Software to empower workers on the factory floor

Manufacturers are constantly tweaking their processes to get rid of waste and improve productivity. As such, the software they use should be as nimble and responsive as the operations on their factory floors.

Instead, much of the software in today’s factories is static. In many cases, it’s developed by an outside company to work in a broad range of factories, and implemented from the top down by executives who know software can help but don’t know how best to adopt it.

That’s where MIT spinout Tulip comes in. The company has developed a customizable manufacturing app platform that connects people, machines, and sensors to help optimize processes on a shop floor. Tulip’s apps provide workers with interactive instructions, quality checks, and a way to easily communicate with managers if something is wrong.

Managers, in turn, can make changes or additions to the apps in real-time and use Tulip’s analytics dashboard to pinpoint problems with machines and assembly processes.

“With this notion of agile manufacturing [in which changes are constant], you need your software to match the philosophical process you’re using to improve your organization,” says Tulip co-founder and CTO Rony Kubat ’01, SM ’08, PhD ’12. “With our platform, we’re empowering the manufacturing engineers on the line to make changes themselves. That’s in contrast to the traditional way of making manufacturing software. It’s a bottom-up kind of thing.”

Tulip, founded by Kubat and CEO Natan Linder SM ’11, PhD ’17, is currently working with multiple Fortune 100 and Fortune 500 companies operating in 13 different countries, including Bosch, Jabil, and Kohler. Tulip’s customers make everything from shoes to jewelry, medical devices, and consumer electronics.

With the platform’s scalable design, Kubat says it can help factories of any size, as long as they employ people on the shop floor.

In that way, Tulip’s tools are empowering workers in an industry that has historically trended toward automation. As the company continues building out its platform — including adding machine vision and machine learning capabilities — it hopes to continue encouraging manufacturers to see people as an indispensable resource.

A new approach to manufacturing software

In 2012, Kubat was pursuing his PhD in the MIT Media Lab’s Fluid Interface group when he met Linder, then a graduate student. During their research, several Media Lab member companies gave the founders tours of their factory floors and introduced them to some of the production challenges they were grappling with.

“The Media Lab is such a special place,” Kubat says. “You have this contrast of an antidisciplinary mentality, where you’re putting faculty from completely different walks of life in the same building, giving it this creative wildness that is really invigorating, plus this grounding in the real world that comes from the member organizations that are part of the Media Lab.”

During those factory tours, the founders noticed similar problems across industries.

“The typical way manufacturing software is deployed is in these multiyear cycles,” Kubat says. “You sign a multimillion dollar contract that’s going to overhaul everything, and you get three years to deploy it all, and you get your screens in the end that everyone isn’t really happy with because they solve yesterday’s problems. We’re bringing a more modern approach to software development for manufacturing.”

In 2014, just as Linder completed his PhD research, the founders decided to start Tulip. (Linder would later return to MIT to defend his thesis.) Relying on their personal savings for funding, they recruited a team of students from MIT’s Undergraduate Research Opportunities Program and began building a prototype for New Balance, a Media Lab member company that has factories in New England.

“We worked really closely with the first customers to do super fast iterations to make these proofs of concept that we’d try to deploy as quickly as possible,” Kubat says. “That approach isn’t new from a software perspective — deploy fast and iterate — but it is new for the manufacturing software world.”

An engine for manufacturing

The app-based platform the founders eventually built out has little in common with the sweeping software implementations that traditionally upend factory operations for better or worse. Tulip’s apps can be installed in just one workstation then scaled up as needed.

The apps can also be designed by managers with no coding experience, over the course of an afternoon. Typically they can use Tulip’s app templates, which can be customized for common tasks like guiding a worker through an assembly process or completing a checklist.

Workers using the apps on the shop floor can submit comments on their interactive screens to do things like point out defects. Those comments are sent directly to the manager, who can make changes to the apps remotely.

“It’s a data-driven opportunity to engage the operators on the line, to gain some ownership over the process,” Kubat says.

The apps are integrated with machines and tools on the factory floor through Tulip’s router-like gateways. Those gateways also sync with sensors and cameras to give managers data from both humans and machines. All that information helps managers find bottlenecks and other factors holding back productivity.

Workers, meanwhile, are given real-time feedback on their actions from the cameras, which are usually trained on the part as it’s being assembled or on the bins the workers are reaching into. If a worker assembles a part improperly, for example, Tulip’s camera can detect the mistake, and its app can alert the worker to the error, presenting instructions on fixing it.

A demonstration of a worker assembling a part wrong, Tulip's sensors detecting the error, and then Tulip's app providing instructions for correcting the mistake.

Such quality checks can be sprinkled throughout a production line. That’s a big upgrade over traditional methods for data collection in factories, which often include a stopwatch and a clipboard, the founders say.

“That process is expensive,” Kubat says of traditional data collection methods. “It’s also biased, because when you’re being observed you might behave differently. It’s also a sampling of things, not the true picture. Our take is that all of that execution data should be something you get for free from a system that gives you additional value.”

The data Tulip collects are channeled into its analytics dashboard, which can be used to make customized tables displaying certain metrics to managers and shop floor workers.

In April, the company launched its first machine vision feature, which further helps workers minimize mistakes and improve productivity. Those objectives are in line with Tulip’s broader goal of empowering workers in factories rather than replacing them.

“We’re helping companies launch products faster and improve efficiency,” Kubat says. “That means, because you can reduce the cost of making products with people, you push back the [pressure of] automation. You don’t need automation to give you quality at scale. This has the potential to really change the dynamics of how products are delivered to the public.”

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Speeding up drug discovery for brain diseases

A research team led by Whitehead Institute scientists has identified 30 distinct chemical compounds — 20 of which are drugs undergoing clinical trial or have already been approved by the FDA — that boost the protein production activity of a critical gene in the brain and improve symptoms of Rett syndrome, a rare neurodevelopmental condition that often provokes autism-like behaviors in patients. The new study, conducted in human cells and mice, helps illuminate the biology of an important gene, called KCC2, which is implicated in a variety of brain diseases, including autism, epilepsy, schizophrenia, and depression. The researchers’ findings, published in the July 31 online issue of Science Translational Medicine, could help spur the development of new treatments for a host of devastating brain disorders.

“There’s increasing evidence that KCC2 plays important roles in several different disorders of the brain, suggesting that it may act as a common driver of neurological dysfunction,” says senior author Rudolf Jaenisch, a founding member of Whitehead Institute and professor of biology at MIT. “These drugs we’ve identified may help speed up the development of much-needed treatments.”

KCC2 works exclusively in the brain and spinal cord, carrying ions in and out of specialized cells known as neurons. This shuttling of electrically charged molecules helps maintain the cells’ electrochemical makeup, enabling neurons to fire when they need to and to remain idle when they don’t. If this delicate balance is upset, brain function and development go awry.

Disruptions in KCC2 function have been linked to several human brain disorders, including Rett syndrome (RTT), a progressive and often debilitating disorder that typically emerges early in life in girls and can involve disordered movement, seizures, and communication difficulties. Currently, there is no effective treatment for RTT.

Jaenisch and his colleagues, led by first author Xin Tang, devised a high-throughput screen assay to uncover drugs that increase KCC2 gene activity. Using CRISPR/Cas9 genome editing and stem cell technologies, they engineered human neurons to provide rapid readouts of the amount of KCC2 protein produced. The researchers created these so-called reporter cells from both healthy human neurons as well as RTT neurons that carry disease-causing mutations in the MECP2 gene. These reporter neurons were then fed into a drug-screening pipeline to find chemical compounds that can enhance KCC2 gene activity.

Tang and his colleagues screened over 900 chemical compounds, focusing on those that have been FDA-approved for use in other conditions, such as cancer, or have undergone at least some level of clinical testing. “The beauty of this approach is that many of these drugs have been studied in the context of non-brain diseases, so the mechanisms of action are known,” says Tang. “Such molecular insights enable us to learn how the KCC2 gene is regulated in neurons, while also identifying compounds with potential therapeutic value.”

The Whitehead Institute team identified a total of 30 drugs with KCC2-enhancing activity. These compounds, referred to as KEECs (short for KCC2 expression-enhancing compounds), work in a variety of ways. Some block a molecular pathway, called FLT3, which is found to be overactive in some forms of leukemia. Others inhibit the GSK3b pathway that has been implicated in several brain diseases. Another KEEC acts on SIRT1, which plays a key role in a variety of biological processes, including aging.

In followup experiments, the researchers exposed RTT neurons and mouse models to KEEC treatment and found that some compounds can reverse certain defects associated with the disease, including abnormalities in neuronal signaling, breathing, and movement. These efforts were made possible by a collaboration with Mriganka Sur’s group at the Picower Institute for Learning and Memory, in which Keji Li and colleagues led the behavioral experiments in mice that were essential for revealing the drugs’ potency.

“Our findings illustrate the power of an unbiased approach for discovering drugs that could significantly improve the treatment of neurological disease,” says Jaenisch. “And because we are starting with known drugs, the path to clinical translation is likely to be much shorter.”

In addition to speeding up drug development for Rett syndrome, the researchers’ unique drug-screening strategy, which harnesses an engineered gene-specific reporter to unearth promising drugs, can also be applied to other important disease-related genes in the brain. “Many seemingly distinct brain diseases share common root causes of abnormal gene expression or disrupted signaling pathways,” says Tang. “We believe our method has broad applicability and could help catalyze therapeutic discovery for a wide range of neurological conditions.”

