Aurelia Butler

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    in Environment

    Unlocking the secrets of natural materials

    Growing up in Milan, Benedetto Marelli liked figuring out how things worked. He repaired broken devices simply to have the opportunity to take them apart and put them together again. Also, from a young age, he had a strong desire to make a positive impact on the world. Enrolling at the Polytechnic University of Milan, he chose to study engineering.

    “Engineering seemed like the right fit to fulfill my passions at the intersection of discovering how the world works, together with understanding the rules of nature and harnessing this knowledge to create something new that could positively impact our society,” says Marelli, MIT’s Paul M. Cook Career Development Associate Professor of Civil and Environmental Engineering.

    Marelli decided to focus on biomedical engineering, which at the time was the closest thing available to biological engineering. “I liked the idea of pursuing studies that provided me a background to engineer life,” in order to improve human health and agriculture, he says.

    Marelli went on to earn a PhD in materials science and engineering at McGill University and then worked in Tufts University’s biomaterials Silklab as a postdoc. After his postdoc, Marelli was drawn to MIT’s Department of Civil and Environmental in large part because of the work of Markus Buehler, MIT’s McAfee Professor of Engineering, who studies how to design new materials by understanding the architecture of natural ones.

    “This resonated with my training and idea of using nature’s building blocks to build a more sustainable society,” Marelli says. “It was a big leap forward for me to go from biomedical engineering to civil and environmental engineering. It meant completely changing my community, understanding what I could teach and how to mentor students in a new engineering branch. As Markus is working with silk to study how to engineer better materials, this made me see a clear connection with what I was doing and what I could be doing. I consider him one of my mentors here at MIT and was fortunate to end up collaborating with him.”

    Marelli’s research is aimed at mitigating several pressing global problems, he says.

    “Boosting food production to provide food security to an ever-increasing population, soil restoration, decreasing the environmental impact of fertilizers, and addressing stressors coming from climate change are societal challenges that need the development of rapidly scalable and deployable technologies,” he says.

    Marelli and his fellow researchers have developed coatings derived from natural silk that extend the shelf life of food, deliver biofertilizers to seeds planted in salty, unproductive soils, and allow seeds to establish healthier plants and increase crop yield in drought-stricken lands. The technologies have performed well in field tests being conducted in Morocco in collaboration with the Mohammed VI Polytechnic University in Ben Guerir, according to Marelli, and offer much potential.

    “I believe that with this technology, together with the common efforts shared by the MIT PIs participating in the Climate Grand Challenge on Revolutionizing Agriculture, we have a  real opportunity to positively impact planetary health and find new solutions that work in both rural settings and highly modernized agricultural fields,” says Marelli, who recently earned tenure.

    As a researcher and entrepreneur with about 20 patents to his name and awards including a National Science Foundation CAREER award, the Presidential Early Career Award for Scientists and Engineers award, and the Ole Madsen Mentoring Award, Marelli says that in general his insights into structural proteins — and how to use that understanding to manufacture advanced materials at multiple scales — are among his proudest achievements.

    More specifically, Marelli cites one of his breakthroughs involving a strawberry. Having dipped the berry in an odorless, tasteless edible silk suspension as part of a cooking contest held in his postdoctoral lab, he accidentally left it on his bench, only to find a week or so later that it had been well-preserved.

    “The coating of the strawberry to increase its shelf life is difficult to beat when it comes to inspiring people that natural polymers can serve as technical materials that can positively impact our society” by lessening food waste and the need for energy-intensive refrigerated shipping, Marelli says.

    When Marelli won the BioInnovation Institute and Science Prize for Innovation in 2022, he told the journal Science that he thinks students should be encouraged to choose an entrepreneurial path. He acknowledged the steepness of the learning curve of being an entrepreneur but also pointed out how the impact of research can be exponentially increased.

    He expanded on this idea more recently.

    “I believe an increasing number of academics and graduate students should try to get their hands ‘dirty’ with entrepreneurial efforts. We live in a time where academics are called to have a tangible impact on our society, and translating what we study in our labs is clearly a good way to employ our students and enhance the global effort to develop new technology that can make our society more sustainable and equitable,” Marelli says.

    Referring to a spinoff company, Mori, that grew out of the coated strawberry discovery and that develops silk-based products to preserve a wide range of perishable foods, Marelli says he finds it very satisfying to know that Mori has a product on the market that came out of his research efforts — and that 80 people are working to translate the discovery from “lab to fork.”

    “Knowing that the technology can move the needle in crises such as food waste and food-related environmental impact is the highest reward of all,” he says.

    Marelli says he tells students who are seeking solutions to extremely complicated problems to come up with one solution, “however crazy it might be,” and then do an extensive literature review to see what other researchers have done and whether “there is any hint that points toward developing their solution.”

    “Once we understand the feasibility, I typically work with them to simplify it as much as we can, and then to break down the problem in small parts that are addressable in series and/or in parallel,” Marelli says.

    That process of discovery is ongoing. Asked which of his technologies will have the greatest impact on the world, Marelli says, “I’d like to think it’s the ones that still need to be discovered.” More

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    in Environment

    A mineral produced by plate tectonics has a global cooling effect, study finds

    MIT geologists have found that a clay mineral on the seafloor, called smectite, has a surprisingly powerful ability to sequester carbon over millions of years.

    Under a microscope, a single grain of the clay resembles the folds of an accordion. These folds are known to be effective traps for organic carbon.

    Now, the MIT team has shown that the carbon-trapping clays are a product of plate tectonics: When oceanic crust crushes against a continental plate, it can bring rocks to the surface that, over time, can weather into minerals including smectite. Eventually, the clay sediment settles back in the ocean, where the minerals trap bits of dead organisms in their microscopic folds. This keeps the organic carbon from being consumed by microbes and expelled back into the atmosphere as carbon dioxide.

