Aurelia Butler

Methane, the main component of natural gas, is the cleanest-burning of all the fossil fuels, but when emitted into the atmosphere it is a much more potent greenhouse gas than carbon dioxide. By some estimates, seafloor methane contained in frozen formations along the continental margins may equal or exceed the total amount of coal, oil, and gas in all other reservoirs worldwide. Yet, the way methane escapes from these deep formations is poorly understood.
In particular, scientists have been faced with a puzzle. Observations at sites around the world have shown vigorous columns of methane gas bubbling up from these formations in some places, yet the high pressure and low temperature of these deep-sea environments should create a solid frozen layer that would be expected to act as a kind of capstone, preventing gas from escaping. So how does the gas get out?
A new study helps explain how and why columns of the gas can stream out of these formations, known as methane hydrates. Using a combination of deep-sea observations, laboratory experiments, and computer modeling, researchers have found phenomena that explain and predict the way the gas breaks free from the icy grip of a frozen mix of water and methane. The findings are reported today in the journal PNAS, in a paper by Xiaojing (Ruby) Fu SM ’15, PhD ’17, now at the University of California at Berkeley; Professor Ruben Juanes at MIT; and five others in Switzerland, Spain, New Mexico, and California.
Surprisingly, not only does the frozen hydrate formation fail to prevent methane gas from escaping into the ocean column, but in some cases it actually facilitates that escape.
Early on, Fu saw photos and videos showing plumes of methane, taken from a NOAA research ship in the Gulf of Mexico, revealing the process of bubble formation right at the seafloor. It was clear that the bubbles themselves often formed with a frozen crust around them, and would float upward with their icy shells like tiny helium balloons.
Later, Fu used sonar to detect similar bubble plumes from a research ship off the coast of Virginia. “This cruise alone detected thousands of these plumes,” says Fu, who led the research project while a graduate student and postdoc at MIT. “We could follow these methane bubbles encrusted by hydrate shells into the water column,” she says. “That’s when we first knew that hydrate forming on these gas interfaces can be a very common occurrence.”
But exactly what was going on beneath the seafloor to trigger the release of these bubbles remained unknown. Through a series of lab experiments and simulations, the mechanisms at work gradually became apparent.
Seismic studies of the subsurface of the seafloor in these vent regions show a series of relatively narrow conduits, or chimneys, through which the gas escapes. But the presence of chunks of gas hydrate from these same formations made it clear that the solid hydrate and the gaseous methane could co-exist, Fu explains. To simulate the conditions in the lab, the researchers used a small two-dimensional setup, sandwiching a gas bubble in a layer of water between two plates of glass under high pressure.
As a gas tries to rise through the seafloor, Fu says, if it’s forming a hydrate layer when it hits the cold seawater, that should block its progress: “It’s running into a wall. So how would that wall not be preventing it from continuous migration?” Using the microfluidic experiments, they found a previously unknown phenomenon at work, which they dubbed crustal fingering.
If the gas bubble starts to expand, “what we saw is that the expansion of the gas was able to create enough pressure to essentially rupture the hydrate shell. And it’s almost like it’s hatching out of its own shell,” Fu says. But instead of each rupture freezing back over with the reforming hydrate, the hydrate formation takes place along the sides of the rising bubble, creating a kind of tube around the bubble as it moves upward. “It’s almost like the gas bubble is able to chisel out its own path, and that path is walled by the hydrate solid,” she says. This phenomenon they observed at small scale in the lab, their analysis suggests, is also what would also happen at much larger scale in the seafloor.
That observation, she said, “was really the first time we’ve been aware of a phenomenon like this that could explain how hydrate formation will not inhibit gas flow, but rather in this case, it would facilitate it,” by providing a conduit and directing the flow. Without that focusing, the flow of gas would be much more diffuse and spread out.
As the crust of hydrate forms, it slows down the formation of more hydrate because it forms a barrier between the gas and the seawater. The methane below the barrier can therefore persist in its unfrozen, gaseous form for a long time. The combination of these two phenomena — the focusing effect of the hydrate-walled channels and the segregation of the methane gas from the water by a hydrate layer — “goes a long way toward explaining why you can have some of this vigorous venting, thanks to the hydrate formation, rather than being prevented by it,” says Juanes.

