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In many materials, electrical resistance and voltage change in the presence of a magnetic field, usually varying smoothly as the magnetic field rotates. This simple magnetic response underlies many applications including contactless current sensing, motion sensing, and data storage. In a crystal, the way that the charge and spin of its electrons align and interact underlies these effects. Utilizing the nature of the alignment, called symmetry, is a key ingredient in designing a functional material for electronics and the emerging field of spin-based electronics (spintronics).
Recently a team of researchers from MIT, the French National Center for Scientific Research (CNRS) and École Normale Supérieure (ENS) de Lyon, University of California at Santa Barbara (UCSB), the Hong Kong University of Science and Technology (HKUST), and NIST Center for Neutron Research, led by Joseph G. Checkelsky, assistant professor of physics at MIT, has discovered a new type of magnetically driven electrical response in a crystal composed of cerium, aluminum, germanium, and silicon.
At temperatures below 5.6 kelvins (corresponding to -449.6 degrees Fahrenheit), these crystals show a sharp enhancement of electrical resistivity when the magnetic field is precisely aligned within an angle of 1 degree along the high symmetry direction of the crystal. This effect, which the researchers have named “singular angular magnetoresistance,” can be attributed to the symmetry — in particular, the ordering of the cerium atoms’ magnetic moments. Their results are published today in the journal Science.
Novel response and symmetry
Like an old-fashioned clock designed to chime at 12:00 and at no other position of the hands, the newly discovered magnetoresistance only occurs when the direction, or vector, of the magnetic field is pointed straight in line with the high-symmetry axis in the material’s crystal structure. Turn the magnetic field more than a degree away from that axis and the resistance drops precipitously.
"Rather than responding to the individual components of the magnetic field like a traditional material, here the material responds to the absolute vector direction," says Takehito Suzuki, a research scientist in the Checkelsky group who synthesized these materials and discovered the effect. "The observed sharp enhancement, which we call singular angular magnetoresistance, implies a distinct state realized only under those conditions."
Magnetoresistance is a change in the electrical resistance of a material in response to an applied magnetic field. A related effect known as giant magnetoresistance is the basis for modern computer hard drives and its discoverers were awarded the Nobel Prize in 2007.
"The observed enhancement is so highly confined with the magnetic field along the crystalline axis in this material that it strongly suggests symmetry plays a critical role,” Lucile Savary, permanent CNRS researcher at ENS de Lyon, adds. Savary was a Betty and Gordon Moore Postdoctoral Fellow at MIT from 2014-17, when the team started collaborating.
To elucidate the role of the symmetry, it is crucial to see the alignment of the magnetic moments, for which Suzuki and Jeffrey Lynn, NIST fellow, performed powder neutron diffraction studies on the BT-7 triple axis spectrometer at the NIST Center for Neutron Research (NCNR). The research team used the NCNR’s neutron diffraction capabilities to determine the material’s magnetic structure, which plays an essential role in understanding its topological properties and nature of the magnetic domains. A "topological state" is one that is protected from ordinary disorder. This was a key factor in unraveling the mechanism of the singular response.
Based on the observed ordering pattern, Savary and Leon Balents, professor and permanent member of Kavli Institute of Theoretical Physics at UCSB, constructed a theoretical model where the spontaneous symmetry-breaking caused by the magnetic-moment ordering couples to the magnetic field and the topological electronic structure. As a consequence of the coupling, switching between the uniformly ordered low- and high-resistivity states can be manipulated by the precise control of the magnetic field direction.
“The agreement of the model with the experimental results is outstanding and was the key to understanding what was a mysterious experimental observation,” says Checkelsky, the paper’s senior author.
Universality of the phenomenon
"The interesting question here is whether or not the singular angular magnetoresistance can be widely observed in magnetic materials and, if this feature can be ubiquitously observed, what is the key ingredient for engineering the materials with this effect," Suzuki says.
The theoretical model indicates that the singular response may indeed be found in other materials and predicts material properties beneficial for realizing this feature. One of the important ingredients is an electronic structure with a small number of free charges, which occurs in a point-like electronic structure referred to as nodal. The material in this study has so-called Weyl points that achieve this. In such materials, the allowed electron momenta depends on the configuration of the magnetic order. Such control of the momenta of these charges by the magnetic degree of freedom allows the system to support switchable interface regions where the momenta are mismatched between domains of different magnetic order. This mismatch also leads to the large increase in resistance observed in this study.
This analysis is further supported by the first-principles electronic structure calculation performed by Jianpeng Liu, research assistant professor at the HKUST, and Balents. Using more traditional magnetic elements such as iron or cobalt, rather than rare-earth cerium, may offer a potential path to higher temperature observation of the singular angular magnetoresistance effect. The study also ruled out a change in the arrangement of the atoms, called a structural phase transition, as a cause of the change in resistivity of the cerium-based material.
Kenneth Burch, graduate program director and associate professor of physics at Boston College, whose lab investigates Weyl materials, notes: “The discovery of remarkable sensitivity to magnetic angle is a completely unexpected phenomena in this new class of materials. This result suggests not only new applications of Weyl semimetals in magnetic sensing, but the unique coupling of electronic transport, chirality and magnetism.” Chirality is an aspect of electrons related to their spin that gives them either a left-handed or right-handed orientation.
The discovery of this sharp but narrowly confined resistance peak could eventually be used by engineers as a new paradigm for magnetic sensors. Notes Checkelsky, “One of the exciting things about fundamental discoveries in magnetism is the potential for rapid adoptions for new technologies. With the design principles now in hand, we are casting a wide net to find this phenomena in more robust systems to unlock this potential.”
This research was supported in part by the Gordon and Betty Moore Foundation and the National Science Foundation.
The Phi Beta Kappa Society, the nation’s oldest academic honor society, held its MIT induction ceremony recently, admitting 76 graduating seniors into the MIT chapter, Xi of Massachusetts.
Phi Beta Kappa (PBK), founded in 1776 at the College of William and Mary, honors the nation’s most outstanding undergraduate students for excellence in the liberal arts, which includes the humanities and natural and social science fields. Only 10 percent of higher education institutions have PBK chapters, and fewer than 10 percent of students at those institutions are selected for membership.
Reflective, meaningful lives
Speaking at the event, Diana Henderson, an MIT professor of literature and the president of Xi of Massachusetts, said: “This year’s inductees have been chosen on the basis of their exceptional academic performance. Their educational choices have included not only technical subjects but also a substantial commitment to the humanities and social and natural sciences — the liberal arts."
Henderson noted that MIT's 76 new members of the Phi Beta Kappa Society "have also become more knowledgeable citizens of the world through the study of a second language. Such an education helps prepare them to thrive in particular careers," she said, "and, even more importantly, encourages them to pursue reflective, meaningful lives, using their learning to contribute to the greater good."
