MIT Latest News
Safer skies with self-flying helicopters
In late 2019, after years of studying aviation and aerospace engineering, Hector (Haofeng) Xu decided to learn to fly helicopters. At the time, he was pursuing his PhD in MIT’s Department of Aeronautics and Astronautics, so he was familiar with the risks associated with flying small aircraft. But something about being in the cockpit gave Xu a greater appreciation of those risks. After a couple of nerve-wracking experiences, he was inspired to make helicopter flight safer.
In 2021, he founded the autonomous helicopter company Rotor Technologies, Inc.
It turns out Xu’s near-misses weren’t all that unique. Although large, commercial passenger planes are extremely safe, people die every year in small, private aircraft in the U.S. Many of those fatalities occur during helicopter flights for activities like crop dusting, fighting fires, and medical evacuations.
Rotor is retrofitting existing helicopters with a suite of sensors and software to remove the pilot from some of the most dangerous flights and expand use cases for aviation more broadly.
“People don’t realize pilots are risking their lives every day in the U.S.,” Xu explains. “Pilots fly into wires, get disoriented in inclement weather, or otherwise lose control, and almost all of these accidents can be prevented with automation. We’re starting by targeting the most dangerous missions.”
Rotor’s autonomous machines are able to fly faster and longer and carry heavier payloads than battery powered drones, and by working with a reliable helicopter model that has been around for decades, the company has been able to commercialize quickly. Rotor’s autonomous aircraft are already taking to the skies around its Nashua, New Hampshire, headquarters for demo flights, and customers will be able to purchase them later this year.
“A lot of other companies are trying to build new vehicles with lots of new technologies around things like materials and power trains,” says Ben Frank ’14, Rotor’s chief commercial officer. “They’re trying to do everything. We’re really focused on autonomy. That’s what we specialize in and what we think will bring the biggest step-change to make vertical flight much safer and more accessible.”
Building a team at MIT
As an undergraduate at Cambridge University, Xu participated in the Cambridge-MIT Exchange Program (CME). His year at MIT apparently went well — after graduating Cambridge, he spent the next eight years at the Institute, first as a PhD student, then a postdoc, and finally as a research affiliate in MIT’s Department of Aeronautics and Astronautics (AeroAstro), a position he still holds today. During the CME program and his postdoc, Xu was advised by Professor Steven Barrett, who is now the head of AeroAstro. Xu says Barrett has played an important role in guiding him throughout his career.
“Rotor’s technology didn’t spin out of MIT’s labs, but MIT really shaped my vision for technology and the future of aviation,” Xu says.
Xu’s first hire was Rotor Chief Technology Officer Yiou He SM ’14, PhD ’20, whom Xu worked with during his PhD. The decision was a sign of things to come: The number of MIT affiliates at the 50-person company is now in the double digits.
“The core tech team early on was a bunch of MIT PhDs, and they’re some of the best engineers I’ve ever worked with,” Xu says. “They’re just really smart and during grad school they had built some really fantastic things at MIT. That’s probably the most critical factor to our success.”
To help get Rotor off the ground, Xu worked with the MIT Venture Mentoring Service (VMS), MIT's Industrial Liaison Program (ILP), and the National Science Foundation’s New England Innovation Corps (I-Corps) program on campus.
A key early decision was to work with a well-known aircraft from the Robinson Helicopter Company rather than building an aircraft from scratch. Robinson already requires its helicopters to be overhauled after about 2,000 hours of flight time, and that’s when Rotor jumps in.
The core of Rotor’s solution is what’s known as a “fly by wire” system — a set of computers and motors that interact with the helicopter’s flight control features. Rotor also equips the helicopters with a suite of advanced communication tools and sensors, many of which were adapted from the autonomous vehicle industry.
“We believe in a long-term future where there are no longer pilots in the cockpit, so we’re building for this remote pilot paradigm,” Xu says. “It means we have to build robust autonomous systems on board, but it also means that we need to build communication systems between the aircraft and the ground.”
Rotor is able to leverage Robinson’s existing supply chain, and potential customers are comfortable with an aircraft they’ve worked with before — even if no one is sitting in the pilot seat. Once Rotor’s helicopters are in the air, the startup offers 24/7 monitoring of flights with a cloud-based human supervision system the company calls Cloudpilot. The company is starting with flights in remote areas to avoid risk of human injury.
“We have a very careful approach to automation, but we also retain a highly skilled human expert in the loop,” Xu says. “We get the best of the autonomous systems, which are very reliable, and the best of humans, who are really great at decision-making and dealing with unexpected scenarios.”
Autonomous helicopters take off
Using small aircraft to do things like fight fires and deliver cargo to offshore sites is not only dangerous, it’s also inefficient. There are restrictions on how long pilots can fly, and they can’t fly during adverse weather or at night.
Most autonomous options today are limited by small batteries and limited payload capacities. Rotor’s aircraft, named the R550X, can carry loads up to 1,212 pounds, travel more than 120 miles per hour, and be equipped with auxiliary fuel tanks to stay in the air for hours at a time.
Some potential customers are interested in using the aircraft to extend flying times and increase safety, but others want to use the machines for entirely new kinds of applications.
“It is a new aircraft that can do things that other aircraft couldn’t — or maybe even if technically they could, they wouldn’t do with a pilot,” Xu says. “You could also think of new scientific missions enabled by this. I hope to leave it to people's imagination to figure out what they can do with this new tool.”
Rotor plans to sell a small handful of aircraft this year and scale production to produce 50 to 100 aircraft a year from there.
Meanwhile, in the much longer term, Xu hopes Rotor will play a role in getting him back into helicopters and, eventually, transporting humans.
“Today, our impact has a lot to do with safety, and we’re fixing some of the challenges that have stumped helicopter operators for decades,” Xu says. “But I think our biggest future impact will be changing our daily lives. I’m excited to be flying in safer, more autonomous, and more affordable vertical take-off and-landing aircraft, and I hope Rotor will be an important part of enabling that.”
Annie Liau: Infinite caring for the MIT community
Growing up in Thailand, Annie Srethabhakti Liau could not have imagined spending the bulk of her career working at the storied Massachusetts Institute of Technology. Now, as she heads into retirement, she and those around her are reflecting on her journey to Cambridge, Massachusetts, and on four decades as an integral member of the MIT community.
One of the longest-serving physicians at MIT Health, Liau is an obstetrician and gynecologist who managed the delivery of some 1,500 babies and oversaw an estimated 100,000 visits with patients during her tenure at the Institute. For her extraordinary work ethic and unsurpassed care for patients and colleagues alike, Liau has become a beloved figure at both MIT and at the affiliated hospitals she’s worked at for the past 39 years.
From Bangkok to Cambridge
Liau was born in Bangkok to Chinese parents, the eldest of six children. Her father was a physician who traveled the world for his training and practice, so Liau was exposed early on to the idea of caring for others as a vocation. Her parents strongly valued education for all their children and made that a priority, starting with young Annie. In school, her teachers encouraged her inclinations toward math and science, and her stellar grades earned her a place at Mahidol University, where she decided to follow in her father’s footsteps and pursue a career in medicine.
In the 1970s, when her mother opted to move the family to the U.S. to be closer to relatives already here, Liau, then a young adult, followed suit. She initially stayed in Thailand to complete her medical training at Mahidol. After passing a number of exams, Liau began her career in New England, at medical centers in Waltham and Brighton, Massachusetts, and Danbury, Connecticut. By this time, she had decided to specialize in obstetrics and gynecology. “I feel that it’s a miracle to be part of the beginning” of life, she says. “Continuing the journey with the patient to all the stages in life, it seemed to be very fulfilling.”
Before long, she saw a position listed in the New England Journal of Medicine for a full-time physician at what was then MIT Medical — now MIT Health. It was the mid 1980s, and MIT Health had recently moved into its current location in Building E23 from its previous headquarters in Building 11. Liau was excited about the opportunity to serve a changing Institute population — one in which women were an increasing percentage of the student and faculty bodies.
“I just love the feeling of caring and healing,” Liau says. “I always felt from the beginning that MIT Medical is MIT Health: It always embraces the wellness, immunizations, community support. It wasn’t just taking care of the sick. … We need to take care of the MIT population so that they are well and they can focus on their work, so they can actually achieve their goals.”
Infinite care
From the start, Liau’s services were in high demand. An MIT Tech Talk article from the early 1990s described a period in which “the queue to see her was extremely long.” At the time, MIT Health doctors oversaw the births of some 200 babies per year — a number that Liau says has since dropped by about two-thirds, largely mirroring a national trend in birth rate.
During her time at MIT, Liau held appointments at several Boston-area hospitals, where she helped Institute affiliates give birth at all hours of the day and night. In addition, she served as a part-time instructor with Harvard Medical School (HMS). She was also a preceptor for gynecology residents at Brigham and Women’s Hospital, and for medical students from HMS, the Harvard-MIT Program in Health Sciences and Technology, and Boston University. And she has served on numerous committees and professional societies, including as the past president of the Obstetrical Society of Boston.
Back on campus, Liau not only supported those expanding their families but also any community members in need of basic gynecological care.
“With our recent rebrand to MIT Health, we’ve been talking about ‘Infinite Caring’ as the underpinning of how we care for the people of MIT. To me, Dr. Liau is the epitome of Infinite Caring — and has been for 39 years,” says Cecilia Stuopis, MIT’s chief health officer and a fellow obstetrician/gynecologist. “She has cared for generations of women at MIT by being curious about their lives, their well-being, and their overall state of health. She is always learning and always teaching her patients and colleagues about what she has learned. Most importantly, she does all of these things with incomparable levels of kindness; kindness defines Dr. Liau in all aspects — professionally and personally.”
“Dr. Liau has been the foundation of our department,” says Chana Wasserman, chief of obstetrics and gynecology at MIT Health who has worked with Liau for over 26 years. “She is very personable and truly interested in people’s wellness. She always wants to learn from everyone and everything. She reads and retains everything she hears or learns. When professors, graduate students, or postdocs request her help with their research studies, she goes above and beyond to really try to help them. She has tremendous empathy for patients and colleagues alike.”
At a recent farewell event during which Liau had a chance to say goodbye to longtime patients, one attendee noted that while it’s unusual to look forward to gynecological appointments, she found that to be the case every time she went to see Liau.
“With Annie, it seems the construct of time is nonexistent and all that matters is that patient and their well-being,” says Nicole Napier, population health manager at MIT Health who worked closely with Liau for 18 years in her former role as the OB/GYN nurse practice manager. “She understands the true ‘health’ of a person is shaped by their personal relationships, diet, sleep, overall outlook on life, and many other factors. Her goal is to assess and advise on as many of these factors as possible to make you the best human being you can be. … Her ability to care knows no limits.”
Part of the family
In recognition of her remarkable service, Liau has over the years earned four MIT Health awards, including two Infinite Mile Awards, for clinical excellence and for lifetime contribution; the Commitment to Care Team Award; and the Patient Choice Award. She also regularly earned MIT Health’s highest Press Ganey scores, which measure patient satisfaction.
Colleagues and patients have expressed myriad ways in which Liau will be missed — from sharing findings from seminars she’d attend to constantly serving as a valued partner in health as well as a cherished friend.
Several colleagues mentioned Liau’s gifts of fruit — oranges and persimmons, especially — that would frequently appear on their desks. “I had always thought that Dr. Liau only gave me fruit since she knew I would never bring lunch to work,” says Wasserman. “At her retirement party at Mount Auburn [Hospital], though, one of the speakers asked the audience to raise their hand if they had ever received a piece of fruit from Dr. Liau. Almost the entire crowd raised their hands! This is just a small way that she made sure not only that I had something to eat, but that everyone she knew was kept healthy and well.”
“Every day she walks into the building, whether she’s scheduled to work or not, she cares about her patients and colleagues,” adds Eleashea Passley, a patient service representative at MIT Health who worked with Liau for 19 years. Liau was, according to Passley, “a social butterfly” who, in addition to fruit offerings, often delighted her team with lunch orders of comfort food to help keep spirits high.
In retirement, Liau is looking forward to quality time with family. She plans to help care for her mother, who is now 90 and looking to move back to Massachusetts following four years on the West Coast. She also aims to visit with her siblings, nieces, nephews, and their children around the country. And she hopes to get a bit more sleep and exercise, and to attend more lectures, services, and other events.
“I will miss the connection between me and my patients, and also the staff at MIT and at the hospital. I have been at MIT more than half of my life, so it’s really special. I feel like I grew up here,” says Liau. “I feel very moved and very thankful for the love and appreciation from my patients, and I’m grateful for their trust and for the support throughout the years. I feel like they’re part of my family. … I just help to navigate the care, like someone in the family, but I’m really grateful and thankful that they looked out for me, too.”