Support for this work was provided by the National Institutes of Health, the Simons Foundation Autism Research Initiative, the Simons Center for the Social Brain at MIT, the Rett Syndrome Research Trust, the International Rett Syndrome Foundation, the Damon Runyon Cancer Foundation, and the National Cancer Institute.

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Lowering emissions without breaking the bank

India’s economy is booming, driving up electric power consumption to unprecedented levels. The nation’s installed electricity capacity, which increased fivefold in the past three decades, is expected to triple over the next 20 years. At the same time, India has committed to limiting its carbon dioxide emissions growth; its Paris Agreement climate pledge is to decrease its carbon dioxide emissions intensity of GDP (CO₂ emissions per unit of GDP) by 33 to 35 percent by 2030 from 2005 levels, and to boost carbon-free power to about 40 percent of installed capacity in 2030.

Can India reach its climate targets without adversely impacting its rate of economic growth — now estimated at 7 percent annually — and what policy strategy would be most effective in achieving that goal?

To address these questions, researchers from the MIT Joint Program on the Science and Policy of Global Change developed an economy-wide model of India with energy-sector detail, and applied it to simulate the achievement of each component of the nation’s Paris pledge. Representing the emissions intensity target with an economy-wide carbon price and the installed capacity target with a Renewable Portfolio Standard (RPS), they assessed the economic implications of three policy scenarios — carbon pricing, an RPS, and a combination of carbon pricing with an RPS. Their findings appear in the journal Climate Change Economics.

As a starting point, the researchers determined that imposing an economy-wide emissions reduction policy alone to meet the target emissions intensity, simulated through a carbon price, would result in the lowest cost to India’s economy. This approach would lead to emissions reductions not only in the electric power sector but throughout the economy. By contrast, they found that an RPS, which would enforce a minimum level of currently more expensive carbon-free electricity, would have the highest per-ton cost — more than 10 times higher than the economy-wide CO₂ intensity policy.

“In our modeling framework, allowing emissions reduction across all sectors of the economy through an economy-wide carbon price ensures that the least-cost pathways for reducing emissions are observed,” says Arun Singh, lead author of the study. “This is constrained when electricity sector-specific targets are introduced. If renewable electricity costs are higher than the average cost of electricity, a higher share of renewables in the electricity mix makes electricity costlier, and the impacts of higher electricity prices reverberate across the economy.” A former research assistant at the MIT joint program and graduate student at the MIT Institute for Data, Systems and Society’s Technology and Policy Program, Singh now serves as an energy specialist consultant at the World Bank.

Combining an economy-wide carbon price with an RPS would, however, bring the price per ton of CO₂ down from $23.38/tCO₂ (in 2011 U.S. dollars) under a standalone carbon-pricing policy to a far more politically viable $6.17/tCO₂ when an RPS is added. If wind and solar costs decline significantly, the cost to the economy would decrease considerably; at the lowest wind and solar cost levels simulated, the model projects that economic losses under a carbon price with RPS would be only slightly higher than those under a standalone carbon price. Thus, declining wind and solar costs could enable India to set more ambitious climate policies in future years without significantly impeding economic growth.

“Globally, it has been politically impossible to introduce CO₂ prices high enough to mitigate climate change in line with the Paris Agreement goals,” says Valerie Karplus, co-author and assistant professor at the MIT Sloan School of Management. “Combining pricing approaches with technology-specific policies may be important in India, as they have elsewhere, for the politics to work.”

Developed by Singh in collaboration with his master’s thesis advisors at MIT (Karplus, and MIT Joint Program Principal Research Scientist Niven Winchester, who also co-authored the study), the economy-wide model of India enables researchers to gauge the cost-effectiveness and efficiency of different technology and policy choices designed to transition the country to a low-carbon energy system.

“The study provides important insights about the costs of different policies, which are relevant to nations that have pledged emission targets under the Paris Agreement but have not yet developed polices to meet those targets,” says Winchester, who is also a senior fellow at Motu Economic and Public Policy Research.

The study was supported by the MIT Tata Center for Technology and Design, the Energy Information Administration of the U.S. Department of Energy, and the MIT Joint Program.

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Why did my classifier just mistake a turtle for a rifle?

A few years ago, the idea of tricking a computer vision system by subtly altering pixels in an image or hacking a street sign seemed like more of a hypothetical threat than anything to seriously worry about. After all, a self-driving car in the real world would perceive a manipulated object from multiple viewpoints, cancelling out any misleading information. At least, that’s what one study claimed.

“We thought, there’s no way that’s true!” says MIT PhD student Andrew Ilyas, then a sophomore at MIT. He and his friends — Anish Athalye, Logan Engstrom, and Jessy Lin — holed up at the MIT Student Center and came up with an experiment to refute the study. They would print a set of three-dimensional turtles and show that a computer vision classifier could mistake them for rifles.

The results of their experiments, published at last year’s International Conference on Machine Learning (ICML), were widely covered in the media, and served as a reminder of just how vulnerable the artificial intelligence systems behind self-driving cars and face-recognition software could be. “Even if you don’t think a mean attacker is going to perturb your stop sign, it’s troubling that it’s a possibility,” says Ilyas. “Adversarial example research is about optimizing for the worst case instead of the average case.”

With no faculty co-authors to vouch for them, Ilyas and his friends published their study under the pseudonym “Lab 6,” a play on Course 6, their Department of Electrical Engineering and Computer Science (EECS) major. Ilyas and Engstrom, now an MIT graduate student, would go on to publish five more papers together, with a half-dozen more in the pipeline.

At the time, the risk posed by adversarial examples was still poorly understood. Yann LeCun, the head of Facebook AI, famously downplayed the problem on Twitter. “Here’s one of the pioneers of deep learning saying, this is how it is, and they say, nah!” says EECS Professor Aleksander Madry. “It just didn’t sound right to them and they were determined to prove why. Their audacity is very MIT.” 

The extent of the problem has grown clearer. In 2017, IBM researcher Pin-Yu Chen showed that a computer vision model could be compromised in a so-called black-box attack by simply feeding it progressively altered images until one caused the system to fail. Expanding on Chen’s work at ICML last year, the Lab 6 team highlighted multiple cases in which classifiers could be duped into confusing cats and skiers for guacamole and dogs, respectively.

This spring, Ilyas, Engstrom, and Madry presented a framework at ICML for making black-box attacks several times faster by exploiting information gained from each spoofing attempt. The ability to mount more efficient black-box attacks allows engineers to redesign their models to be that much more resilient.

“When I met Andrew and Logan as undergraduates, they already seemed like experienced researchers,” says Chen, who now works with them via the MIT-IBM Watson AI Lab. “They’re also great collaborators. If one is talking, the other jumps in and finishes his thought.”

That dynamic was on display recently as Ilyas and Engstrom sat down in Stata to discuss their work. Ilyas seemed introspective and cautious, Engstrom, outgoing, and at times, brash.

“In research, we argue a lot,” says Ilyas. “If you’re too similar you reinforce each other’s bad ideas.” Engstrom nodded. “It can get very tense.”

When it comes time to write papers, they take turns at the keyboard. “If it’s me, I add words,” says Ilyas. “If it’s me, I cut words,” says Engstrom.

Engstrom joined Madry’s lab for a SuperUROP project as a junior; Ilyas joined last fall as a first-year PhD student after finishing his undergraduate and MEng degrees early. Faced with offers from other top graduate schools, Ilyas opted to stay at MIT. A year later, Engstrom followed.

This spring the pair was back in the news again, with a new way of looking at adversarial examples: not as bugs, but as features corresponding to patterns too subtle for humans to perceive that are still useful to learning algorithms. We know instinctively that people and machines see the world differently, but the paper showed that the difference could be isolated and measured.

They trained a model to identify cats based on “robust” features recognizable to humans, and “non-robust” features that humans typically overlook, and found that visual classifiers could just as easily identify a cat from non-robust features as robust. If anything, the model seemed to rely more on the non-robust features, suggesting that as accuracy improves, the model may become more susceptible to adversarial examples. 

“The only thing that makes these features special is that we as humans are not sensitive to them,” Ilyas told Wired.

Their eureka moment came late one night in Madry’s lab, as they often do, following hours of talking. “Conversation is the most powerful tool for scientific discovery,” Madry likes to say. The team quickly sketched out experiments to test their idea.

“There are many beautiful theories proposed in deep learning,” says Madry. “But no hypothesis can be accepted until you come up with a way of verifying it.”

“This is a new field,” he adds. “We don’t know the answers to the questions, and I would argue we don’t even know the right questions. Andrew and Logan have the brilliance and drive to help lead the way.”

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Jack Kerrebrock, professor emeritus of aeronautics and astronautics, dies at 91

Jack L. Kerrebrock, professor emeritus of aeronautics and astronautics at MIT, died at home on July 19. He was 91.

Born in Los Angeles in 1928, Kerrebrock received his BS in 1950 from Oregon State University, his MS in 1951 from Yale University, and his PhD in 1956 from Caltech. With a passion for aerospace, he held positions with the National Advisory Committee for Aeronautics, Caltech, and Oak Ridge National Laboratory before joining the faculty of MIT as an assistant professor in 1960.

