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      in Energy

      Making nuclear energy facilities easier to build and transport

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      For the United States to meet its net zero goals, nuclear energy needs to be on the smorgasbord of options. The problem: Its production still suffers from a lack of scale. To increase access rapidly, we need to stand up reactors quickly, says Isabel Naranjo De Candido, a third-year doctoral student advised by Professor Koroush Shirvan.

      One option is to work with microreactors, transportable units that can be wheeled to areas that need clean electricity. Naranjo De Candido’s master’s thesis at MIT, supervised by Professor Jacopo Buongiorno, focused on such reactors.

      Another way to improve access to nuclear energy is to develop reactors that are modular so their component units can be manufactured quickly while still maintaining quality. “The idea is that you apply the industrialization techniques of manufacturing so companies produce more [nuclear] vessels, with a more predictable supply chain,” she says. The assumption is that working with standardized recipes to manufacture just a few designed components over and over again improves speed and reliability and decreases cost.

      As part of her doctoral studies, Naranjo De Candido is working on optimizing the operations and management of these small, modular reactors so they can be efficient in all stages of their lifecycle: building; operations and maintenance; and decommissioning. The motivation for her research is simple: “We need nuclear for climate change because we need a reliable and stable source of energy to fight climate change,” she says.

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      A childhood in Italy

      Despite her passion for nuclear energy and engineering today, Naranjo De Candido was unsure what she wanted to pursue after high school in Padua, Italy. The daughter of a physician Italian mother and an architect Spanish father, she enrolled in a science-based high school shortly after middle school, as she knew that was the track she enjoyed best.

      Having earned very high marks in school, she won a full scholarship to study in Pisa, at the special Sant’Anna School of Advanced Studies. Housed in a centuries-old convent, the school granted only masters and doctoral degrees. “I had to select what to study but I was unsure. I knew I was interested in engineering,” she recalls, “so I selected mechanical engineering because it’s more generic.”

      It turns out Sant’Anna was a perfect fit for Naranjo De Candido to explore her passions. An inspirational nuclear engineering course during her studies set her on the path toward studying the field as part of her master’s studies in Pisa. During her time there, she traveled around the world — to China as part of a student exchange program and to Switzerland and the United States for internships. “I formed a good background and curriculum and that allowed me to [gain admission] to MIT,” she says.

      At an internship at NASA’s Jet Propulsion Lab, she met an MIT mechanical engineering student who encouraged her to apply to the school for doctoral studies. Yet another mentor in the Italian nuclear sector had also suggested she apply to MIT to pursue nuclear engineering, so she decided to take the leap.

      And she is glad she did.

      Improving access to nuclear energy

      At MIT, Naranjo De Candido is working on improving access to nuclear energy by scaling down reactor size and, in the case of microreactors, making them mobile enough to travel to places where they’re needed. “The idea with a microreactor is that when the fuel is exhausted, you replace the entire microreactor onsite with a freshly fueled unit and take the old one back to a central facility where it’s going to be refueled,” she says. One of the early use cases for such microreactors has been remote mining sites which need reliable power 24/7.

      Modular reactors, about 10 times the size of microreactors, ensure access differently: The components can be manufactured and installed at scale. These reactors don’t just deliver electricity but also cater to the market for industrial heat, she says. “You can locate them close to industrial facilities and use the heat directly to power ammonia or hydrogen production or water desalinization for example,” she adds.

      As more of these modular reactors are installed, the industry is expected to expand to include enterprises that choose to simply build them and hand off operations to other companies. Whereas traditional nuclear energy reactors might have a full suite of staff on board, smaller-scale reactors such as modular ones cannot afford to staff in large numbers, so talent needs to be optimized and staff shared among many units. “Many of these companies are very interested in knowing exactly how many people and how much money to allocate, and how to organize resources to serve more than one reactor at the same time,” she says.