Miguel Zenón, assistant professor of jazz at MIT, wins Grammy Award
MIT Music and Theater Arts Assistant Professor Miguel Zenón has won a Grammy for Best Latin Jazz Album for his work on “El Arte Del Bolero Vol. 2.” Zenón recorded the album with Luis Perdomo, a follow-up to their critically-acclaimed “El Arte Del Bolero Vol. 1.”
“I’m incredibly happy and honored with this Grammy win,” says Zenón, a 12-time Grammy nominee. “We’ve been making albums for a long time, so it’s extremely rewarding to earn this recognition. This will certainly be an incentive to keep moving forward and creating more music.”
The album’s title references the beauty of the Latin-American Songbook and the Bolero in particular.
“The Latin-American Songbook is so vast and varied that it naturally lends itself to limitless explorations,” says Zenón in the album's liner notes. “We purposely looked beyond the Caribbean (exploring composers from México, Venezuela and Panamá, for example) because we wanted to emphasize the point that these songs deserved to be explored and recognized for what they are, beyond labels, categories, and regionalisms. Just beautiful music that is a joy to perform and listen to.”
Critics lauded the album, naming it the top Latin Jazz recording of 2023 in the Jazz Critics Poll.
"In an extraordinary follow-up to 'El Arte Del Bolero Vol. 1,' these timeless tunes are slowed down, blended with unusual elements, played out of time, deconstructed and reconstructed as Zenón and Perdomo extract nuances from the originals that we hardly imagined could exist,” said critic Catalina Maria Johnson.
Born and raised in San Juan, Puerto Rico, Zenón has recorded and toured with a wide variety of musicians including Charlie Haden, Fred Hersch, David Sánchez, Danilo Pérez, Kenny Werner, Bobby Hutcherson, and The SFJAZZ Collective.
A renowned saxophonist, Zenón joined the MIT faculty in 2023 as an assistant professor of jazz. He is also the current visiting scholar for the Harmony and Jazz Composition Department at Berklee College of Music.
In 2008, Zenón received a fellowship from the prestigious John Simon Guggenheim Foundation. Also that year, he received the coveted MacArthur Fellowship, also known as the “genius grant.”
In 2011, Zenón founded Caravana Cultural, a program that presents free-of-charge Jazz concerts in rural areas of Puerto Rico. In 2022, he also received an honorary doctorate from La Universidad del Sagrado Corazón in San Juan, the highest honor bestowed by the institution.
MIT physicists capture the first sounds of heat “sloshing” in a superfluid
In most materials, heat prefers to scatter. If left alone, a hotspot will gradually fade as it warms its surroundings. But in rare states of matter, heat can behave as a wave, moving back and forth somewhat like a sound wave that bounces from one end of a room to the other. In fact, this wave-like heat is what physicists call “second sound.”
Signs of second sound have been observed in only a handful of materials. Now MIT physicists have captured direct images of second sound for the first time.
The new images reveal how heat can move like a wave, and “slosh” back and forth, even as a material’s physical matter may move in an entirely different way. The images capture the pure movement of heat, independent of a material’s particles.
“It’s as if you had a tank of water and made one half nearly boiling,” Assistant Professor Richard Fletcher offers as analogy. “If you then watched, the water itself might look totally calm, but suddenly the other side is hot, and then the other side is hot, and the heat goes back and forth, while the water looks totally still.”
Led by Martin Zwierlein, the Thomas A Frank Professor of Physics, the team visualized second sound in a superfluid — a special state of matter that is created when a cloud of atoms is cooled to extremely low temperatures, at which point the atoms begin to flow like a completely friction-free fluid. In this superfluid state, theorists have predicted that heat should also flow like a wave, though scientists had not been able to directly observe the phenomenon until now.
The new results, reported today in the journal Science, will help physicists get a more complete picture of how heat moves through superfluids and other related materials, including superconductors and neutron stars.
“There are strong connections between our puff of gas, which is a million times thinner than air, and the behavior of electrons in high-temperature superconductors, and even neutrons in ultradense neutron stars,” Zwierlein says. “Now we can probe pristinely the temperature response of our system, which teaches us about things that are very difficult to understand or even reach.”
Zwierlein and Fletcher’s co-authors on the study are first author and former physics graduate student Zhenjie Yan and former physics graduate students Parth Patel and Biswaroop Mikherjee, along with Chris Vale at Swinburne University of Technology in Melbourne, Australia. The MIT researchers are part of the MIT-Harvard Center for Ultracold Atoms (CUA).
Super sound
When clouds of atoms are brought down to temperatures close to absolute zero, they can transition into rare states of matter. Zwierlein’s group at MIT is exploring the exotic phenomena that emerge among ultracold atoms, and specifically fermions — particles, such as electrons, that normally avoid each other.
Under certain conditions, however, fermions can be made to strongly interact and pair up. In this coupled state, fermions can flow in unconventional ways. For their latest experiments, the team employs fermionic lithium-6 atoms, which are trapped and cooled to nanokelvin temperatures.
In 1938, the physicist László Tisza proposed a two-fluid model for superfluidity — that a superfluid is actually a mixture of some normal, viscous fluid and a friction-free superfluid. This mixture of two fluids should allow for two types of sound, ordinary density waves and peculiar temperature waves, which physicist Lev Landau later named “second sound.”
Since a fluid transitions into a superfluid at a certain critical, ultracold temperature, the MIT team reasoned that the two types of fluid should also transport heat differently: In normal fluids, heat should dissipate as usual, whereas in a superfluid, it could move as a wave, similarly to sound.
“Second sound is the hallmark of superfluidity, but in ultracold gases so far you could only see it in this faint reflection of the density ripples that go along with it,” Zwierlein says. “The character of the heat wave could not be proven before.”
Tuning in
Zwierlein and his team sought to isolate and observe second sound, the wave-like movement of heat, independent of the physical motion of fermions in their superfluid. They did so by developing a new method of thermography — a heat-mapping technique. In conventional materials one would use infrared sensors to image heat sources.
But at ultracold temperatures, gases do not give off infrared radiation. Instead, the team developed a method to use radio frequency to “see” how heat moves through the superfluid. They found that the lithium-6 fermions resonate at different radio frequencies depending on their temperature: When the cloud is at warmer temperatures, and carries more normal liquid, it resonates at a higher frequency. Regions in the cloud that are colder resonate at a lower frequency.
The researchers applied the higher resonant radio frequency, which prompted any normal, “hot” fermions in the liquid to ring in response. The researchers then were able to zero in on the resonating fermions and track them over time to create “movies” that revealed heat’s pure motion — a sloshing back and forth, similar to waves of sound.
“For the first time, we can take pictures of this substance as we cool it through the critical temperature of superfluidity, and directly see how it transitions from being a normal fluid, where heat equilibrates boringly, to a superfluid where heat sloshes back and forth,” Zwierlein says.
The experiments mark the first time that scientists have been able to directly image second sound, and the pure motion of heat in a superfluid quantum gas. The researchers plan to extend their work to more precisely map heat’s behavior in other ultracold gases. Then, they say their findings can be scaled up to predict how heat flows in other strongly interacting materials, such as in high-temperature superconductors, and in neutron stars.
“Now we will be able to measure precisely the thermal conductivity in these systems, and hope to understand and design better systems,” Zwierlein concludes.
This work was supported by the National Science Foundation (NSF), the Air Force Office of Scientific Research, and the Vannevar Bush Faculty Fellowship. The MIT team is part of the MIT-Harvard Center for Ultracold Atoms (an NSF Physics Frontier Center) and affiliated with the MIT Department of Physics and the Research Laboratory of Electronics (RLE).
Letter to the MIT community: Announcing the Climate Project at MIT
The following letter was sent to the MIT community today by President Sally Kornbluth.
Dear members of the MIT community,
At my inauguration, echoing a sentiment I heard everywhere on my campus listening tour, I called on the people of MIT to come together in new ways to marshal a bold, tenacious response to the run-away crisis of climate change.
I write with an update on how we’re bringing this vision to life.
This letter includes several significant announcements – including an accelerated search for faculty leaders and a very substantial commitment of MIT funds – so please read on.
A Record of MIT Leadership
Since the late Professor Jule Charney led a 1979 National Academy of Sciences report that foretold the likely risks of global warming, MIT researchers have made pioneering contributions in countless relevant fields. Today, more than 300 faculty, working with their students and research and teaching staff, are engaged in leading-edge work on climate issues. The Institute has also taken important steps to enhance climate education, expand public outreach on climate and decarbonize the campus.
But – as the community told me loud and clear – this moment demands a different order of speed, ambition, focus and scale.
The Climate Project at MIT
After extensive consultation with more than 150 faculty and senior researchers across the Institute – and building on the strengths of Fast Forward: MIT's Climate Action Plan for the Decade, issued in 2021 – Vice Provost Richard Lester has led us in framing a new approach: the Climate Project at MIT.
Representing a compelling new strategy for accelerated, university-led innovation, the Climate Project at MIT will focus our community’s talent and resources on solving critical climate problems with all possible speed – and will connect us with a range of partners to deliver those technological, behavioral and policy solutions to the world.
As Richard explains in this MIT News 3Q, the Climate Project at MIT is still in its early stages; as it gains new leaders and new allies from academia, industry, philanthropy and government, it will continue to be shaped by their insight and expertise.
For now, we begin with a new structure and strategy for organizing the work. The Climate Project at MIT will consist of three interlocking elements:
- The Climate Missions
- The Climate Frontier projects
- The Climate HQ
To learn more about these components, I encourage you to read this summary of the plan (PDF).
Recruiting Leaders for the Six Climate Missions
The central focus will be six Climate Missions – each constituting a cross-disciplinary Institute-wide problem-solving community focused on a strategic area of the climate challenge:
- Decarbonizing Energy and Industry
- Restoring the Atmosphere, Protecting the Land and Oceans
- Empowering Frontline Communities
- Building and Adapting Healthy, Resilient Cities
- Inventing New Policy Approaches
- Wild Cards
We’re now recruiting an MIT faculty leader for each of these missions – on an accelerated timeline. We welcome any interested faculty member to apply to be a Climate Mission leader or to nominate a colleague. Please submit your CV and statement of interest at climatesearch@mit.edu by February 22.
You can learn more about the role on the Climate Project’s preliminary webpage. All submissions will be treated as confidential.
A New Leadership Role, a Search Committee – and Significant MIT Resources
The Climate Project at MIT is gathering steam – and we will build its momentum with these three important steps.
1. Vice President for Climate
To match the prime importance of this work, we have created a new leadership role, reporting to me: Vice President for Climate (VPC). The VPC will oversee the Climate Project at MIT, take the lead on fundraising and implementation, and shape its strategic vision. We are opening the search now and welcome candidates from inside and outside MIT. You may submit your CV and statement of interest in the VPC role at climatesearch@mit.edu. A formal job description will be posted soon.
2. Climate Search Advisory Committee
To advise me in selecting the six mission leaders and the VPC, I have appointed the following faculty members to serve on the Climate Search Advisory Committee:
- Richard Lester, Chair
- Daron Acemoglu
- Yet-Ming Chiang
- Penny Chisholm
- Dava Newman
- Ron Rivest
- Susan Solomon
- John Sterman
- Larry Vale
- Rob van der Hilst
- Anne White
3. $75 million in support from the Institute and MIT Sloan
And finally: We will jumpstart the Climate Project at MIT with a commitment of $50 million in Institute resources – the largest direct investment the Institute has ever made in funding climate work, and just the beginning of a far more ambitious effort to raise the funds this extraordinary challenge demands. In addition, the Sloan School will contribute $25 million to endow a new climate policy center, to be formally announced in the coming days. Together, these funds will allow for early advances and express the seriousness of our intentions to potential partners around the world.
* * *
The Climate Project at MIT is ambitious, multifaceted and more complex than I could capture in a letter; I urge you to explore the summary of the plan (PDF) to see where you might fit. There will be a place for everyone, including all of our existing climate-involved DLCs. (And you might enjoy this brief video, which celebrates MIT’s distinctive gift for collaborative problem-solving on a grand scale.)
At last spring’s inauguration, I said I hoped that, a decade hence, all of us at MIT could take pride in having “helped lead a powerful cross-sector coalition and placed big bets on big solutions, to dramatically accelerate progress against climate change.”
With your creativity, support and drive, we have every reason to hope that the Climate Project at MIT can make that aspiration real.