    Over millions of years, smectite can have a global effect, helping to cool the entire planet. Through a series of analyses, the researchers showed that smectite was likely produced after several major tectonic events over the last 500 million years. During each tectonic event, the clays trapped enough carbon to cool the Earth and induce the subsequent ice age.

    The findings are the first to show that plate tectonics can trigger ice ages through the production of carbon-trapping smectite.

    These clays can be found in certain tectonically active regions today, and the scientists believe that smectite continues to sequester carbon, providing a natural, albeit slow-acting, buffer against humans’ climate-warming activities.

    “The influence of these unassuming clay minerals has wide-ranging implications for the habitability of planets,” says Joshua Murray, a graduate student in MIT’s Department of Earth, Atmospheric, and Planetary Sciences. “There may even be a modern application for these clays in offsetting some of the carbon that humanity has placed into the atmosphere.”

    Murray and Oliver Jagoutz, professor of geology at MIT, have published their findings today in Nature Geoscience.

    A clear and present clay

    The new study follows up on the team’s previous work, which showed that each of the Earth’s major ice ages was likely triggered by a tectonic event in the tropics. The researchers found that each of these tectonic events exposed ocean rocks called ophiolites to the atmosphere. They put forth the idea that, when a tectonic collision occurs in a tropical region, ophiolites can undergo certain weathering effects, such as exposure to wind, rain, and chemical interactions, that transform the rocks into various minerals, including clays.

    “Those clay minerals, depending on the kinds you create, influence the climate in different ways,” Murray explains.

    At the time, it was unclear which minerals could come out of this weathering effect, and whether and how these minerals could directly contribute to cooling the planet. So, while it appeared there was a link between plate tectonics and ice ages, the exact mechanism by which one could trigger the other was still in question.

    With the new study, the team looked to see whether their proposed tectonic tropical weathering process would produce carbon-trapping minerals, and in quantities that would be sufficient to trigger a global ice age.

    The team first looked through the geologic literature and compiled data on the ways in which major magmatic minerals weather over time, and on the types of clay minerals this weathering can produce. They then worked these measurements into a weathering simulation of different rock types that are known to be exposed in tectonic collisions.

    “Then we look at what happens to these rock types when they break down due to weathering and the influence of a tropical environment, and what minerals form as a result,” Jagoutz says.

    Next, they plugged each weathered, “end-product” mineral into a simulation of the Earth’s carbon cycle to see what effect a given mineral might have, either in interacting with organic carbon, such as bits of dead organisms, or with inorganic, in the form of carbon dioxide in the atmosphere.

    From these analyses, one mineral had a clear presence and effect: smectite. Not only was the clay a naturally weathered product of tropical tectonics, it was also highly effective at trapping organic carbon. In theory, smectite seemed like a solid connection between tectonics and ice ages.

    But were enough of the clays actually present to trigger the previous four ice ages? Ideally, researchers should confirm this by finding smectite in ancient rock layers dating back to each global cooling period.

    “Unfortunately, as clays are buried by other sediments, they get cooked a bit, so we can’t measure them directly,” Murray says. “But we can look for their fingerprints.”

    A slow build

    The team reasoned that, as smectites are a product of ophiolites, these ocean rocks also bear characteristic elements such as nickel and chromium, which would be preserved in ancient sediments. If smectites were present in the past, nickel and chromium should be as well.

    To test this idea, the team looked through a database containing thousands of oceanic sedimentary rocks that were deposited over the last 500 million years. Over this time period, the Earth experienced four separate ice ages. Looking at rocks around each of these periods, the researchers observed large spikes of nickel and chromium, and inferred from this that smectite must also have been present.

    By their estimates, the clay mineral could have increased the preservation of organic carbon by less than one-tenth of a percent. In absolute terms, this is a miniscule amount. But over millions of years, they calculated that the clay’s accumulated, sequestered carbon was enough to trigger each of the four major ice ages.

    “We found that you really don’t need much of this material to have a huge effect on the climate,” Jagoutz says.

    “These clays also have probably contributed some of the Earth’s cooling in the last 3 to 5 million years, before humans got involved,” Murray adds. “In the absence of humans, these clays are probably making a difference to the climate. It’s just such a slow process.”

    “Jagoutz and Murray’s work is a nice demonstration of how important it is to consider all biotic and physical components of the global carbon cycle,” says Lee Kump, a professor of geosciences at Penn State University, who was not involved with the study. “Feedbacks among all these components control atmospheric greenhouse gas concentrations on all time scales, from the annual rise and fall of atmospheric carbon dioxide levels to the swings from icehouse to greenhouse over millions of years.”

    Could smectites be harnessed intentionally to further bring down the world’s carbon emissions? Murray sees some potential, for instance to shore up carbon reservoirs such as regions of permafrost. Warming temperatures are predicted to melt permafrost and expose long-buried organic carbon. If smectites could be applied to these regions, the clays could prevent this exposed carbon from escaping into and further warming the atmosphere.

    “If you want to understand how nature works, you have to understand it on the mineral and grain scale,” Jagoutz says. “And this is also the way forward for us to find solutions for this climatic catastrophe. If you study these natural processes, there’s a good chance you will stumble on something that will be actually useful.”

    This research was funded, in part, by the National Science Foundation. More

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    in Environment

    Merging science and systems thinking to make materials more sustainable

    For Professor Elsa Olivetti, tackling a problem as large and complex as climate change requires not only lab research but also understanding the systems of production that power the global economy.

    Her career path reflects a quest to investigate materials at scales ranging from the microscopic to the mass-manufactured.

    “I’ve always known what questions I wanted to ask, and then set out to build the tools to help me ask those questions,” says Olivetti, the Jerry McAfee Professor in Engineering.

    Olivetti, who earned tenure in 2022 and was recently appointed associate dean of engineering, has sought to equip students with similar skills, whether in the classroom, in her lab group, or through the interdisciplinary programs she leads at MIT. Those efforts have earned her accolades including the Bose Award for Excellence in Teaching, a MacVicar Faculty Fellowship in 2021, and the McDonald Award for Excellence in Mentoring and Advising in 2023.