      Naranjo De Candido is working on a complex software program that factors in a large range of variables — from raw materials cost and worker training, reactor size, megawatt output and more — and leans on historical data to predict what resources newer plants might need. The program also informs operators about the tradeoffs they need to accept. For example, she explains, “if you reduce people below the typical level assigned, how does that impact the reliability of the plant, that is, the number of hours that it is able to operate without malfunctions and failures?”

      And managing and operating a nuclear reactor is particularly complex because safety standards limit how much time workers can work in certain areas and how safe zones need to be handled.

      “There’s a shortage of [qualified talent] in the industry so this is not just about reducing costs but also about making it possible to have plants out there,” Naranjo De Candido says. Different types of talent are needed, from professionals who specialize in mechanical components to electronic controls. The model that she is working on considers the need for such specialized skillsets as well as making room for cross-training talent in multiple fields as needed.

      In keeping with her goal of making nuclear energy more accessible, the optimization software will be open-source, available for all to use. “We want this to be a common ground for utilities and vendors and other players to be able to communicate better,” Naranjo De Candido says, Doing so will accelerate the operation of nuclear energy plants at scale, she hopes — an achievement that will come not a moment too soon. More

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      in Energy

      New study shows how universities are critical to emerging fusion industry

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      A new study suggests that universities have an essential role to fulfill in the continued growth and success of any modern high-tech industry, and especially the nascent fusion industry; however, the importance of that role is not reflected in the number of fusion-oriented faculty and educational channels currently available. Academia’s responsiveness to the birth of other modern scientific fields, such as aeronautics and nuclear fission, provides a template for the steps universities can take to enable a robust fusion industry.

      Authored by Dennis Whyte, the Hitachi America Professor of Engineering and director of the Plasma Science and Fusion Center at MIT; Carlos Paz-Soldan, associate professor of applied physics and applied mathematics at Columbia University; and Brian D. Wirth, the Governor’s Chair Professor of Computational Nuclear Engineering at the University of Tennessee, the paper was recently published in the journal Physics of Plasmas as part of a special collection titled “Private Fusion Research: Opportunities and Challenges in Plasma Science.”

      With contributions from authors in academia, government, and private industry, the collection outlines a framework for public-private partnerships that will be essential for the success of the fusion industry.

      Now being seen as a potential source of unlimited green energy, fusion is the same process that powers the sun — hydrogen atoms combine to form helium, releasing vast amounts of clean energy in the form of light and heat.

      The excitement surrounding fusion’s arrival has resulted in the proliferation of dozens of for-profit companies positioning themselves at the forefront of the commercial fusion energy industry. In the near future, those companies will require a significant network of fusion-fluent workers to take on varied tasks requiring a range of skills.

      While the authors acknowledge the role of private industry, especially as an increasingly dominant source of research funding, they also show that academia is and will continue to be critical to industry’s development, and it cannot be decoupled from private industry’s growth. Despite the evidence of this burgeoning interest, the size and scale of the field’s academic network at U.S.-based universities is sparse.

      According to Whyte, “Diversifying the [fusion] field by adding more tracks for master’s students and undergraduates who can transition into industry more quickly is an important step.”

      An analysis found that while there are 57 universities in the United States active in plasma and fusion research, the average number of tenured or tenure-track plasma/fusion faculty at each institution is only two. By comparison, a sampling of US News and World Report’s top 10 programs for nuclear fission and aeronautics/astronautics found an average of nearly 20 faculty devoted to fission and 32 to aero/astro.

      “University programs in fusion and their sponsors need to up their game and hire additional faculty if they want to provide the necessary workforce to support a growing U.S. fusion industry,” adds Paz-Soldan.

      The growth and proliferation of those fields and others, such as computing and biotechnology, were historically in lockstep with the creation of academic programs that helped drive the fields’ progress and widespread acceptance. Creating a similar path for fusion is essential to ensuring its sustainable growth, and as Wirth notes, “that this growth should be pursued in a way that is interdisciplinary across numerous engineering and science disciplines.”

      At MIT, an example of that path is seen at the Plasma Science and Fusion Center.