Belonging and community
In her address at the induction ceremony, Hazel Sive, an MIT professor of biology and member of the Whitehead Institute at MIT, reflected on the need we all have for a sense of belonging to a community. She enjoined the initiates to find, and cultivate, such communities in their own lives.
Sive shared some of her own journey across the world and back again, all while embedded in a dynamic university community. She posited that the role of a university is to create such a culture by bringing people together and providing coherence to the world in the midst of their diversity.
As she spoke about being a young woman from apartheid South Africa and becoming a leading world biologist, she assured the new PBK members that a life in the lab can be fulfilling and full of human (and animal) connection, and urged them to prioritize cultivating their own communities, beginning with the people in the room.
Sive was made an honorary PBK member at the induction ceremony, as was Rebecca Saxe, an MIT professor of brain and cognitive sciences.
Henderson, who specializes in Shakespeare studies, provided the inductees and their families with a lively overview of the PBK society. With assistance from chapter historian Anne McCants, professor of history, and chapter guardian Margery Resnick, professor of literature, Henderson introduced the 2019 inductees to the rights and responsibilities of PBK members.
The 76 inductees were then recognized individually, shown the society’s secret handshake, and received by a group of MIT faculty. After signing the register of the Xi of Massachusetts chapter, the new members received their certificates of membership.
The MIT Libraries honored the outstanding contributions of its employees June 11 with its Infinite Mile Awards. The theme of this year’s festivities was “Treat Yo’ Self: Rest, Renew, Relax.” An awards ceremony in Killian Hall was followed by a celebratory luncheon featuring live music by the libraries' staff band, The Dust Jackets, and a guest appearance by Tim the Beaver.
Director Chris Bourg presented awards to individuals and teams in the categories listed below; award recipients are listed along with excerpts from the award presentations.
Innovation, Creativity, and Problem Solving
In June 2018, the team of Ben Abrahamse, Helen Bailey, Li Cheung, Mike Graves, Rhonda Kauffman, and Jeremy Prevost set out to build the MIT Libraries’ first API, an indexing platform for populating searches/discovery, consolidating various source metadata into a single index. Nicknamed “TIMDEX,” the API is now being used and will enable the libraries to advance discovery and access, improve relevance and context, and bring together fragmented silos of content.
Collaboration and Inclusion
Shannon Hunt, Stephanie Kohler, and Sam Spencer had the difficult task of creating and overseeing a staff-driven nominating and voting process for the Staff Advisory Council, the first of its kind in the libraries. The team kept fairness and transparency at the forefront of the process, was an endless source of help and encouragement to those considering whether to participate, and demonstrated care and commitment throughout the launch of the council.
Results, Outcome, and Productivity
The team of Grace Mlady, Beverly Turner, and Kelly Hopkins was recognized for its awe-inspiring efforts to move 70 staff members (representing nearly 40 percent of the total staff) from across the libraries to a new office location. Despite the knotty logistics, the team made every effort to involve the community, listen to hopes and dreams as well as major concerns, and ensure equity and fairness in the end results. The team approached the project with “grace and aplomb” and their colleagues with “poise, kindness, and joy.”
Bringing Out the Best Award
Human Resources Generalist Cherry Ibrahim is widely praised for her compassion, foresight, thoughtfulness, and can-do attitude. “She consistently models the caring organization we hope to be,” said one nominator. Ibrahim has used her remarkable organizational and problem-solving skills to help recruit, hire, and onboard new staff; plan the annual libraries staff breakfast; and serve on fast-moving search committees, all with a smile.
Tough Questions/Critical Thinker
Aeronautics/Astronautics and Physics Librarian Barbara Williams is not afraid to ask questions, especially when they pertain to the well-being and professional growth of her colleagues. Williams is driven by a sense of fairness and a respect for the expertise and talent of others. While the feedback she offers might be difficult, she manages to provide it with a smile and an honesty that empowers her colleagues to have the kind of uncomfortable conversations needed to live up to the libraries’ values.
User Service and Support
Georgiana McReynolds, reference services and user experience librarian, received this award recognizing a staff member who consistently keeps library users in mind when implementing services. Nominators highlighted her “tireless, exemplary work on tools and services that connect our communities to the information they need.” Another wrote, “Any question handled by Georgiana is guaranteed to be addressed thoroughly, thoughtfully, and professionally. She takes the time to understand and interpret users’ information needs and provides tailored strategies and solutions.”
Administrative Assistant Renee Hellenbrecht is a treasured member of the MIT Libraries staff who daily makes a positive impact in many ways. She has led Webex training for her colleagues, helps keep kitchen items in supply, and even “MacGyvers” the industrial coffee machine when it breaks. As one nominator wrote, “she gets things done, often without other people even realizing that there was something that needed to be done.”
Christine Moulen “Good Citizen” Award
Jeremiah Graves, access services manager for Barker and Rotch libraries, was acknowledged for his “relentless” support of his staff’s professional development. Praised for his ability to anticipate and solve both large-scale problems and quick questions, Graves is a co-chair of the recently created Staff Advisory Council. His efforts to build community via the libraries’ softball team, the Bibliotechs, have been sustained and considerable, and he truly displays the spirit of teamwork, courtesy, and generosity that characterized Christine Moulen '94, the inspiration for this award.
With a new telescope situated on a scenic plateau in Tenerife, Spain, MIT planetary scientists now have an added way to search for Earth-sized exoplanets. Artemis, the first ground-based telescope of the SPECULOOS Northern Observatory (SNO), joins a network of 1-meter-class robotic telescopes as part of the SPECULOOS project (Search for habitable Planets EClipsing ULtra-cOOl Stars), which is led by Michael Gillon at the University of Liège in Belgium and carried out in collaboration with MIT and several other institutions and financial supporters. Artemis is the latest product of a collaboration with MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS). The other network telescopes that make up the SPECULOOS Southern Observatory — named Io, Europa, Ganymede, and Callisto after the four Galilean moons of Jupiter — are up and running at the Paranal Observatory in Chile, busily scanning the skies for exoplanets in the Southern Hemisphere.
Together, these SPECULOOS telescopes will look for terrestrial planets circling very faint, nearby stars, called ultra-cool dwarfs, and the new Artemis telescope will allow the research group to expand the search into the Northern Hemisphere skies. Artemis was unveiled today at an inauguration event attended by scientists and dignitaries from MIT, the University of Liège, and the Instituto de Astrofísica de Canarias (IAC) in Tenerife. Artemis was funded by MIT donors Peter A. Gilman, the Heising-Simons Foundation, and Colin and Leslie Masson, with additional support from the Ministry of Higher Education of the Federation Wallonie-Bruxelles, and the Balzan Foundation.