Promoted to associate professor in 1962 and to full professor in 1965, Kerrebrock founded and directed the Department of Aeronautics and Astronautics’ Space Propulsion Laboratory from 1962 until 1976, when it merged with the department’s Gas Turbine Laboratory, of which he had become director in 1968. In 1978, he accepted the role of head of the Department of Aeronautics and Astronautics (AeroAstro).

Kerrebrock enjoyed an international reputation as an expert in the development of propulsion systems for aircraft and spacecraft. Over the years, he served as chair or member of multiple advisory committees — both government and professional — and as NASA associate administrator of aeronautics and space technology.

As associate director of engineering, Kerrebrock was the faculty leader of the Daedalus Project in AeroAstro. Daedalus was a human-powered aircraft that, on 23 April 1988, flew a distance of 72.4 miles (115.11 kilometers) in three hours, 54 minutes, from Heraklion on the island of Crete to the island of Santorini. Daedalus still holds the world record for human-powered flight. This flight was the culmination of a decade of work by MIT students and alumni and made a major contribution to the understanding of the science and engineering of human-powered flight.

Elected to the National Academy of Engineering in 1978, Kerrebrock was the recipient of numerous accolades, including election to the status goof honorary fellow of the American Institute of Aeronautics and Astronautics, as well as the Explorers Club and the American Academy of Arts and Sciences. A member of the American Association for the Advancement of Science, Sigma Xi, Tau Beta Pi, and Phi Kappa Phi, he received NASA’s Distinguished Service Medal in 1983. He was also a contributor to the Intergovernmental  Panel on Climate Change, which along with Al Gore won the Nobel Prize in 2007.

Although a luminary in his field, Kerrebrock — an enthusiastic outdoorsman — was perhaps never happier than when climbing a mountain, hiking a wilderness trail, or leading a group of young people through ice and snow to teach them independence and survival skills. He ran his first Boston Marathon in his early 50s on a whim, with no training, following that with several more marathons, including the Marine Corps Marathon in Washington.

Kerrebrock and his wife Crickett traveled widely, to destinations including South Africa, Scotland, Tuscany, Paris, and a very special trip to Canaveral for one of the last Space Shuttle launches, where he was able to introduce his wife to his friend Neil Armstrong, who was one of her heroes.

Kerrebrock was married to Rosemary “Crickett” Redmond (Keough) Kerrebrock for the last 12 years of his life. He was previously married for 50 years to the late Bernice “Vickie” (Veverka) Kerrebrock, who died in 2003. In addition to his wife, Kerrebrock leaves behind two children, Nancy Kerrebrock (Clint Cummins) of Palo Alto, California, and Peter Kerrebrock (Anne) of Hingham, Masachusetts; and five grandchildren, Lewis Kerrebrock, Gale Kerrebrock, Renata Cummins, Skyler Cummins, and Lance Cummins. He was preceded in death by his son Christopher Kerrebrock, brother Glenn, and sister Ann. He also is remembered fondly by the Redmond children, Paul J. Redmond Jr. and his partner Joe Palombo, Kelly Redmond and her husband Philip Davis, Maura Redmond, Meaghan Winokur and James Winokur and their children, Laine and Alicia.

A public memorial service is being planned at MIT and will be announced soon. In lieu of flowers, contributions in his memory may be made to the Jack and Vickie Kerrebrock Fellowship Fund, Massachusetts Institute of Technology, 600 Memorial Drive, Cambridge MA 02139.

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Professor Emeritus Samuel Bowring, pioneering geologist and expert in geochronology, dies at 65

Professor Emeritus Samuel A. Bowring, a longtime MIT professor of geology, died on July 17 at age 65.

Known for his exceptional skill as a field geologist and innovator in uranium-lead isotopic geochronology, Bowring worked to achieve unprecedented analytical precision and accuracy in calibrating the geologic record and reconstructing the co-evolution of life and the solid Earth.

No dates, no rates

A favorite aphorism, “No dates, no rates,” appeared in many of Bowring’s lectures and talks — meaning, to fully understand the past events preserved in the rock record you have to understand their timing. One of his earliest major contributions, which transformed what geologist know about the early evolution of the Earth, was his work in the 1980s on the Acasta gneiss complex, a rock body in northwestern Canada, pushing back the date of the oldest-known rocks to 4.03 billion years. The granitic samples he collected from an outcrop on an island in the remote Acasta River basin turned out to be rare remnants of the Earth’s earliest crust.  

“What is more important about the Acasta gneiss complex than its 4.03 billion year age alone is its character, which Sam recognized and documented,” said Paul Hoffman, Harvard University Sturgis Hooper Professor Emeritus of Geology and career-long Bowring collaborator and friend. Hoffman explains that the Acasta rocks, paired with Bowring’s advocacy, fundamentally changed geologists’ understanding of continental formation. Prior to Bowring’s work the prevailing view was that the continents had steadily grown over geologic time. But, with these ancient gneiss samples, Bowring was able to characterize a complex history which predated the moment of their crystallization, which points instead to a process of ongoing crustal “recycling” — where rock near the Earth’s surface, through the mechanisms of plate tectonics, is subsumed and transformed by the mantle’s convective currents. According to Hoffman, “Sam’s fascination with the creation and preservation of continental crust never left him, whether he was at Great Bear Lake, the Grand Canyon, or the High Cascades in Washington State.”

Beyond studying the physical processes which shape the lithosphere, Bowring also sought to understand those which shape the biosphere. His work on sedimentary layers of the Precambrian/Cambrian boundary age determined the timing and rate of the pivotal biological event known as the Cambrian Explosion, beginning nearly 540 million years ago. He was able to establish that the Early Cambrian period which saw the most dramatic burst of evolutionary activity and animal diversity ever known — including the first emergence of chordates, brachiopods, and arthropods — spanned not 10 to 50 million years as was previously-believed, but instead lasted a mere 5 to 6 million years.

Longtime friend and colleague Tim Grove, the Robert R. Shrock Professor of Earth and Planetary Sciences at MIT, wrote of the achievement in a citation for the American Geophysical Union when Bowring was awarded the Walter H. Bucher Medal in 2016: “Sam showed that during this brief time interval more phyla than have ever since existed on Earth came into existence. This represents a truly profound and astonishing new discovery about how life evolved on Earth.”

Bowring also established the timing and duration of what has come to be known as “The Great Dying”: the largest of Earth’s five major mass extinctions, which marked the end of the Permian period and saw the elimination of over 96% of marine species and about 70% of species on land. Rocks collected by Bowring and collaborators from sites across China spanning the Permian-Triassic boundary revealed that the ecological collapse happened at breakneck speed — occurring in less than 30,000 years at a rate many times faster than previous estimates — and with little-to-no warning in geological terms.

A world-expert in uranium-lead isotopic dating, by 2002 Bowring began to see what he later termed “the double-edged sword of high-precision geochronology.” As the field experienced rapid advancements in precision, resolution, and quantitative stratigraphic analyses, many new techniques were developing in parallel. He recognized that without calibration and intercalibration of radioisotopic dating methods and quantitative chronostratigraphy, their accuracy and capacity as individual tools for understanding deep time were diminished. In response, he and colleague Doug Erwin conceived the EARTHTIME Initiative, a community-based effort to foster collaboration across the disciplines and eliminate inter-laboratory and inter-technique biases. Bowring’s common refrain to members to “check our egos at the door” reflected his unwavering goal to push the accuracy of geochronology to new levels, and helped the initiative build consensus and develop best practices and protocols. EARTHTIME continues to lead international workshops, expanding beyond topics of calibration and standardization to engage with the broader geoscience community, seeking to understand the rock record in ever more refined and nuanced ways.

“If the art of geochronology is the rendering of dates in their proper geologic context, Sam is our Michelangelo,” former MIT Department of Earth, Atmospheric and Planetary Sciences (EAPS) department head and close friend and colleague Tom Jordan said of Bowring. “He has always insisted that knowing what you are dating and why are as important as fixing the date itself; that the precision of absolute dating is most powerful when samples can be placed precisely in section.”

Bowring’s interest in the applications of tracer isotopes to examine Earth systems also extended to their utility in tracking environmental contaminants. His lab has developed methods for not only tracing naturally-occurring sources and establishing natural regional baselines, but also for documenting variations which correlate with anthropogenic inputs associated with urbanization and industrialization.

A dedicated teacher and mentor

Bowring joined the faculty of EAPS at MIT in 1991 where, in addition to fostering the careers of over two dozen graduate students and postdocs, he demonstrated a career-long commitment to advancing undergraduate education. For more than 20 years Bowring served as a first-year and undergraduate advisor, eventually being named a Margaret MacVicar Faculty Fellow in 2006 by the Institute program which recognizes faculty for, “exemplary and sustained contributions to the teaching and education of undergraduates at MIT,” and later earning the MIT Everett Moore Baker Memorial Award for Excellence in Undergraduate Teaching in 2007. He was also deeply involved in helping to shape curricula, serving on the MIT Committee on Curriculum from 2007 to 2010. He also served as chair of the EAPS Program in Geology and Geochemistry from 1999 until 2002, at which time he became chair of the EAPS Undergraduate Committee, serving until 2015. As a field geologist, he took his keen interest in engaging students to off-campus venues, leading annual trips into the field which were fixtures in the department’s calendar — from western Massachusetts to Yellowstone to the Las Vegas desert.