      The center has deep historical ties to government research programs, and the largest fusion company in the world, Commonwealth Fusion Systems (CFS), was spun out of the PSFC by Whyte’s former students and an MIT postdoc. Whyte also serves as the primary investigator in collaborative research with CFS on SPARC, a proof-of-concept fusion platform for advancing tokamak science that is scheduled for completion in 2025.

      “Public and private roles in the fusion community are rapidly evolving in response to the growth of privately funded commercial product development,” says Michael Segal, head of open innovation at CFS. “The fusion industry will increasingly rely on its university partners to train students, work across diverse disciplines, and execute small and midsize programs at speed.”

      According to the authors, another key reason academia will remain essential to the continued growth and development of fusion is because it is unconflicted. Whyte comments, “Our mandate is sharing information and education, which means we have no competitive conflict and innovation can flow freely.” Furthermore, fusion science is inherently multidisciplinary: “[It] requires physicists, computer scientists, engineers, chemists, etc. and it’s easy to tap into all those disciplines in an academic environment where they’re all naturally rubbing elbows and collaborating.”

      Creating a new energy industry, however, will also require a workforce skilled in disciplines other than STEM, say the authors. As fusion companies continue to grow, they will need expertise in finance, safety, licensing, and market analysis. Any successful fusion enterprise will also have major geopolitical, societal, and economic impacts, all of which must be managed.

      Ultimately, there are several steps the authors identify to help build the connections between academia and industry that will be important going forward: The first is for universities to acknowledge the rapidly changing fusion landscape and begin to adapt. “Universities need to embrace the growth of the private sector in fusion, recognize the opportunities it provides, and seek out mutually beneficial partnerships,” says Paz-Soldan.

      The second step is to reconcile the mission of educational institutions — unconflicted open access — with condensed timelines and proprietary outputs that come with private partnerships. At the same time, the authors note that private fusion companies should embrace the transparency of academia by publishing and sharing the findings they can through peer-reviewed journals, which will be a necessary part of building the industry’s credibility.

      The last step, the authors say, is for universities to become more flexible and creative in their technology licensing strategies to ensure ideas and innovations find their way from the lab into industry.

      “As an industry, we’re in a unique position because everything is brand new,” Whyte says. “But we’re enough students of history that we can see what’s needed to succeed; quantifying the status of the private and academic landscape is an important strategic touchstone. By drawing attention to the current trajectory, hopefully we’ll be in a better position to work with our colleagues in the public and private sector and make better-informed choices about how to proceed.” More

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      in Environment

      Forging climate connections across the Institute

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      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

      Smart irrigation technology covers “more crop per drop”

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      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.”

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      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

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      in Energy

      Printing a new approach to fusion power plant materials

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      When Alexander O’Brien sent in his application for graduate school at MIT’s Department of Nuclear Science and Engineering, he had a germ of a research idea already brewing. So when he received a phone call from Professor Mingda Li, he shared it: The student from Arkansas wanted to explore the design of materials that could hold nuclear reactors together.

      Li listened to him patiently and then said, “I think you’d be a really good fit for Professor Ju Li,” O’Brien remembers. Ju Li, the Battelle Energy Alliance Professor in Nuclear Engineering, had wanted to explore 3D printing for nuclear reactors and O’Brien seemed like the right candidate. “At that moment I decided to go to MIT if they accepted me,” O’Brien remembers.

      And they did.

      Under the advisement of Ju Li, the fourth-year doctoral student now explores 3D printing of ceramic-metal composites, materials that can be used to construct fusion power plants.

      An early interest in the sciences

      Growing up in Springdale, Arkansas as a self-described “band nerd,” O’Brien was particularly interested in chemistry and physics. It was one thing to mix baking soda and vinegar to make a “volcano” and quite another to understand why that was happening. “I just enjoyed understanding things on a deeper level and being able to figure out how the world works,” he says.

      At the same time, it was difficult to ignore the economics of energy playing out in his own backyard. When Arkansas, a place that had hardly ever seen earthquakes, started registering them in the wake of fracking in neighboring Oklahoma, it was “like a lightbulb moment” for O’Brien. “I knew this was going to create problems down the line, I knew there’s got to be a better way to do [energy],” he says.