With enthusiasm and anticipation,
Sally Kornbluth
3 Questions: The Climate Project at MIT
MIT is preparing a major campus-wide effort to develop technological, behavioral, and policy solutions to some of the toughest problems now impeding an effective global climate response. The Climate Project at MIT, as the new enterprise is known, includes new arrangements for promoting cross-Institute collaborations and new mechanisms for engaging with outside partners to speed the development and implementation of climate solutions.
MIT News spoke with Richard K. Lester, MIT’s vice provost for international activities, who has helped oversee the development of the project.
Q: What is the Climate Project at MIT?
A: In her inaugural address last May, President Kornbluth called on the MIT community to join her in a “bold, tenacious response” to climate change. The Climate Project at MIT is a response to that call. It aims to mobilize every part of MIT to develop, deliver, and scale up practical climate solutions, as quickly as possible.
At MIT, well over 300 of our faculty are already working with their students and research staff members on different aspects of the climate problem. Almost all of our academic departments and more than a score of our interdepartmental labs and centers are involved in some way. What they are doing is remarkable, and this decentralized structure reflects the best traditions of MIT as a “bottom up,” entrepreneurial institution. But, as President Kornbluth said, we must do much more. We must be bolder in our research choices and more creative in how we organize ourselves to work with each other and with our partners. The purpose of the Climate Project is to support our community’s efforts to do bigger things faster in the climate domain. We will have succeeded if our work changes the trajectory of global climate outcomes for the better.
I want to be clear that the clay is still wet here. The Climate Project will continue to take shape as more members of the MIT community bring their excellence, their energy, and their ambition to bear on the climate challenge. But I believe we have a vision and a framework for accelerating and amplifying MIT’s real-world climate impact, and I know that President Kornbluth is eager to share this progress report with the MIT community now to convey the breadth and ambition of what we’re planning.
Q: How will the project be organized?
A: The Climate Project will have three core components: the Climate Missions; their offshoots, the Climate Frontier Projects; and Climate HQ. A new vice president for climate will lead the enterprise.
Initially there will be six missions, which you can read about in the plan. Each will address a different domain of climate impact where new solutions are required and where a critical mass of research excellence exists at MIT. One such mission, of course, is to decarbonize energy and industry, an area where we estimate that about 150 of our faculty are already working.
The mission leaders will build multidisciplinary problem-solving communities reaching across the Institute and beyond. Each of these will be charged with roadmapping and assessing progress toward its mission, identifying critical gaps and bottlenecks, and launching applied research projects to accelerate progress where the MIT community and our partners are well-positioned to achieve impactful results. These projects — the climate frontier projects — will benefit from active, professional project management, with clear metrics and milestones. We are in a critical decade for responding to climate change, so it’s important that these research projects move quickly, with an eye on producing real-world results.
The new Climate HQ will drive the overall vision for the Climate Project and support the work of the missions. We’ve talked about a core focus on impact-driven research, but much is still unknown about the Earth’s physical and biogeochemical systems, and there is also much to be learned about the behavior of the social and political systems that led us to the very difficult situation the world now faces. Climate HQ will support fundamental research in the scientific and humanistic disciplines related to climate, and will promote engagement between these disciplines and the missions. We must also advance climate-related education, led by departments and programs, as well as policy work, public outreach, and more, including an MIT-wide student-centric Climate Corps to elevate climate-related, community-focused service in MIT’s culture.
Q: Why are partners a key part of this project?
A: It is important to build strong partners right from the very start for our innovations, inventions, and discoveries to have any prospect of achieving scale. And in many cases, with climate change, it’s all about scale.
One of the aims of this initiative is to strengthen MIT’s climate “scaffolding” — the people and processes connecting what we do on campus to the practical world of climate impact and response. We can build on MIT’s highly developed infrastructure for translation, innovation, and entrepreneurship, even as we promote other important pathways to scale involving communities, municipalities, and other not-for-profit organizations. Working with all these different organizations will help us build a broad infrastructure to help us get traction in the world. On a related note, the Sloan School of Management will be sharing details in the coming days of an exciting new effort to enhance MIT’s contributions in the climate policy arena.
MIT is committing $75 million, including $25 million from Sloan, at the outset of the project. But we anticipate developing new partnerships, including philanthropic partnerships, to increase that scope dramatically.
MIT students win national materials design competition
Two MIT undergrads recently took the top spot — and $2,000 in prize money to share — in the annual ASM Materials Education Foundation’s 2023 Undergraduate Design Competition. Louise Anderfaas and Darsh Grewal, students in Professor Gregory Olson’s class 3.041 (Computational Materials Design), worked with MIT postdoc mentor Margianna Tzini on the complex project.
“This is probably the highest level of complexity that an undergraduate team has undertaken,” says Olson, who came to MIT from Northwestern University in 2020. He has supervised teams in the contest at both schools. Last year MIT took third place for designing a 3D printable alloy for stamping out Tesla parts.
ASM Materials Education Foundation is the charitable division of materials engineering organization ASM International. It promotes applied science careers to students and teachers.
Super-strong and affordable
Anderfaas and Grewal’s winning project was about creating a super-strong aluminum plate, 10 centimeters thick, for use in applications like planes and cars. It was critical that the material be very tough, resisting things like stress corrosion and fractures. They made a video to explain their step-by-step process, using computer models and calculations to figure out the best combination of materials and design.
“For the material to be affordable and to be used in industrial applications, we used conventional processing roots,” Anderfaas says, referring to traditional manufacturing methods such as cutting and milling rather than more cutting-edge techniques, which offer improved performance and other benefits but are often more expensive. “But in order to be used in airplanes, we had to make a large-scale product.”
Anderfaas and partner Grewal, both seniors in the Department of Materials Science and Engineering (DMSE), had just three months to integrate all these properties and use computational tools to accelerate their design.
The ultra-high strength aluminum plate alloy satisfies real-life property requirements provided by the DSO National Laboratory in Singapore, which collaborated with MIT on the project. To develop a material that was strong and flexible and could withstand stress without corroding, the students used computational tools based on CALPHAD, a method for calculating the properties of materials, and incorporated density functional theory (DFT) data. DFT data provides insights into the electronic structure of the material, aiding in the optimization of its properties.
The team used multi-objective optimization, which was key in balancing the necessary variables. “When you try to design something, internally, there is always a cost. When you try to increase the strength, you’re losing something else,” recalls Grewal. Making something stronger might make it less flexible, for example. So instead of focusing on individual properties, “we treated the system as a whole.”
Anderfaas and Grewal cited the classic hierarchical approach to materials design that Olson teaches during his classes. “It goes in two ways, both the structure affects the properties, and the properties affect your structure,” says Grewal. “You have to understand this relationship.”
The challenge: There are lots of relationships to distinguish in a complex problem. “You have to distinguish which are the important parts, and how all these parts are related and connected to each other,” adds Grewal.
Anatomy of computational design
Olson’s class breaks new ground in a field he helped invent: the computational design of new materials. The class brings together core concepts from the MIT materials science curriculum — thermodynamics, kinetics, and mechanical properties, for instance — and teaches students how to design materials by developing an understanding of the process-structure-property-performance relationships that define material behavior. The class culminates with a final design project — the subject matter of the competition — in which student teams design a novel material that addresses current practical material challenges.
“I’ve devoted my research career to this technology and its commercialization,” says Olson, the Thermo-Calc Professor of the Practice for DMSE. Through his startup, QuesTek, the technology has been adopted by industry giants including Apple, SpaceX, and Tesla. “Those companies tend to be very interested in the students who take my class and typically offer internships and some permanent positions.”
The class is organized into team projects drawn from funded graduate research, so grad students and postdocs can serve as the coaches to the student teams, allowing them to go to a much higher technical level than would otherwise be possible, says Olson. Tzini guided the students with specific details about the project and helped them distinguish the different aspects and then connect them.
The databases the students used for the project are aligned with the Materials Genome Initiative, a U.S. government initiative aimed at accelerating the discovery and development of new materials. They include information on the properties, structures, and behaviors of a huge assortment of materials. The same way the human genome serves as a database that directs the assembly of structures of life, here the materials genome contains equally fundamental data that can be used to direct the assembly of a multiscale microstructure of a material that evolves throughout sequential stages of processing.
“So the databases are allowing us to take the mechanistic knowledge we have and apply it in a quantitative systems-specific way. The class really integrates the whole curriculum of the undergraduate materials program in those design projects,” Olson says. He’s proud to see students like Anderfaas and Grewal having success with the subject matter.
The students were surprised but pleased by their ASM competition win. “Grasping all of these concepts and balancing everything was difficult,” says Grewal. “This is definitely the hardest class I’ve taken, but also the most rewarding.”
Second prize in the competition went to Purdue University for improving the process of flattening forged aluminum components, and third prize went to Michigan Technological University for reducing the presence of boron impurities when making cast iron from recycled steel.
Technique could improve the sensitivity of quantum sensing devices
In quantum sensing, atomic-scale quantum systems are used to measure electromagnetic fields, as well as properties like rotation, acceleration, and distance, far more precisely than classical sensors can. The technology could enable devices that image the brain with unprecedented detail, for example, or air traffic control systems with precise positioning accuracy.
As many real-world quantum sensing devices are emerging, one promising direction is the use of microscopic defects inside diamonds to create “qubits” that can be used for quantum sensing. Qubits are the building blocks of quantum devices.
Researchers at MIT and elsewhere have developed a technique that enables them to identify and control a greater number of these microscopic defects. This could help them build a larger system of qubits that can perform quantum sensing with greater sensitivity.
Their method builds off a central defect inside a diamond, known as a nitrogen-vacancy (NV) center, which scientists can detect and excite using laser light and then control with microwave pulses. This new approach uses a specific protocol of microwave pulses to identify and extend that control to additional defects that can’t be seen with a laser, which are called dark spins.
The researchers seek to control larger numbers of dark spins by locating them through a network of connected spins. Starting from this central NV spin, the researchers build this chain by coupling the NV spin to a nearby dark spin, and then use this dark spin as a probe to find and control a more distant spin which can’t be sensed by the NV directly. The process can be repeated on these more distant spins to control longer chains.
“One lesson I learned from this work is that searching in the dark may be quite discouraging when you don’t see results, but we were able to take this risk. It is possible, with some courage, to search in places that people haven’t looked before and find potentially more advantageous qubits,” says Alex Ungar, a PhD student in electrical engineering and computer science and a member of the Quantum Engineering Group at MIT, who is lead author of a paper on this technique, which is published today in PRX Quantum.
His co-authors include his advisor and corresponding author, Paola Cappellaro, the Ford Professor of Engineering in the Department of Nuclear Science and Engineering and professor of physics; as well as Alexandre Cooper, a senior research scientist at the University of Waterloo’s Institute for Quantum Computing; and Won Kyu Calvin Sun, a former researcher in Cappellaro’s group who is now a postdoc at the University of Illinois at Urbana-Champaign.
Diamond defects
To create NV centers, scientists implant nitrogen into a sample of diamond.
But introducing nitrogen into the diamond creates other types of atomic defects in the surrounding environment. Some of these defects, including the NV center, can host what are known as electronic spins, which originate from the valence electrons around the site of the defect. Valence electrons are those in the outermost shell of an atom. A defect’s interaction with an external magnetic field can be used to form a qubit.
Researchers can harness these electronic spins from neighboring defects to create more qubits around a single NV center. This larger collection of qubits is known as a quantum register. Having a larger quantum register boosts the performance of a quantum sensor.
Some of these electronic spin defects are connected to the NV center through magnetic interaction. In past work, researchers used this interaction to identify and control nearby spins. However, this approach is limited because the NV center is only stable for a short amount of time, a principle called coherence. It can only be used to control the few spins that can be reached within this coherence limit.
In this new paper, the researchers use an electronic spin defect that is near the NV center as a probe to find and control an additional spin, creating a chain of three qubits.
They use a technique known as spin echo double resonance (SEDOR), which involves a series of microwave pulses that decouple an NV center from all electronic spins that are interacting with it. Then, they selectively apply another microwave pulse to pair the NV center with one nearby spin.
Unlike the NV, these neighboring dark spins can’t be excited, or polarized, with laser light. This polarization is a required step to control them with microwaves.
Once the researchers find and characterize a first-layer spin, they can transfer the NV’s polarization to this first-layer spin through the magnetic interaction by applying microwaves to both spins simultaneously. Then once the first-layer spin is polarized, they repeat the SEDOR process on the first-layer spin, using it as a probe to identify a second-layer spin that is interacting with it.