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A better understanding of the process could help in predicting where and when such methane seeps will be found, and how changes in environmental conditions could affect the distribution and output of these seeps. While there have been suggestions that a warming climate could increase the rate of such venting, Fu says there is little evidence of that so far. She notes that temperatures at the depths where these formations occur — 600 meters (1,900 feet) deep or more — are expected to experience a smaller temperature increase than would be needed to trigger a widespread release of the frozen gas.
Some researchers have suggested that these vast undersea methane formations might someday be harnessed for energy production. Though there would be great technical hurdles to such use, Juanes says, these findings might help in assessing the possibilities.
“The problem of how gas can move through the hydrate stability zone, where we would expect the gas to be immobilized by being converted to hydrate, and instead escape at the seafloor, is still not fully understood,” says Hugh Daigle, an associate professor of petroleum and geosystems engineering at the University of Texas at Austin, who was not associated with this research. “This work presents a probable new mechanism that could plausibly allow this process to occur, and nicely integrates previous laboratory observations with modeling at a larger scale.”
“In a practical sense, the work here takes a phenomenon at a small scale and allows us to use it in a model that only considers larger scales, and will be very useful for implementing in future work,” Daigle says.
The research team included Joaquin Jimenez-Martinez at the Swiss Federal Institute of Aquatic Science and Technology; Than Phon Nguyen, William Carey and Hari Vinaswanathan at Los Alamos National Laboratory; and Luis Cueto-Felgueroso at the Technical University of Madrid. The work was supported by the U.S. Department of Energy. More

The clothing rental service Armoire helps customers sustainably maintain a fresh ward-robe. More

MIT Lincoln Laboratory has established a new research and development division, the Biotechnology and Human Systems Division. The division will address emerging threats to both national security and humanity. Research and development will encompass advanced technologies and systems for improving chemical and biological defense, human health and performance, and global resilience to climate change, conflict, and disasters.
“We strongly believe that research and development in biology, biomedical systems, biological defense, and human systems is a critically important part of national and global security. The new division will focus on improving human conditions on many fronts,” says Eric Evans, Lincoln Laboratory director.
The new division unifies four research groups: Humanitarian Assistance and Disaster Relief (HADR) Systems, Counter-Weapons of Mass Destruction Systems, Biological and Chemical Technologies, and Human Health and Performance Systems.
“We are in a historic moment in the country, and it is a historic moment for Lincoln Laboratory to create a new division. The nation and laboratory are faced with several growing security threats, and there is a pressing need to focus our research and development efforts to address these challenges,” says Edward Wack, who is head of the division.
The laboratory began its initial work in biotechnology in 1995, through several programs that leveraged expertise in sensors and signal processing for chemical and biological defense systems. Work has since grown to include prototyping systems for protecting high-value facilities and transportation systems, architecting integrated early-warning biodefense systems for the U.S. Department of Defense (DoD), and applying artificial intelligence and synthetic biology technologies to accelerate the development of new drugs. In recent years, synthetic biology programs have expanded to include complex metabolic engineering for the production of novel materials and therapeutic molecules. 
“The ability to leverage the laboratory’s deep technical expertise to solve today’s challenges has long laid the foundation for the new division,” says Christina Rudzinski, who is an assistant head of the division and formerly led the Counter-Weapons of Mass Destruction Systems Group.
In recent years, the laboratory has also been growing its work for improving the health and performance of service members, veterans, and civilians. Laboratory researchers have applied decades of expertise in human language technology to understand disorders and injuries of the brain. Other programs have used physiological signals captured with wearable devices to detect heat strain, injury, and infection. The laboratory’s AI and robotics expertise has been leveraged to create prototypes of semi-autonomous medical interventions to help medics save lives on the battlefield and in disaster environments.
The laboratory’s transition to disaster response technology extends over the past decade. Its rich history developing sensors and decision-support software translated well to the area of emergency response, leading to the development in 2010 of an emergency communications platform now in use worldwide, and the deployment of its advanced laser detection and ranging imaging system to quickly assess earthquake damage in Haiti. In 2015, the HADR Systems Group was established to build on this work.
Today, the group develops novel sensors, communication tools, and decision-support systems to aid national and global responses to disasters and humanitarian crises. Last year, the group launched its climate change initiative to develop new programs to monitor, predict, and address current and future climate change impacts.
Through these initiatives, the laboratory has come to view its work not only in the context of national security, but also global security.
“Pandemics and climate change can cause instability, and that instability can breed conflict,” says Wack. “It benefits the United States to have a stable world. To the degree that we can, mitigating future pandemics and reducing the impacts of climate change would improve global stability and national security.”