      With the idea of energy alternatives simmering on the back burner, O’Brien enrolled for undergraduate studies at the University of Arkansas. He participated in the school’s marching band — “you show up a week before everyone else and there’s 400 people who automatically become your friends” — and enjoyed the social environment that a large state school could offer.

      O’Brien double-majored in chemical engineering and physics and appreciated “the ability to get your hands dirty on machinery to make things work.” Deciding to begin exploring his interest in energy alternatives, O’Brien researched transition metal dichalcogenides, coatings of which could catalyze the hydrogen evolution reaction and more easily create hydrogen gas, a green energy alternative.

      It was shortly after his sophomore year, however, that O’Brien really found his way in the field of energy alternatives — in nuclear engineering. The American Chemical Society was soliciting student applications for summer study of nuclear chemistry in San Jose, California. O’Brien applied and got accepted. “After years of knowing I wanted to work in green energy but not knowing what that looked like, I very quickly fell in love with [nuclear engineering],” he says. That summer also cemented O’Brien’s decision to attend graduate school. “I came away with this idea of ‘I need to go to grad school because I need to know more about this,’” he says.

      O’Brien especially appreciated an independent project, assigned as part of the summer program: He chose to research nuclear-powered spacecraft. In digging deeper, O’Brien discovered the challenges of powering spacecraft — nuclear was the most viable alternative, but it had to work around extraneous radiation sources in space. Getting to explore national laboratories near San Jose sealed the deal. “I got to visit the National Ignition Facility, which is the big fusion center up there, and just seeing that massive facility entirely designed around this one idea of fusion was kind of mind-blowing to me,” O’Brien says.

      A fresh blueprint for fusion power plants

      O’Brien’s current research at MIT’s Department of Nuclear Science and Engineering (NSE) is equally mind-blowing.

      As the design of new fusion devices kicks into gear, it’s becoming increasingly apparent that the materials we have been using just don’t hold up to the higher temperatures and radiation levels in operating environments, O’Brien says. Additive manufacturing, another term for 3D printing, “opens up a whole new realm of possibilities for what you can do with metals, which is exactly what you’re going to need [to build the next generation of fusion power plants],” he says.

      Metals and ceramics by themselves might not do the job of withstanding high temperatures (750 degrees Celsius is the target) and stresses and radiation, but together they might get there. Although such metal matrix composites have been around for decades, they have been impractical for use in reactors because they’re “difficult to make with any kind of uniformity and really limited in size scale,” O’Brien says. That’s because when you try to place ceramic nanoparticles into a pool of molten metal, they’re going to fall out in whichever direction they want. “3D printing quickly changes that story entirely, to the point where if you want to add these nanoparticles in very specific regions, you have the capability to do that,” O’Brien says.

      O’Brien’s work, which forms the basis of his doctoral thesis and a research paper in the journal Additive Manufacturing, involves implanting metals with ceramic nanoparticles. The net result is a metal matrix composite that is an ideal candidate for fusion devices, especially for the vacuum vessel component, which must be able to withstand high temperatures, extremely corrosive molten salts, and internal helium gas from nuclear transmutation.

      O’Brien’s work focuses on nickel superalloys like Inconel 718, which are especially robust candidates because they can withstand higher operating temperatures while retaining strength. Helium embrittlement, where bubbles of helium caused by fusion neutrons lead to weakness and failure, is a problem with Inconel 718, but composites exhibit potential to overcome this challenge.

      To create the composites, first a mechanical milling process coats the ceramic onto the metal particles. The ceramic nanoparticles act as reinforcing strength agents, especially at high temperatures, and make materials last longer. The nanoparticles also absorb helium and radiation defects when uniformly dispersed, which prevent these damage agents from all getting to the grain boundaries.

      The composite then goes through a 3D printing process called powder bed fusion (non-nuclear fusion), where a laser passes over a bed of this powder melting it into desired shapes. “By coating these particles with the ceramic and then only melting very specific regions, we keep the ceramics in the areas that we want, and then you can build up and have a uniform structure,” O’Brien says.