Controlling a chain of dark spins
This repeated SEDOR process allows the researchers to detect and characterize a new, distinct defect located outside the coherence limit of the NV center. To control this more distant spin, they carefully apply a specific series of microwave pulses that enable them to transfer the polarization from the NV center along the chain to this second-layer spin.
“This is setting the stage for building larger quantum registers to higher-layer spins or longer spin chains, and also showing that we can find these new defects that weren’t discovered before by scaling up this technique,” Ungar says.
To control a spin, the microwave pulses must be very close to the resonance frequency of that spin. Tiny drifts in the experimental setup, due to temperature or vibrations, can throw off the microwave pulses.
The researchers were able to optimize their protocol for sending precise microwave pulses, which enabled them to effectively identify and control second-layer spins, Ungar says.
“We are searching for something in the unknown, but at the same time, the environment might not be stable, so you don’t know if what you are finding is just noise. Once you start seeing promising things, you can put all your best effort in that one direction. But before you arrive there, it is a leap of faith,” Cappellaro says.
While they were able to effectively demonstrate a three-spin chain, the researchers estimate they could scale their method to a fifth layer using their current protocol, which could provide access to hundreds of potential qubits. With further optimization, they may be able to scale up to more than 10 layers.
In the future, they plan to continue enhancing their technique to efficiently characterize and probe other electronic spins in the environment and explore different types of defects that could be used to form qubits.
This research is supported, in part, by the U.S. National Science Foundation and the Canada First Research Excellence Fund.
Illustrating India’s complex environmental crises
Abhijit Banerjee, the Ford Foundation International Professor of Economics at MIT, and Sarnath Banerjee (no relation), an MIT Center for Art, Science, and Technology (CAST) visiting artist share a similar background, but have very different ways of thinking. Both were raised for a time in Kolkata before leaving India to pursue divergent careers, Abhijit as an economist who went on to win the 2019 Nobel Memorial Prize in Economic Sciences (an award he shares with MIT Professor Esther Duflo and Harvard University Professor Michael Kremer), and Sarnath as a visual artist and graphic novelist.
The two collaborated on a pair of short films, “The Land of Good Intentions” and “The Eternal Swamp,” that blend their expertise in a unique and captivating form. Each film addresses a particular environmental crisis facing present-day India by tracing its origins back through the centuries. The films are presented in a kind of lecture style, with Abhijit appearing as the narrator, unraveling historical details, as graphics by Sarnath visualize the story with an often wry and easy wit. The results apply logic and narrative coherence to problems with complex roots in the forces of nature, economics, and local culture.
“The Land of Good Intentions” explores the conditions and policies that led to mass protests by farmers, in Punjab and elsewhere, following the passage of farming legislation in September 2020. The film begins by providing historical context from multiple angles, including the significance of rice to regional culture, its growing conditions (which require a lot of water), the region’s climate (which produces very little), and previous government subsidies that led to its overproduction. The 2020 Farm Bills were intended to address rice overproduction and its consequences, including the depletion of Punjab’s groundwater supply, pollution from the burning of rice stalks, and a surplus going to waste. But farmers considered that they were being asked to shoulder the costs of a problem the government created.
“The arguments in the film don’t necessarily align with popular liberal arguments, but it gives subtler shape and layers to them,” Sarnath says. “That dialectical way of thinking is important to the liberal movement, which is driven by passion and a sense of justice. Abhijit is driven by factual analysis, which sometimes makes the argument more complex.”
Their second film, “The Eternal Swamp,” addresses the crisis of flooding in Kolkata and its causes in the geographical and economic development of the city from the start. Because Kolkata was built on very wet land, and real estate has long been one of the only viable industries in the city, it has been developed without regard to proper drainage in a climate that produces more rainfall than it can handle. There is a pervading sense that Kolkata will eventually be entirely below water.
“It was a good collaboration from the beginning,” Sarnath says of working with Abhijit on the CAST Visiting Artist project, a process which began just before Abhijit was awarded the Nobel Prize in 2019 and continued through the pandemic. “Both of us work on instinct, but the way he shapes an argument is very different from me,” Sarnath says. “My work does not follow a linear approach to telling a story; it’s fragmentary, driven by mood and emotion more than narrative, like composing a piece of music.”
Since they first met at a literary conference years ago, Abhijit and Sarnath have been close friends and intellectual sparring partners. Though Sarnath is based in Berlin and Abhijit in Boston, the two often cross paths in different locales and have long, ambling discussions that traverse a wide array of topics. “We spend a lot of time walking together wherever we find ourselves, whether it’s down the Longfellow Bridge in Boston or through Delhi or Kolkata,” Sarnath says. The idea for this project was born out of such conversations, in response to pressing events in their home country.
Abhijit wrote a proposal to MIT CAST, and the questions they received through the process helped them further shape the project. “It's important, when you have the luxury, just to spend time together. Thanks to MIT, we managed to do that across continents,” Sarnath says of their creative process. “It’s more than just telling a story; Abhijit unpacked what was in his head, and I drew and wrote a bit as well,” Sarnath says. And they worked with the editor and animator Niusha Ramzani, whom Sarnath says lent an Iranian aesthetic to the film’s animations.
As for the format of the films, they wanted to capture the sense of a serene Bengali afternoon, with Abhijit seated in his home in Kolkata speaking in a relaxed tone. “We wanted it to be a bit like a Royal Society lecture,” Sarnath says, somewhat like a TED Talk but more personable and intimate. The aim was to make their complicated subjects more easily comprehensible, through the language of Abhijit’s narration and with the help of visual metaphors. Still, they did not want to sacrifice complexity.
“Economists are fabulists,” says Abhijit Banerjee. “We tell stories, simple stories, but that tends to get obscured in the telling, often because we like to be very careful about not overstating our case. Irony and the kind of playful humor that Sarnath brings to narration seemed to offer a different way to avoid being too emphatic, while allowing the story to be told in a way that it reaches a much larger audience. What is brilliant about Sarnath’s work is the play between reliable and the unreliable — the readers are happy to be misdirected because they know that it will ultimately lead them where they want to be. I was hoping we could bring a little of that into economics.”
“You have to emancipate yourself from any one definitive answer,” Sarnath Banerjee says, describing Abhijit’s expansive way of thinking, through which he follows multiple thought processes to their logical conclusions. The result allows for ambiguity and contradiction, though the pathways of thinking are clear. The films illustrate the situations facing farmers in Punjab and the waterlogged streets of Kolkata by tracing their roots and examining the history of cause and effect. The results provide clarity, but no simple answers.
The process was an enriching one for both of them, the kind of advancement in understanding that can only come in dialogue. “With each collaboration, you learn, and learning to me is an artistic form,” Sarnath says. “We are always learning.”
Scientists develop a low-cost device to make cell therapy safer
A tiny device built by scientists at MIT and the Singapore-MIT Alliance for Research and Technology could be used to improve the safety and effectiveness of cell therapy treatments for patients suffering from spinal cord injuries.
In cell therapy, clinicians create what are known as induced pluripotent stem cells by reprogramming some skin or blood cells taken from a patient. To treat a spinal cord injury, they would coax these pluripotent stem cells to become progenitor cells, which are destined to differentiate into spinal cord cells. These progenitors are then transplanted back into the patient.
These new cells can regenerate part of the injured spinal cord. However, pluripotent stem cells that don’t fully change into progenitors can form tumors.
This research team developed a microfluidic cell sorter that can remove about half of the undifferentiated cells — those that can potentially become tumors — in a batch, without causing any damage to the fully-formed progenitor cells.
The high-throughput device, which doesn’t require special chemicals, can sort more than 3 million cells per minute. In addition, the researchers have shown that chaining many devices together can sort more than 500 million cells per minute, making this a more viable method to someday improve the safety of cell therapy treatments.
Plus, the plastic chip that contains the microfluidic cell sorter can be mass-produced in a factory at very low cost, so the device would be easier to implement at scale.
“Even if you have a life-saving cell therapy that is doing wonders for patients, if you cannot manufacture it cost-effectively, reliably, and safely, then its impact might be limited. Our team is passionate about that problem — we want to make these therapies more reliable and easily accessible,” says Jongyoon Han, an MIT professor of electrical engineering and computer science and of biological engineering, a member of the Research Laboratory of Electronics (RLE), and co-lead principal investigator of the CAMP (Critical Analytics for Manufacturing Personalized Medicine) research group at the Singapore-MIT Alliance for Research and Technology (SMART).
Han is joined on the paper by co-senior author Sing Yian Chew, professor of chemistry, chemical engineering, and biotechnology at the Lee Kong Chian School of Medicine and Materials Science and Engineering at Nanyang Technological University in Singapore and a CAMP principal investigator; co-lead authors Tan Dai Nguyen, a CAMP researcher; Wai Hon Chooi, a senior research fellow at the Singapore Agency for Science, Technology, and Research (A*STAR); and Hyungkook Jeon, an MIT postdoc; as well as others at NTU and A*STAR. The research appears today in Stem Cells Translational Medicine.
Reducing risk
The cancer risk posed by undifferentiated induced pluripotent stem cells remains one of the most pressing challenges in this type of cell therapy.
“Even if you have a very small population of cells that are not fully differentiated, they could still turn into cancer-like cells,” Han adds.
Clinicians and researchers often seek to identify and remove these cells by looking for certain markers on their surfaces, but so far researchers have not been able to find a marker that is specific to these undifferentiated cells. Other methods use chemicals to selectively destroy these cells, yet the chemical treatment techniques may be harmful to the differentiated cells.
The high-throughput microfluidic sorter, which can sort cells based on size, had been previously developed by the CAMP team after more than a decade of work. It has been previously used for sorting immune cells and mesenchymal stromal cells (another type of stem cell), and now the team is expanding its use to other stem cell types, such as induced pluripotent stem cells, Han says.
“We are interested in regenerative strategies to enhance tissue repair after spinal cord injuries, as these conditions lead to devasting functional impairment. Unfortunately, there is currently no effective regenerative treatment approach for spinal cord injuries,” Chew says. “Spinal cord progenitor cells derived from pluripotent stem cells hold great promise, since they can generate all cell types found within the spinal cord to restore tissue structure and function. To be able to effectively utilize these cells, the first step would be to ensure their safety, which is the aim of our work.”
The team discovered that pluripotent stem cells tend to be larger than the progenitors derived from them. It is hypothesized that before a pluripotent stem cell differentiates, its nucleus contains a large number of genes that haven’t been turned off, or suppressed. As it differentiates for a specific function, the cell suppresses many genes it will no longer need, significantly shrinking the nucleus.
The microfluidic device leverages this size difference to sort the cells.
Spiral sorting
Microfluidic channels in the quarter-sized plastic chip form an inlet, a spiral, and four outlets that output cells of different sizes. As the cells are forced through the spiral at very high speeds, various forces, including centrifugal forces, act on the cells. These forces counteract to focus the cells in a certain location in the fluid stream. This focusing point will be dependent on the size of the cells, effectively sorting them through separate outlets.
The researchers found they could improve the sorter’s operation by running it twice, first at a lower speed so larger cells stick to the walls and smaller cells are sorted out, then at a higher speed to sort out larger cells.
In a sense, the device operates like a centrifuge, but the microfluidic sorter does not require human intervention to pick out sorted cells, Han adds.
The researchers showed that their device could remove about 50 percent of the larger cells with one pass. They conducted experiments to confirm that the larger cells they removed were, in fact, associated with higher tumor risk.
“While we can’t remove 100 percent of these cells, we still believe this is going to reduce the risk significantly. Hopefully, the original cell type is good enough that we don’t have too many undifferentiated cells. Then this process could make these cells even safer,” he says.
Importantly, the low-cost microfluidic sorter, which can be produced at scale with standard manufacturing techniques, does not use any type of filtration. Filters can become clogged or break down, so a filter-free device can be used for a much longer time.
Now that they have shown success at a small scale, the researchers are embarking on larger studies and animal models to see if the purified cells function better in vivo.
Nondifferentiated cells can become tumors, but they can have other random effects in the body, so removing more of these cells could boost the efficacy of cell therapies, as well as improve safety.
“If we can convincingly demonstrate these benefits in vivo, the future might hold even more exciting applications for this technique,” Han says.
This research is supported, in part, by the National Research Foundation of Singapore and the Singapore-MIT Alliance for Research and Technology.