In anticipation of the growing importance of these global security issues, the laboratory has been significantly increasing program development, strategic hiring, and investment in biotechnology and human systems research over the past few years. Now, that strategic planning and investment in biotechnology research has come to fruition.
One of the division’s initial goals is to continue to build relationships with MIT partners, including the Department of Biological Engineering, the Institute for Medical Engineering and Science, and the McGovern Institute for Brain Research, as well as Harvard University and local hospitals such as Massachusetts General Hospital. These collaborators have helped bring the laboratory’s sensor technology and algorithms to clinical applications for Covid-19 diagnostics, lung and liver disorders, bone injury, and spinal surgical tools. “We can have a bigger impact by drawing on some of the great expertise on campus and in our Boston medical ecosystem,” says Wack. 
Another goal is to lead the nation in research surrounding the intersection of AI and biology. This research includes developing advanced AI algorithms for analyzing multimodal biological data, prototyping intelligent autonomous systems, and making AI-enabled biotechnology that is ethical and transparent.
“Because of our extensive experience supporting the DoD, the laboratory is in a unique position to translate this cutting-edge research, including that from the commercial sector, into a government and national security context,” says Bill Streilein, principal staff in the Biotechnology and Human System Division. “This means not only addressing typical AI application issues of data collection and curation, model selection and training, and human-machine teaming, but also issues related to traceability, explainability, and fairness.”
Leadership also sees this new division as an opportunity to continue to shape an innovative, diverse, and inclusive culture at the laboratory. They will be emphasizing the importance of an interdisciplinary approach to solving the complex research challenges the division faces. 
“We want help from the rest of the laboratory,” says Jeffrey Palmer, an assistant head of the division who previously led the Human Health and Performance Systems Group. “I think there are many ways that we can help other divisions in their missions, and we absolutely need them for success in ours. These challenges are too big to face without applying the combined capabilities of the entire laboratory.”
The Biotechnology and Human Systems Division joins Lincoln Laboratory’s eight other divisions: Advanced Technology; Air, Missile, and Maritime Defense Technology; Communication Systems; Cyber Security and Information Sciences; Engineering; Homeland Protection and Air Traffic Control; ISR and Tactical Systems; and Space Systems and Technology. Lincoln Laboratory is a federally funded research and development center. More

Thanh Nguyen is in the habit of breaking down barriers. Take languages, for instance: Nguyen, a third-year doctoral candidate in nuclear science and engineering (NSE), wanted “to connect with other people and cultures” for his work and social life, he says, so he learned Vietnamese, French, German, and Russian, and is now taking an MIT course in Mandarin. But this drive to push past obstacles really comes to the fore in his research, where Nguyen is trying to crack the secrets of a new and burgeoning branch of physics.
“My dissertation focuses on neutron scattering on topological semimetals, which were only experimentally discovered in 2015,” he says. “They have very special properties, but because they are so novel, there’s a lot that’s unknown, and neutrons offer a unique perspective to probe their properties at a new level of clarity.”
Topological materials don’t fit neatly into conventional categories of substances found in everyday life. They were first materialized in the 1980s, but only became practical in the mid-2000s with deepened understanding of topology, which concerns itself with geometric objects whose properties remain the same even when the objects undergo extreme deformation. Researchers experimentally discovered topological materials even more recently, using the tools of quantum physics.
Within this domain, topological semimetals, which share qualities of both metals and semiconductors, are of special interest to Nguyen. “They offer high levels of thermal and electric conductivity, and inherent robustness, which makes them very promising for applications in microelectronics, energy conversions, and quantum computing,” he says.
Intrigued by the possibilities that might emerge from such “unconventional physics,” Nguyen is pursuing two related but distinct areas of research: “On the one hand, I’m trying to identify and then synthesize new, robust topological semimetals, and on the other, I want to detect fundamental new physics with neutrons and further design new devices.”
On a fast research track
Reaching these goals over the next few years might seem a tall order. But at MIT, Nguyen has seized every opportunity to master the specialized techniques required for conducting large-scale experiments with topological materials, and getting results. Guided by his advisor, Mingda Li, the Norman C Rasmussen Assistant Professor and director of the Quantum Matter Group within NSE, Nguyen was able to dive into significant research even before he set foot on campus.
