Aurelia Butler

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    in Security

    From seawater to drinking water, with the push of a button

    MIT researchers have developed a portable desalination unit, weighing less than 10 kilograms, that can remove particles and salts to generate drinking water.

    The suitcase-sized device, which requires less power to operate than a cell phone charger, can also be driven by a small, portable solar panel, which can be purchased online for around $50. It automatically generates drinking water that exceeds World Health Organization quality standards. The technology is packaged into a user-friendly device that runs with the push of one button.

    Unlike other portable desalination units that require water to pass through filters, this device utilizes electrical power to remove particles from drinking water. Eliminating the need for replacement filters greatly reduces the long-term maintenance requirements.

    This could enable the unit to be deployed in remote and severely resource-limited areas, such as communities on small islands or aboard seafaring cargo ships. It could also be used to aid refugees fleeing natural disasters or by soldiers carrying out long-term military operations.

    “This is really the culmination of a 10-year journey that I and my group have been on. We worked for years on the physics behind individual desalination processes, but pushing all those advances into a box, building a system, and demonstrating it in the ocean, that was a really meaningful and rewarding experience for me,” says senior author Jongyoon Han, a professor of electrical engineering and computer science and of biological engineering, and a member of the Research Laboratory of Electronics (RLE).

    Joining Han on the paper are first author Junghyo Yoon, a research scientist in RLE; Hyukjin J. Kwon, a former postdoc; SungKu Kang, a postdoc at Northeastern University; and Eric Brack of the U.S. Army Combat Capabilities Development Command (DEVCOM). The research has been published online in Environmental Science and Technology.

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    Filter-free technology

    Commercially available portable desalination units typically require high-pressure pumps to push water through filters, which are very difficult to miniaturize without compromising the energy-efficiency of the device, explains Yoon.

    Instead, their unit relies on a technique called ion concentration polarization (ICP), which was pioneered by Han’s group more than 10 years ago. Rather than filtering water, the ICP process applies an electrical field to membranes placed above and below a channel of water. The membranes repel positively or negatively charged particles — including salt molecules, bacteria, and viruses — as they flow past. The charged particles are funneled into a second stream of water that is eventually discharged.

    The process removes both dissolved and suspended solids, allowing clean water to pass through the channel. Since it only requires a low-pressure pump, ICP uses less energy than other techniques.

    But ICP does not always remove all the salts floating in the middle of the channel. So the researchers incorporated a second process, known as electrodialysis, to remove remaining salt ions.

    Yoon and Kang used machine learning to find the ideal combination of ICP and electrodialysis modules. The optimal setup includes a two-stage ICP process, with water flowing through six modules in the first stage then through three in the second stage, followed by a single electrodialysis process. This minimized energy usage while ensuring the process remains self-cleaning.

    “While it is true that some charged particles could be captured on the ion exchange membrane, if they get trapped, we just reverse the polarity of the electric field and the charged particles can be easily removed,” Yoon explains.

    They shrunk and stacked the ICP and electrodialysis modules to improve their energy efficiency and enable them to fit inside a portable device. The researchers designed the device for nonexperts, with just one button to launch the automatic desalination and purification process. Once the salinity level and the number of particles decrease to specific thresholds, the device notifies the user that the water is drinkable.

    The researchers also created a smartphone app that can control the unit wirelessly and report real-time data on power consumption and water salinity.

    Beach tests

    After running lab experiments using water with different salinity and turbidity (cloudiness) levels, they field-tested the device at Boston’s Carson Beach.

    Yoon and Kwon set the box near the shore and tossed the feed tube into the water. In about half an hour, the device had filled a plastic drinking cup with clear, drinkable water.

    “It was successful even in its first run, which was quite exciting and surprising. But I think the main reason we were successful is the accumulation of all these little advances that we made along the way,” Han says.

    The resulting water exceeded World Health Organization quality guidelines, and the unit reduced the amount of suspended solids by at least a factor of 10. Their prototype generates drinking water at a rate of 0.3 liters per hour, and requires only 20 watts of power per liter.

    “Right now, we are pushing our research to scale up that production rate,” Yoon says.

    One of the biggest challenges of designing the portable system was engineering an intuitive device that could be used by anyone, Han says.

    Yoon hopes to make the device more user-friendly and improve its energy efficiency and production rate through a startup he plans to launch to commercialize the technology.

    In the lab, Han wants to apply the lessons he’s learned over the past decade to water-quality issues that go beyond desalination, such as rapidly detecting contaminants in drinking water.