“Sam was an exceptionally effective and dedicated undergraduate educator, having gone well ‘above and beyond’ for EAPS and our students,” recalls Grove. “He took on more undergraduate teaching than any other member of our department in the last 25 years and was deeply committed to the importance of training undergraduates in the field — providing students with hands-on experience and using real-world geology to inspire and teach fundamentals.”

Bowring also was instrumental in guiding Terrascope, a first-year learning community created jointly by EAPS and the Department of Civil and Environmental Engineering in 2002. Bowring became associate director of the program in 2006, going on to serve as director from 2008 to 2015. The nationally-recognized program, which has been the subject of several academic papers and has grown to become one of MIT’s largest first-year communities, asks students with diverse research interests to tackle complex, global problems involving sustainability, climate, and the Earth system in a series of team-oriented, student-driven classes. In 2013, Bowring and his coauthors described the innovative curriculum by saying, “Our emphasis is on using a multidisciplinary approach to show that understanding the geosciences … is important to the students' world view, whether they know it or not. We believe it is our responsibility to teach as many students as we can about the Earth system, and in our experience, Terrascope students have a greatly expanded consciousness about the Earth and humans’ effect on it.”

Born in Portsmouth, New Hampshire, on Sept. 27, 1953, Bowring was raised in Durham, New Hampshire, where he also later attended the University of New Hampshire. After graduating in 1976 with a bachelor’s degree in geology, he went on to study at the New Mexico Institute of Mining and Technology, where he earned a master’s in 1980.

At the University of Kansas, Bowring had the opportunity early on to work with PhD advisor Randall Van Schmus on a project in the Northwest Territories of Canada (NWT) — where he was first introduced to collaborator Hoffman — which laid the foundation for both his PhD and continuing studies in the NWT’s Proterozozoic Wopmay orogen after joining the faculty at Washington University in St. Louis (WU) in 1984. It was as an assistant professor at WU that Bowring made his seminal analysis of the Acasta gneiss from the region, along with Ian Williams from the Australian National University.

In addition to being named a member of the National Academy of Sciences and the American Academy for the Advancement of Science, Bowring, the Robert R. Schrock Emeritus Professor of Geology, was a fellow of the American Geophysical Union and was recognized by the organization with both the Norman L. Bowen Award and Walter H. Bucher Medal. He was also a fellow of both the Geochemical Society and the Geological Society of America.

He is survived by his wife of 30 years, Kristine M. (Fox) Bowring, two stepdaughters, Kelley Kintner and Sara Henrick, as well as his siblings, James Bowring, Joseph Bowring, and Margaret Ann Bowring-Price. At the family’s request, there will be no formal services.

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School of Engineering second quarter 2019 awards

Members of the MIT engineering faculty receive many awards in recognition of their scholarship, service, and overall excellence. Every quarter, the School of Engineering publicly recognizes their achievements by highlighting the honors, prizes, and medals won by faculty working in their academic departments, labs, and centers.

Antione Allanore, of the Department of Materials Science and Engineering, won the Elsevier Atlas Award on May 15; he also won third place for best conference proceedings manuscript at the TMS Annual Meeting and Exhibition on March 14.

Dimitri Antoniada, of the Department of Electrical Engineering and Computer Science, was elected to the American Academy of Arts and Sciences on April 18.

Martin Bazant, of the Department of Chemical Engineering, was named a fellow of the American Physical Society on Oct. 17, 2018.

Sangeeta Bhatia, of the Department of Electrical Engineering and Computer Science, was awarded an honorary degree of doctor of science from the University of London on July 4; she was also awarded the Othmer Gold Medal from the Science History Institute on March 8.

Richard Braatz, of the Department of Chemical Engineering, was elected to the National Academy of Engineering on Feb. 11.

Tamara Broderick, of the Department of Electrical Engineering and Computer Science, won the Notable Paper Award at the International Conference on Artificial Intelligence and Statistics on April 18.

Fikile Brushett, of the Department of Chemical Engineering, won the Electrochemical Society’s 2019 Supraniam Srinivasan Young Investigator Award on Oct. 9, 2018; he was also named to the annual Talented Twelve list by Chemical Engineering News on Aug. 22, 2017.

Vincent W.S. Chan, of the Department of Electrical Engineering and Computer Science, received the Best Paper Award at the IEEE International Conference on Communications on May 10.

Arup Chakraborty, of the Department of Chemical Engineering, won a Guggenheim Fellowship on March 4, 2018.

Anantha Chandrakasan, of the Department of Electrical Engineering and Computer Science, was elected to American Academy of Arts and Sciences on April 18.

Kwanghun Chung, of the Department of Chemical Engineering, was awarded a Presidential Early Career Awards for Scientists and Engineers on July 10.

Constantinos Daskalakis, of the Department of Electrical Engineering and Computer Science, won the Grace Murray Hopper Award for Outstanding Computer Scientist from the Association of Computing Machinery on May 8.

Jesús del Alamo, Department of Electrical Engineering and Computer Science, was named a Fellow of the Materials Research Society on May 2.

Elazer R. Edelman, of the Institute for Medical Engineering and Science, won the Excellence in Mentoring Award from the Corrigan Minehan Heart Center at the Massachusetts General Hospital on June 18.

Karen K. Gleason, of the Department of Chemical Engineering, was honored with the John M. Prausnitz Institute AIChE Lecturer Award by the American Institute of Chemical Engineers on April 3.

Bill Green, of the Department of Chemical Engineering, won the R.H. Wilhelm Award in Chemical Reaction Engineering from the American Institute of Chemical Engineers on July 19.

Paula Hammond, of the Department of Chemical Engineering, was honored with the Margaret H. Rousseau Pioneer Award for Lifetime Achievement by a Woman Chemical Engineer from the American Institute of Chemical Engineers on June 1; she also recieved the American Chemical Society Award in Applied Polymer Science on Jan. 8, 2018.

Ruonan Han, of the Department of Electrical Engineering and Computer Science, won the Outstanding Researcher Award from Intel Corporation on April 1.

Song Han, of the Department of Electrical Engineering and Computer Science, was named to the annual list of Innovators Under 35 by MIT Technology Review on June 25.

Klavs Jensen, of the Department of Chemical Engineering, was honored with the John M. Prausnitz Institute AIChE Lecturer Award by the American Institute of Chemical Engineers on Aug. 21, 2018; he also recognized with the Corning International Prize for Outstanding Work in Continuous Flow Reactors on May 1, 2018.

David R. Karger, of the Department of Electrical Engineering and Computer Science, was elected to the American Academy of Arts and Sciences on April 18.

Dina Katbi, of the Department of Electrical Engineering and Computer Science, was named a Great Immigrant by the Carnegie Corporation of New York on June 27.

Manolis Kellis, of the Department of Electrical Engineering and Computer Science, was honored as a speaker by the Mendel Lectures Committee on May 2.

Jeehwan Kim, of the Department of Mechanical Engineering, awarded the Young Faculty Award from the Defense Advanced Research Projects Agency on May 28.

Heather Kulik, of the Department of Chemical Engineering, was awarded a CAREER award from the National Science Foundation on Feb. 7; she won the Journal of Physical Chemistry and PHYS Division Lectureship Award from the Journal of Physical Chemistry and the Physical Chemistry Division of the American Chemical Society on July 1; she was honored with the Marion Milligan Mason Award Oct. 26, 2018; she earned the DARPA Young Faculty Award on June 20, 2018; she also won the Young Investigator Award from the Office of Naval Research on Feb. 21, 2018.

Robert Langer, of the Department of Chemical Engineering, won the Dreyfus Prize for Chemistry in Support of Human Health from the Camille and Henry Dreyfus Foundation on May 14; he also was named on the 2018 Medicine Maker’s Power List on May 8, 2018; he was also named U.S. Science Envoy on June 18, 2018.

John Lienhard, of the Department of Mechanical Engineering, recevied the Edward F. Obert Award from the American Society of Mechanical Engineers on May 28.

Nancy Lynch, of the Department of Electrical Engineering and Computer Science, won TDCP Outstanding Technical Achievement Award from the Institute for Electrical and Electronics Engineers on April 18.

Karthish Manthiram, of the Department of Chemical Engineering, received a Petroleum Research Fund grant from the American Chemical Society on June 28.

Benedetto Marelli, of the Department of Civil and Environmental Engineering, won a Presidential Early Career Awards for Scientists and Engineers on July 10.

Robert T. Morris, of the Department of Electrical Engineering and Computer Science, was elected to the National Academy of Engineering on Feb. 11.

Heidi Nepf, of the Department of Civil and Environmental Engineering, won the Hunter Rouse Hydraulic Engineering Award from the American Society of Civil Engineers on May 20.

Dava Newman, of the Department of Aeronautics and Astronautics, was named co-chair of the Committee on Biological and Physical Sciences in Space by the National Academies of Sciences, Engineering, and Medicine on April 8.

Kristala Prather, of the Department of Chemical Engineering, was elected fellow of American Association for the Advancement of Science on Nov. 27, 2018.

Ellen Roche, of the Department of Mechanical Engineering, won the Child Health Research Award from the Charles H. Hood Foundation on June 13; she was also awarded a CAREER award from the National Science Foundation on Feb. 20.