“The summer, before I joined the group, Mingda sent me on a trip to Argonne National Laboratory for a very fun experiment that used synchrotron X-ray scattering to characterize topological materials,” recalls Nguyen. “Learning the techniques got me fascinated in the field, and I started to see my future.”
During his first two years of graduate school, he participated in four studies, serving as a lead author in three journal papers. In one notable project, described earlier this year in Physical Review Letters, Nguyen and fellow Quantum Matter Group researchers demonstrated, through experiments conducted at three national laboratories, unexpected phenomena involving the way electrons move through a topological semimetal, tantalum phosphide (TaP).
“These materials inherently withstand perturbations such as heat and disorders, and can conduct electricity with a level of robustness,” says Nguyen. “With robust properties like this, certain materials can conductivity electricity better than best metals, and in some circumstances superconductors — which is an improvement over current generation materials.”
This discovery opens the door to topological quantum computing. Current quantum computing systems, where the elemental units of calculation are qubits that perform superfast calculations, require superconducting materials that only function in extremely cold conditions. Fluctuations in heat can throw one of these systems out of whack.
“The properties inherent to materials such as TaP could form the basis of future qubits,” says Nguyen. He envisions synthesizing TaP and other topological semimetals — a process involving the delicate cultivation of these crystalline structures — and then characterizing their structural and excitational properties with the help of neutron and X-ray beam technology, which probe these materials at the atomic level. This would enable him to identify and deploy the right materials for specific applications.
“My goal is to create programmable artificial structured topological materials, which can directly be applied as a quantum computer,” says Nguyen. “With infinitely better heat management, these quantum computing systems and devices could prove to be incredibly energy efficient.”
Physics for the environment
Energy efficiency and its benefits have long concerned Nguyen. A native of Montreal, Quebec, with an aptitude for math and physics and a concern for climate change, he devoted his final year of high school to environmental studies. “I worked on a Montreal initiative to reduce heat islands in the city by creating more urban parks,” he says. “Climate change mattered to me, and I wanted to make an impact.”
At McGill University, he majored in physics. “I became fascinated by problems in the field, but I also felt I could eventually apply what I learned to fulfill my goals of protecting the environment,” he says.
In both classes and research, Nguyen immersed himself in different domains of physics. He worked for two years in a high-energy physics lab making detectors for neutrinos, part of a much larger collaboration seeking to verify the Standard Model. In the fall of his senior year at McGill, Nguyen’s interest gravitated toward condensed matter studies. “I really enjoyed the interplay between physics and chemistry in this area, and especially liked exploring questions in superconductivity, which seemed to have many important applications,” he says. That spring, seeking to add useful skills to his research repertoire, he worked at Ontario’s Chalk River Laboratories, where he learned to characterize materials using neutron spectroscopes and other tools.
These academic and practical experiences served to propel Nguyen toward his current course of graduate study. “Mingda Li proposed an interesting research plan, and although I didn’t know much about topological materials, I knew they had recently been discovered, and I was excited to enter the field,” he says.
Man with a plan
Nguyen has mapped out the remaining years of his doctoral program, and they will prove demanding. “Topological semimetals are difficult to work with,” he says. “We don’t yet know the optimal conditions for synthesizing them, and we need to make these crystals, which are micrometers in scale, in quantities large enough to permit testing.” 
With the right materials in hand, he hopes to develop “a qubit structure that isn’t so vulnerable to perturbations, quickly advancing the field of quantum computing so that calculations that now take years might require just minutes or seconds,” he says. “Vastly higher computational speeds could have enormous impacts on problems like climate, or health, or finance that have important ramifications for society.” If his research on topological materials “benefits the planet or improves how people live,” says Nguyen, “I would be totally happy.” More

To stave off the worst immediate outcomes of climate change, the U.S. needs to reach net zero carbon emissions by 2050, according to a report released this June by the U.S. House Select Committee on the Climate Crisis.
In the final event in MIT’s Climate Action Symposia series, held Nov. 16, a panel of policymakers agreed the 2050 deadline means that the time for small-scale climate solutions has passed. Swift and massive investment by the U.S. federal government is essential, they said, beginning with the incoming Biden administration.
Rep. Kathy Castor of Florida said previous climate legislation has stalled in the face of climate change deniers in Congress and the influence of entrenched interests such as fossil fuel companies. Castor is the chair of the House Select Committee on Climate Crisis. She called its report a roadmap for how the U.S. can decarbonize the power and transportation sectors of the economy, among other recommendations.