    “I think to make real progress in sustainability, materials scientists need to think in interdisciplinary, systems-level ways, but at a deep technical level,” Olivetti says. “Supporting my students so that’s something that a lot more people can do is very rewarding for me.”

    Her mission to make materials more sustainable also makes Olivetti grateful [EAO1] she’s at MIT, which has a long tradition of both interdisciplinary collaboration and technical know-how.

    “MIT’s core competencies are well-positioned for bold achievements in climate and sustainability — the deep expertise on the economics side, the frontier knowledge in science, the computational creativity,” Olivetti says. “It’s a really exciting time and place where the key ingredients for progress are simmering in transformative ways.”

    Answering the call

    The moment that set Olivetti on her life’s journey began when she was 8, with a knock at her door. Her parents were in the other room, so Olivetti opened the door and met an organizer for Greenpeace, a nonprofit that works to raise awareness of environmental issues.

    “I had a chat with that guy and got hooked on environmental concerns,” Olivetti says. “I still remember that conversation.”

    The interaction changed the way Olivetti thought about her place in the world, and her new perspective manifested itself in some unique ways. Her elementary school science fair projects became elaborate pursuits of environmental solutions involving burying various items in the backyard to test for biodegradability. There was also an awkward attempt at natural pesticide development, which lead to a worm hatching in her bedroom.

    As an undergraduate at the University of Virginia, Olivetti gravitated toward classes in environmentalism and materials science.

    “There was a link between materials science and a broader, systems way of framing design for environment, and that just clicked for me in terms of the way I wanted to think about environmental problems — from the atom to the system,” Olivetti recalls.

    That interest led Olivetti to MIT for a PhD in 2001, where she studied the feasibility of new materials for lithium-ion batteries.

    “I really wanted to be thinking of things at a systems level, but I wanted to ground that in lab-based research,” Olivetti says. “I wanted an experiential experience in grad school, and that’s why I chose MIT’s program.”

    Whether it was her undergraduate studies, her PhD, or her ensuing postdoc work at MIT, Olivetti sought to learn new skills to continue bridging the gap between materials science and environmental systems thinking.

    “I think of it as, ‘Here’s how I can build up the ways I ask questions,’” Olivetti explains. “How do we design these materials while thinking about their implications as early as possible?”

    Since joining MIT’s faculty in 2014, Olivetti has developed computational models to measure the cost and environmental impact of new materials, explored ways to adopt more sustainable and circular supply chains, and evaluated potential materials limitations as lithium-ion battery production is scaled. That work helps companies increase their use of greener, recyclable materials and more sustainably dispose of waste.

    Olivetti believes the wide scope of her research gives the students in her lab a more holistic understanding of the life cycle of materials.

    “When the group started, each student was working on a different aspect of the problem — like on the natural language processing pipeline, or on recycling technology assessment, or beneficial use of waste — and now each student can link each of those pieces in their research,” Olivetti explains.

    Beyond her research, Olivetti also co-directs the MIT Climate and Sustainability Consortium, which has established a set of eight areas of sustainability that it organizes coalitions around. Each coalition involves technical leaders at companies and researchers at MIT that work together to accelerate the impact of MIT’s research by helping companies adopt innovative and more sustainable technologies.

    “Climate change mitigation and resilience is such a complex problem, and at MIT we have practice in working together across disciplines on many challenges,” Olivetti says. “It’s been exciting to lean on that culture and unlock ways to move forward more effectively.”

    Bridging divides

    Today, Olivetti tries to maximize the impact of her and her students’ research in materials industrial ecology by maintaining close ties to applications. In her research, this means working directly with aluminum companies to design alloys that could incorporate more scrap material or with nongovernmental organizations to incorporate agricultural residues in building products. In the classroom, that means bringing in people from companies to explain how they think about concepts like heat exchange or fluid flow in their products.

    “I enjoy trying to ground what students are learning in the classroom with what’s happening in the world,” Olivetti explains.

    Exposing students to industry is also a great way to help them think about their own careers. In her research lab, she’s started using the last 30 minutes of meetings to host talks from people working in national labs, startups, and larger companies to show students what they can do after their PhDs. The talks are similar to the Industry Seminar series Olivetti started that pairs undergraduate students with people working in areas like 3D printing, environmental consulting, and manufacturing.

    “It’s about helping students learn what they’re excited about,” Olivetti says.

    Whether in the classroom, lab, or at events held by organizations like MCSC, Olivetti believes collaboration is humanity’s most potent tool to combat climate change.

    “I just really enjoy building links between people,” Olivetti says. “Learning about people and meeting them where they are is a way that one can create effective links. It’s about creating the right playgrounds for people to think and learn.” More

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    in Security

    Microbes could help reduce the need for chemical fertilizers

    Production of chemical fertilizers accounts for about 1.5 percent of the world’s greenhouse gas emissions. MIT chemists hope to help reduce that carbon footprint by replacing some chemical fertilizer with a more sustainable source — bacteria.

    Bacteria that can convert nitrogen gas to ammonia could not only provide nutrients that plants need, but also help regenerate soil and protect plants from pests. However, these bacteria are sensitive to heat and humidity, so it’s difficult to scale up their manufacture and ship them to farms.

    To overcome that obstacle, MIT chemical engineers have devised a metal-organic coating that protects bacterial cells from damage without impeding their growth or function. In a new study, they found that these coated bacteria improved the germination rate of a variety of seeds, including vegetables such as corn and bok choy.

    This coating could make it much easier for farmers to deploy microbes as fertilizers, says Ariel Furst, the Paul M. Cook Career Development Assistant Professor of Chemical Engineering at MIT and the senior author of the study.