Yuriy Román, of the Department of Chemical Engineering, received the Early Career in Catalysis Award from the American Chemical Society Catalysis Science and Technology Division on Feb. 28; he also received the Rutherford Aris Award from the North American Symposium on Chemical Reaction Engineering on March 10.

Julian Shun, of the Department of Electrical Engineering and Computer Science, awarded a CAREER award from the National Science Foundation on Feb. 26.

Hadley Sikes, of the Department of Chemical Engineering, was honored with the Best of BIOT award from the ACS Division of Biochemical Technology on Sept. 9, 2018.

Zachary Smith, of the Department of Chemical Engineering, was awarded the Doctoral New Investigator Grant from the American Chemical Society, on May 22.

Michael Strano, of the Department of Chemical Engineering, won the Andreas Acrivos Award for Professional Progress in Chemical Engineering from American Institute of Chemical Engineers on July 1.

Greg Stephanopoulos, of the Department of Chemical Engineering, was honored with the Gaden Award for Biotechnology and Bioengineering on March 31.

Harry Tuller, of the Department of Materials Science and Engineering, received the Thomas Egleston Medal for Distinguished Engineering Achievement from Columbia University on May 3.

Caroline Uhler, of the Department of Electrical Engineering and Computer Science, won the Simons Investigator Award in the Mathematical Model of Living Systems from Simmons Foundation on June 19.

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University of Regensburg and MIT-Germany expand partnership

“MISTI brought me beyond the tourism level of being in Germany,” says MIT junior Tatsuya Daniel. “Through my Global Teaching Labs experience with the University of Regensburg, I was able to be directly immersed in the German education style.” Daniel is a student in the MIT-Germany Program and is one of many to benefit from the growing partnership between the program and the University of Regensburg (UR). MIT International Science and Technology Initiatives (MISTI) creates relationships with universities and other organizations around the world, providing students and faculty with opportunities to broaden their research and education. UR was the first university to create an official collaboration with MIT-Germany, helping the program create a model that has now been adopted by other German university partners.

The original agreement was built on a solid foundation of student experiences, and the renewal continues and expands UR’s unique versions of MISTI’s Global Teaching Labs (GTL) and Global Startup Labs (GSL), as well as opportunities for research.

“The renewal of the partnership with the University of Regensburg is an exciting milestone for the MIT-Germany Program,” says faculty director Markus Buehler. “It will allow MIT students to gain valuable teaching and research experiences and participate in cutting edge research. For example, one of our students has joined their theoretical physics department this summer to work on conducting lattice quantum chromodynamics calculations of hadronic observables. We anticipate that many other MIT students will have the opportunity to live, learn, and work in Bavaria through this partnership.”

GTL has proven to be one of the most popular pieces of the collaboration, giving MIT students the opportunity to learn through teaching. GTL challenges MIT students to synthesize and present what they know, work in a team, and communicate with peers of a different cultural background, all while sharing MIT's unique approach to science and engineering education with high school students around the world.

Daniel speaks highly of his experience as a GTL instructor from both an educational and cultural perspective. “By working with UR professors and students, we were able to identify differences in how students are taught in the U.S. and Germany. This helped our preparation by ensuring that we were able to clarify any points of confusion among the high school students.”

Regensburg’s Entrepreneurship Boot Camp is modeled after MISTI’s successful GSL programs. A small team of MIT graduate and undergraduate students work with UR Professor Christian Wolff to create and deliver a six-week entrepreneurship seminar for students in the UR Media Informatics MSc program.

“This was a wonderful experience for me,” said MIT doctoral candidate Madhav Kumar, who visited UR as a GSL instructor last summer. “Teaching entrepreneurship to students with advanced technical degrees was both challenging and extremely enriching. Our one-on-one brainstorming sessions with UR student groups helped us learn each other’s perspectives much better in this shared entrepreneurial journey."  

UR students benefit from participating in the intensive curriculum that ranges from direct exercises to guest speakers “I learned a lot in the GSL,” said UR participant Andrea Fischer. “We not only learned about business, we also trained to speak in front of people and give presentations. And the guest speakers were great — entrepreneurs talking not only about their success, but about their failures as well.”

Another unique feature of the UR partnership is the development of short annual workshops or roundtables on a variety of topics, held at MIT and UR alternately. Past workshops have addressed the latest pedagogical techniques in STEM to select groups of faculty and students. This cultural exchange has proven valuable so far, as participants are able to compare and contrast their experience and best practices.

"We were very surprised to see how diverse and with which original methodical approaches university teaching is done at MIT,” said 2017 workshop attendee Oliver Tempner, professor of chemistry didactics. “I hope that more and more university teachers in Germany will take these student-centered learning approaches into account in their seminars."

This commitment to a student-focused educational experience was also highlighted by participant Arne Dittmer, professor of biology didactics. "I was very impressed by all the activities to improve academic teaching. All the people we met were highly motivated to enhance the culture of teaching and learning at MIT."

New workshop topics are selected each year, and the next session may focus on Regensburg’s deep expertise in physics research. This expansion and strengthening of faculty programs was a critical goal of the renewal.

Another exciting faculty-facing component of the new agreement is the integration of the University of Regensburg/MIT-Germany partnership into the MISTI Global Seed Fund (GSF) program. The inaugural year will provide one award to support the international exchange of faculty and students to jump-start new collaborative projects. The 2019-20 GSF call for proposals is now open for this and the rest of the MISTI funds.

“The creation of a dedicated seed fund is an exciting new piece of our partnership,” says Justin Leahey, MIT-Germany program manager. “It will be a great complement to our workshops and will further strengthen MIT’s ties with the University of Regensburg.” 

MIT International Science and Technology Initiatives (MISTI) creates experiential learning opportunities across the globe for MIT students that increase their ability to understand and address real-world problems. MISTI’s Global Seed Funds grant program promotes collaboration between MIT faculty members and their counterparts abroad. A nucleus of international activity at MIT, MISTI is made possible through partnerships with corporations, governments, universities, foundations, and individuals. MISTI is located in the Center for International Studies within the School of Humanities, Arts, and Social Sciences.

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New material could make it easier to remove colon polyps

More than 15 million colonoscopies are performed in the United States every year, and in at least 20 percent of those, gastroenterologists end up removing precancerous growths from the colon. Eliminating these early-stage lesions, known as polyps, is the best way to prevent colon cancer from developing.

To reduce the risk of tearing the colon during this procedure, doctors often inject a saline solution into the space below the lesion, forming a “cushion” that lifts the polyp so that it’s easier to remove safely. However, this cushion doesn’t last long.

MIT researchers have now devised an alternative — a solution that can be injected as a liquid but turns into a solid gel once it reaches the tissue, creating a more stable and longer-lasting cushion.

“That really makes a huge difference to the gastroenterologist who is performing the procedure, to ensure that there’s a stable area that they can then resect using endoscopic tools,” says Giovanni Traverso, an assistant professor in MIT’s Department of Mechanical Engineering and a gastroenterologist at Brigham and Women’s Hospital.

Traverso is the senior author of the study, which appears in the July 30 issue of Advanced Science. The lead authors of the study are former MIT postdocs Yan Pang and Jinyao Liu. Other authors include MIT undergraduate Zaina Moussa, technical associate Joy Collins, former technician Shane McDonnell, Division of Comparative Medicine veterinarian Alison Hayward, Brigham and Women’s Hospital gastroenterologist Kunal Jajoo, and David H. Koch Institute Professor Robert Langer.

A stable cushion

While many colon polyps are harmless, some can eventually become cancerous if not removed. Gastroenterologists often perform this procedure during a routine colonoscopy, using a lasso-like tool to snare the tissue before cutting it off.

This procedure carries some risk of tearing the lining of the colon, which is why doctors usually inject saline into the area just below the lining, called the submucosal space, to lift the polyp away from the surface of the colon.

“What that does is separate those tissue layers briefly, and it gives one a little bit of a raised area so it’s easier to snare the lesion,” Traverso says. “The challenge is that saline dissipates very quickly, so we don’t always have enough time to go in and intervene, and may need to reinject saline.”

Complex lesions can take 10 to 20 minutes to remove, or even longer, but the saline cushion only lasts for a few minutes. Researchers have tried to make the cushions longer-lived by adding thickening agents such as gelatin and cellulose, but those are very difficult to inject through the narrow needle that is used for the procedure.

To overcome that, the MIT team decided to create a shear-thinning gel. These materials are semisolid gels under normal conditions, but when force is applied to them, their viscosity decreases and they flow more easily. This means that the material can be easily injected through a narrow needle, then turn back into a solid gel once it exits into the colon tissue.

Shear-thinning gels can be made from many different types of materials. For this purpose, the researchers decided on a combination of two biocompatible materials that can form gels — Laponite, a powdery clay used in cosmetics and other products, and alginate, a polysaccharide derived from algae.

“We chose these materials because they are biocompatible and they allow us to tune the flowing behavior of the resulting gels,” Pang says.

Using these materials, the researchers created a shear-thinning gel that could be injected and form a stable cushion for more than an hour, in pigs. This would give gastroenterologists much more time to remove any polyps.

“Otherwise, you inject the saline, then you change tools, and by the time you’re ready the tissue is kind of flat again. It becomes really difficult to resect things safely,” Traverso says.