The Biden administration climate change plan, which includes many of the same elements as the House report, would cost $2 trillion, Castor noted, likening it to past massive federal efforts such as building the interstate highway system or mobilizing the country for World War II.
To reach the 2050 emissions goal, “it’s all hands on deck,” she said. “We don’t have any more time to waste to take small measures. We have to take the larger steps to make progress.”
Investments toward the 2050 goal also can help rebuild an economy that has been devastated by the Covid-19 pandemic, said John Podesta, chair and counselor at the Center for American Progress. The Biden plan and the House report emphasize new job and industry creation through zero-emission vehicle manufacture, new power transmission systems for clean energy, and new low-carbon construction.
“It’s a shift of thinking from where we were a decade ago,” said Podesta, who served as a counselor to the president on climate and environmental policy in the Obama administration. “It really calls for these major investments sustained by the federal government but deployed by the private sector and by state and local government.”
The Biden plan also includes a goal for 40 percent of all clean energy and infrastructure benefits contained in the plan to go disadvantaged communities, he noted, “to build back a more just and equitable economy.”
The past four years have weakened global trust in the U.S. when it comes addressing climate change, said Todd Stern, a nonresident senior fellow at The Brookings Institution.
“Countries are not going to look at us in just the same way, but I will say this: I think countries are going to be very eager to have the U.S. back,” said Stern, who led the U.S. effort in negotiating the Paris climate agreement. “Somewhat wary, for understandable reasons, but eager.”
Along with rejoining the Paris agreement, the U.S must make climate change a “core part” of its national security and diplomatic strategy, said Stern. As a start, the U.S. should renew its partnerships with the European Union’s climate leaders and attempt to repair a deteriorated relationship with China to prod it to speed up its own zero carbon goals.
In a lively discussion moderated by MIT’s John Deutch, Institute Professor Emeritus, and Paul Joskow, Elizabeth and James Killian Professor of Economics Emeritus, the panelists argued over whether decarbonization by 2050 was more aspirational than realistic. Faced with the prospect of the collapse of water and food systems, climate refugees, and failed states, “I don’t ask myself it it’s realistic,” Podesta said. “I ask myself is it critical or necessary, and the answer to that is yes.”
MIT President L. Rafael Reif, speaking at the symposium’s start, said the pandemic has many thinking about similarly about the imminent climate challenge.
“This tragic, natural crisis has demonstrated that as individuals and as a society, we can actually change, more and faster than we have believed possible,” he said. “It has also made clear that refusing to change can be catastrophic, and that nature does not respond to wishful thinking.” More

When MIT students walk into the Johnson Athletic Center for fall career fair — or this year, hop onto Zoom — they’re greeted with flashy displays from hundreds of employers vying for some of the top tech and engineering students in the world. Company reps eagerly tell them about salaries, office perks, and opportunities to contribute to cutting-edge work.
Now, thanks to a tool developed by MIT’s Environmental Solutions Initiative (ESI), students can also learn how environmentally responsible their prospective employers are.
Sarah Meyers, ESI’s education program manager, says ESI had heard from students interested in sustainability that the career fair gave them the impression they would have few employment options in that field.
“Even those big companies with sustainability divisions don’t highlight the work they do,” says Meyers. “It’s just not part of the norm.”
Students sometimes say they feel “lured into” lucrative fields like computer science, even if that’s not what they wanted to do, she says. “For years now, we have known that MIT students are interested in working for companies that take environmental challenges seriously,” adds ESI Director John E. Fernández.
So Fernández asked Meyers to explore the development of a resource for the career fair to enable students to find meaningful positions at companies that prioritize sustainability.
Meyers thought a starting point could be rating whether or not companies were environmentally minded using environmental social governance (ESG) ratings. Companies that had high ESG scores would get a green leaf next to their name in career fair handouts.
Sounds easy enough, but the results were puzzling. Exxon Mobil got a green leaf, while the Massachusetts Department of Environmental Protection did not. Meyers wondered whether this was because larger companies have the resources to hire teams to focus on ESG ratings.
To learn more about what was going on, the ESI team turned to Roberto Rigobon, a professor of applied economics at the MIT Sloan School of Management who had recently authored a paper on issues with ESG ratings. While credit ratings from Moody’s and Standard & Poor correlate at .92 out of 1, meaning the same company would receive a similar score from different agencies, ESG ratings from five of the main agencies only correlate at .54.