      Printing an exciting future

      The 3D printing of nuclear materials exhibits such promise that O’Brien is looking at pursuing the prospect after his doctoral studies. “The concept of these metal matrix composites and how they can enhance material property is really interesting,” he says. Scaling it up commercially through a startup company is on his radar.

      For now, O’Brien is enjoying research and catching an occasional Broadway show with his wife. While the band nerd doesn’t pick up his saxophone much anymore, he does enjoy driving up to New Hampshire and going backpacking. “That’s my newfound hobby,” O’Brien says, “since I started grad school.” More

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      in Environment

      A reciprocal relationship with the land in Hawaiʻi

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      Aja Grande grew up on the Hawaiian island of Oʻahu, between the Kona and ʻEwa districts, nurtured by her community and the natural environment. Her family has lived in Hawaiʻi for generations; while she is not “Kanaka ʻŌiwi,” of native Hawaiian descent, she is proud to trace her family’s history to the time of the Hawaiian Kingdom in the 19th century. Grande is now a PhD candidate in MIT’s HASTS (History, Anthropology, Science, Technology and Society) program, and part of her dissertation tracks how Hawaiian culture and people’s relationship with the land has evolved throughout time.

      “The fondest memories I have are camping on the north shore every summer with my friends,” says Grande. “I loved being in ‘ke kai’ (the sea) and ‘ma uka,’ (inland, in the mountains) with my friends when I was younger. It was just pure fun exploring ‘ʻāina’ like that.” “‘Āina” in the Hawaiian language is often defined as “land,” but is understood to the people of Hawaiʻi as “that which feeds.”

      “Now that I’m older,” Grande adds, “I’m connecting the dots and realizing how much knowledge about the complex systems of ‘ahupuaʻa’ [traditional Hawaiian divisions of land that extend from the mountains to the sea], I actually gained through these experiences.”

      Grande recently completed a year of fieldwork in Hawaiʻi where she volunteered with land-based, or ‘āina-based organizations. In the movement to restore ‘āina to “momona,” or  “fertile and abundant lands,” the land and the people who serve as its stewards are of equal importance.

      “I’m looking at how people who are not Kanaka ‘Ōiwi, or native Hawaiian, by descent can participate in this kind of restoration, and what it means for both Kanaka ‘Ōiwi and non-Kanaka ‘Ōiwi to participate in it,” says Grande, who herself descends from immigrants of other island nations. “Some of my ancestors were born and raised in Hawaiʻi before the U.S. subjected Hawaiʻi as a state and territory, meaning that some of them were Hawaiian Kingdom subjects. While, I am not Kanaka ʻŌiwi by lineage, some of my ‘ohana nui (extended family), from these same ancestors, are Kanaka ʻŌiwi. I’m writing about how being Hawaiian, from a Hawaiian sovereignty standpoint, is not just about race and ethnicity. When Hawaiʻi was a sovereign nation, Hawaiian citizenship was never afforded on the basis of race alone. It was also based on your lifelong commitment to ‘āina and the people of Hawaiʻi.”

      The project is personal to Grande, who describes both the content and the process of writing it as part of her healing journey. She hopes to lay the groundwork for others who are “hoaʻāina,” or “those who actively care for ʻāina,” in Hawaiʻi, but not Kanaka ʻŌiwi to better articulate their identities and foster a deeper connection with the ʻāina and the “kaiāulu,” or “community,” they love and actively care for.

      Returning home

      Grande has spent her academic career on the East Coast, first at Brown University, where she received a degree in science, technology, and society, and now at MIT in the HASTS program. She swam competitively through her second year of college, and had earlier represented Hawaiʻi at the 2012 Oceania Games in New Caledonia. Once she stopped swimming, Grande first used her newfound time to travel the world. Tired of this transient lifestyle, she realized she was more interested in exploring her connection to land in a more rooted way.