This approach could offer “an elegant solution” to the problem of keeping lesions elevated during a surgical removal, says Jay Pasricha, a professor of medicine and neuroscience at Johns Hopkins School of Medicine.

“It’s a growing unmet need,” says Pasricha, who was not involved in the research. “In the last decade, we’ve shifted toward trying to resect more complex tumors from the colon endoscopically, rather than through traditional forms of surgery. It would be great to have a material that can last throughout the duration of the procedure.”

Controlling viscosity

By varying the composition of the gel components, the researchers can control features such as the viscosity, which influences how long the cushion remains stable. If made to last longer, this kind of injectable gel could be useful for applications such as narrowing the GI tract, which could be used to prevent acid reflux or to help with weight loss by making people feel full. It could also potentially be used to deliver drugs to the intestinal tract, Traverso says.

The researchers also found that the material had no harmful side effects in pigs, and they hope to begin trials in human patients within the next three to five years.

“This is something we think can get into patients fairly quickly,” Traverso says. “We’re really excited about moving it forward.”

The research was funded by the National Institutes of Health, the Alexander von Humboldt Foundation, the Division of Gastroenterology at Brigham and Women’s Hospital and the MIT Department of Mechanical Engineering.

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Health effects of China’s climate policy extend across Pacific

Improved air quality can be a major bonus of climate mitigation policies aimed at reducing greenhouse gas emissions. By cutting air pollution levels in the country where emissions are produced, such policies can avoid significant numbers of premature deaths. But other nations downwind from the host country may also benefit.

A new MIT study in the journal Environmental Research Letters shows that if the world’s top emitter of greenhouse gas emissions, China, fulfills its climate pledge to peak carbon dioxide emissions in 2030, the positive effects would extend all the way to the United States, where improved air quality would result in nearly 2,000 fewer premature deaths.       

The study estimates China’s climate policy air quality and health co-benefits resulting from reduced atmospheric concentrations of ozone, as well as co-benefits from reduced ozone and particulate air pollution (PM2.5) in three downwind and populous countries: South Korea, Japan, and the United States. As ozone and PM2.5  give a well-rounded picture of air quality and can be transported over long distances, accounting for both pollutants enables a more accurate projection of associated health co-benefits in the country of origin and those downwind.  

Using a modeling framework that couples an energy-economic model with an atmospheric chemistry model, and assuming a climate policy consistent with China’s pledge to peak CO₂ emissions in 2030, the researchers found that atmospheric ozone concentrations in China would fall by 1.6 parts per billion in 2030 compared to a no-policy scenario, and thus avoid 54,300 premature deaths — nearly 60 percent of those resulting from PM2.5. Total avoided premature deaths in South Korea and Japan are 1,200 and 3,500, respectively, primarily due to PM2.5; for the U.S. total, 1,900 premature deaths, ozone is the main contributor, due to its longer lifetime in the atmosphere.

Total avoided deaths in these countries amount to about 4 percent of those in China. The researchers also found that a more stringent climate policy would lead to even more avoided premature deaths in the three downwind countries, as well as in China.

The study breaks new ground in showing that co-benefits of climate policy from reducing ozone-related premature deaths in China are comparable to those from PM2.5, and that co-benefits from reduced ozone and PM2.5 levels are not insignificant beyond China’s borders.

“The results show that climate policy in China can influence air quality even as far away as the U.S.,” says Noelle Eckley Selin, an associate professor in MIT’s Institute for Data, Systems, and Society and Department of Earth, Atmospheric and Planetary Sciences (EAPS), who co-led the study. “This shows that policy action on climate is indeed in everyone’s interest, in the near term as well as in the longer term.”

The other co-leader of the study is Valerie Karplus, the assistant professor of global economics and management in MIT’s Sloan School of Management. Both co-leaders are faculty affiliates of the MIT Joint Program on the Science and Policy of Global Change. Their co-authors include former EAPS graduate student and lead author Mingwei Li, former Joint Program research scientist Da Zhang, and former MIT postdoc Chiao-Ting Li. 

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Removing carbon dioxide from power plant exhaust

Reducing carbon dioxide (CO₂) emissions from power plants is widely considered an essential component of any climate change mitigation plan. Many research efforts focus on developing and deploying carbon capture and sequestration (CCS) systems to keep CO₂ emissions from power plants out of the atmosphere. But separating the captured CO₂ and converting it back into a gas that can be stored can consume up to 25 percent of a plant’s power-generating capacity. In addition, the CO₂ gas is generally injected into underground geological formations for long-term storage — a disposal method whose safety and reliability remain unproven. 

A better approach would be to convert the captured CO₂ into useful products such as value-added fuels or chemicals. To that end, attention has focused on electrochemical processes — in this case, a process in which chemical reactions release electrical energy, as in the discharge of a battery. The ideal medium in which to conduct electrochemical conversion of CO₂ would appear to be water. Water can provide the protons (positively charged particles) needed to make fuels such as methane. But running such “aqueous” (water-based) systems requires large energy inputs, and only a small fraction of the products formed are typically those of interest. 

Betar Gallant, an assistant professor of mechanical engineering, and her group at MIT have therefore been focusing on non-aqueous (water-free) electrochemical reactions — in particular, those that occur inside lithium-CO₂ batteries. 

Research into lithium-CO₂ batteries is in its very early stages, according to Gallant, but interest in them is growing because CO₂ is used up in the chemical reactions that occur on one of the electrodes as the battery is being discharged. However, CO₂ isn’t very reactive. Researchers have tried to speed things up by using different electrolytes and electrode materials. Despite such efforts, the need to use expensive metal catalysts to elicit electrochemical activity has persisted. 

Given the lack of progress, Gallant wanted to try something different. “We were interested in trying to bring a new chemistry to bear on the problem,” she says. And enlisting the help of the sorbent molecules that so effectively capture CO₂ in CCS seemed like a promising way to go. 

Rethinking amine 

The sorbent molecule used in CCS is an amine, a derivative of ammonia. In CCS, exhaust is bubbled through an amine-containing solution, and the amine chemically binds the CO₂, removing it from the exhaust gases. The CO₂ — now in liquid form — is then separated from the amine and converted back to a gas for disposal. 

In CCS, those last steps require high temperatures, which are attained using some of the electrical output of the power plant. Gallant wondered whether her team could instead use electrochemical reactions to separate the CO₂ from the amine — and then continue the reaction to make a solid, CO₂-containing product. If so, the disposal process would be simpler than it is for gaseous CO₂. The CO₂ would be more densely packed, so it would take up less space, and it couldn’t escape, so it would be safer. Better still, additional electrical energy could be extracted from the device as it discharges and forms the solid material. “The vision was to put a battery-like device into the power plant waste stream to sequester the captured CO₂ in a stable solid, while harvesting the energy released in the process,” says Gallant. 

Research on CCS technology has generated a good understanding of the carbon-capture process that takes place inside a CCS system. When CO₂ is added to an amine solution, molecules of the two species spontaneously combine to form an “adduct,” a new chemical species in which the original molecules remain largely intact. In this case, the adduct forms when a carbon atom in a CO₂ molecule chemically bonds with a nitrogen atom in an amine molecule. As they combine, the CO₂ molecule is reconfigured: It changes from its original, highly stable, linear form to a “bent” shape with a negative charge — a highly reactive form that’s ready for further reaction. 

In her scheme, Gallant proposed using electrochemistry to break apart the CO₂-amine adduct — right at the carbon-nitrogen bond. Cleaving the adduct at that bond would separate the two pieces: the amine in its original, unreacted state, ready to capture more CO₂, and the bent, chemically reactive form of CO₂, which might then react with the electrons and positively charged lithium ions that flow during battery discharge. The outcome of that reaction could be the formation of lithium carbonate (Li₂CO₃), which would deposit on the carbon electrode. 
 
At the same time, the reactions on the carbon electrode should promote the flow of electrons during battery discharge — even without a metal catalyst. “The discharge of the battery would occur spontaneously,” Gallant says. “And we’d break the adduct in a way that allows us to renew our CO₂ absorber while taking CO₂ to a stable, solid form.” 

A process of discovery 

In 2016, Gallant and mechanical engineering doctoral student Aliza Khurram began to explore that idea. 

Their first challenge was to develop a novel electrolyte. A lithium-CO₂ battery consists of two electrodes — an anode made of lithium and a cathode made of carbon — and an electrolyte, a solution that helps carry charged particles back and forth between the electrodes as the battery is charged and discharged. For their system, they needed an electrolyte made of amine plus captured CO₂ dissolved in a solvent — and it needed to promote chemical reactions on the carbon cathode as the battery discharged. 

They started by testing possible solvents. They mixed their CO₂-absorbing amine with a series of solvents frequently used in batteries and then bubbled CO₂ through the resulting solution to see if CO₂ could be dissolved at high concentrations in this unconventional chemical environment. None of the amine-solvent solutions exhibited observable changes when the CO₂ was introduced, suggesting that they might all be viable solvent candidates. 

However, for any electrochemical device to work, the electrolyte must be spiked with a salt to provide positively charged ions. Because it’s a lithium battery, the researchers started by adding a lithium-based salt — and the experimental results changed dramatically. With most of the solvent candidates, adding the salt instantly caused the mixture either to form solid precipitates or to become highly viscous — outcomes that ruled them out as viable solvents. The sole exception was the solvent dimethyl sulfoxide, or DMSO. Even when the lithium salt was present, the DMSO could dissolve the amine and CO₂. 