Before the SPECULOOS telescopes were conceived, researchers had already established the proof of concept for this technique with a project using a small, ground-based telescope located in La Silla, Chile, known as TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope). With the TRAPPIST telescope, researchers looked at a limited sample of 50 target stars and discovered the TRAPPIST-1 system, which consists of seven terrestrial planets orbiting their cool, ultra-dwarf star. To date, these are the only known planets that are nearby, Earth-sized, temperate, and amenable for future atmospheric characterization, setting them apart from previous exoplanet findings. The SPECULOOS group is building on this earlier project with its new telescope network to scan more of the sky for similar Earth-sized exoplanets, and deliver more targets that can be assessed for habitability and potentially signs of life in the future.
Julien de Wit is an EAPS assistant professor, SPECULOOS collaborator, Artemis principal investigator, and SNO co-principal investigator with Gillon. As a postdoc in the group of MIT Professor Sara Seager, he worked with Gillon and the TRAPPIST team to identify and characterize the TRAPPIST-1 system. Later he spearheaded the expansion of the SPECULOOS venture into the Northern Hemisphere. EAPS recently spoke with de Wit about the capabilities of Artemis and what we can expect to find with the SPECULOOS project.
Q: Tell us about the new Artemis telescope. Why is it particularly exciting?
A: The first telescope of the SPECULOOS Northern Observatory is named Artemis, built and owned by MIT, after the Greek goddess of the hunt, the wilderness, the moon, which seemed appropriate as we are hunting for planets and signs of life.
Artemis is located on the Spanish Canary Island of Tenerife about 150 miles off the coast of Morocco. The SNO is built within the Teide Observatory, which is an astronomical observatory by the Teide Volcano, 2,400 meters above sea level and operated by the Insituto de Astrofisica de Canarias. The location, which hosts one of the first major international observatories, boasts excellent astronomical conditions for viewing.
As far as the telescope itself, it measures about 4 meters high, with an optical quality of less than 0.8 arcsec and a field of view, 12 arcmin by 12 arcmin. Artemis, which was built by the German company ASTELCO, has a robot mount, and its detectors are very sensitive to the near-infrared wavelengths that we find emanating from these ultra-cool dwarf stars. We will be operating it remotely from MIT or any other collaborating institutes.
With TRAPPIST, we demonstrated a proof of concept — confirming that ultra-cool dwarf stars have the capacity to host planets — and are investigating the atmospheres of these TRAPPIST-1 planets with the Hubble Space Telescope. To date, there are no other temperate Earth-sized planets that would be such exquisite targets for atmospheric study. This justified fully scaling up with the SPECULOOS project.
Telescopes like this provide two important observational advantages. One, due to similar planet-to-star area ratios, the signal we’ll get from an Earth-sized planet transiting an ultra-cool dwarf star will be similar to a Jupiter-sized planet crossing in front of a sun-like star. Two, the vicinity of their habitable zone, due to their small size and temperature, means that habitable planets will have small transit periodicities, similar to gas giants, which are in close orbit around solar-type stars. This means that each star will require less monitoring time, and that the transit search targeting the roughly 1,200 nearest ultra-cool stars could be done in about 10 years with four telescopes scanning each hemisphere.
Q: What is the goal of Artemis, and how many exoplanets do you estimate can be evaluated by MIT’s new SPECULOOS Northern Observatory?
A: Over each night, we will be gathering pictures of a specific section of the sky, focused on our target stars in order to search for a brightness drop characteristic of a planetary transit.
The goal of the Artemis telescope is to look at the roughly 800 nearest ultra-cool dwarf stars located in the northern skies (and a sliver of the southern skies) to find Earth-sized planets that may have a temperate climate and be amenable for further in-depth characterization with the next generation of observatories, such as the James Webb Space Telescope (JWST) and the Extremely Large Telescopes. These will be able to tell us more about their atmosphere, climate, and what molecules might be present on them. We are confidently expecting to identify about 15 temperate planets with the SPECULOOS network, and doing so on a relevant timeline, which will allow for their atmospheres to be studied with the JWST, which is expected to launch in 2021 and last for 10 years.
Additionally, we’ll expand Artemis’s scope of work. We plan to do a follow-up of some of the trickiest planet candidates (terrestrial planets around small M-dwarfs) identified by the MIT-led TESS [Transiting Exoplanet Survey Satellite] NASA mission, since Artemis has 100 times larger viewing areas. We’ll also be able to study asteroids, comets, and other objects, such as observations of the Quaoar occultation, with other scientists at MIT and outside of the Institute.
Q: You mentioned that Artemis is the first telescope for the SPECULOOS Northern Observatory. Does that mean more telescopes might be added to the SPECULOOS network in the future?
A: Yes, we hope to build out the SPECULOOS Northern Observatory and add telescopes to accompany Artemis. As a matter of fact, we have already built an additional platform ready to host a twin to Artemis, as soon as we have found additional funding. Our agreement with the Teide Observatory reserves space to accommodate up to three additional telescopes. Doing so will allow us to thoroughly study all the nearest ultra-cool dwarf stars and complete the Northern Hemisphere survey in time to perform the atmospheric characterization of their transiting planets with the JWST.
With SPECULOOS, we are giving it our best shot at enabling the identification of habitats beyond Earth within the next decade. Our team is looking forward to sharing “first light” with our donors and the public, and it is a privilege for MIT to be working with our international partners on this exciting venture.
A new MIT-developed technique enables robots to quickly identify objects hidden in a three-dimensional cloud of data, reminiscent of how some people can make sense of a densely patterned “Magic Eye” image if they observe it in just the right way.
Robots typically “see” their environment through sensors that collect and translate a visual scene into a matrix of dots. Think of the world of, well, “The Matrix,” except that the 1s and 0s seen by the fictional character Neo are replaced by dots — lots of dots — whose patterns and densities outline the objects in a particular scene.
Conventional techniques that try to pick out objects from such clouds of dots, or point clouds, can do so with either speed or accuracy, but not both.
With their new technique, the researchers say a robot can accurately pick out an object, such as a small animal, that is otherwise obscured within a dense cloud of dots, within seconds of receiving the visual data. The team says the technique can be used to improve a host of situations in which machine perception must be both speedy and accurate, including driverless cars and robotic assistants in the factory and the home.
“The surprising thing about this work is, if I ask you to find a bunny in this cloud of thousands of points, there’s no way you could do that,” says Luca Carlone, assistant professor of aeronautics and astronautics and a member of MIT’s Laboratory for Information and Decision Systems (LIDS). “But our algorithm is able to see the object through all this clutter. So we’re getting to a level of superhuman performance in localizing objects.”