      “Moving around, especially as a college student, it’s very hard to grow things,” says Grande. “People are a lot like plants. You really just need to let plants do their thing in place. We do really well and we thrive when we can be connected to place.”

      Grande started by founding the Ethnobotany Society at Brown to explore the relationship people have to plants. With the group she organized nature walks, collaborated with local farms, and connected it to the history she was learning in class.

      Still, the East Coast never quite felt like home to Grande. When she started planning for the fieldwork portion of her program, she envisioned spending half the year in New England and half in Hawaiʻi. But she soon realized how important it was for both her research and herself to dedicate everything to Hawai’i.

      “When I came back, it just felt so right to be back home,” says Grande. “The feeling in your naʻau — your ‘gut’ — of knowing that you have to contribute to Hawaiʻi is very powerful, and I think a lot of people here understand what that means. It’s kind of like a calling.”

      Hoaʻāina, community, family

      Once Grande made the decision to return home for her field work, she says everything fell into place.

      “I knew that I wanted to do something close to my heart. It’s a huge privilege because I was able to come home and learn more about myself and my family and how we are connected to Hawaiʻi,” she says.

      During her year of fieldwork, Grande learned how hoaʻāina cultivate spaces where the community can can work alongside one another to plant traditional food and medicinal crops, control invasive species, and more. She wasn’t just an observer, either. As much as Grande learned from an academic perspective, her personal growth has been intertwined with the entire process.

      “The most interesting part was that all the hoaʻāina I volunteered with helped me to understand my place back home,” says Grande. “They were my informants but also — this usually happens with anthropologists — people become your friends. The hoaʻāina I volunteered with treated me like family. They also got to know some of my family members, who joined me to volunteer at different sites. It’s sometimes hard to drop a hard line between what fieldwork is and what your personal life is because when you’re in the field, there’s so many events that are connected to your work. It was so fun and meaningful to write about the ʻāina and people I consider my community and family.”

      The movement doesn’t start or end with Grande’s dissertation. Pursuing this project has given her the language to articulate her own relationship with ‘āina, and she hopes it will empower others to reexamine how they exist in relation to land.

      After completing her program, Grande intends to stay in Hawaiʻi and continue philanthropy work while contributing to the movement of ʻāina momona.

      “We want the land to live and to keep a relationship with the land. That’s the emotional part. I have a ‘kuleana,’ (duty and responsibility) to everything that I learned while growing up, including the ʻāina and ‘kaiāulu,’ (community) who raised me. The more you learn, there’s so much that you want to protect about the culture and this ‘āina.” More

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      in Energy

      Jackson Jewett wants to design buildings that use less concrete

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      After three years leading biking tours through U.S. National Parks, Jackson Jewett decided it was time for a change.

      “It was a lot of fun, but I realized I missed buildings,” says Jewett. “I really wanted to be a part of that industry, learn more about it, and reconnect with my roots in the built environment.”

      Jewett grew up in California in what he describes as a “very creative household.”

      “I remember making very elaborate Halloween costumes with my parents, making fun dioramas for school projects, and building forts in the backyard, that kind of thing,” Jewett explains.

      Both of his parents have backgrounds in design; his mother studied art in college and his father is a practicing architect. From a young age, Jewett was interested in following in his father’s footsteps. But when he arrived at the University of California at Berkeley in the midst of the 2009 housing crash, it didn’t seem like the right time. Jewett graduated with a degree in cognitive science and a minor in history of architecture. And even as he led tours through Yellowstone, the Grand Canyon, and other parks, buildings were in the back of his mind.

      It wasn’t just the built environment that Jewett was missing. He also longed for the rigor and structure of an academic environment.

      Jewett arrived at MIT in 2017, initially only planning on completing the master’s program in civil and environmental engineering. It was then that he first met Josephine Carstensen, a newly hired lecturer in the department. Jewett was interested in Carstensen’s work on “topology optimization,” which uses algorithms to design structures that can achieve their performance requirements while using only a limited amount of material. He was particularly interested in applying this approach to concrete design, and he collaborated with Carstensen to help demonstrate its viability.