Rigobon and his team found that there is too much variety in what categories are included in different ESG ratings and in how those categories are measured for them to be of much use to investors — or MIT students.
“I think that more transparency would be helpful, and more asking the investors (what they value) would be helpful,” Rigobon says.
He advised the ESI team to use emissions data to do their own analysis of the companies coming to career fair. 
Building the database
This summer, computer science, economics, and data science major Christopher Noga set out to do that by finding emissions and financial information from companies that had registered in past years for the career fair. This, too, would prove to be easier said than done.
Noga combed through company websites, financial statements, and reports made to the Carbon Disclosure Project, a nonprofit that encourages companies to report their environmental impacts. But he could only find emissions data for about a third of the companies, and many private companies did not have publicly available financial statements.
Some companies “really do hide what they do, how much they emit, and, in some cases, how much money they’re making and where they’re making it,” Noga says.
For the companies that had data, the ESI team divided total emissions by operating costs to measure each company’s “emissions intensity,” working with MIT Sloan to include historical data from 2011 on. This measurement allows students to better compare companies of different sizes, and see changes in emissions as companies grow, rather than just looking at total emissions.
Mining, fossil fuel, and manufacturing companies have the highest emissions intensity scores, while technology, health care, and government agencies have the lowest scores.
Meyers and Noga both emphasized limitations with the data, noting that they were struck by how little you know about a company just from looking at their emissions and financial statements. For example, the emissions intensity for Salesforce has been going up as they’ve grown, but the company also has plans to purchase 100% renewable electricity by 2022.
Surveying companies about their stance on climate change
To better get at the story behind the data, ESI worked with Oxford University to develop a four-question survey for the 238 companies who signed up for career fair. The answers were revealing: for instance, only 8 percent of companies surveyed have a plan to get to net-zero emissions. Most strikingly, only 60 percent said they recognize the climate crisis and agree with climate science.
“That shocked me, that it wasn’t just an easy ‘yes’,” Meyers says. She adds that this might just reflect that the employees who filled out the surveys were unaware of their company’s stance on these issues, as many responded with “I don’t know” rather than an outright no. Even so, this is a useful result, signaling to these companies that MIT is interested in their stance on climate change and that they should have an answer prepared in future years.
ESI also put together a list of questions for students to ask companies to learn more about their environmental and social responsibility practices.
“It seems like a real opportunity for students to become more engaged with the career fair and realize that they’re able to ask questions of companies that they might have been intimidated to ask,” Meyers says.
All this work resulted in the MIT Career Fair Sustainability Initiative website, which students can visit to compare company emissions, and learn how to engage with potential employers about their environmental commitments.
Fernández, director of ESI, says that one of the main goals of this project is to communicate to students that they are an “enormously valuable asset” to employers.
“Companies want MIT students as employees,” says Fernández. “Therefore, our students are in a position to influence a company’s policies toward climate mitigation and their overall approach to sustainability. The career fair is the ideal venue through which MIT students can begin to express their values and interests to industry.”
So far, 359 people have visited the new site. Vivian Song ’20, who worked with ESI to create the site, was surprised to learn that MIT was one of the only universities putting out this type of information about companies that come to career fair.
“I think it would be great if MIT could help lead the way to encourage other universities to do something similar,” she says. More

“Global issues can only be solved with international collaboration and innovative ideas,” states Professor Maggie Dallman, vice president (international) at Imperial College London. “The MIT-Imperial College London Seed Fund provides a platform for scientists to do that.” The fund, managed by MIT International Science and Technology Initiatives (MISTI) on behalf of the associate provost for international activities, builds on an existing partnership, with an exciting new focus.
This year, the fund is calling on researchers at each institution to submit proposals that address climate solutions and zero pollution. The new theme reflects research priorities already underway at each institution, with Imperial’s Zero Pollution initiative seeking to create a future free from human pollution, and MIT’s Climate Grand Challenges focusing the research community’s efforts on breakthroughs in climate mitigation and adaptation.
“This seed fund marks an exciting new chapter in our collaboration with MIT and will enable our scientists to work more closely together to reduce the impact of pollution on the climate and people’s health,” Dallman says.