Carlone and graduate student Heng Yang will present details of the technique later this month at the Robotics: Science and Systems conference in Germany.
“Failing without knowing”
Robots currently attempt to identify objects in a point cloud by comparing a template object — a 3-D dot representation of an object, such as a rabbit — with a point cloud representation of the real world that may contain that object. The template image includes “features,” or collections of dots that indicate characteristic curvatures or angles of that object, such the bunny’s ear or tail. Existing algorithms first extract similar features from the real-life point cloud, then attempt to match those features and the template’s features, and ultimately rotate and align the features to the template to determine if the point cloud contains the object in question.
But the point cloud data that streams into a robot’s sensor invariably includes errors, in the form of dots that are in the wrong position or incorrectly spaced, which can significantly confuse the process of feature extraction and matching. As a consequence, robots can make a huge number of wrong associations, or what researchers call “outliers” between point clouds, and ultimately misidentify objects or miss them entirely.
Carlone says state-of-the-art algorithms are able to sift the bad associations from the good once features have been matched, but they do so in “exponential time,” meaning that even a cluster of processing-heavy computers, sifting through dense point cloud data with existing algorithms, would not be able to solve the problem in a reasonable time. Such techniques, while accurate, are impractical for analyzing larger, real-life datasets containing dense point clouds.
Other algorithms that can quickly identify features and associations do so hastily, creating a huge number of outliers or misdetections in the process, without being aware of these errors.
“That’s terrible if this is running on a self-driving car, or any safety-critical application,” Carlone says. “Failing without knowing you’re failing is the worst thing an algorithm can do.”
A relaxed view
Yang and Carlone instead devised a technique that prunes away outliers in “polynomial time,” meaning that it can do so quickly, even for increasingly dense clouds of dots. The technique can thus quickly and accurately identify objects hidden in cluttered scenes.
The MIT-developed technique quickly and smoothly matches objects to those hidden in dense point clouds (left), versus existing techniques (right) that produce incorrect, disjointed matches. Gif: Courtesy of the researchers
The researchers first used conventional techniques to extract features of a template object from a point cloud. They then developed a three-step process to match the size, position, and orientation of the object in a point cloud with the template object, while simultaneously identifying good from bad feature associations.
The team developed an “adaptive voting scheme” algorithm to prune outliers and match an object’s size and position. For size, the algorithm makes associations between template and point cloud features, then compares the relative distance between features in a template and corresponding features in the point cloud. If, say, the distance between two features in the point cloud is five times that of the corresponding points in the template, the algorithm assigns a “vote” to the hypothesis that the object is five times larger than the template object.
The algorithm does this for every feature association. Then, the algorithm selects those associations that fall under the size hypothesis with the most votes, and identifies those as the correct associations, while pruning away the others. In this way, the technique simultaneously reveals the correct associations and the relative size of the object represented by those associations. The same process is used to determine the object’s position.
The researchers developed a separate algorithm for rotation, which finds the orientation of the template object in three-dimensional space.
To do this is an incredibly tricky computational task. Imagine holding a mug and trying to tilt it just so, to match a blurry image of something that might be that same mug. There are any number of angles you could tilt that mug, and each of those angles has a certain likelihood of matching the blurry image.
Existing techniques handle this problem by considering each possible tilt or rotation of the object as a “cost” — the lower the cost, the more likely that that rotation creates an accurate match between features. Each rotation and associated cost is represented in a topographic map of sorts, made up of multiple hills and valleys, with lower elevations associated with lower cost.
But Carlone says this can easily confuse an algorithm, especially if there are multiple valleys and no discernible lowest point representing the true, exact match between a particular rotation of an object and the object in a point cloud. Instead, the team developed a “convex relaxation” algorithm that simplifies the topographic map, with one single valley representing the optimal rotation. In this way, the algorithm is able to quickly identify the rotation that defines the orientation of the object in the point cloud.
With their approach, the team was able to quickly and accurately identify three different objects — a bunny, a dragon, and a Buddha — hidden in point clouds of increasing density. They were also able to identify objects in real-life scenes, including a living room, in which the algorithm quickly was able to spot a cereal box and a baseball hat.
Carlone says that because the approach is able to work in “polynomial time,” it can be easily scaled up to analyze even denser point clouds, resembling the complexity of sensor data for driverless cars, for example.
“Navigation, collaborative manufacturing, domestic robots, search and rescue, and self-driving cars is where we hope to make an impact,” Carlone says.
This research was supported in part by the Army Research Laboratory, the Office of Naval Research, and the Google Daydream Research Program.
EdX, Arizona State University, and MIT have announced the launch of an online master’s degree program in supply chain management. This unique credit pathway between MIT and ASU takes a MicroMasters program from one university, MIT, and stacks it up to a full master’s degree on edX from ASU. Learners who complete and pass the Supply Chain Management MicroMasters program and then apply and gain admission to ASU are eligible to earn a top-ranked graduate degree from ASU’s W. P. Carey School of Business and ASU Online. MIT and ASU are both currently ranked in the top three for graduate supply chain and logistics by U.S. News and World Report.
This new master’s degree is the latest program to launch following edX’s October 2018 announcement of 10 disruptively priced and top-ranked online master’s degree programs available on edX.org. Master’s degrees on edX are unique because they are stacked, degree-granting programs with a MicroMasters program component. A MicroMasters program is a series of graduate-level courses that provides learners with valuable standalone skills that translate into career-focused advancement, as well as the option to use the completed coursework as a stepping stone toward credit in a full master’s degree program.
“We are excited to strengthen our relationship with ASU to offer this innovative, top-ranked online master’s degree program in supply chain management,” says Anant Agarwal, edX CEO and MIT professor. “This announcement comes at a time when the workplace is changing more rapidly than ever before, and employers are in need of highly skilled talent, especially in the fields most impacted by advances in technology. This new offering truly transforms traditional graduate education by bringing together two top-ranked schools in supply chain management to create the world’s first stackable, hybrid graduate degree program. This approach to a stackable, flexible, top-quality online master’s degree is the latest milestone in addressing today’s global skills gap.”
ASU’s online master’s degree program will help prepare a highly technical and competent global workforce for advancement in supply chain management careers across a broad diversity of industries and functions. Students enrolled in the program will also gain an in-depth understanding of the role the supply chain manager can play in an enterprise supply chain and in determining overall strategy.
“We’re very excited to collaborate with MIT and edX to increase accessibility to a top-ranked degree in supply chain management,” says Amy Hillman, dean of the W. P. Carey School of Business at ASU. “We believe there will be many students who are eager to dive deeper after their MicroMasters program to earn a master's degree from ASU, and that more learners will be drawn to the MIT Supply Chain Management MicroMasters program as this new pathway to a graduate degree within the edX platform becomes available.”