    “We can protect them from the drying process, which would allow us to distribute them much more easily and with less cost because they’re a dried powder instead of in liquid,” she says. “They can also withstand heat up to 132 degrees Fahrenheit, which means that you wouldn’t have to use cold storage for these microbes.”

    Benjamin Burke ’23 and postdoc Gang Fan are the lead authors of the open-access paper, which appears in the Journal of the American Chemical Society Au. MIT undergraduate Pris Wasuwanich and Evan Moore ’23 are also authors of the study.

    Protecting microbes

    Chemical fertilizers are manufactured using an energy-intensive process known as Haber-Bosch, which uses extremely high pressures to combine nitrogen from the air with hydrogen to make ammonia.

    In addition to the significant carbon footprint of this process, another drawback to chemical fertilizers is that long-term use eventually depletes the nutrients in the soil. To help restore soil, some farmers have turned to “regenerative agriculture,” which uses a variety of strategies, including crop rotation and composting, to keep soil healthy. Nitrogen-fixing bacteria, which convert nitrogen gas to ammonia, can aid in this approach.

    Some farmers have already begun deploying these “microbial fertilizers,” growing them in large onsite fermenters before applying them to the soil. However, this is cost-prohibitive for many farmers.

    Shipping these bacteria to rural areas is not currently a viable option, because they are susceptible to heat damage. The microbes are also too delicate to survive the freeze-drying process that would make them easier to transport.

    To protect the microbes from both heat and freeze-drying, Furst decided to apply a coating called a metal-phenol network (MPN), which she has previously developed to encapsulate microbes for other uses, such as protecting therapeutic bacteria delivered to the digestive tract.

    The coatings contain two components — a metal and an organic compound called a polyphenol — that can self-assemble into a protective shell. The metals used for the coatings, including iron, manganese, aluminum, and zinc, are considered safe as food additives. Polyphenols, which are often found in plants, include molecules such as tannins and other antioxidants. The FDA classifies many of these polyphenols as GRAS (generally regarded as safe).

    “We are using these natural food-grade compounds that are known to have benefits on their own, and then they form these little suits of armor that protect the microbes,” Furst says.

    For this study, the researchers created 12 different MPNs and used them to encapsulate Pseudomonas chlororaphis, a nitrogen-fixing bacterium that also protects plants against harmful fungi and other pests. They found that all of the coatings protected the bacteria from temperatures up to 50 degrees Celsius (122 degrees Fahrenheit), and also from relative humidity up to 48 percent. The coatings also kept the microbes alive during the freeze-drying process.

    A boost for seeds

    Using microbes coated with the most effective MPN — a combination of manganese and a polyphenol called epigallocatechin gallate (EGCG) — the researchers tested their ability to help seeds germinate in a lab dish. They heated the coated microbes to 50 C before placing them in the dish, and compared them to fresh uncoated microbes and freeze-dried uncoated microbes.

    The researchers found that the coated microbes improved the seeds’ germination rate by 150 percent, compared to seeds treated with fresh, uncoated microbes. This result was consistent across several different types of seeds, including dill, corn, radishes, and bok choy.

    Furst has started a company called Seia Bio to commercialize the coated bacteria for large-scale use in regenerative agriculture. She hopes that the low cost of the manufacturing process will help make microbial fertilizers accessible to small-scale farmers who don’t have the fermenters needed to grow such microbes.

    “When we think about developing technology, we need to intentionally design it to be inexpensive and accessible, and that’s what this technology is. It would help democratize regenerative agriculture,” she says.

    The research was funded by the Army Research Office, a National Institutes of Health New Innovator Award, a National Institute for Environmental Health Sciences Core Center Grant, the CIFAR Azrieli Global Scholars Program, the MIT J-WAFS Program, the MIT Climate and Sustainability Consortium, and the MIT Deshpande Center. More

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    in Environment

    Robert van der Hilst to step down as head of the Department of Earth, Atmospheric and Planetary Sciences

    Robert van der Hilst, the Schlumberger Professor of Earth and Planetary Sciences, has announced his decision to step down as the head of the Department of Earth, Atmospheric and Planetary Sciences at the end of this academic year.  A search committee will convene later this spring to recommend candidates for Van der Hilst’s successor.

    “Rob is a consummate seismologist whose images of Earth’s interior structure have deepened our understanding of how tectonic plates move, how mantle convection works, and why some areas of the Earth are hot-spots for seismic and geothermal activity,” says Nergis Mavalvala, the Curtis and Kathleen Marble Professor of Astrophysics and the dean of the MIT School of Science. “As an academic leader, Rob has been a steadfast champion of the department’s cross-cutting research and education missions, especially regarding climate sciences writ large at MIT. His commitment to diversity and community have made the department — and indeed, MIT — a better place to do our best work.”

    “For 12 years, it has been my honor to lead this department and collaborate with all our community members — faculty, staff, and students,” says Van der Hilst. “EAPS is at the vanguard of climate science research at MIT, as well Earth and planetary sciences and studies into the co-evolution of life and changing environments.”

    Among his other leadership roles on campus, Van der Hilst most recently served as co-chair of the faculty review committee for MIT’s Climate Grand Challenges in which EAPS researchers secured nine finalists and two, funded flagship projects. He also serves on the Institute’s Climate Nucleus to help enact Fast Forward: MIT’s Climate Action Plan for the Decade.

    In his more-than-decade as department head, one of Van der Hilst’s major initiatives has been developing, funding, and constructing the Tina and Hamid Moghadam Building, rapidly nearing completion adjacent to Building 54. The $35 million, LEED-platinum Building 55 will be a vital center and showcase for environmental and climate research on MIT’s campus. With assistance from the Institute and generous donors, the renovations and expansion will add classrooms, meeting, and event spaces, and bring headquarters offices for EAPS, the MIT/Woods Hole Oceanographic Institution (WHOI) Joint Program in Oceanography/Applied Ocean Science, and MIT’s Environmental Solutions Initiative (ESI) together, all under one roof.