“The new focus of the MIT-Imperial seed fund on climate change and environmental sustainability reflects research priorities at both institutions,” says Associate Provost for International Activities and Japan Steel Industry Professor Richard Lester, who drives the fund at MIT. “The world’s leading research universities have a special responsibility to develop science-based solutions to these great challenges, and by working together on these problems, MIT and Imperial can reasonably hope to strengthen their combined impact.”
The UK has emerged as a leader in international efforts to tackle the climate crisis, and faculty at MIT are encouraged that this seed fund will provide more opportunity for experts at both institutions to collaborate on innovative solutions to meet the defining challenge of our age. “The UK was the first major economy to pass binding legislation to meet the ‘net zero’ commitment by 2050,” says MIT Sloan School of Management Professor Fiona Murray, a member of the UK Prime Minister’s Council for Science and Technology (CST) and also co-director of the MIT-UK program at MISTI. “Achieving that goal will require major advances in science, technology, and business practices: To that end, this year’s focus of the MIT-Imperial seed fund to bring their faculty and researchers together is a welcome contribution.”
“The fund’s new focus on climate change is fundamentally important,” agrees Phil Budden, senior lecturer at MIT Sloan and co-director of the MIT-UK program. “Not least as the UK will host the UN’s 26th ‘Conference of the Parties’ (COP26) in Glasgow, in November next year. Collaborations over this academic year — like those seeded by the MIT-Imperial fund — could help shape the way the world comes together at ‘COP26’ for the first ‘global stock-take’ since Paris in 2015, and beyond.”
Professor Mary Ryan, vice dean (research) of the faculty of engineering, and lead of Imperial’s Transition to Zero Pollution program, is also enthusiastic about the possibilities. “If we are to find meaningful solutions to climate change and build a sustainable future, we need to think about how to address pollution at its source and understand the impact of it in the whole life cycle,” says Ryan. “This seed fund will accelerate research in areas such as the way materials are used in manufacturing, how we produce food and energy, and ways to mitigate the impact of air pollution on people’s health.”
Since its launch in 2015, the MIT-Imperial Seed Fund has financed 15 early-stage projects, disbursing over $250,000 to support collaboration between MIT and Imperial faculty. The seed fund is part of a portfolio of collaborations between MIT and Imperial that are managed by the MIT-UK program at MISTI.
Other collaboration areas continue to strengthen links between students and faculty across the Atlantic, despite the pandemic. This summer’s undergraduate research exchange evolved into a virtual experience, with students in materials sciences connecting remotely with faculty at their partner institution to collaborate on Undergraduate Research Opportunity Program-style projects. Meanwhile, this year’s academic exchange has seen MIT (virtually) welcome five Imperial students this fall.
MIT electrical engineering and computer science senior Sharon Lin, who spent fall 2019 at Imperial as part of the academic exchange, is keen to point out the benefits of studying abroad at another world-class institution. “I had a transformative semester at Imperial College London. I was so inspired by the professors and students I met, who were all working on technical challenges with global impact. The breadth of opportunities for students — from hands-on work at Imperial’s cutting-edge lab spaces to travel opportunities throughout Europe — was incredible.”
The MIT-Imperial College London Seed Fund is a part of MISTI Global Seed Funds (GSF). The call for proposals is open through Dec. 14. All general GSF criteria, application, and evaluation procedures apply. More

GPS isn’t waterproof. The navigation system depends on radio waves, which break down rapidly in liquids, including seawater. To track undersea objects like drones or whales, researchers rely on acoustic signaling. But devices that generate and send sound usually require batteries — bulky, short-lived batteries that need regular changing. Could we do without them?
MIT researchers think so. They’ve built a battery-free pinpointing system dubbed Underwater Backscatter Localization (UBL). Rather than emitting its own acoustic signals, UBL reflects modulated signals from its environment. That provides researchers with positioning information, at net-zero energy. Though the technology is still developing, UBL could someday become a key tool for marine conservationists, climate scientists, and the U.S. Navy.
These advances are described in a paper being presented this week at the Association for Computing Machinery’s Hot Topics in Networks workshop, by members of the Media Lab’s Signal Kinetics group. Research Scientist Reza Ghaffarivardavagh led the paper, along with co-authors Sayed Saad Afzal, Osvy Rodriguez, and Fadel Adib, who leads the group and is the Doherty Chair of Ocean Utilization as well as an associate professor in the MIT Media Lab and the MIT Department of Electrical Engineering and Computer Science.