Researchers discover new channels to excite magnetic waves with terahertz light
Plucking a guitar string is a simple action that generates a harmonic series of overtones. However, skilled guitar players can elevate their performance by applying pressure to the strings while plucking them. This subtle technique causes the pitch of the note to bend — rising or falling with each deft movement — and infuses the music with expressiveness, texture, and character by intentionally harnessing the "nonlinear effects" of guitar strings.
In a study published Jan. 24 in Nature Physics, researchers from MIT and the University of Texas at Austin draw a fascinating scientific parallel to this musical artistry. The paper, authored by MIT graduate student Zhuquan Zhang, University of Texas at Austin postdoc Frank Gao PhD ’22, MIT Haslam and Dewey Professor of Chemistry Keith Nelson, and University of Texas at Austin Assistant Professor Edoardo Baldini, demonstrates the ability to control the dancing patterns of tiny magnetic bits, often referred to as “spin waves” or “magnons,” in a nonlinear manner, akin to how skilled guitar players manipulate guitar strings.
To do this, the researchers used intense terahertz (THz) fields — specially designed laser pulses operating at extreme infrared frequencies — to resonantly launch a spin wave at its characteristic frequency. But instead of simply exciting one spin wave, as one would normally expect — another distinct spin wave with a higher frequency was also excited. “This really surprised us. It meant that we could nonlinearly control the energy flow within these magnetic systems,” says Zhang.
To identify these nonlinear excitation pathways, the researchers developed a sophisticated spectrometer to uncover the mutual coupling between distinct spin waves and reveal their underlying symmetries. “Unlike visible light that can be easily seen by the eye, THz light is challenging to detect,” Gao explains. “These experiments would be otherwise impossible without the technique development which allowed us to measure THz signals with only a single light pulse.”
The team’s work provides new insights into how light can interact with spins in an unconventional way. Since the collective dancing motions of these minuscule magnetic bits and their propagation consume significantly less energy than electrical charges, they have attracted much fanfare from scientists for their potential to revolutionize computing. This discovery provides a tool that brings us ever closer to a future of high-speed spin-based information processing, enabling applications like magnonic transistors and quantum computing devices.
Other authors on the paper include Yu-Che Chien ’23; Zi-Jie Liu and Eric R. Sung, two current MIT chemistry graduate students; Alexander von Hoegen, an MIT postdoc from the Department of Physics; Jonathan B. Curtis and Professor Prineha Narang from the University of California Los Angeles; and Xiaoxuan Ma, Professor Wei Ren, and Professor Shixun Cao from Shanghai University.
This work was primarily supported by the U.S. Department of Energy Office of Basic Energy Sciences, the Robert A. Welch Foundation, and the United States Army Research Office.
Reflecting on COP28 — and humanity’s progress toward meeting global climate goals
With 85,000 delegates, the 2023 United Nations climate change conference, known as COP28, was the largest U.N. climate conference in history. It was held at the end of the hottest year in recorded history. And after 12 days of negotiations, from Nov. 30 to Dec. 12, it produced a decision that included, for the first time, language calling for “transitioning away from fossil fuels,” though it stopped short of calling for their complete phase-out.
U.N. Climate Change Executive Secretary Simon Stiell said the outcome in Dubai, United Arab Emirates, COP28’s host city, signaled “the beginning of the end” of the fossil fuel era.
COP stands for “conference of the parties” to the U.N. Framework Convention on Climate Change, held this year for the 28th time. Through the negotiations — and the immense conference and expo that takes place alongside them — a delegation of faculty, students, and staff from MIT was in Dubai to observe the negotiations, present new climate technologies, speak on panels, network, and conduct research.
On Jan. 17, the MIT Center for International Studies (CIS) hosted a panel discussion with MIT delegates who shared their reflections on the experience. Asking what’s going on at COP is “like saying, ‘What’s going on in the city of Boston today?’” quipped Evan Lieberman, the Total Professor of Political Science and Contemporary Africa, director of CIS, and faculty director of MIT International Science and Technology Initiatives (MISTI). “The value added that all of us can provide for the MIT community is [to share] what we saw firsthand and how we experienced it.”
Phase-out, phase down, transition away?
In the first week of COP28, over 100 countries issued a joint statement that included a call for “the global phase out of unabated fossil fuels.” The question of whether the COP28 decision — dubbed the “UAE Consensus” — would include this phase-out language animated much of the discussion in the days and weeks leading up to COP28.
Ultimately, the decision called for “transitioning away from fossil fuels in energy systems, in a just, orderly and equitable manner.” It also called for “accelerating efforts towards the phase down of unabated coal power,” referring to the combustion of coal without efforts to capture and store its emissions.
In Dubai to observe the negotiations, graduate student Alessandra Fabbri said she was “confronted” by the degree to which semantic differences could impose significant ramifications — for example, when negotiators referred to a “just transition,” or to “developed vs. developing nations” — particularly where evolution in recent scholarship has produced more nuanced understandings of the terms.
COP28 also marked the conclusion of the first global stocktake, a core component of the 2015 Paris Agreement. The effort every five years to assess the world’s progress in responding to climate change is intended as a basis for encouraging countries to strengthen their climate goals over time, a process often referred to as the Paris Agreement’s “ratchet mechanism.”
The technical report of the first global stocktake, published in September 2023, found that while the world has taken actions that have reduced forecasts of future warming, they are not sufficient to meet the goals of the Paris Agreement, which aims to limit global average temperature increase to “well below” 2 degrees Celsius, while pursuing efforts to limit the increase to 1.5 degrees above pre-industrial levels.
“Despite minor, punctual advancements in climate action, parties are far from being on track to meet the long-term goals of the Paris Agreement,” said Fabbri, a graduate student in the School of Architecture and Planning and a fellow in MIT's Leventhal Center for Advanced Urbanism. Citing a number of persistent challenges, including some parties’ fears that rapid economic transition may create or exacerbate vulnerabilities, she added, “There is a noted lack of accountability among certain countries in adhering to their commitments and responsibilities under international climate agreements.”
Climate and trade
COP28 was the first climate summit to formally acknowledge the importance of international trade by featuring an official “Trade Day” on Dec. 4. Internationally traded goods account for about a quarter of global greenhouse gas emissions, raising complex questions of accountability and concerns about offshoring of industrial manufacturing, a phenomenon known as “emissions leakage.” Addressing the nexus of climate and trade is therefore considered essential for successful decarbonization, and a growing number of countries are leveraging trade policies — such as carbon fees applied to imported goods — to secure climate benefits.
Members of the MIT delegation participated in several related activities, sharing research and informing decision-makers. Catherine Wolfram, professor of applied economics in the MIT Sloan School of Management, and Michael Mehling, deputy director of the MIT Center for Energy and Environmental Policy Research (CEEPR), presented options for international cooperation on such trade policies at side events, including ones hosted by the World Trade Organization and European Parliament.
“While COPs are often criticized for highlighting statements that don’t have any bite, they are also tremendous opportunities to get people from around the world who care about climate and think deeply about these issues in one place,” said Wolfram.
Climate and health
For the first time in the conference’s nearly 30-year history, COP28 included a thematic “Health Day” that featured talks on the relationship between climate and health. Researchers from MIT’s Abdul Latif Jameel Poverty Action Lab (J-PAL) have been testing policy solutions in this area for years through research funds such as the King Climate Action Initiative (K-CAI).
“An important but often-neglected area where climate action can lead to improved health is combating air pollution,” said Andre Zollinger, K-CAI’s senior policy manager. “COP28's announcement on reducing methane leaks is an important step because action in this area could translate to relatively quick, cost-effective ways to curb climate change while improving air quality, especially for people living near these industrial sites.” K-CAI has an ongoing project in Colorado investigating the use of machine learning to predict leaks and improve the framework for regulating industrial methane emissions, Zollinger noted.
This was J-PAL’s third time at COP, which Zollinger said typically presented an opportunity for researchers to share new findings and analysis with government partners, nongovernmental organizations, and companies. This year, he said, “We have [also] been working with negotiators in the [Middle East and North Africa] region in the months preceding COP to plug them into the latest evidence on water conservation, on energy access, on different challenging areas of adaptation that could be useful for them during the conference.”
Sharing knowledge, learning from others
MIT student Runako Gentles described COP28 as a “springboard” to greater impact. A senior from Jamaica studying civil and environmental engineering, Gentles said it was exciting to introduce himself as an MIT undergraduate to U.N. employees and Jamaican delegates in Dubai. “There’s a lot of talk on mitigation and cutting carbon emissions, but there needs to be much more going into climate adaptation, especially for small-island developing states like those in the Caribbean,” he said. “One of the things I can do, while I still try to finish my degree, is communicate — get the story out there to raise awareness.”
At an official side event at COP28 hosted by MIT, Pennsylvania State University, and the American Geophysical Union, Maria T. Zuber, MIT’s vice president for research, stressed the importance of opportunities to share knowledge and learn from people around the world.
“The reason this two-way learning is so important for us is simple: The ideas we come up with in a university setting, whether they’re technological or policy or any other kind of innovations — they only matter in the practical world if they can be put to good use and scaled up,” said Zuber. “And the only way we can know that our work has practical relevance for addressing climate is by working hand-in-hand with communities, industries, governments, and others.”
Marcela Angel, research program director at the Environmental Solutions Initiative, and Sergey Paltsev, deputy director of MIT’s Joint Program on the Science and Policy of Global Change, also spoke at the event, which was moderated by Bethany Patten, director of policy and engagement for sustainability at the MIT Sloan School of Management.
Six MIT students selected as spring 2024 MIT-Pillar AI Collective Fellows
The MIT-Pillar AI Collective has announced six fellows for the spring 2024 semester. With support from the program, the graduate students, who are in their final year of a master’s or PhD program, will conduct research in the areas of AI, machine learning, and data science with the aim of commercializing their innovations.
Launched by MIT’s School of Engineering and Pillar VC in 2022, the MIT-Pillar AI Collective supports faculty, postdocs, and students conducting research on AI, machine learning, and data science. Supported by a gift from Pillar VC and administered by the MIT Deshpande Center for Technological Innovation, the mission of the program is to advance research toward commercialization.
The spring 2024 MIT-Pillar AI Collective Fellows are:
Yasmeen AlFaraj
Yasmeen AlFaraj is a PhD candidate in chemistry whose interest is in the application of data science and machine learning to soft materials design to enable next-generation, sustainable plastics, rubber, and composite materials. More specifically, she is applying machine learning to the design of novel molecular additives to enable the low-cost manufacturing of chemically deconstructable thermosets and composites. AlFaraj’s work has led to the discovery of scalable, translatable new materials that could address thermoset plastic waste. As a Pillar Fellow, she will pursue bringing this technology to market, initially focusing on wind turbine blade manufacturing and conformal coatings. Through the Deshpande Center for Technological Innovation, AlFaraj serves as a lead for a team developing a spinout focused on recyclable versions of existing high-performance thermosets by incorporating small quantities of a degradable co-monomer. In addition, she participated in the National Science Foundation Innovation Corps program and recently graduated from the Clean Tech Open, where she focused on enhancing her business plan, analyzing potential markets, ensuring a complete IP portfolio, and connecting with potential funders. AlFaraj earned a BS in chemistry from University of California at Berkeley.
Ruben Castro Ornelas
Ruben Castro Ornelas is a PhD student in mechanical engineering who is passionate about the future of multipurpose robots and designing the hardware to use them with AI control solutions. Combining his expertise in programming, embedded systems, machine design, reinforcement learning, and AI, he designed a dexterous robotic hand capable of carrying out useful everyday tasks without sacrificing size, durability, complexity, or simulatability. Ornelas’s innovative design holds significant commercial potential in domestic, industrial, and health-care applications because it could be adapted to hold everything from kitchenware to delicate objects. As a Pillar Fellow, he will focus on identifying potential commercial markets, determining the optimal approach for business-to-business sales, and identifying critical advisors. Ornelas served as co-director of StartLabs, an undergraduate entrepreneurship club at MIT, where he earned an BS in mechanical engineering.
Keeley Erhardt
Keeley Erhardt is a PhD candidate in media arts and sciences whose research interests lie in the transformative potential of AI in network analysis, particularly for entity correlation and hidden link detection within and across domains. She has designed machine learning algorithms to identify and track temporal correlations and hidden signals in large-scale networks, uncovering online influence campaigns originating from multiple countries. She has similarly demonstrated the use of graph neural networks to identify coordinated cryptocurrency accounts by analyzing financial time series data and transaction dynamics. As a Pillar Fellow, Erhardt will pursue the potential commercial applications of her work, such as detecting fraud, propaganda, money laundering, and other covert activity in the finance, energy, and national security sectors. She has had internships at Google, Facebook, and Apple and held software engineering roles at multiple tech unicorns. Erhardt earned an MEng in electrical engineering and computer science and a BS in computer science, both from MIT.