    He also helped secure the generous gift that funded the Norman C. Rasmussen Laboratory for climate research in Building 4, as well as the Peter H. Stone and Paola Malanotte Stone Professorship, now held by prominent atmospheric scientist Arlene Fiore.

    On the academic side of the house, Van der Hilst and his counterpart from the Department of Civil and Environmental Engineering (CEE), Ali Jadbabaie, the JR East Professor and CEE department head, helped develop MIT’s new bachelor of science in climate system science and engineering (Course 1-12), jointly offered by EAPS and CEE.

    As part of MIT’s commitment to aid the global response to climate change, the new degree program is designed to train the next generation of leaders, providing a foundational understanding of both the Earth system and engineering principles — as well as an understanding of human and institutional behavior as it relates to the climate challenge.

    Beyond climate research, Van der Hilst’s tenure at the helm of the department has seen many research breakthroughs and accomplishments: from high-profile NASA missions with EAPS science leadership, including the most recent launch of the Psyche mission and the successful asteroid sample return from OSIRIS-REx, to the development of next-generation models capable of describing Earth systems with increasing detail and accuracy. Van der Hilst helped enable such scientific advancements through major improvements to experimental facilities across the department, and, more generally, his mission to double the number of fellowships available to EAPS graduate students.

    “By reducing the silos and inequities created by our disciplinary groups, we were able to foster collaborations that allow faculty, students, and researchers to explore fundamental science questions in novel ways that expand our understanding of the natural world — with profound implications for helping to guide communities and policymakers toward a sustainable future,” says Van der Hilst.

    Community-focused

    In 2019, Van der Hilst began looking ahead to the department’s 40th anniversary in 2023 and charged a number of working groups to evaluate the department’s past and present, and to re-imagine its future. Led by faculty, staff, and students, Task Force 2023 was a yearlong exercise of data-gathering and community deliberation, looking broadly at three focus areas: Image, Visibility, and Relevance; External Synergies: collaboration and partnerships across campus; and Departmental Organization and Cohesion. Despite being interrupted by the pandemic, the resulting reports became a detailed blueprint for EAPS to capitalize on its strengths and begin to effect systemic improvements in areas like undergraduate education, external messaging, and recognition and belonging for administrative and research staff.

    In addition to helping the department mark its 40th anniversary with a celebration this coming spring, Van der Hilst will oversee the dedication of the Moghadam Building, including the renaming of lecture hall 54-100 for Dixie Lee Bryant, the first recipient (woman or man) of a geology degree from MIT in 1891.

    As department head, faculty renewal and retention were key areas of focus for Van der Hilst. In addition to improvements in the faculty search process, he was responsible for the appointment of 20 new faculty members, and in the process shifted the gender ratio from one-fifth to one-third of the faculty identifying as female; he also oversaw the development and implementation of a successful junior faculty mentoring program within EAPS in 2013.

    Van der Hilst also made great strides toward improving diversity, equity, and inclusion within the department in other ways. In 2016, he formed the inaugural EAPS Diversity Council (now the Diversity, Equity and Inclusion Committee) and, in 2020, made EAPS the first department at MIT to appoint an associate department head for diversity, equity, and inclusion, tapping Associate Professor David McGee to guide ongoing community dialogues and initiatives supporting improvements in composition, achievement, belonging, engagement, and accountability.

    With McGee and EAPS student leadership, Van der Hilst supported the EAPS response to calls for social justice leadership and participation in national initiatives such as the American Geophysical Union’s Unlearning Racism in Geoscience program, and he helped navigate the changes brought on by the Covid-19 pandemic while maintaining a sense of community.

    Seismic shift

    After stepping down from his current role, Van der Hilst will have more time to catch up on research aimed at understanding of Earth’s deep interior structure and its evolution. With research collaborators, he developed seismic imaging methods to explore Earth’s interior from sedimentary basins near its surface down to the core–mantle boundary some 2,800 kilometers under the surface. Recently, he authored a Nature Communications paper with doctoral student Shujuan Mao PhD ’21 on a pilot application that uses seismometers as a cost-effective way to monitor and map groundwater fluctuations in order to measure groundwater reserves.

    Before becoming department head, Van der Hilst served as the director of the Earth Resources Laboratory (ERL). In the eight years he served as director, he helped to integrate across disciplines, departments, and schools, transforming ERL into MIT’s primary home for research and education focused on subsurface energy resources.

    Van der Hilst was named a fellow of the American Geophysical Union (AGU) in 1997 and became a fellow of the American Academy of Arts and Sciences in 2014. Before he was named the Schlumberger Professor in 2011, Van der Hilst held a Cecil and Ida Green professorship chair. He has received many awards, including the Doornbos Memorial Prize from the International Association of Seismology and Physics of the Earth’s Interior, AGU’s James B. Macelwane Medal, a Packard Fellowship, and a VICI Innovative Research Award from the Dutch National Science Foundation.

    Van der Hilst received his PhD in geophysics from Utrecht University in 1990. After postdoctoral research at the University of Leeds and the Australian National University, he joined the MIT faculty in 1996. He was ERL director from 2004 to 2012, when he was then named EAPS department head, succeeding Maria Zuber, the E. A. Griswold Professor of Geophysics, MIT vice president for research, and presidential advisor for science and technology policy. More

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    in Environment

    Forging climate connections across the Institute

    Climate change is the ultimate cross-cutting issue: Not limited to any one discipline, it ranges across science, technology, policy, culture, human behavior, and well beyond. The response to it likewise requires an all-of-MIT effort.

    Now, to strengthen such an effort, a new grant program spearheaded by the Climate Nucleus, the faculty committee charged with the oversight and implementation of Fast Forward: MIT’s Climate Action Plan for the Decade, aims to build up MIT’s climate leadership capacity while also supporting innovative scholarship on diverse climate-related topics and forging new connections across the Institute.