With this new pathway, the MIT Supply Chain Management MicroMasters program now offers learners pathways to completing a master’s degree at 21 institutions. This new program with ASU for the supply chain management online master’s degree offers a seamless learner experience through an easy transition of credit and a timely completion of degree requirements without leaving the edX platform.
“Learners who complete the MITx MicroMasters program credential from the MIT Center for Transportation and Logistics will now have the opportunity to transition seamlessly online to a full master’s degree from ASU,” says Krishna Rajagopal, dean for digital learning at MIT Open Learning. “We are delighted to add this program to MIT’s growing number of pathways that provide learners with increased access to higher education and career advancement opportunities in a flexible, affordable manner.”
The online Master of Science in supply chain management from ASU will launch in January 2020. Students currently enrolled in, or who have already completed, the MITx Supply Chain Management MicroMasters program can apply now for the degree program, with an application deadline of Dec. 16.
Each year, the Armed Forces Communications and Electronics Association (AFCEA) presents the Young AFCEA 40 Under 40 award to 40 individuals under age 40 for their significant contributions to science, technology, engineering, and mathematics (STEM). This year, the Lincoln Laboratory is home to four winners: Anu Myne, Mark Veillette, Meredith Drennan, and Alexander Stolyarov. The recipients are chosen by AFCEA for the innovation, leadership, and support they provide to their organizations, particularly through the application of information technology to make advancements in STEM.
Myne currently serves as an associate technology officer within the Lincoln Laboratory Technology Office, where she supports the strategic development of the laboratory’s internal investments and innovation initiatives, and furthers collaboration with MIT campus. In this role, she’s focusing on the laboratory’s overall strategies for advancing research and development in artificial intelligence (AI) for national security. Among various other projects, Myne organized the AI Technical Interchange meeting for laboratory-wide participation last year, and is now planning the inaugural Recent Advances in AI for National Security Workshop that will be held in 2019.
"It has been a distinct privilege to work with Anu, one of our rising stars at the laboratory," says Robert Bond, chief technology officer. "Anu has an impressively diverse professional resume spanning hardware design, signal processing, and machine learning. This background, coupled with her natural inquisitiveness and ability to zero in on the important technology issues, has made her ideal for her current role as associate technology officer."
Before joining the Technology Office, Myne made significant contributions to a diverse set of problems addressing challenges in electronic warfare and radar systems for next-generation defense. Her efforts ranged from system analysis and development of simulation tools to hardware design, implementation, and testing.
Myne believes that every opportunity she's had to develop, test, and demonstrate system concepts was a great experience. She’s been most recognized for her efforts in developing a novel electromagnetic environment simulation tool and a Bayesian network approach for intelligent test design — successes she attributes to an appreciation for both real hardware and software design challenges and her willingness to try out new ideas or approaches.
Upon winning the award, Myne said, "The laboratory is filled with talent and I'm honored to be recognized this way."
Veillette began working in the Air Traffic Control Systems Group in 2010. Since then, his main focus has been the application of AI and machine learning in weather sensing and forecasting. "As you can imagine, weather involves a lot of data and uncertainty, so I think it's a very rich and exciting space to be applying these types of algorithms," Veillette says.
Currently, Veillette is working on a project to create a global picture of synthetic weather radar. The data used for the project are similar to weather radar imagery seen on the news, except that these data will be available globally, even in areas without weather radar.
"Mark is not only an expert in his field, he is a consummate teacher," colleague Christopher Mattioli says. "Even at his most busy and stressful times, he's always willing to offer technical guidance and listen to new ideas. His type of character fosters a healthy working environment, which ultimately strengthens and expedites innovation."
Veillette says he is particularly proud of organizing and teaching a technical education course titled Decision Making Under Uncertainty. He has also been involved in various support roles across groups and divisions, and has served on the Laboratory's Advanced Concepts Committee for the past two and a half years.
"There are so many talented people here at the laboratory and at other institutions supporting the Department of Defense, so to be recognized by the AFCEA is very nice," Veillette says. "I’m thankful to the Director’s Office for nominating me."
Drennan has been working at the laboratory since 2010, when she started as an associate staff member in the Integrated Systems and Concepts Group. Since that time, she has worked on an assortment of laboratory projects and is now an assistant leader of her group.
From 2010-14, as part of the Multi-Aperture Sparse Imager Video System and Wide-Area Infrared System for Persistent Surveillance teams, she developed software for wide-area motion imagery processing.
Since 2014, Drennan has been the lead flight software developer for the SensorSat program — a project to build a next-generation surveillance satellite. She was made program manager of this project in 2018.
What Drennan appreciates most about her work at the laboratory has been the opportunity to contribute technically while working with great people on difficult problems. She pointed to her work on SensorSat as the reason for her receiving this award: "While I admit I worked very hard on that program, I was one of many. Any successes the satellite has had are a result of the hard work and dedication of dozens of individuals, not just one."
Alexander (Sasha) Stolyarov
Stolyarov, a staff member in the Chemical, Microsystem, and Nanoscale Technologies Group, currently leads the Defense Fabric Discovery Center (DFDC) — an end-to-end advanced fabrics prototyping facility focused on developing multifunctional fibers and fabrics for national security. The DFDC, opened in October 2017, is one of a planned network of fabric discovery centers and was built in a joint venture among the laboratory, the Commonwealth of Massachusetts, the Advanced Functional Fabrics of America, and the Combat Capabilities Development Command Soldier Center (formerly called the U.S. Army Natick Soldier Research, Development and Engineering Center).
Shortly after joining the laboratory in 2014, Stolyarov began working on a program involving multimaterial fiber devices. The program seeks to incorporate these devices into fabrics for a variety of uses, including fabric-based chemical sensors and optical communication systems.
Stolyarov says that his greatest accomplishment at the laboratory has been "starting and growing the advanced fibers technical area, which has grown from a group project to an enterprise involving collaborations with many of the laboratory’s system divisions."
Livia Racz, associate leader of the Chemical, Microsystem, and Nanoscale Technologies Group, says, "Sasha had a passion for this subject since he first started at the laboratory. When we first saw his proposal, we realized that it promised to become a perfect example of what we were looking for — a rapid, scalable way to break the paradigm of electronics on flat circuit boards."