Vineet Jagadeesan Nair
Vineet Jagadeesan Nair is a PhD candidate in mechanical engineering whose research focuses on modeling power grids and designing electricity markets to integrate renewables, batteries, and electric vehicles. He is broadly interested in developing computational tools to tackle climate change. As a Pillar Fellow, Nair will explore the application of machine learning and data science to power systems. Specifically, he will experiment with approaches to improve the accuracy of forecasting electricity demand and supply with high spatial-temporal resolution. In collaboration with Project Tapestry @ Google X, he is also working on fusing physics-informed machine learning with conventional numerical methods to increase the speed and accuracy of high-fidelity simulations. Nair’s work could help realize future grids with high penetrations of renewables and other clean, distributed energy resources. Outside academics, Nair is active in entrepreneurship, most recently helping to organize the 2023 MIT Global Startup Workshop in Greece. He earned an MS in computational science and engineering from MIT, an MPhil in energy technologies from Cambridge University as a Gates Scholar, and a BS in mechanical engineering and a BA in economics from University of California at Berkeley.
Mahdi Ramadan
Mahdi Ramadan is a PhD candidate in brain and cognitive sciences whose research interests lie at the intersection of cognitive science, computational modeling, and neural technologies. His work uses novel unsupervised methods for learning and generating interpretable representations of neural dynamics, capitalizing on recent advances in AI, specifically contrastive and geometric deep learning techniques capable of uncovering the latent dynamics underlying neural processes with high fidelity. As a Pillar Fellow, he will leverage these methods to gain a better understanding of dynamical models of muscle signals for generative motor control. By supplementing current spinal prosthetics with generative AI motor models that can streamline, speed up, and correct limb muscle activations in real time, as well as potentially using multimodal vision-language models to infer the patients’ high-level intentions, Ramadan aspires to build truly scalable, accessible, and capable commercial neuroprosthetics. Ramadan’s entrepreneurial experience includes being the co-founder of UltraNeuro, a neurotechnology startup, and co-founder of Presizely, a computer vision startup. He earned a BS in neurobiology from University of Washington.
Rui (Raymond) Zhou
Rui (Raymond) Zhou is a PhD candidate in mechanical engineering whose research focuses on multimodal AI for engineering design. As a Pillar Fellow, he will advance models that could enable designers to translate information in any modality or combination of modalities into comprehensive 2D and 3D designs, including parametric data, component visuals, assembly graphs, and sketches. These models could also optimize existing human designs to accomplish goals such as improving ergonomics or reducing drag coefficient. Ultimately, Zhou aims to translate his work into a software-as-a-service platform that redefines product design across various sectors, from automotive to consumer electronics. His efforts have the potential to not only accelerate the design process but also reduce costs, opening the door to unprecedented levels of customization, idea generation, and rapid prototyping. Beyond his academic pursuits, Zhou founded UrsaTech, a startup that integrates AI into education and engineering design. He earned a BS in electrical engineering and computer sciences from University of California at Berkeley.
MADMEC winner creates “temporary tattoos” for T-shirts
Have you ever gotten a free T-shirt at an event that you never wear? What about a music or sports-themed shirt you wear to one event and then lose interest in entirely? Such one-off T-shirts — and the waste and pollution associated with them — are an unfortunately common part of our society.
But what if you could change the designs on shirts after each use? The winners of this year's MADMEC competition developed biodegradable "temporary tattoos" for T-shirts to make one-wear clothing more sustainable.
Members of the winning team, called Me-Shirts, got their inspiration from the MADMEC event itself, which ordinarily makes a different T-shirt each year.
“If you think about all the textile waste that’s produced for all these shirts, it’s insane,” team member and PhD candidate Isabella Caruso said in the winning presentation. “The main markets we are trying to address are for one-time T-shirts and custom T-shirts.”
The problem is a big one. According to the team, the custom T-shirt market is a $4.3 billion industry. That doesn’t include trends like fast fashion that contribute to the 17 million tons of textile waste produced each year.
“Our proposed solution is a temporary shirt tattoo made from biodegradable, nontoxic materials,” Caruso explained. “We wanted designs that are fully removable through washing, so that you can wear your T-shirt for your one-time event and then get a nice white T-shirt back afterward.”
The team’s scalable design process mixes three simple ingredients: potato starch, glycerin, and water. The design can be imprinted on the shirt temporarily through ironing.
The Me-Shirt team, which earned $10,000 with the win, plans to continue exploring material combinations to make the design more flexible and easier for people to apply at home. Future iterations could allow users to decide if they want the design to stay on the shirt during washes based on the settings of the washing machine.
Hosted by MIT’s Department of Materials Science and Engineering (DMSE), the competition was the culmination of team projects that began in the fall and included a series of design challenges throughout the semester. Each team received guidance, access to equipment and labs, and up to $1,000 in funding to build and test their prototypes.
“The main goal is that they gained some confidence in their ability to design and build devices and platforms that are different from their normal experiences,” Mike Tarkanian, a senior lecturer in DMSE and coordinator of MADMEC, said at the event. “If it’s a departure from their normal research and coursework activities that’s a win, I think, to make them better engineers.”
The second-place, $6,000 prize went to Alkalyne, which is creating a carbon-neutral polymer for petrochemical production. The company is developing approaches for using electricity and inorganic carbon to generate a high-energy hydrocarbon precursor. If developed using renewable energy, the approach could be used to achieve carbon negative petrochemical production.
“A lot of our research, and a lot of the research around MIT in general, has to do with sustainability, so we wanted to try an angle that we think looks promising but doesn’t seem to be investigated enough,” PhD candidate Christopher Mallia explained.
The third-place prize went to Microbeco, which is exploring the use of microbial fuel cells for continuous water quality monitoring. Microbes have been proposed as a way to detect and measure contaminants in water for decades, but the team believes the varying responses of microbes to different contaminants has limited the effectiveness of the approach.
To overcome that problem, the team is working to isolate microbial strains that respond more regularly to specific contaminants.
Overall, Tarkanian believes this year’s program was a success not only because of the final results presented at the competition, but because of the experience the students got along the way using equipment like laser cutters, 3D printers, and soldering irons. Many participants said they had never used that type of equipment before. They also said by working to build physical prototypes, the program helped make their coursework come to life.
“It was a chance to try something new by applying my skills to a different environment,” PhD candidate Zachary Adams said. “I can see a lot of the concepts I learn in my classes through this work.”
Remembering MIT Copytech Director Casey Harrington
Casey Harrington, who led MIT Copytech’s recovery from pandemic-era disruptions and built close friendships across campus, passed away unexpectedly on Jan. 13. He was 49.
Copytech’s director since 2022, Harrington modernized the department’s equipment and services to improve its financial outlook, and led his staff with a personal touch.
“Casey was beloved by our team,” says Alfred Ironside, MIT’s vice president for communications. “He was a great manager, had a vision for the future, spent time with his co-workers, cared for them, and loved MIT. He turned around Copytech’s fortunes, too, setting it on an upward trajectory that reflected his wonderful abilities as a leader. His loss is enormous — for his wife, his children, his family, and for us.”
Although Harrington’s time at MIT was brief, he left a lasting impression on his team at Copytech and the people he worked with every day.
“Casey was a great leader, with a rare combination of vision, approachability, and genuine care and appreciation for our team,” Financial Officer Suha Bekdash says. “Since he joined two years ago, he made an immediate impact steering Copytech toward a more successful future after the pandemic.”
For those who knew Harrington well, he will be remembered for his numerous “Casey-isms,” which included “Be grateful” and “Do the next right thing.”
“I want his legacy to be, ‘Do the next right thing,’” his wife Marilyn Harrington says. “Coming to MIT was the next right thing for our family, and he always did the next right thing for our family. There was no way for us to predict this tragedy. He did the next right thing for his staff and for MIT leadership. He always did his best. He left this world very loved, very respected, and he left a hole that will never be filled.”
Leading Copytech by building friendships
Harrington came to MIT with big shoes to fill. His predecessor, Steven Dimond, had worked at Copytech for 50 years. On top of that, Copytech was emerging from a pandemic that caused business to stall as people left campus and more events went online.
“That had been an extremely difficult number of years for Copytech, both financially and also just for the morale of people,” says Danyel Barnard, MIT's executive director of digital, brand, and internal communications. “He took a job that was a challenge. We needed someone who could come in and help turn things around. He was really excited about the opportunity, and about being at MIT, and he was eager to lead the organization through those challenges.”
Harrington came to MIT with deep expertise about the print industry. Prior to MIT, he had worked at large private companies, global health care groups, and Vanderbilt University.
“He could take the transcript of a book and say, ‘It needs to be this size book print with this size paper and this many pages,’” Marilyn Harrington recalls.
At MIT, he hit the ground running by working out new service contracts and pitching ideas for new equipment, including a new, large-format printing machine.
“In his two years here, he did amazing things with the operation,” says Barnard. “He led a big turnaround financially, a lot of which I credit to his management and leadership. He had great foresight and truly exceeded expectations."
Most importantly, Harrington established personal connections with the Copytech team and his colleagues across the Institute.
“Casey was a great leader,” Administrative Assistant Taj Dickson says. “He loved Copytech and he loved MIT. When he came, he fit right in with us. People have been in Copytech for so long, and when they leave there’s always trepidation that the new person is not going to understand how to deal with the department. But he came in and figured it out, and the transition was really smooth because of his emotional intelligence as a leader. I think that was one of his hallmarks: He was a very emotionally intelligent leader.”
It was perhaps an unlikely match. Harrington’s southern accent was a stark contrast with many of the Bostonians in Copytech. But their different backgrounds served as a conversation piece more than a point of difference.
“The staff universally loved him,” Barnard says. “He was a perfect fit and a perfect leader for them. He really cared about them, and that is so important at Copytech, where they consider themselves a family.”
His wife describes MIT as Harrington’s “dream job” and says he was grateful to Copytech’s staff for embracing him.
“He left MIT in a better place than he found it because of the support he got from the team and from MIT leadership,” she says.
A strong leader
Harrington was born in Nashville and was a proud graduate of the University of Tennessee at Knoxville. He was also deeply devoted to his family. He met Marilyn when he was 13, and their friendship blossomed into a 27-year marriage.
Casey moved to Boston while his family figured out where their youngest child would attend high school, but they made a point to see each other as much as possible — Marilyn estimates they spent well over 400 days together in his first two years living in Boston.
“Once, I texted him that I wasn’t doing well and I needed to see him, and he was on my doorstep four hours later,” Marilyn recalls. “He didn’t even have a bag, only his laptop. That was the kind of person he was.”
“You could really have honest conversations with Casey,” Dickson says. “He would have no problem talking about his experiences, good and bad, and it was up to you to find the lesson in those stories.”
When news of Harrington’s passing got around MIT, Barnard heard from people in disparate departments who she didn’t even realize knew Harrington explaining they had become friends.
“He found ways to connect with people,” Barnard says. “I was amazed by his reach.”
In honor of Harrington and in a nod to his love for University of Tennessee football, the Copytech team wore orange shirts and blue jeans to work on Jan. 29. They say they’ll continue to honor Harrington through their work.
“He was a strong leader who was full of life, and he still had so much to offer Copytech,” Dickson says. “His ability to communicate, his unique sense of humor, and his love for our department were just a few of the highlights that made Casey shine.”
MIT-led team receives funding to pursue new treatments for metabolic disease
A team of MIT researchers will lead a $65.67 million effort, awarded by the U.S. Advanced Research Projects Agency for Health (ARPA-H), to develop ingestible devices that may one day be used to treat diabetes, obesity, and other conditions through oral delivery of mRNA. Such devices could potentially be deployed for needle-free delivery of mRNA vaccines as well.
The five-year project also aims to develop electroceuticals, a new form of ingestible therapies based on electrical stimulation of the body’s own hormones and neural signaling. If successful, this approach could lead to new treatments for a variety of metabolic disorders.
“We know that the oral route is generally the preferred route of administration for both patients and health care providers,” says Giovanni Traverso, an associate professor of mechanical engineering at MIT and a gastroenterologist at Brigham and Women’s Hospital. “Our primary focus is on disorders of metabolism because they affect a lot of people, but the platforms we’re developing could be applied very broadly.”
Traverso is the principal investigator for the project, which also includes Robert Langer, MIT Institute Professor, and Anantha Chandrakasan, dean of the MIT School of Engineering and the Vannevar Bush Professor of Electrical Engineering and Computer Science. As part of the project, the MIT team will collaborate with investigators from Brigham and Women’s Hospital, New York University, and the University of Colorado School of Medicine.