    Called the Fast Forward Faculty Fund (F^4 for short), the program has named its first cohort of six faculty members after issuing its inaugural call for proposals in April 2023. The cohort will come together throughout the year for climate leadership development programming and networking. The program provides financial support for graduate students who will work with the faculty members on the projects — the students will also participate in leadership-building activities — as well as $50,000 in flexible, discretionary funding to be used to support related activities. 

    “Climate change is a crisis that truly touches every single person on the planet,” says Noelle Selin, co-chair of the nucleus and interim director of the Institute for Data, Systems, and Society. “It’s therefore essential that we build capacity for every member of the MIT community to make sense of the problem and help address it. Through the Fast Forward Faculty Fund, our aim is to have a cohort of climate ambassadors who can embed climate everywhere at the Institute.”

    F^4 supports both faculty who would like to begin doing climate-related work, as well as faculty members who are interested in deepening their work on climate. The program has the core goal of developing cohorts of F^4 faculty and graduate students who, in addition to conducting their own research, will become climate leaders at MIT, proactively looking for ways to forge new climate connections across schools, departments, and disciplines.

    One of the projects, “Climate Crisis and Real Estate: Science-based Mitigation and Adaptation Strategies,” led by Professor Siqi Zheng of the MIT Center for Real Estate in collaboration with colleagues from the MIT Sloan School of Management, focuses on the roughly 40 percent of carbon dioxide emissions that come from the buildings and real estate sector. Zheng notes that this sector has been slow to respond to climate change, but says that is starting to change, thanks in part to the rising awareness of climate risks and new local regulations aimed at reducing emissions from buildings.

    Using a data-driven approach, the project seeks to understand the efficient and equitable market incentives, technology solutions, and public policies that are most effective at transforming the real estate industry. Johnattan Ontiveros, a graduate student in the Technology and Policy Program, is working with Zheng on the project.

    “We were thrilled at the incredible response we received from the MIT faculty to our call for proposals, which speaks volumes about the depth and breadth of interest in climate at MIT,” says Anne White, nucleus co-chair and vice provost and associate vice president for research. “This program makes good on key commitments of the Fast Forward plan, supporting cutting-edge new work by faculty and graduate students while helping to deepen the bench of climate leaders at MIT.”

    During the 2023-24 academic year, the F^4 faculty and graduate student cohorts will come together to discuss their projects, explore opportunities for collaboration, participate in climate leadership development, and think proactively about how to deepen interdisciplinary connections among MIT community members interested in climate change.

    The six inaugural F^4 awardees are:

    Professor Tristan Brown, History Section: Humanistic Approaches to the Climate Crisis  

    With this project, Brown aims to create a new community of practice around narrative-centric approaches to environmental and climate issues. Part of a broader humanities initiative at MIT, it brings together a global working group of interdisciplinary scholars, including Serguei Saavedra (Department of Civil and Environmental Engineering) and Or Porath (Tel Aviv University; Religion), collectively focused on examining the historical and present links between sacred places and biodiversity for the purposes of helping governments and nongovernmental organizations formulate better sustainability goals. Boyd Ruamcharoen, a PhD student in the History, Anthropology, and Science, Technology, and Society (HASTS) program, will work with Brown on this project.

    Professor Kerri Cahoy, departments of Aeronautics and Astronautics and Earth, Atmospheric, and Planetary Sciences (AeroAstro): Onboard Autonomous AI-driven Satellite Sensor Fusion for Coastal Region Monitoring

    The motivation for this project is the need for much better data collection from satellites, where technology can be “20 years behind,” says Cahoy. As part of this project, Cahoy will pursue research in the area of autonomous artificial intelligence-enabled rapid sensor fusion (which combines data from different sensors, such as radar and cameras) onboard satellites to improve understanding of the impacts of climate change, specifically sea-level rise and hurricanes and flooding in coastal regions. Graduate students Madeline Anderson, a PhD student in electrical engineering and computer science (EECS), and Mary Dahl, a PhD student in AeroAstro, will work with Cahoy on this project.

    Professor Priya Donti, Department of Electrical Engineering and Computer Science: Robust Reinforcement Learning for High-Renewables Power Grids 

    With renewables like wind and solar making up a growing share of electricity generation on power grids, Donti’s project focuses on improving control methods for these distributed sources of electricity. The research will aim to create a realistic representation of the characteristics of power grid operations, and eventually inform scalable operational improvements in power systems. It will “give power systems operators faith that, OK, this conceptually is good, but it also actually works on this grid,” says Donti. PhD candidate Ana Rivera from EECS is the F^4 graduate student on the project.

    Professor Jason Jackson, Department of Urban Studies and Planning (DUSP): Political Economy of the Climate Crisis: Institutions, Power and Global Governance

    This project takes a political economy approach to the climate crisis, offering a distinct lens to examine, first, the political governance challenge of mobilizing climate action and designing new institutional mechanisms to address the global and intergenerational distributional aspects of climate change; second, the economic challenge of devising new institutional approaches to equitably finance climate action; and third, the cultural challenge — and opportunity — of empowering an adaptive socio-cultural ecology through traditional knowledge and local-level social networks to achieve environmental resilience. Graduate students Chen Chu and Mrinalini Penumaka, both PhD students in DUSP, are working with Jackson on the project.

    Professor Haruko Wainwright, departments of Nuclear Science and Engineering (NSE) and Civil and Environmental Engineering: Low-cost Environmental Monitoring Network Technologies in Rural Communities for Addressing Climate Justice 

    This project will establish a community-based climate and environmental monitoring network in addition to a data visualization and analysis infrastructure in rural marginalized communities to better understand and address climate justice issues. The project team plans to work with rural communities in Alaska to install low-cost air and water quality, weather, and soil sensors. Graduate students Kay Whiteaker, an MS candidate in NSE, and Amandeep Singh, and MS candidate in System Design and Management at Sloan, are working with Wainwright on the project, as is David McGee, professor in earth, atmospheric, and planetary sciences.