      After earning his master’s, Jewett spent a year and a half as a structural engineer in New York City. But when Carstensen was hired as a professor, she reached out to Jewett about joining her lab as a PhD student. He was ready for another change.

      Now in the third year of his PhD program, Jewett’s dissertation work builds upon his master’s thesis to further refine algorithms that can design building-scale concrete structures that use less material, which would help lower carbon emissions from the construction industry. It is estimated that the concrete industry alone is responsible for 8 percent of global carbon emissions, so any efforts to reduce that number could help in the fight against climate change.

      Implementing new ideas

      Topology optimization is a small field, with the bulk of the prior work being computational without any experimental verification. The work Jewett completed for his master’s thesis was just the start of a long learning process.

      “I do feel like I’m just getting to the part where I can start implementing my own ideas without as much support as I’ve needed in the past,” says Jewett. “In the last couple of months, I’ve been working on a reinforced concrete optimization algorithm that I hope will be the cornerstone of my thesis.”

      The process of fine-tuning a generative algorithm is slow going, particularly when tackling a multifaceted problem.

      “It can take days or usually weeks to take a step toward making it work as an entire integrated system,” says Jewett. “The days when that breakthrough happens and I can see the algorithm converging on a solution that makes sense — those are really exciting moments.”

      By harnessing computational power, Jewett is searching for materially efficient components that can be used to make up structures such as bridges or buildings. These are other constraints to consider as well, particularly ensuring that the cost of manufacturing isn’t too high. Having worked in the industry before starting the PhD program, Jewett has an eye toward doing work that can be feasibly implemented.

      Inspiring others

      When Jewett first visited MIT campus, he was drawn in by the collaborative environment of the institute and the students’ drive to learn. Now, he’s a part of that process as a teaching assistant and a supervisor in the Undergraduate Research Opportunities Program.  

      Working as a teaching assistant isn’t a requirement for Jewett’s program, but it’s been one of his favorite parts of his time at MIT.

      “The MIT undergrads are so gifted and just constantly impress me,” says Jewett. “Being able to teach, especially in the context of what MIT values is a lot of fun. And I learn, too. My coding practices have gotten so much better since working with undergrads here.”

      Jewett’s experiences have inspired him to pursue a career in academia after the completion of his program, which he expects to complete in the spring of 2025. But he’s making sure to take care of himself along the way. He still finds time to plan cycling trips with his friends and has gotten into running ever since moving to Boston. So far, he’s completed two marathons.

      “It’s so inspiring to be in a place where so many good ideas are just bouncing back and forth all over campus,” says Jewett. “And on most days, I remember that and it inspires me. But it’s also the case that academics is hard, PhD programs are hard, and MIT — there’s pressure being here, and sometimes that pressure can feel like it’s working against you.”

      Jewett is grateful for the mental health resources that MIT provides students. While he says it can be imperfect, it’s been a crucial part of his journey.

      “My PhD thesis will be done in 2025, but the work won’t be done. The time horizon of when these things need to be implemented is relatively short if we want to make an impact before global temperatures have already risen too high. My PhD research will be developing a framework for how that could be done with concrete construction, but I’d like to keep thinking about other materials and construction methods even after this project is finished.” More

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      in Environment

      Uncovering how biomes respond to climate change

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      Before Leila Mirzagholi arrived at MIT’s Department of Civil and Environmental Engineering (CEE) to begin her postdoc appointment, she had spent most of her time in academia building cosmological models to detect properties of gravitational waves in the cosmos.

      But as a member of Assistant Professor César Terrer’s lab in CEE, Mirzagholi uses her physics and mathematical background to improve our understanding of the different factors that influence how much carbon land ecosystems can store under climate change.

      “What was always important to me was thinking about how to solve a problem and putting all the pieces together and building something from scratch,” Mirzagholi says, adding this was one of the reasons that it was possible for her to switch fields — and what drives her today as a climate scientist.