“We found that — fortuitously — the lithium-based salt was important in enabling the reaction to proceed,” says Gallant. “There’s something about the positively charged lithium ion that chemically coordinates with the amine-CO₂ adduct, and together those species make the electrochemically reactive species.” 

Exploring battery behavior during discharge 

To examine the discharge behavior of their system, the researchers set up an electrochemical cell consisting of a lithium anode, a carbon cathode, and their special electrolyte — for simplicity, already loaded with CO₂. They then tracked discharge behavior at the carbon cathode. 

As they had hoped, their special electrolyte actually promoted discharge reaction in the test cell. “With the amine incorporated into the DMSO-based electrolyte along with the lithium salt and the CO₂, we see very high capacities and significant discharge voltages — almost three volts,” says Gallant. Based on those results, they concluded that their system functions as a lithium-CO₂ battery with capacities and discharge voltages competitive with those of state-of-the-art lithium-gas batteries. 

The next step was to confirm that the reactions were indeed separating the amine from the CO₂ and further continuing the reaction to make CO₂-derived products. To find out, the researchers used a variety of tools to examine the products that formed on the carbon cathode. 

In one test, they produced images of the post-reaction cathode surface using a scanning electron microscope (SEM). Immediately evident were spherical formations with a characteristic size of 500 nanometers, regularly distributed on the surface of the cathode. According to Gallant, the observed spherical structure of the discharge product was similar to the shape of Li₂CO₃ observed in other lithium-based batteries. Those spheres were not evident in SEM images of the “pristine” carbon cathode taken before the reactions occurred. 
 
Other analyses confirmed that the solid deposited on the cathode was Li₂CO₃. It included only CO₂-derived materials; no amine molecules or products derived from them were present. Taken together, those data provide strong evidence that the electrochemical reduction of the CO₂-loaded amine occurs through the selective cleavage of the carbon-nitrogen bond. 

“The amine can be thought of as effectively switching on the reactivity of the CO₂,” says Gallant. “That’s exciting because the amine commonly used in CO₂ capture can then perform two critical functions. It can serve as the absorber, spontaneously retrieving CO₂ from combustion gases and incorporating it into the electrolyte solution. And it can activate the CO₂ for further reactions that wouldn’t be possible if the amine were not there.” 
 
Future directions 

Gallant stresses that the work to date represents just a proof-of-concept study. “There’s a lot of fundamental science still to understand,” she says, before the researchers can optimize their system. 

She and her team are continuing to investigate the chemical reactions that take place in the electrolyte as well as the chemical makeup of the adduct that forms — the “reactant state” on which the subsequent electrochemistry is performed. They are also examining the detailed role of the salt composition. 

In addition, there are practical concerns to consider as they think about device design. One persistent problem is that the solid deposit quickly clogs up the carbon cathode, so further chemical reactions can’t occur. In one configuration they’re investigating — a rechargeable battery design — the cathode is uncovered during each discharge-charge cycle. Reactions during discharge deposit the solid Li₂CO₃, and reactions during charging lift it off, putting the lithium ions and CO₂ back into the electrolyte, ready to react and generate more electricity. However, the captured CO₂ is then back in its original gaseous form in the electrolyte. Sealing the battery would lock that CO₂ inside, away from the atmosphere — but only so much CO₂ can be stored in a given battery, so the overall impact of using batteries to capture CO₂ emissions would be limited in this scenario. 

The second configuration the researchers are investigating — a discharge-only setup — addresses that problem by never allowing the gaseous CO₂ to re-form. “We’re mechanical engineers, so what we’re really keen on doing is developing an industrial process where you can somehow mechanically or chemically harvest the solid as it forms,” Gallant says. “Imagine if by mechanical vibration you could gently remove the solid from the cathode, keeping it clear for sustained reaction.” Placed within an exhaust stream, such a system could continuously remove CO₂ emissions, generating electricity and perhaps producing valuable solid materials at the same time. 

Gallant and her team are now working on both configurations of their system. “We don’t know which is better for applications yet,” she says. While she believes that practical lithium-CO₂ batteries are still years away, she’s excited by the early results, which suggest that developing novel electrolytes to pre-activate CO₂ could lead to alternative CO₂ reaction pathways. And she and her group are already working on some. 

One goal is to replace the lithium with a metal that’s less costly and more earth-abundant, such as sodium or calcium. With seed funding from the MIT Energy Initiative, the team has already begun looking at a system based on calcium, a material that’s not yet well-developed for battery applications. If the calcium-CO₂ setup works as they predict, the solid that forms would be calcium carbonate — a type of rock now widely used in the construction industry. 

In the meantime, Gallant and her colleagues are pleased that they have found what appears to be a new class of reactions for capturing and sequestering CO₂. “CO₂ conversion has been widely studied over many decades,” she says, “so we’re excited to think we may have found something that’s different and provides us with a new window for exploring this topic.” 

This research was supported by startup funding from the MIT Department of Mechanical Engineering. Mingfu He, a postdoc in mechanical engineering, also contributed to the research. Work on a calcium-based battery is being supported by the MIT Energy Initiative Seed Fund Program.

This article appears in the Spring 2019 issue of Energy Futures, the magazine of the MIT Energy Initiative.

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TESS discovers three new planets nearby, including temperate “sub-Neptune”

NASA’s Transiting Exoplanet Survey Satellite, or TESS, has discovered three new worlds that are among the smallest, nearest exoplanets known to date. The planets orbit a star just 73 light-years away and include a small, rocky super-Earth and two sub-Neptunes — planets about half the size of our own icy giant.

The sub-Neptune furthest out from the star appears to be within a “temperate” zone, meaning that the very top of the planet’s atmosphere is within a temperature range that could support some forms of life. However, scientists say the planet’s atmosphere is likely a thick, ultradense heat trap that renders the planet’s surface too hot to host water or life.

Nevertheless, this new planetary system, which astronomers have dubbed TOI-270, is proving to have other curious qualities. For instance, all three planets appear to be relatively close in size. In contrast, our own solar system is populated with planetary extremes, from the small, rocky worlds of Mercury, Venus, Earth, and Mars, to the much more massive Jupiter and Saturn, and the more remote ice giants of Neptune and Uranus.

There’s nothing in our solar system that resembles an intermediate planet, with a size and composition somewhere in the middle of Earth and Neptune. But TOI-270 appears to host two such planets: both sub-Neptunes are smaller than our own Neptune and not much larger than the rocky planet in the system.

Astronomers believe TOI-270’s sub-Neptunes may be a “missing link” in planetary formation, as they are of an intermediate size and could help researchers determine whether small, rocky planets like Earth and more massive, icy worlds like Neptune follow the same formation path or evolve separately.

TOI-270 is an ideal system for answering such questions, because the star itself is nearby and therefore bright, and also unusually quiet. The star is an M-dwarf, a type of star that is normally extremely active, with frequent flares and solar storms. TOI-270 appears to be an older M-dwarf that has since quieted down, giving off a steady brightness, against which scientists can measure many properties of the orbiting planets, such as their mass and atmospheric composition.

“There are a lot of little pieces of the puzzle that we can solve with this system,” says Maximilian Günther, a postdoc in MIT’s Kavli Institute for Astrophysics and Space Research and lead author of a study published today in Nature Astronomy that details the discovery. “You can really do all the things you want to do in exoplanet science, with this system.”

Compare and contrast worlds in the TOI 270 system with these illustrations. Temperatures given for TOI 270 planets are equilibrium temperatures, calculated without the warming effects of any possible atmospheres. Credit: NASA’s Goddard Space Flight Center

A planetary pattern

Günther and his colleagues detected the three new planets after looking through measurements of stellar brightness taken by TESS. The MIT-developed satellite stares at patches of the sky for 27 days at a time, monitoring thousands of stars for possible transits — characteristic dips in brightness that could signal a planet temporarily blocking the star’s light as it passes in front of it.

The team isolated several such signals from a nearby  star, located 73 light years away in the southern sky. They named the star TOI-270, for the 270th “TESS Object of Interest” identified to date. The researchers used ground-based instruments to follow up on the star’s activity, and confirmed that the signals are the result of three orbiting exoplanets: planet b, a rocky super-Earth with a roughly three-day orbit; planet c, a sub-Neptune with a five-day orbit; and planet d, another sub-Neptune slightly further out, with an 11-day orbit.

Günther notes that the planets seem to line up in what astronomers refer to as a “resonant chain,” meaning that the ratio of their orbits are close to whole integers — in this case, 3:5 for the inner pair, and 2:1 for the outer pair — and that the planets are therefore in “resonance” with each other. Astronomers have discovered other small stars with similarly resonant planetary formations. And in our own solar system, the moons of Jupiter also happen to line up in resonance with each other.

“For TOI-270, these planets line up like pearls on a string,” Günther says. “That’s a very interesting thing, because it lets us study their dynamical behavior. And you can almost expect, if there are more planets, the next one would be somewhere further out, at another integer ratio.”

“An exceptional laboratory”

TOI-270’s discovery initially caused a stir of excitement within the TESS science team, as it seemed, in the first analysis, that planet d might lie in the star’s habitable zone, a region that would be cool enough for the planet’s surface to support water, and possibly life. But the researchers soon realized that the planet’s atmosphere was probably extremely thick, and would therefore generate an intense greenhouse effect, causing the planet’s surface to be too hot to be habitable.