    Professor Siqi Zheng, MIT Center for Real Estate and DUSP: Climate Crisis and Real Estate: Science-based Mitigation and Adaptation Strategies 

    See the text above for the details on this project. More

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    in Environment

    In a surprising finding, light can make water evaporate without heat

    Evaporation is happening all around us all the time, from the sweat cooling our bodies to the dew burning off in the morning sun. But science’s understanding of this ubiquitous process may have been missing a piece all this time.

    In recent years, some researchers have been puzzled upon finding that water in their experiments, which was held in a sponge-like material known as a hydrogel, was evaporating at a higher rate than could be explained by the amount of heat, or thermal energy, that the water was receiving. And the excess has been significant — a doubling, or even a tripling or more, of the theoretical maximum rate.

    After carrying out a series of new experiments and simulations, and reexamining some of the results from various groups that claimed to have exceeded the thermal limit, a team of researchers at MIT has reached a startling conclusion: Under certain conditions, at the interface where water meets air, light can directly bring about evaporation without the need for heat, and it actually does so even more efficiently than heat. In these experiments, the water was held in a hydrogel material, but the researchers suggest that the phenomenon may occur under other conditions as well.

    The findings are published this week in a paper in PNAS, by MIT postdoc Yaodong Tu, professor of mechanical engineering Gang Chen, and four others.

    The phenomenon might play a role in the formation and evolution of fog and clouds, and thus would be important to incorporate into climate models to improve their accuracy, the researchers say. And it might play an important part in many industrial processes such as solar-powered desalination of water, perhaps enabling alternatives to the step of converting sunlight to heat first.

    The new findings come as a surprise because water itself does not absorb light to any significant degree. That’s why you can see clearly through many feet of clean water to the surface below. So, when the team initially began exploring the process of solar evaporation for desalination, they first put particles of a black, light-absorbing material in a container of water to help convert the sunlight to heat.

    Then, the team came across the work of another group that had achieved an evaporation rate double the thermal limit — which is the highest possible amount of evaporation that can take place for a given input of heat, based on basic physical principles such as the conservation of energy. It was in these experiments that the water was bound up in a hydrogel. Although they were initially skeptical, Chen and Tu starting their own experiments with hydrogels, including a piece of the material from the other group. “We tested it under our solar simulator, and it worked,” confirming the unusually high evaporation rate, Chen says. “So, we believed them now.” Chen and Tu then began making and testing their own hydrogels.

    They began to suspect that the excess evaporation was being caused by the light itself —that photons of light were actually knocking bundles of water molecules loose from the water’s surface. This effect would only take place right at the boundary layer between water and air, at the surface of the hydrogel material — and perhaps also on the sea surface or the surfaces of droplets in clouds or fog.

    In the lab, they monitored the surface of a hydrogel, a JELL-O-like matrix consisting mostly of water bound by a sponge-like lattice of thin membranes. They measured its responses to simulated sunlight with precisely controlled wavelengths.

    The researchers subjected the water surface to different colors of light in sequence and measured the evaporation rate. They did this by placing a container of water-laden hydrogel on a scale and directly measuring the amount of mass lost to evaporation, as well as monitoring the temperature above the hydrogel surface. The lights were shielded to prevent them from introducing extra heat. The researchers found that the effect varied with color and peaked at a particular wavelength of green light. Such a color dependence has no relation to heat, and so supports the idea that it is the light itself that is causing at least some of the evaporation.

    The puffs of white condensation on glass is water being evaporated from a hydrogel using green light, without heat.Image: Courtesy of the researchers

    The researchers tried to duplicate the observed evaporation rate with the same setup but using electricity to heat the material, and no light. Even though the thermal input was the same as in the other test, the amount of water that evaporated never exceeded the thermal limit. However, it did so when the simulated sunlight was on, confirming that light was the cause of the extra evaporation.

    Though water itself does not absorb much light, and neither does the hydrogel material itself, when the two combine they become strong absorbers, Chen says. That allows the material to harness the energy of the solar photons efficiently and exceed the thermal limit, without the need for any dark dyes for absorption.

    Having discovered this effect, which they have dubbed the photomolecular effect, the researchers are now working on how to apply it to real-world needs. They have a grant from the Abdul Latif Jameel Water and Food Systems Lab to study the use of this phenomenon to improve the efficiency of solar-powered desalination systems, and a Bose Grant to explore the phenomenon’s effects on climate change modeling.

    Tu explains that in standard desalination processes, “it normally has two steps: First we evaporate the water into vapor, and then we need to condense the vapor to liquify it into fresh water.” With this discovery, he says, potentially “we can achieve high efficiency on the evaporation side.” The process also could turn out to have applications in processes that require drying a material.

    Chen says that in principle, he thinks it may be possible to increase the limit of water produced by solar desalination, which is currently 1.5 kilograms per square meter, by as much as three- or fourfold using this light-based approach. “This could potentially really lead to cheap desalination,” he says.

    Tu adds that this phenomenon could potentially also be leveraged in evaporative cooling processes, using the phase change to provide a highly efficient solar cooling system.

    Meanwhile, the researchers are also working closely with other groups who are attempting to replicate the findings, hoping to overcome skepticism that has faced the unexpected findings and the hypothesis being advanced to explain them.

    The research team also included Jiawei Zhou, Shaoting Lin, Mohammed Alshrah, and Xuanhe Zhao, all in MIT’s Department of Mechanical Engineering. More

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    in Environment

    Smart irrigation technology covers “more crop per drop”

    In agriculture today, robots and drones can monitor fields, temperature and moisture sensors can be automated to meet crop needs, and a host of other systems and devices make farms more efficient, resource-conscious, and profitable. The use of precision agriculture, as these technologies are collectively known, offers significant advantages. However, because the technology can be costly, it remains out of reach for the majority of the world’s farmers.