Over the past several years, Traverso’s and Langer’s labs have designed many types of ingestible devices that can deliver drugs to the GI tract. This approach could be especially useful for protein drugs and nucleic acids, which typically can’t be given orally because they break down in the acidic environment of the digestive tract.
Messenger RNA has already proven useful as a vaccine, directing cells to produce fragments of viral proteins that trigger an immune response. Delivering mRNA to cells also holds potential to stimulate production of therapeutic molecules to treat a variety of diseases. In this project, the researchers plan to focus on metabolic diseases such as diabetes.
“What mRNA can do is enable the potential for dosing therapies that are very difficult to dose today, or provide longer-term coverage by essentially creating an internal factory that produces a therapy for a prolonged period,” Traverso says.
In the mRNA portion of the project, the research team intends to identify lipid and polymer nanoparticle formulations that can most effectively deliver mRNA to cells, using machine learning to help identify the best candidates. They will also develop and test ingestible devices to carry the mRNA-nanoparticle payload, with the goal of running a clinical trial in the final year of the five-year project.
The work will build on research that Traverso’s lab has already begun. In 2022, Traverso and his colleagues reported that they could deliver mRNA in capsules that inject mRNA-nanoparticle complexes into the lining of the stomach.
The other branch of the project will focus on ingestible devices that can deliver a small electrical current to the lining of the stomach. In a study published last year, Traverso’s lab demonstrated this approach for the first time, using a capsule coated with electrodes that apply an electrical current to cells of the stomach. In animal studies, they found that this stimulation boosted production of ghrelin, a hormone that stimulates appetite.
Traverso envisions that this type of treatment could potentially replace or complement some of the existing drugs used to prevent nausea and stimulate appetite in people with anorexia or cachexia (loss of body mass that can occur in patients with cancer or other chronic diseases). The researchers also hope to develop ways to stimulate production of GLP-1, a hormone that is used to help manage diabetes and promote weight loss.
“What this approach starts to do is potentially maximize our ability to treat disease without administering a new drug, but instead by simply modulating the body’s own systems through electrical stimulation,” Traverso says.
At MIT, Langer will help to develop nanoparticles for mRNA delivery, and Chandrakasan will work on ways to reduce energy consumption and miniaturize the electronic functions of the capsules, including secure communication, stimulation, and power generation.
The Brigham and Women’s Hospital’s portion of the project will be co-led by Traverso, Ameya Kirtane, Jason Li, and Peter Chai, who will amplify efforts on the formulation and stabilization of the mRNA nanoparticles, engineering of the ingestible devices, and running of clinical trials. At NYU, the effort will be led by assistant professor of bioengineering Khalil Ramadi SM ’16, PhD ’19, focusing on biological characterization of the effects of electrical stimulation. Researchers at the University of Colorado, led by Matthew Wynia and Eric G. Campbell of the CU Center for Bioethics and Humanities, will focus on exploring the ethical dimensions and public perceptions of these types of biomedical interventions.
“We felt like we had an opportunity here not only to do fundamental engineering science and early-stage clinical trials, but also to start to understand the data behind some of the ethical implications and public perceptions of these technologies through this broad collaboration,” Traverso says.
The project described here is supported by ARPA-H under award number D24AC00040-00. The content of this announcement does not necessarily represent the official views of the Advanced Research Projects Agency for Health.
MIT researchers map the energy transition’s effects on jobs
A new analysis by MIT researchers shows the places in the U.S. where jobs are most linked to fossil fuels. The research could help policymakers better identify and support areas affected over time by a switch to renewable energy.
While many of the places most potentially affected have intensive drilling and mining operations, the study also measures how areas reliant on other industries, such as heavy manufacturing, could experience changes. The research examines the entire U.S. on a county-by-county level.
“Our result is that you see a higher carbon footprint for jobs in places that drill for oil, mine for coal, and drill for natural gas, which is evident in our maps,” says Christopher Knittel, an economist at the MIT Sloan School of Management and co-author of a new paper detailing the findings. “But you also see high carbon footprints in areas where we do a lot of manufacturing, which is more likely to be missed by policymakers when examining how the transition to a zero-carbon economy will affect jobs.”
So, while certain U.S. areas known for fossil-fuel production would certainly be affected — including west Texas, the Powder River Basin of Montana and Wyoming, parts of Appalachia, and more — a variety of industrial areas in the Great Plains and Midwest could see employment evolve as well.
The paper, “Assessing the distribution of employment vulnerability to the energy transition using employment carbon footprints,” is published this week in Proceedings of the National Academy of Sciences. The authors are Kailin Graham, a master’s student in MIT’s Technology and Policy Program and graduate research assistant at MIT’s Center for Energy and Environmental Policy Research; and Knittel, who is the George P. Shultz Professor at MIT Sloan.
“Our results are unique in that we cover close to the entire U.S. economy and consider the impacts on places that produce fossil fuels but also on places that consume a lot of coal, oil, or natural gas for energy,” says Graham. “This approach gives us a much more complete picture of where communities might be affected and how support should be targeted.”
Adjusting the targets
The current study stems from prior research Knittel has conducted, measuring carbon footprints at the household level across the U.S. The new project takes a conceptually related approach, but for jobs in a given county. To conduct the study, the researchers used several data sources measuring energy consumption by businesses, as well as detailed employment data from the U.S. Census Bureau.
The study takes advantage of changes in energy supply and demand over time to estimate how strongly a full range of jobs, not just those in energy production, are linked to use of fossil fuels. The sectors accounted for in the study comprise 86 percent of U.S. employment, and 94 percent of U.S. emissions apart from the transportation sector.
The Inflation Reduction Act, passed by Congress and signed into law by President Joe Biden in August 2022, is the first federal legislation seeking to provide an economic buffer for places affected by the transition away from fossil fuels. The act provides expanded tax credits for economic projects located in “energy community” areas — defined largely as places with high fossil-fuel industry employment or tax revenue and with high unemployment. Areas with recently closed or downsized coal mines or power plants also qualify.
Graham and Knittel measured the “employment carbon footprint” (ECF) of each county in the U.S., producing new results. Out of more than 3,000 counties in the U.S., the researchers found that 124 are at the 90th percentile or above in ECF terms, while not qualifying for Inflation Reduction Act assistance. Another 79 counties are eligible for Inflation Reduction Act assistance, while being in the bottom 20 percent nationally in ECF terms.
Those may not seem like colossal differences, but the findings identify real communities potentially being left out of federal policy, and highlight the need for new targeting of such programs. The research by Graham and Knittel offers a precise way to assess the industrial composition of U.S. counties, potentially helping to target economic assistance programs.
“The impact on jobs of the energy transition is not just going to be where oil and natural gas are drilled, it’s going to be all the way up and down the value chain of things we make in the U.S.,” Knittel says. “That’s a more extensive, but still focused, problem.”
Graham adds: “It’s important that policymakers understand these economy-wide employment impacts. Our aim in providing these data is to help policymakers incorporate these considerations into future policies like the Inflation Reduction Act.”
Adapting policy
Graham and Knittel are still evaluating what the best policy measures might be to help places in the U.S. adapt to a move away from fossil fuels.
“What we haven’t necessarily closed the loop on is the right way to build a policy that takes account of these factors,” Knittel says. “The Inflation Reduction Act is the first policy to think about a [fair] energy transition because it has these subsidies for energy-dependent counties.” But given enough political backing, there may be room for additional policy measures in this area.
One thing clearly showing through in the study’s data is that many U.S. counties are in a variety of situations, so there may be no one-size-fits-all approach to encouraging economic growth while making a switch to clean energy. What suits west Texas or Wyoming best may not work for more manufacturing-based local economies. And even among primary energy-production areas, there may be distinctions, among those drilling for oil or natural gas and those producing coal, based on the particular economics of those fuels. The study includes in-depth data about each county, characterizing its industrial portfolio, which may help tailor approaches to a range of economic situations.
“The next step is using this data more specifically to design policies to protect these communities,” Knittel says.
How symmetry can come to the aid of machine learning
Behrooz Tahmasebi — an MIT PhD student in the Department of Electrical Engineering and Computer Science (EECS) and an affiliate of the Computer Science and Artificial Intelligence Laboratory (CSAIL) — was taking a mathematics course on differential equations in late 2021 when a glimmer of inspiration struck. In that class, he learned for the first time about Weyl’s law, which had been formulated 110 years earlier by the German mathematician Hermann Weyl. Tahmasebi realized it might have some relevance to the computer science problem he was then wrestling with, even though the connection appeared — on the surface — to be thin, at best. Weyl’s law, he says, provides a formula that measures the complexity of the spectral information, or data, contained within the fundamental frequencies of a drum head or guitar string.
Tahmasebi was, at the same time, thinking about measuring the complexity of the input data to a neural network, wondering whether that complexity could be reduced by taking into account some of the symmetries inherent to the dataset. Such a reduction, in turn, could facilitate — as well as speed up — machine learning processes.
Weyl’s law, conceived about a century before the boom in machine learning, had traditionally been applied to very different physical situations — such as those concerning the vibrations of a string or the spectrum of electromagnetic (black-body) radiation given off by a heated object. Nevertheless, Tahmasebi believed that a customized version of that law might help with the machine learning problem he was pursuing. And if the approach panned out, the payoff could be considerable.
He spoke with his advisor, Stefanie Jegelka — an associate professor in EECS and affiliate of CSAIL and the MIT Institute for Data, Systems, and Society — who believed the idea was definitely worth looking into. As Tahmasebi saw it, Weyl’s law had to do with gauging the complexity of data, and so did this project. But Weyl’s law, in its original form, said nothing about symmetry.
He and Jegelka have now succeeded in modifying Weyl’s law so that symmetry can be factored into the assessment of a dataset’s complexity. “To the best of my knowledge,” Tahmasebi says, “this is the first time Weyl’s law has been used to determine how machine learning can be enhanced by symmetry.”
The paper he and Jegelka wrote earned a “Spotlight” designation when it was presented at the December 2023 conference on Neural Information Processing Systems — widely regarded as the world’s top conference on machine learning.
This work, comments Soledad Villar, an applied mathematician at Johns Hopkins University, “shows that models that satisfy the symmetries of the problem are not only correct but also can produce predictions with smaller errors, using a small amount of training points. [This] is especially important in scientific domains, like computational chemistry, where training data can be scarce.”
In their paper, Tahmasebi and Jegelka explored the ways in which symmetries, or so-called “invariances,” could benefit machine learning. Suppose, for example, the goal of a particular computer run is to pick out every image that contains the numeral 3. That task can be a lot easier, and go a lot quicker, if the algorithm can identify the 3 regardless of where it is placed in the box — whether it’s exactly in the center or off to the side — and whether it is pointed right-side up, upside down, or oriented at a random angle. An algorithm equipped with the latter capability can take advantage of the symmetries of translation and rotations, meaning that a 3, or any other object, is not changed in itself by altering its position or by rotating it around an arbitrary axis. It is said to be invariant to those shifts. The same logic can be applied to algorithms charged with identifying dogs or cats. A dog is a dog is a dog, one might say, irrespective of how it is embedded within an image.
The point of the entire exercise, the authors explain, is to exploit a dataset’s intrinsic symmetries in order to reduce the complexity of machine learning tasks. That, in turn, can lead to a reduction in the amount of data needed for learning. Concretely, the new work answers the question: How many fewer data are needed to train a machine learning model if the data contain symmetries?
There are two ways of achieving a gain, or benefit, by capitalizing on the symmetries present. The first has to do with the size of the sample to be looked at. Let’s imagine that you are charged, for instance, with analyzing an image that has mirror symmetry — the right side being an exact replica, or mirror image, of the left. In that case, you don’t have to look at every pixel; you can get all the information you need from half of the image — a factor of two improvement. If, on the other hand, the image can be partitioned into 10 identical parts, you can get a factor of 10 improvement. This kind of boosting effect is linear.
To take another example, imagine you are sifting through a dataset, trying to find sequences of blocks that have seven different colors — black, blue, green, purple, red, white, and yellow. Your job becomes much easier if you don’t care about the order in which the blocks are arranged. If the order mattered, there would be 5,040 different combinations to look for. But if all you care about are sequences of blocks in which all seven colors appear, then you have reduced the number of things — or sequences — you are searching for from 5,040 to just one.