Urban residents hear a lot about public transit fares, but to what extent do transportation costs really affect riders? A group of urban studies researchers at MIT has conducted a new experiment — a randomized, controlled trial — on Boston’s MBTA system showing that if low-income people are offered a 50 percent fare discount, their ridership increases by over 30 percent. A new white paper with the results was issued this month. The paper’s lead author is MIT PhD student Jeffrey Rosenblum; his co-authors are Department of Urban Studies and Planning professors Jinhua Zhao, Mariana Arcaya, Justin Steil, and Chris Zegras. MIT News spoke to Rosenblum about the results.
Q: What was the impetus for the study, and what did you find?
A: The idea was to look at travel behavior of riders. One of the things we don’t ordinarily have access to is how low-income people use the system. We can track seniors because seniors have a special card. But for low-income people, a lot of the information had previously been anecdotal.
There were hardly any studies to help me understand how low-income riders would respond to fare decreases. When I have to look back to a 1964 study from New York City as one of the prime examples that looked at low-income riders, you know there’s some missing data.
There have been two hypotheses in this area. One is that low-income people have no choice but to use public transit, so they have to take it out of their food budget or child budget. The other is that they do change behavior when fares decrease. The second is what we ended up finding: Low-income people did take significantly more trips, about a third more, based on the analysis. This suggests that for the low-income people in the study group, who were selected out of food stamps recipients, affordability was a big factor. So that’s really the take-home message.
Q: There is another layer to the results, though, which is that the increased use of public transit was strongly linked to certain purposes, such as using social services.
A: This gets into an important concept in transportation. No one gets on a bus to get on a bus. They want to go someplace. In the past transit systems really just cared about the numbers of people using the system, and they didn’t really care about the purposes of those trips.
In most categories of trip purpose, we didn’t see much difference, but in the social services category, we did. Usually when people think of public transportation, they think of commuting to work. And when people think about low-income riders, they don’t think about other really important things in life. Low-income people also spend more time on public transit doing errands, visiting family, as well as going to social services and health care providers.
Q: So this is not just a matter of household finance, since it seems like lower fares for low-income people have a kind of multiplier effect, allowing them to access other goods, right?
A: Yes. And any decisions related to implementation and the impact on the system would be as important as trying to find the money to fund such a program. Whenever studies like this get done, the implication is that this is an important issue to address.
But then one question is: Who is going to pay for it, and how? And the second is: Who would administer it? One option would be just to say the MBTA has to do it all. A more creative option would be to incorporate it into an existing government program, like Mass Health, or SNAP, the food stamps program, where those agencies already have a whole customer-service system set up, a database of low-income people, and are already issuing them cards. Imagine if a low-income person had one card, with a debit-card for food stamps, the Mass Health information, and a Charlie Card [an MBTA metro card] chip embedded in it. That’s where government efficiency counts. The technology is there but the lack of interagency coordination is a significant barrier.
MIT researchers have devised a novel method to glean more information from images used to train machine-learning models, including those that can analyze medical scans to help diagnose and treat brain conditions.
An active new area in medicine involves training deep-learning models to detect structural patterns in brain scans associated with neurological diseases and disorders, such as Alzheimer’s disease and multiple sclerosis. But collecting the training data is laborious: All anatomical structures in each scan must be separately outlined or hand-labeled by neurological experts. And, in some cases, such as for rare brain conditions in children, only a few scans may be available in the first place.
In a paper presented at the recent Conference on Computer Vision and Pattern Recognition, the MIT researchers describe a system that uses a single labeled scan, along with unlabeled scans, to automatically synthesize a massive dataset of distinct training examples. The dataset can be used to better train machine-learning models to find anatomical structures in new scans — the more training data, the better those predictions.
The crux of the work is automatically generating data for the “image segmentation” process, which partitions an image into regions of pixels that are more meaningful and easier to analyze. To do so, the system uses a convolutional neural network (CNN), a machine-learning model that’s become a powerhouse for image-processing tasks. The network analyzes a lot of unlabeled scans from different patients and different equipment to “learn” anatomical, brightness, and contrast variations. Then, it applies a random combination of those learned variations to a single labeled scan to synthesize new scans that are both realistic and accurately labeled. These newly synthesized scans are then fed into a different CNN that learns how to segment new images.
“We’re hoping this will make image segmentation more accessible in realistic situations where you don’t have a lot of training data,” says first author Amy Zhao, a graduate student in the Department of Electrical Engineering and Computer Science (EECS) and Computer Science and Artificial Intelligence Laboratory (CSAIL). “In our approach, you can learn to mimic the variations in unlabeled scans to intelligently synthesize a large dataset to train your network.”
There’s interest in using the system, for instance, to help train predictive-analytics models at Massachusetts General Hospital, Zhao says, where only one or two labeled scans may exist of particularly uncommon brain conditions among child patients.
Joining Zhao on the paper are: Guha Balakrishnan, a postdoc in EECS and CSAIL; EECS professors Fredo Durand and John Guttag, and senior author Adrian Dalca, who is also a faculty member in radiology at Harvard Medical School.
The “Magic” behind the system
Although now applied to medical imaging, the system actually started as a means to synthesize training data for a smartphone app that could identify and retrieve information about cards from the popular collectable card game, “Magic: The Gathering.” Released in the early 1990s, “Magic” has more than 20,000 unique cards — with more released every few months — that players can use to build custom playing decks.
Zhao, an avid “Magic” player, wanted to develop a CNN-powered app that took a photo of any card with a smartphone camera and automatically pulled information such as price and rating from online card databases. “When I was picking out cards from a game store, I got tired of entering all their names into my phone and looking up ratings and combos,” Zhao says. “Wouldn’t it be awesome if I could scan them with my phone and pull up that information?”
But she realized that’s a very tough computer-vision training task. “You’d need many photos of all 20,000 cards, under all different lighting conditions and angles. No one is going to collect that dataset,” Zhao says.
Instead, Zhao trained a CNN on smaller dataset of around 200 cards, with 10 distinct photos of each card, to learn how to warp a card into various positions. It computed different lighting, angles, and reflections — for when cards are placed in plastic sleeves — to synthesized realistic warped versions of any card in the dataset. It was an exciting passion project, Zhao says: “But we realized this approach was really well-suited for medical images, because this type of warping fits really well with MRIs.”
Magnetic resonance images (MRIs) are composed of three-dimensional pixels, called voxels. When segmenting MRIs, experts separate and label voxel regions based on the anatomical structure containing them. The diversity of scans, caused by variations in individual brains and equipment used, poses a challenge to using machine learning to automate this process.
Some existing methods can synthesize training examples from labeled scans using “data augmentation,” which warps labeled voxels into different positions. But these methods require experts to hand-write various augmentation guidelines, and some synthesized scans look nothing like a realistic human brain, which may be detrimental to the learning process.