    “Many of the poor around the world are small, subsistence farmers,” says Susan Amrose, research scientist with the Global Engineering and Research (GEAR) Lab at MIT. “With intensification of food production needs, worsening soil, water scarcity, and smaller plots, these farmers can’t continue with their current practices.”

    By some estimates, the global demand for fresh water will outstrip supply by as much as 40 percent by the end of the decade. Nearly 80 percent of the world’s 570 million farms are classed as smallholder farms, with many located in under-resourced and water-stressed regions. With rapid population growth and climate change driving up demand for food, and with more strain on natural resources, increasing the adoption of sustainable agricultural practices among smallholder farmers is vital. 

    Amrose, who helps lead desalination, drip irrigation, water, and sanitation projects for GEAR Lab, says these small farmers need to move to more mechanized practices. “We’re trying to make it much, much more affordable for farmers to utilize solar-powered irrigation, and to have access to tools that, right now, they’re priced out of,” she says. “More crop per drop, more crop per area, that’s our goal.”

    Play video

    No Drop to Spare: MIT creates affordable, user-driven smart irrigation technology | MIT Mechanical Engineering

    Drip irrigation systems release water and nutrients in controlled volumes directly to the root zone of the crop through a network of pipes and emitters. These systems can reduce water consumption by 20 to 60 percent when compared to conventional flood irrigation methods.

    “Agriculture uses 70 percent of the fresh water that’s in use across the globe. Large-scale adoption and correct management of drip irrigation could help to reduce consumption of fresh water, which is especially critical for regions experiencing water shortages or groundwater depletion,” says Carolyn Sheline SM ’19, a PhD student and member of the GEAR Lab’s Drip Irrigation team. “A lot of irrigation technology is developed for larger farms that can put more money into it — but inexpensive doesn’t need to mean ‘not technologically advanced.’”

    GEAR Lab has created several drip irrigation technology solutions to date, including a low-pressure drip emitter that has been shown to reduce pumping energy by more than 50 percent when compared to existing emitters; a systems-level optimization model that analyzes factors like local weather conditions and crop layouts, to cut overall system operation costs by up to 30 percent; and a low-cost precision irrigation controller that optimizes system energy and water use, enabling farmers to operate the system on an ideal schedule given their specific resources, needs, and preferences. The controller has recently been shown to reduce water consumption by over 40 percent when compared to traditional practices.

    To build these new, affordable technologies, the team tapped into a critical knowledge source — the farmers themselves.

    “We didn’t just create technology in isolation — we also advanced our understanding of how people would interact with and value this technology, and we did that before the technology had come to fruition,” says Amos Winter SM ’05, PhD ’11, associate professor of mechanical engineering and MIT GEAR Lab principal investigator. “Getting affirmations that farmers would value what the technology would do before we finished it was incredibly important.”

    The team held “Farmer Field Days” and conducted interviews with more than 200 farmers, suppliers, and industry professionals in Kenya, Morocco, and Jordan, the regions selected to host field pilot test sites. These specific sites were selected for a variety of reasons, including solar availability and water scarcity, and because all were great candidate markets for eventual adoption of the technology.

    “People usually understand their own problems really well, and they’re very good at coming up with solutions to them,” says Fiona Grant ’17, SM ’19, also a PhD candidate with the GEAR Lab Drip Irrigation team. “As designers, our role really is to provide a different set of expertise and another avenue for them to get the tools or the resources that they need.”

    The controller, for example, takes in weather information, like relative humidity, temperature, wind speed values, and precipitation. Then, using artificial intelligence, it calculates and predicts the area’s solar exposure for the day and the exact irrigation needs for the farmer, and sends information to their smartphone. How much, or how little, automation an individual site uses remains up to the farmer. In its first season of operation on a Moroccan test site, GEAR Lab technology reduced water consumption by 44 percent and energy by 38 percent when compared to a neighboring farm using traditional drip irrigation practice.

    “The way you’re going to operate a system is going to have a big impact on the way you design it,” says Grant. “We gained a sense of what farmers would be willing to change, or not, regarding interactions with the system. We found that what we might change, and what would be acceptable to change, were not necessarily the same thing.”

    GEAR Lab alumna Georgia Van de Zande ’15, SM ’18, PhD ’23, concurs. “It’s about more than just delivering a lower-cost system, it’s also about creating something they’re going to want to use and want to trust.”

    In Jordan, researchers at a full-scale test farm are operating a solar-powered drip system with a prototype of the controller and are receiving smartphone commands on when to open and close the manual valves. In Morocco, the controller is operating at a research farm with a fully automated hydraulic system; researchers are monitoring the irrigation and conducting additional agronomic tasks. In Kenya, where precision agriculture and smart irrigation haven’t yet seen very much adoption, a simpler version of the controller serves to provide educational and training information in addition to offering scheduling and control capabilities.

    Knowledge is power for the farmers, and for designers and engineers, too. If an engineer can know a user’s requirements, Winter says, they’re much more likely to create a successful solution.

    “The most powerful tool a designer can have is perspective. I have one perspective — the math and science and tech innovation side — but I don’t know a thing about what it’s like to live every day as a farmer in Jordan or Morocco,” says Winter. “I don’t know what clogs the filters, or who shuts off the water. If you can see the world through the eyes of stakeholders, you’re going to spot requirements and constraints that you wouldn’t have picked up on otherwise.”

    Winter says the technology his team is building is exciting for a lot of reasons.

    “To be in a situation where the world is saying, ‘we need to deal with water stress, we need to deal with climate adaptation, and we need to particularly do this in resource-constrained countries,’ and to be in a position where we can do something about it and produce something of tremendous value and efficacy is incredible,” says Winter. “Solving the right problem at the right time, on a massive scale, is thrilling.” More