected the sandwich cookie to rigorous materials tests to get to the center of a tantalizing question: Why does the cookie’s cream stick to just one wafer when twisted apart?

      “There’s the fascinating problem of trying to get the cream to distribute evenly between the two wafers, which turns out to be really hard,” says Max Fan, an undergraduate in MIT’s Department of Mechanical Engineering.

      In pursuit of an answer, the team subjected cookies to standard rheology tests in the lab and found that no matter the flavor or amount of stuffing, the cream at the center of an Oreo almost always sticks to one wafer when twisted open. Only for older boxes of cookies does the cream sometimes separate more evenly between both wafers.

      The researchers also measured the torque required to twist open an Oreo, and found it to be similar to the torque required to turn a doorknob and about 1/10th what’s needed to twist open a bottlecap. The cream’s failure stress — i.e. the force per area required to get the cream to flow, or deform — is twice that of cream cheese and peanut butter, and about the same magnitude as mozzarella cheese. Judging from the cream’s response to stress, the team classifies its texture as “mushy,” rather than brittle, tough, or rubbery.

      So, why does the cookie’s cream glom to one side rather than splitting evenly between both? The manufacturing process may be to blame.

      “Videos of the manufacturing process show that they put the first wafer down, then dispense a ball of cream onto that wafer before putting the second wafer on top,” says Crystal Owens, an MIT mechanical engineering PhD candidate who studies the properties of complex fluids. “Apparently that little time delay may make the cream stick better to the first wafer.”

      The team’s study isn’t simply a sweet diversion from bread-and-butter research; it’s also an opportunity to make the science of rheology accessible to others. To that end, the researchers have designed a 3D-printable “Oreometer” — a simple device that firmly grasps an Oreo cookie and uses pennies and rubber bands to control the twisting force that progressively twists the cookie open. Instructions for the tabletop device can be found here.

      The new study, “On Oreology, the fracture and flow of ‘milk’s favorite cookie,’” appears today in Kitchen Flows, a special issue of the journal Physics of Fluids. It was conceived of early in the Covid-19 pandemic, when many scientists’ labs were closed or difficult to access. In addition to Owens and Fan, co-authors are mechanical engineering professors Gareth McKinley and A. John Hart.

      Confection connection

      A standard test in rheology places a fluid, slurry, or other flowable material onto the base of an instrument known as a rheometer. A parallel plate above the base can be lowered onto the test material. The plate is then twisted as sensors track the applied rotation and torque.

      Owens, who regularly uses a laboratory rheometer to test fluid materials such as 3D-printable inks, couldn’t help noting a similarity with sandwich cookies. As she writes in the new study:

      “Scientifically, sandwich cookies present a paradigmatic model of parallel plate rheometry in which a fluid sample, the cream, is held between two parallel plates, the wafers. When the wafers are counter-rotated, the cream deforms, flows, and ultimately fractures, leading to separation of the cookie into two pieces.”

      While Oreo cream may not appear to possess fluid-like properties, it is considered a “yield stress fluid” — a soft solid when unperturbed that can start to flow under enough stress, the way toothpaste, frosting, certain cosmetics, and concrete do.

      Curious as to whether others had explored the connection between Oreos and rheology, Owens found mention of a 2016 Princeton University study in which physicists first reported that indeed, when twisting Oreos by hand, the cream almost always came off on one wafer.

      “We wanted to build on this to see what actually causes this effect and if we could control it if we mounted the Oreos carefully onto our rheometer,” she says.

      Play video

      Cookie twist

      In an experiment that they would repeat for multiple cookies of various fillings and flavors, the researchers glued an Oreo to both the top and bottom plates of a rheometer and applied varying degrees of torque and angular rotation, noting the values  that successfully twisted each cookie apart. They plugged the measurements into equations to calculate the cream’s viscoelasticity, or flowability. For each experiment, they also noted the cream’s “post-mortem distribution,” or where the cream ended up after twisting open.

      In all, the team went through about 20 boxes of Oreos, including regular, Double Stuf, and Mega Stuf levels of filling, and regular, dark chocolate, and “golden” wafer flavors. Surprisingly, they found that no matter the amount of cream filling or flavor, the cream almost always separated onto one wafer.

      “We had expected an effect based on size,” Owens says. “If there was more cream between layers, it should be easier to deform. But that’s not actually the case.”

      Curiously, when they mapped each cookie’s result to its original position in the box, they noticed the cream tended to stick to the inward-facing wafer: Cookies on the left side of the box twisted such that the cream ended up on the right wafer, whereas cookies on the right side separated with cream mostly on the left wafer. They suspect this box distribution may be a result of post-manufacturing environmental effects, such as heating or jostling that may cause cream to peel slightly away from the outer wafers, even before twisting.

      The understanding gained from the properties of Oreo cream could potentially be applied to the design of other complex fluid materials.

      “My 3D printing fluids are in the same class of materials as Oreo cream,” she says. “So, this new understanding can help me better design ink when I’m trying to print flexible electronics from a slurry of carbon nanotubes, because they deform in almost exactly the same way.”

      As for the cookie itself, she suggests that if the inside of Oreo wafers were more textured, the cream might grip better onto both sides and split more evenly when twisted.

      “As they are now, we found there’s no trick to twisting that would split the cream evenly,” Owens concludes.

      This research was supported, in part, by the MIT UROP program and by the National Defense Science and Engineering Graduate Fellowship Program. More