“Power-hungry”
It’s nearly impossible to escape GPS’ grasp on modern life. The technology, which relies on satellite-transmitted radio signals, is used in shipping, navigation, targeted advertising, and more. Since its introduction in the 1970s and ’80s, GPS has changed the world. But it hasn’t changed the ocean. If you had to hide from GPS, your best bet would be underwater.
Because radio waves quickly deteriorate as they move through water, subsea communications often depend on acoustic signals instead. Sound waves travel faster and further underwater than through air, making them an efficient way to send data. But there’s a drawback.
“Sound is power-hungry,” says Adib. For tracking devices that produce acoustic signals, “their batteries can drain very quickly.” That makes it hard to precisely track objects or animals for a long time-span — changing a battery is no simple task when it’s attached to a migrating whale. So, the team sought a battery-free way to use sound.
Good vibrations
Adib’s group turned to a unique resource they’d previously used for low-power acoustic signaling: piezoelectric materials. These materials generate their own electric charge in response to mechanical stress, like getting pinged by vibrating soundwaves. Piezoelectric sensors can then use that charge to selectively reflect some soundwaves back into their environment. A receiver translates that sequence of reflections, called backscatter, into a pattern of 1s (for soundwaves reflected) and 0s (for soundwaves not reflected). The resulting binary code can carry information about ocean temperature or salinity.
In principle, the same technology could provide location information. An observation unit could emit a soundwave, then clock how long it takes that soundwave to reflect off the piezoelectric sensor and return to the observation unit. The elapsed time could be used to calculate the distance between the observer and the piezoelectric sensor. But in practice, timing such backscatter is complicated, because the ocean can be an echo chamber.
The sound waves don’t just travel directly between the observation unit and sensor. They also careen between the surface and seabed, returning to the unit at different times. “You start running into all of these reflections,” says Adib. “That makes it complicated to compute the location.” Accounting for reflections is an even greater challenge in shallow water — the short distance between seabed and surface means the confounding rebound signals are stronger.
The researchers overcame the reflection issue with “frequency hopping.” Rather than sending acoustic signals at a single frequency, the observation unit sends a sequence of signals across a range of frequencies. Each frequency has a different wavelength, so the reflected sound waves return to the observation unit at different phases. By combining information about timing and phase, the observer can pinpoint the distance to the tracking device. Frequency hopping was successful in the researchers’ deep-water simulations, but they needed an additional safeguard to cut through the reverberating noise of shallow water.
Where echoes run rampant between the surface and seabed, the researchers had to slow the flow of information. They reduced the bitrate, essentially waiting longer between each signal sent out by the observation unit. That allowed the echoes of each bit to die down before potentially interfering with the next bit. Whereas a bitrate of 2,000 bits/second sufficed in simulations of deep water, the researchers had to dial it down to 100 bits/second in shallow water to obtain a clear signal reflection from the tracker. But a slow bitrate didn’t solve everything.
To track moving objects, the researchers actually had to boost the bitrate. One thousand bits/second was too slow to pinpoint a simulated object moving through deep water at 30 centimeters/second. “By the time you get enough information to localize the object, it has already moved from its position,” explains Afzal. At a speedy 10,000 bits/second, they were able to track the object through deep water.
Efficient exploration
Adib’s team is working to improve the UBL technology, in part by solving challenges like the conflict between low bitrate required in shallow water and the high bitrate needed to track movement. They’re working out the kinks through tests in the Charles River. “We did most of the experiments last winter,” says Rodriguez. That included some days with ice on the river. “It was not very pleasant.”
Conditions aside, the tests provided a proof-of-concept in a challenging shallow-water environment. UBL estimated the distance between a transmitter and backscatter node at various distances up to nearly half a meter. The team is working to increase UBL’s range in the field, and they hope to test the system with their collaborators at the Wood Hole Oceanographic Institution on Cape Cod.
They hope UBL can help fuel a boom in ocean exploration. Ghaffarivardavagh notes that scientists have better maps of the moon’s surface than of the ocean floor. “Why can’t we send out unmanned underwater vehicles on a mission to explore the ocean? The answer is: We will lose them,” he says.
UBL could one day help autonomous vehicles stay found underwater, without spending precious battery power. The technology could also help subsea robots work more precisely, and provide information about climate change impacts in the ocean. “There are so many applications,” says Adib. “We’re hoping to understand the ocean at scale. It’s a long-term vision, but that’s what we’re working toward and what we’re excited about.”
This work was supported, in part, by the Office of Naval Research. More