Tahmasebi and Jegelka discovered that it is possible to achieve a different kind of gain — one that is exponential — that can be reaped for symmetries that operate over many dimensions. This advantage is related to the notion that the complexity of a learning task grows exponentially with the dimensionality of the data space. Making use of a multidimensional symmetry can therefore yield a disproportionately large return. “This is a new contribution that is basically telling us that symmetries of higher dimension are more important because they can give us an exponential gain,” Tahmasebi says.
The NeurIPS 2023 paper that he wrote with Jegelka contains two theorems that were proved mathematically. “The first theorem shows that an improvement in sample complexity is achievable with the general algorithm we provide,” Tahmasebi says. The second theorem complements the first, he added, “showing that this is the best possible gain you can get; nothing else is achievable.”
He and Jegelka have provided a formula that predicts the gain one can obtain from a particular symmetry in a given application. A virtue of this formula is its generality, Tahmasebi notes. “It works for any symmetry and any input space.” It works not only for symmetries that are known today, but it could also be applied in the future to symmetries that are yet to be discovered. The latter prospect is not too farfetched to consider, given that the search for new symmetries has long been a major thrust in physics. That suggests that, as more symmetries are found, the methodology introduced by Tahmasebi and Jegelka should only get better over time.
According to Haggai Maron, a computer scientist at Technion (the Israel Institute of Technology) and NVIDIA who was not involved in the work, the approach presented in the paper “diverges substantially from related previous works, adopting a geometric perspective and employing tools from differential geometry. This theoretical contribution lends mathematical support to the emerging subfield of ‘Geometric Deep Learning,’ which has applications in graph learning, 3D data, and more. The paper helps establish a theoretical basis to guide further developments in this rapidly expanding research area.”
Doctors have more difficulty diagnosing disease when looking at images of darker skin
When diagnosing skin diseases based solely on images of a patient’s skin, doctors do not perform as well when the patient has darker skin, according to a new study from MIT researchers.
The study, which included more than 1,000 dermatologists and general practitioners, found that dermatologists accurately characterized about 38 percent of the images they saw, but only 34 percent of those that showed darker skin. General practitioners, who were less accurate overall, showed a similar decrease in accuracy with darker skin.
The research team also found that assistance from an artificial intelligence algorithm could improve doctors’ accuracy, although those improvements were greater when diagnosing patients with lighter skin.
While this is the first study to demonstrate physician diagnostic disparities across skin tone, other studies have found that the images used in dermatology textbooks and training materials predominantly feature lighter skin tones. That may be one factor contributing to the discrepancy, the MIT team says, along with the possibility that some doctors may have less experience in treating patients with darker skin.
“Probably no doctor is intending to do worse on any type of person, but it might be the fact that you don’t have all the knowledge and the experience, and therefore on certain groups of people, you might do worse,” says Matt Groh PhD ’23, an assistant professor at the Northwestern University Kellogg School of Management. “This is one of those situations where you need empirical evidence to help people figure out how you might want to change policies around dermatology education.”
Groh is the lead author of the study, which appears today in Nature Medicine. Rosalind Picard, an MIT professor of media arts and sciences, is the senior author of the paper.
Diagnostic discrepancies
Several years ago, an MIT study led by Joy Buolamwini PhD ’22 found that facial-analysis programs had much higher error rates when predicting the gender of darker skinned people. That finding inspired Groh, who studies human-AI collaboration, to look into whether AI models, and possibly doctors themselves, might have difficulty diagnosing skin diseases on darker shades of skin — and whether those diagnostic abilities could be improved.
“This seemed like a great opportunity to identify whether there’s a social problem going on and how we might want fix that, and also identify how to best build AI assistance into medical decision-making,” Groh says. “I’m very interested in how we can apply machine learning to real-world problems, specifically around how to help experts be better at their jobs. Medicine is a space where people are making really important decisions, and if we could improve their decision-making, we could improve patient outcomes.”
To assess doctors’ diagnostic accuracy, the researchers compiled an array of 364 images from dermatology textbooks and other sources, representing 46 skin diseases across many shades of skin.
Most of these images depicted one of eight inflammatory skin diseases, including atopic dermatitis, Lyme disease, and secondary syphilis, as well as a rare form of cancer called cutaneous T-cell lymphoma (CTCL), which can appear similar to an inflammatory skin condition. Many of these diseases, including Lyme disease, can present differently on dark and light skin.
The research team recruited subjects for the study through Sermo, a social networking site for doctors. The total study group included 389 board-certified dermatologists, 116 dermatology residents, 459 general practitioners, and 154 other types of doctors.
Each of the study participants was shown 10 of the images and asked for their top three predictions for what disease each image might represent. They were also asked if they would refer the patient for a biopsy. In addition, the general practitioners were asked if they would refer the patient to a dermatologist.
“This is not as comprehensive as in-person triage, where the doctor can examine the skin from different angles and control the lighting,” Picard says. “However, skin images are more scalable for online triage, and they are easy to input into a machine-learning algorithm, which can estimate likely diagnoses speedily.”
The researchers found that, not surprisingly, specialists in dermatology had higher accuracy rates: They classified 38 percent of the images correctly, compared to 19 percent for general practitioners.
Both of these groups lost about four percentage points in accuracy when trying to diagnose skin conditions based on images of darker skin — a statistically significant drop. Dermatologists were also less likely to refer darker skin images of CTCL for biopsy, but more likely to refer them for biopsy for noncancerous skin conditions.
“This study demonstrates clearly that there is a disparity in diagnosis of skin conditions in dark skin. This disparity is not surprising; however, I have not seen it demonstrated in the literature such a robust way. Further research should be performed to try and determine more precisely what the causative and mitigating factors of this disparity might be,” says Jenna Lester, an associate professor of dermatology and director of the Skin of Color Program at the University of California at San Francisco, who was not involved in the study.
A boost from AI
After evaluating how doctors performed on their own, the researchers also gave them additional images to analyze with assistance from an AI algorithm the researchers had developed. The researchers trained this algorithm on about 30,000 images, asking it to classify the images as one of the eight diseases that most of the images represented, plus a ninth category of “other.”
This algorithm had an accuracy rate of about 47 percent. The researchers also created another version of the algorithm with an artificially inflated success rate of 84 percent, allowing them to evaluate whether the accuracy of the model would influence doctors’ likelihood to take its recommendations.
“This allows us to evaluate AI assistance with models that are currently the best we can do, and with AI assistance that could be more accurate, maybe five years from now, with better data and models,” Groh says.
Both of these classifiers are equally accurate on light and dark skin. The researchers found that using either of these AI algorithms improved accuracy for both dermatologists (up to 60 percent) and general practitioners (up to 47 percent).
They also found that doctors were more likely to take suggestions from the higher-accuracy algorithm after it provided a few correct answers, but they rarely incorporated AI suggestions that were incorrect. This suggests that the doctors are highly skilled at ruling out diseases and won’t take AI suggestions for a disease they have already ruled out, Groh says.
“They’re pretty good at not taking AI advice when the AI is wrong and the physicians are right. That’s something that is useful to know,” he says.
While dermatologists using AI assistance showed similar increases in accuracy when looking at images of light or dark skin, general practitioners showed greater improvement on images of lighter skin than darker skin.
“This study allows us to see not only how AI assistance influences, but how it influences across levels of expertise,” Groh says. “What might be going on there is that the PCPs don't have as much experience, so they don’t know if they should rule a disease out or not because they aren’t as deep into the details of how different skin diseases might look on different shades of skin.”
The researchers hope that their findings will help stimulate medical schools and textbooks to incorporate more training on patients with darker skin. The findings could also help to guide the deployment of AI assistance programs for dermatology, which many companies are now developing.
The research was funded by the MIT Media Lab Consortium and the Harold Horowitz Student Research Fund.
How to avoid a “winner’s curse” for social programs
Back in the 1980s, researchers tested a job-training program called JOBSTART in 13 U.S. cities. In 12 locations, the program had a minimal benefit. But in San Jose, California, results were good: After a few years, workers earned about $6,500 more annually than peers not participating in it. So, in the 1990s, U.S. Department of Labor researchers implemented the program in another 12 cities. The results were not replicated, however. The initial San Jose numbers remained an outlier.
This scenario could be a consequence of something scholars call the “winner’s curse.” When programs or policies or ideas get tested, even in rigorous randomized experiments, things that function well one time may perform worse the next time out. (The term “winner’s curse” also refers to high winning bids at an auction, a different, but related, matter.)
This winner’s curse presents a problem for public officials, private-sector firm leaders, and even scientists: In choosing something that has tested well, they may be buying into decline. What goes up will often come down.
“In cases where people have multiple options, they pick the one they think is best, often based on the results of a randomized trial,” says MIT economist Isaiah Andrews. “What you will find is that if you try that program again, it will tend to be disappointing relative to the initial estimate that led people to pick it.”
Andrews is co-author of a newly published study that examines this phenomenon and provides new tools to study it, which could also help people avoid it.
The paper, “Inference on Winners,” appears in the February issue of the Quarterly Journal of Economics. The authors are Andrews, a professor in the MIT Department of Economics and an expert in econometrics, the statistical methods of the field; Toru Kitagawa, a professor of economics at Brown University; and Adam McCloskey, an associate professor of economics at the University of Colorado.
Distinguishing differences
The kind of winner’s curse addressed in this study dates back a few decades as a social science concept, and also comes up in the natural sciences: As the scholars note in the paper, the winner’s curse has been observed in genome-wide association studies, which attempt to link genes to traits.
When seemingly notable findings fail to hold up, there may be varying reasons for it. Sometimes experiments or programs are not all run the same way when people attempt to replicate them. At other times, random variation by itself can create this kind of situation.
“Imagine a world where all these programs are exactly equally effective,” Andrews says. “Well, by chance, one of them is going to look better, and you will tend to pick that one. What that means is you overestimated how effective it is, relative to the other options.” Analyzing the data well can help distinguish whether the outlier result was due to true differences in effectiveness or to random fluctuation.
To distinguish between these two possibilities, Andrews, Kitagawa, and McCloskey have developed new methods for analyzing results. In particular, they have proposed new estimators — a means of projecting results — which are “median unbiased.” That is, they are equally likely to over- and underestimate effectiveness, even in settings with a winner’s curse. The methods also produce confidence intervals that help quantify the uncertainty of these estimates. Additionally, the scholars propose “hybrid” inference approaches, which combine multiple methods of weighing research data, and, as they show, often yield more precise results than alternative methods.
With these new methods, Andrews, Kitagawa, and McCloskey establish firmer boundaries on the use of data from experiments — including confidence intervals, median unbiased estimates, and more. And to test their method’s viability, the scholars applied it to multiple instances of social science research, beginning with the JOBSTART experiment.
Intriguingly, of the different ways experimental results can become outliers, the scholars found that the San Jose result from JOBSTART was probably not just the result of random chance. The results are sufficiently different that there may have been differences in the way the program was administered, or in its setting, compared to the other programs.
The Seattle test
To further test the hybrid inference method, Andrews, Kitagawa, and McCloskey then applied it to another research issue: programs providing housing vouchers to help people move into neighborhoods where residents have greater economic mobility.
Nationwide economics studies have shown that some areas generate greater economic mobility than others, all things being equal. Spurred by these findings, other researchers collaborated with officials in King County, Washington, to develop a program to help voucher recipients move to higher-opportunity areas. However, predictions for the performance of such programs might be susceptible to a winner’s curse, since the level of opportunity in each neighborhood is imperfectly estimated.
Andrews, Kitagawa, and McCloskey thus applied the hybrid inference method to a test of this neighborhood-level data, in 50 “commuting zones” (essentially, metro areas) across the U.S. The hybrid method again helped them understand how certain the previous estimates were.
Simple estimates in this setting suggested that for children growing up in households at the 25th percentile of annual income in the U.S., housing relocation programs would create a 12.25 percentage-point gain in adult income. The hybrid inference method suggests there would instead be a 10.27 percentage-point gain — lower, but still a substantial impact.
Indeed, as the authors write in the paper, “even this smaller estimate is economically large,” and “we conclude that targeting tracts based on estimated opportunity succeeds in selecting higher-opportunity tracts on average.” At the same time, the scholars saw that their method does make a difference.
Overall, Andrews says, “the ways we measure uncertainty can actually become themselves unreliable.” That problem is compounded, he notes, “when the data tells us very little, but we’re wrongly overconfident and think the data is telling us a lot. … Ideally you would like something that is both reliable and telling us as much as possible.”
Support for the research was provided, in part, by the U.S. National Science Foundation, the Economic and Social Research Council of the U.K., and the European Research Council.