Instead, the researchers’ system automatically learns how to synthesize realistic scans. The researchers trained their system on 100 unlabeled scans from real patients to compute spatial transformations — anatomical correspondences from scan to scan. This generated as many “flow fields,” which model how voxels move from one scan to another. Simultaneously, it computes intensity transformations, which capture appearance variations caused by image contrast, noise, and other factors.
In generating a new scan, the system applies a random flow field to the original labeled scan, which shifts around voxels until it structurally matches a real, unlabeled scan. Then, it overlays a random intensity transformation. Finally, the system maps the labels to the new structures, by following how the voxels moved in the flow field. In the end, the synthesized scans closely resemble the real, unlabeled scans — but with accurate labels.
To test their automated segmentation accuracy, the researchers used Dice scores, which measure how well one 3-D shape fits over another, on a scale of 0 to 1. They compared their system to traditional segmentation methods — manual and automated — on 30 different brain structures across 100 held-out test scans. Large structures were comparably accurate among all the methods. But the researchers’ system outperformed all other approaches on smaller structures, such as the hippocampus, which occupies only about 0.6 percent of a brain, by volume.
“That shows that our method improves over other methods, especially as you get into the smaller structures, which can be very important in understanding disease,” Zhao says. “And we did that while only needing a single hand-labeled scan.”
In a nod to the work’s “Magic” roots, the code is publicly available on Github under the name of one of the game’s cards, “Brainstorm.”
Hearing aids, dental crowns, and limb prosthetics are some of the medical devices that can now be digitally designed and customized for individual patients, thanks to 3-D printing. However, these devices are typically designed to replace or support bones and other rigid parts of the body, and are often printed from solid, relatively inflexible material.
Now MIT engineers have designed pliable, 3-D-printed mesh materials whose flexibility and toughness they can tune to emulate and support softer tissues such as muscles and tendons. They can tailor the intricate structures in each mesh, and they envision the tough yet stretchy fabric-like material being used as personalized, wearable supports, including ankle or knee braces, and even implantable devices, such as hernia meshes, that better match to a person’s body.
As a demonstration, the team printed a flexible mesh for use in an ankle brace. They tailored the mesh’s structure to prevent the ankle from turning inward — a common cause of injury — while allowing the joint to move freely in other directions. The researchers also fabricated a knee brace design that could conform to the knee even as it bends. And, they produced a glove with a 3-D-printed mesh sewn into its top surface, which conforms to a wearer’s knuckles, providing resistance against involuntary clenching that can occur following a stroke.
“This work is new in that it focuses on the mechanical properties and geometries required to support soft tissues,” says Sebastian Pattinson, who conducted the research as a postdoc at MIT.
Pattinson, now on the faculty at Cambridge University, is the lead author of a study published today in the journal Advanced Functional Materials. His MIT co-authors include Meghan Huber, Sanha Kim, Jongwoo Lee, Sarah Grunsfeld, Ricardo Roberts, Gregory Dreifus, Christoph Meier, and Lei Liu, as well as Sun Jae Professor in Mechanical Engineering Neville Hogan and associate professor of mechanical engineering A. John Hart.
Riding collagen’s wave
The team’s flexible meshes were inspired by the pliable, conformable nature of fabrics.
“3-D-printed clothing and devices tend to be very bulky,” Pattinson says. “We were trying to think of how we can make 3-D-printed constructs more flexible and comfortable, like textiles and fabrics.”
Pattinson found further inspiration in collagen, the structural protein that makes up much of the body’s soft tissues and is found in ligaments, tendons, and muscles. Under a microscope, collagen can resemble curvy, intertwined strands, similar to loosely braided elastic ribbons. When stretched, this collagen initially does so easily, as the kinks in its structure straighten out. But once taut, the strands are harder to extend.
Inspired by collagen’s molecular structure, Pattinson designed wavy patterns, which he 3-D-printed using thermoplastic polyurethane as the printing material. He then fabricated a mesh configuration to resemble stretchy yet tough, pliable fabric. The taller he designed the waves, the more the mesh could be stretched at low strain before becoming more stiff — a design principle that can help to tailor a mesh’s degree of flexibility and helped it to mimic soft tissue.
The researchers printed a long strip of the mesh and tested its support on the ankles of several healthy volunteers. For each volunteer, the team adhered a strip along the length of the outside of the ankle, in an orientation that they predicted would support the ankle if it turned inward. They then put each volunteer’s ankle into an ankle stiffness measurement robot — named, logically, Anklebot — that was developed in Hogan’s lab. The Anklebot moved their ankle in 12 different directions, and then measured the force the ankle exerted with each movement, with the mesh and without it, to understand how the mesh affected the ankle’s stiffness in different directions.
In general, they found the mesh increased the ankle’s stiffness during inversion, while leaving it relatively unaffected as it moved in other directions.
“The beauty of this technique lies in its simplicity and versatility. Mesh can be made on a basic desktop 3-D printer, and the mechanics can be tailored to precisely match those of soft tissue,” Hart says.
Stiffer, cooler drapes
The team’s ankle brace was made using relatively stretchy material. But for other applications, such as implantable hernia meshes, it might be useful to include a stiffer material, that is at the same time just as conformable. To this end, the team developed a way to incorporate stronger and stiffer fibers and threads into a pliable mesh, by printing stainless steel fibers over regions of an elastic mesh where stiffer properties would be needed, then printing a third elastic layer over the steel to sandwich the stiffer thread into the mesh.
The combination of stiff and elastic materials can give a mesh the ability to stretch easily up to a point, after which it starts to stiffen, providing stronger support to prevent, for instance, a muscle from overstraining.
The team also developed two other techniques to give the printed mesh an almost fabric-like quality, enabling it to conform easily to the body, even while in motion.
“One of the reasons textiles are so flexible is that the fibers are able to move relative to each other easily,” Pattinson says. “We also wanted to mimic that capability in the 3-D-printed parts.”
In traditional 3-D printing, a material is printed through a heated nozzle, layer by layer. When heated polymer is extruded it bonds with the layer underneath it. Pattinson found that, once he printed a first layer, if he raised the print nozzle slightly, the material coming out of the nozzle would take a bit longer to land on the layer below, giving the material time to cool. As a result, it would be less sticky. By printing a mesh pattern in this way, Pattinson was able to create a layers that, rather than being fully bonded, were free to move relative to each other, and he demonstrated this in a multilayer mesh that draped over and conformed to the shape of a golf ball.
Finally, the team designed meshes that incorporated auxetic structures — patterns that become wider when you pull on them. For instance, they were able to print meshes, the middle of which consisted of structures that, when stretched, became wider rather than contracting as a normal mesh would. This property is useful for supporting highly curved surfaces of the body. To that end, the researchers fashioned an auxetic mesh into a potential knee brace design and found that it conformed to the joint.