      Growing up in Iran, Mirzagholi knew she wanted to be a scientist from an early age. As a kid, she became captivated by physics, spending most of her free time in a local cultural center that hosted science events. “I remember in that center there was an observatory that held observational tours and it drew me into science,” says Mirzgholi. She also remembers a time when she was a kid watching the science fiction film “Contact” that introduces a female scientist character who finds evidence of extraterrestrial life and builds a spaceship to make first contact: “After that movie my mind was set on pursuing astrophysics.”

      With the encouragement of her parents to develop a strong mathematical background before pursuing physics, she earned a bachelor’s degree in mathematics from Tehran University. Then she completed a one-year master class in mathematics at Utrecht University before completing her PhD in theoretical physics at Max Planck Institute for Astrophysics in Munich. There, Mirzgholi’s thesis focused on developing cosmological models with a focus on phenomenological aspects like propagation of gravitational waves on the cosmic microwave background.

      Midway through her PhD, Mirzgholi became discouraged with building models to explain the dynamics of the early universe because there is little new data. “It starts to get personal and becomes a game of: ‘Is it my model or your model?’” she explains. She grew frustrated not knowing when the models she’d built would ever be tested.

      It was at this time that Mirzgholi started reading more about the topics of climate change and climate science. “I was really motivated by the problems and the nature of the problems, especially to make global terrestrial ecology more quantitative,” she says. She also liked the idea of contributing to a global problem that we are all facing. She started to think, “maybe I can do my part, I can work on research beneficial for society and the planet.”

      She made the switch following her PhD and started as a postdoc in the Crowther Lab at ETH Zurich, working on understanding the effects of environmental changes on global vegetation activity. After a stint at ETH, where her colleagues collaborated on projects with the Terrer Lab, she relocated to Cambridge, Massachusetts, to join the lab and CEE.

      Her latest article in Science, which was published in July and co-authored by researchers from ETH, shows how global warming affects the timing of autumn leaf senescence. “It’s important to understand the length of the growing season, and how much the forest or other biomes will have the capacity to take in carbon from the atmosphere.” Using remote sensing data, she was able to understand when the growing season will end under a warming climate. “We distinguish two dates — when autumn is onsetting and the leaves are starting to turn yellow, versus when the leaves are 50 percent yellow — to represent the progression of leaf senescence,” she says.

      In the context of rising temperature, when the warming is happening plays a crucial role. If warming temperatures happen before the summer solstice, it triggers trees to begin their seasonal cycles faster, leading to reduced photosynthesis, ending in an earlier autumn. On the other hand, if the warming happens after the summer solstice, it delays the discoloration process, making autumn last longer. “For every degree Celsius of pre-solstice warming, the onset of leaf senescence advances by 1.9 days, while each degree Celsius of post-solstice warming delays the senescence process by 2.6 days,” she explains. Understanding the timing of autumn leaf senescence is essential in efforts to predict carbon storage capacity when modeling global carbon cycles.

      Another problem she’s working on in the Terrer Lab is discovering how deforestation is changing our local climate. How much is it cooling or warming the temperature, and how is the hydrological cycle changing because of deforestation? Investigating these questions will give insight into how much we can depend on natural solutions for carbon uptake to help mitigate climate change. “Quantitatively, we want to put a number to the amount of carbon uptake from various natural solutions, as opposed to other solutions,” she says.

      With year-and-a-half left in her postdoc appointment, Mirzagholi has begun considering her next career steps. She likes the idea of applying to climate scientist jobs in industry or national labs, as well as tenure track faculty positions. Whether she pursues a career in academia or industry, Mirzagholi aims to continue conducting fundamental climate science research. Her multidisciplinary background in physics, mathematics, and climate science has given her a multifaceted perspective, which she applies to every research problem.

      “Looking back, I’m grateful for all my educational experiences from spending time in the cultural center as a kid, my background in physics, the support from colleagues at the Crowther lab at ETH who facilitated my transition from physics to ecology, and now working at MIT alongside Professor Terrer, because it’s shaped my career path and the researcher I am today.” More