    “This is definitely an exciting project, and I am proud of the progress we have made so far, but there is still a lot of work to do,” he says.

    For example, while “development of portable systems using electro-membrane processes is an original and exciting direction in off-grid, small-scale desalination,” the effects of fouling, especially if the water has high turbidity, could significantly increase maintenance requirements and energy costs, notes Nidal Hilal, professor of engineering and director of the New York University Abu Dhabi Water research center, who was not involved with this research.

    “Another limitation is the use of expensive materials,” he adds. “It would be interesting to see similar systems with low-cost materials in place.”

    The research was funded, in part, by the DEVCOM Soldier Center, the Abdul Latif Jameel Water and Food Systems Lab (J-WAFS), the Experimental AI Postdoc Fellowship Program of Northeastern University, and the Roux AI Institute. More

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

    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 Environment

    A community approach to improving the health of the planet

    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

    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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    Amy Moran-Thomas receives the Edgerton Faculty Achievement Award

    Amy Moran-Thomas, the Alfred Henry and Jean Morrison Hayes Career Development Associate Professor of Anthropology, has received the 2021-22 Harold E. Edgerton Faculty Achievement Award in recognition of her “exceptional commitment to innovative and collaborative interdisciplinary approaches to resolving inequitable impacts on human health,” according to a statement by the  selection committee.A medical anthropologist, Moran-Thomas investigates linkages between human and environmental health, with a focus on health disparities. She is the author of the award-winning book “Traveling with Sugar: Chronicles of a Global Epidemic” (University of California Press, 2019), which frames the diabetes epidemic in Belize within the context of 500 years of colonialism.

    On human and planetary well-being Moran-Thomas “stands out in this field by bringing a humanistic approach into dialogue with environmental and science studies to investigate how bodily health is shaped by social well-being at the community level and further conditioned by localized planetary imbalances,” the selection committee’s statement said. “Professor Moran-Thomas shows how diabetes resides not only within human bodies but also across toxic environments, crumbling healthcare infrastructures, and stress-inducing economic inequalities.”Heather Paxson, the William R. Kenan, Jr. Professor of Anthropology and head of the MIT Anthropology program, calls Moran-Thomas “a fast-rising star in her field.” Paxson, who nominated Moran-Thomas for the award, adds, “She is also a highly effective teacher and student mentor, an engaged member of our Institute community, and a budding public intellectual.” A profound discovery for medical equity

    “Professor Moran-Thomas’s work has an extraordinarily profound and impactful reach,” according to the committee, which highlighted a widely read 2020 essay in Boston Review in which Moran-Thomas revealed that the fingertip pulse oximeter — a key tool in monitoring the effects of respiratory distress due to Covid-19 and other illness — gives misleading readings with darkly complected skin. This essay inspired a subsequent medical research study and ultimately led to an alert from the U.S. Food and Drug Administration spotlighting the limitations of pulse oximeters.

    The selection committee further lauded Moran-Thomas for her pedagogy, including her work developing the new subject 21A.311 (The Social Lives of Medical Objects). She was also commended for her service, notably her work on the MIT Climate Action Advisory Committee and with the Social and Ethical Responsibilities of Computing group within MIT’s Schwarzman College of Computing.

    Moran-Thomas earned her bachelor’s degree in literature from American University and her PhD in anthropology from Princeton University. She joined MIT Anthropology in 2015, following postdocs at the Woodrow Institute for Public and International Affairs and at Brown University’s Cogut Humanities Center. She was promoted to associate professor without tenure in 2019.

    The annual Edgerton Faculty Award, established in 1982 as a tribute to Institute Professor Emeritus Harold E. Edgerton, honors achievement in research, teaching, and service by a nontenured member of the faculty.The 2019-20 Edgerton Award Selection Committee was chaired by T.L. Taylor, a professor of Comparative Media Studies/Writing. Other members were Geoffrey Beach, a professor in the Department of Materials Science and Engineering; Mircea Dinca, the W.M. Keck Professor of Energy in the Department of Chemistry; Hazhir Rahmandad, an associate professor of system dynamics in the Sloan School of Management; and Rafi Segal, an associate professor in the Department of Architecture.

    Story prepared by MIT SHASS CommunicationsSenior Writer: Kathryn O’NeillEditorial and Design Director: Emily Hiestand More

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    in Environment

    Using plant biology to address climate change

    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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    Empowering people to adapt on the frontlines of climate change

    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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    MIT engineers introduce the Oreometer

    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