But Günther says there is a good possibility that the system hosts other planets, further out from planet d, that might well lie within the habitable zone. Planet d, with an 11-day orbit, is about 10 million kilometers out from the star. Günther says that, given that the star is small and relatively cool — about half as hot as the sun — its habitable zone could potentially begin at around 15 million kilometers. But whether a planet exists within this zone, and whether it is habitable, depends on a host of other parameters, such as its size, mass, and atmospheric conditions.

Fortunately, the team writes in their paper that “the host star, TOI-270, is remarkably well-suited for future habitability searches, as it is particularly quiet.” The researchers plan to focus other instruments, including the upcoming James Webb Space Telescope, on TOI-270, to pin down various properties of the three planets, as well as search for additional planets in the star’s habitable zone.

“TOI-270 is a true Disneyland for exoplanet science, and one of the prime systems TESS was set out to discover,” Günther says. “It is an exceptional laboratory for not one, but many reasons — it really ticks all the boxes.”

This research was funded, in part, by NASA.

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Mathematical insights through collaboration and perseverance

Wei Zhang’s breakthrough happened on the train. He was riding home to New York after visiting a friend in Boston, during the last year of his PhD studies in mathematics at Columbia University, where he was focusing on L-functions, an important area of number theory.

“All of a sudden, things were linked together,” he recalls, about the flash of insight that allowed him to finish a key project related to his dissertation. “Definitely it was an ‘Aha!’ moment.”

But that moment emerged from years of patient study and encounters with other mathematicians’ ideas. For example, he had attended talks by a certain faculty member in his first and third years at Columbia, but each time he thought the ideas presented in those lectures wouldn’t be relevant for his own work.

“And then two years later, I found this was exactly what I needed to finish a piece of the project!” says Zhang, who joined MIT two years ago as a professor of mathematics.

As Zhang recalls, during that pivotal train ride his mind had been free to wander around the problem and consider it from different angles. With this mindset, “I can have a more panoramic way of putting everything into one piece. It’s like a puzzle — when you close your eyes maybe you can see more. And when the mind is trying to organize different parts of a story, you see this missing part.”

Allowing time for this panoramic view to come into focus has been critical throughout Zhang’s career. His breakthrough on the train 11 years ago led him to propose a set of conjectures that he has just now solved in a recent paper.

“Patience is important for our subject,” he says. “You’re always making infinitesimal progress. All discovery seems to be made in one moment. But without the preparation and long-time accumulation of knowledge, it wouldn’t be possible.”

An early and evolving love for math

Zhang traces his interest in math back to the fourth grade in his village school in a remote part of China’s Sichuan Province. “It was just pure curiosity,” he says. “Some of the questions were so beautifully set up.”

He started participating in math competitions. Seeing his potential, a fifth-grade math teacher let Zhang pore over an extracurricular book of problems. “Those questions made me wonder how such simple solutions to seemingly very complicated questions could be possible,” he says.

Zhang left home to attend a high school 300 miles away in Chengdu, the capital city of Sichuan. By the time he applied to study at Peking University in Beijing, he knew he wanted to study mathematics. And by his final year there, he had decided to pursue a career as a mathematician.

He credits one of his professors with awakening him to some exciting frontiers and more advanced areas of study, during his first year. At that time, around 2000, the successful proof of Fermat’s Last Theorem by Andrew Wiles five years earlier was still relatively fresh, and reverberating through the world of mathematics. “This teacher really liked to chat,” Zhang says, “and he explained the contents of some of those big events and results in a way that was accessible to first-year students.”

“Later on, I read those texts by myself, and I found it was something I liked,” he says. “The tools being developed to prove Fermat’s Last Theorem were a starting point for me.”

Today, Zhang gets to cultivate his own students’ passion for math, even as his teaching informs his own research. “It has happened more than once for me, that while teaching I got inspired,” he says. “For mathematicians, we may understand some sort of result, but that doesn’t mean we actually we know how to prove them. By teaching a course, it really helps us go through the whole process. This definitely helps, especially with very talented students like those at MIT.”

From local to global information

Zhang’s core area of research and expertise is number theory, which is devoted to the study of integers and their properties. Broadly speaking, Zhang explores how to solve equations in integers or in rational numbers. A familiar example is a Pythagorean triple (a²+b²=c²).

“One simple idea is try to solve equations with modular arithmetic,” he says. The most common example of modular arithmetic is a 12-hour clock, which counts time by starting over and repeating after it reaches 12. With modular arithmetic, one can compile a set of data, indexed, for example, by prime numbers.

“But after that, how do you return to the initial question?” he says. “Can you tell an equation has an integer solution by collecting data from modular arithmetic?” Zhang investigates whether and how an equation can be solved by restoring this local data to a global piece of information — like finding a Pythagorean triple.

His research is relevant to an important facet of the Langlands Program — a set of conjectures proposed by mathematician Robert Langlands for connecting number theory and geometry, which some have likened to a kind of “grand unified theory” of mathematics.

Conversations and patience

Bridging other branches of math with number theory has become one of Zhang’s specialties.

In 2018, he won the New Horizons in Mathematics Breakthroughs Prize, a prestigious award for researchers early in their careers. He shared the prize with his old friend and undergraduate classmate, and current MIT colleague, Zhiwei Yun, for their joint work on the Taylor expansion of L-functions, which was hailed as a major advance in a key area of number theory in the past few decades.

Their project grew directly out of his dissertation research. And that work, in turn, opened up new directions in his current research, related to the arithmetic of elliptic curves. But Zhang says the way forward wasn’t clear until five years — and many conversations with Yun — later.

“Conversation is important in mathematics,” Zhang says. “Very often mathematical questions can be solved, or at least progress can be made, by bringing together people with different skills and backgrounds, with new interpretations of the same set of facts. In our case, this is a perfect example. His geometrical way of thinking about the question was exactly complementary to my own perspective, which is more number arithmetic.”

Lately, Zhang’s work has taken place on fewer train rides and more flights. He travels back to China at least once a year, to visit family and colleagues in Beijing. And when he feels stuck on a problem, he likes to take long walks, play tennis, or simply spend time with his young children, to clear his mind.

His recent solution of his own conjecture has led him to contemplate unexplored terrain. “This opened up a new direction,” he says. “I think it’s possible to finally get some higher-dimensional solutions. It opens up new conjectures.”

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MIT “Russian Doll” tech lands $7.9M international award to fight brain tumors

Tiny “Russian doll-like” particles that deliver multiple drugs to brain tumors, developed by researchers at MIT and funded by Cancer Research UK, are at the center of a new international collaboration.

Professor Paula Hammond from the Department of Chemical Engineering developed the nanoparticle technology, which will be used in an effort to treat glioblastoma — the most aggressive and deadly type of brain tumor.

Hammond will be working with Professor Michael Yaffe from the Department of Biological Engineering to determine the combinations of drugs placed within the particles, and the order and timing in which the drugs are released.

The nanoparticles — 1,000 times smaller than a human hair — are coated in a protein called transferrin, which helps them cross the blood-brain barrier. This is a membrane that keeps a tight check on anything trying to get in to the brain, including drugs.

Not only are the nanoparticles able to access hard-to-reach areas of the brain, they have also been designed to carry multiple cancer drugs at once by holding them inside layers, similarly to the way Russian dolls fit inside one another.

To make the nanoparticles even more effective, they will carry signals on their surface so that they are only taken up by brain tumor cells. This means that healthy cells should be left untouched, which will minimize the side effects of treatment.

The researchers, who are based at the Koch Institute for Integrative Cancer Research, are also working with Professor Forest White from the Department of Biological Engineering. The group are one of three international teams to have been given Cancer Research UK Brain Tumor Awards — in partnership with The Brain Tumour Charity — receiving $7.9 million of funding. The awards are designed to accelerate the pace of brain tumor research. Altogether, teams were awarded a total of $23 million.

Just last year, around 24,200 people in the United States were diagnosed with brain tumors. With around 17,500 deaths from brain tumors in the same year, survival remains tragically low.

Brain tumors represent one of the hardest types of cancer to treat because not enough is known about what starts and drives the disease, and current treatments are not effective enough.

The researchers from MIT will now work with teams in the U.K. and Europe to use the nanoparticles to carry multiple drug therapies to treat glioblastoma.

Early research carried out in the lab has already shown that nanoparticles loaded with two different drugs were able to shrink glioblastomas in mice. The team has also demonstrated that the nanoparticles can kill lymphoma cells grown in the lab, and they are also exploring their use in ovarian cancer.

The Cancer Research UK Brain Tumor Award will now allow the researchers and their collaborators to use different drug combinations to find the best parameters to tackle glioblastomas.

Drugs that have already been approved, as well as experimental drugs that have passed initial safety testing in people, will be used. Because of this, if an effective drug combination is found, the team won’t have to navigate the initial regulatory hurdles needed to get them into clinical testing, which could help get promising treatments to patients faster.

“Glioblastoma is particularly challenging because we want to get highly effective but toxic drug combinations safely across the blood-brain barrier, but also want our nanoparticles to avoid healthy brain cells and only target the cancer cells," Hammond says. "We are very excited about this alliance between the MIT Koch Institute and our colleagues in Edinburgh to address these critical challenges.”

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