“There’s potential to make all sorts of devices that interface with the human body,” Pattinson says. Surgical meshes, orthoses, even cardiovascular devices like stents — you can imagine all potentially benefiting from the kinds of structures we show.”
This research was supported in part by the National Science Foundation, the MIT-Skoltech Next Generation Program, and the Eric P. and Evelyn E. Newman Fund at MIT.
This month, 5,000 distinctive cans of Fuzzy Logic beer will appear on local shelves as part of Massachusetts-based Portico Brewing’s attempt to stand out in the aesthetically competitive world of craft beer.
The cans feature eye-catching arrays of holographic triangles that appear three dimensional at certain angles. Curious drinkers might twist the cans and guess how Portico achieved the varying, almost shining appearance. Were special lenses or foils used? Are the optical effects the result of an expensive, holographic film?
It turns out it takes two MIT PhDs to fully explain the technology behind the can’s appearance. The design is the result of Portico’s collaboration with Lumii, a startup founded by Tom Baran SM ’07 PhD ’12 and Matt Hirsch SM ’09, PhD ’14.
Lumii uses complex algorithms to precisely place tens of millions of dots of ink on two sides of clear film to create light fields that achieve the same visual effects as special films and lenses. The designs add depth, motion, and chromatic effect to packages, labels, IDs, and more.
“We describe [the technology] differently to different crowds,” Baran says. “You can formulate this as a machine learning problem or a signal processing problem, but basically at the end of the day we think of it as an optimization problem. To produce a three-dimensional image, you could place dots of ink so that you get a perfect rendition of a three-dimensional image from one perspective. Then you could rotate the print and say, ‘Well now the perspective is off, so I need to readjust all of the dots,’ and that will mess things up from the first perspective. We make it possible to have a three-dimensional image using just two layers of ink from as many perspectives as possible.”
Lumii does not operate its own printing presses. Instead the company is partnering with package manufacturers, who are often surprised to learn that the machines they’ve been operating for decades are capable of printing designs with such special effects.
The Portico collaboration is Lumii’s first project in packaging, and the founders are hoping it serves as technical validation for the large manufacturers who create packages for the world’s biggest brands.
“[The Portico label manufacturers] are using equipment that can start at 5,000 units and go up to hundreds of millions per year,” Baran says. “Our technology can blow people away, but the people who do package printing say, ‘This is beautiful; I just need to make sure I can make one hundred million of these if I have to.’ That’s what this project does.”
Tech for effects
Baran and Hirsch met as undergraduates at Tufts University and stayed in touch as they both came to MIT for their graduate degrees. Hirsch’s PhD work at the Media Lab focused on using algorithms to make something appear three-dimensional, without fancy cameras or display screens.
“The challenge of making something look 3-D is about not just pixels on a screen but light rays in space,” Hirsch explains. “To have a quality 3-D image, for every pixel on your screen you have to have potentially hundreds of different viewpoints to replicate a reality, so the problem is more difficult than just using brute force to build a finer optical system to represent that.”
Baran’s research into new classes of a field of mathematics called nonconvex optimization made it possible for Lumii to process trillions of light rays to create its designs.
Hirsch knew he wanted to start a company around the technology he’d worked on for his PhD, and Lumii was officially incorporated in 2015 when Baran joined.
The founders received support from MIT’s Venture Mentoring Service and the Media Lab-affiliated E14 Fund.
In 2016, they entered MassChallenge, where they decided to move from digital displays to print, which represented a bigger market but a much more complex problem.
“On a digital display, 8K [or 8,000 pixels] is high resolution,” Baran says. “But if I take a magazine and tear off one page from it, I’m probably holding several billion pixels on that one page.”
Still, the size of the various commercial printing sectors made them worth the added complexity. For instance, Baran says consumer packaged goods alone represent a $200 billion industry.
“When we first read some of the numbers for package printing, we thought, ‘This sounds crazy.’ But everything we buy, every product we consume, has some form of language or label on it,” Baran says. “It’s so pervasive people don’t even think about it.”
One type of packaging the founders are especially focused on is the shrink sleeve — the ubiquitous plastic wrap that covers products from mouthwash to energy drinks and spray cleaners. Lumii has also attracted attention in the security sector for applications like ID cards, which often rely on expensive foils to achieve holographic effects.
By charging a small fee for its designs, Hirsch says Lumii offers a significant cost savings for package manufacturers when compared with using holographic foils and lenses that can be impractical at the high volumes required for commercial packaging.
“There aren’t very often direct competitors to what we’re doing,” Hirsch says. “We see our technology as more complementary. If you’re using something like a brightly colored ink, we can use that ink in conjunction with our technology.”
Because Lumii’s algorithms replace foils and other label materials, they can also make bottles and cans recyclable that weren’t previously, a benefit that has resonated with many potential customers.
The Portico Fuzzy Logic can design created by Lumii. Courtesy of Lumii
An intoxicating milestone
Many consumer brands export the production of their packaging to a group of large manufacturers. Hirsch and Baran have impressed some of these manufacturers with their designs, but it’s been difficult getting incorporated into production lines.
“One of the things we’ve realized is it’s really important to be able to prove to people that it will work on their assembly line, and there are significant challenges to getting people to reserve time to try your experiments on their line,” Baran says.
That’s what makes the Portico project so significant for Lumii. Portico wanted an eye-catching design for its new Fuzzy Logic cans, but it couldn’t change the materials or equipment it was using. The cans use a 45-micron-thick shrink sleeve, a relatively thin material that would test Lumii’s technology.
That material is also used by many large consumer brands and so represented a perfect way to demonstrate Lumii’s potential for large companies across industries.
“The Portico project is verification that what we’re doing works with a material that can be applied across a broad range of different markets,” Baran says. “Just the fact that it’s working on those types of materials is a big deal for us.”
Now that they’ve gotten their designs on shelves, the founders have to decide how to focus their efforts to spread Lumii’s technology onto packages and labels everywhere.
“We’re thinking, ‘What are the industries where we can have the biggest impact?’” Baran says. “We get to see the reaction on people’s faces when they see their printing press printing out things that are 3-D. We want to deliver that to more places.”
MIT has again been named the world’s top university by the QS World University Rankings, which were announced today. This is the eighth year in a row MIT has received this distinction.
The full 2019-20 rankings — published by Quacquarelli Symonds, an organization specializing in education and study abroad — can be found at topuniversities.com. The QS rankings were based on academic reputation, employer reputation, citations per faculty, student-to-faculty ratio, proportion of international faculty, and proportion of international students. MIT earned a perfect overall score of 100.
MIT was also ranked the world’s top university in 11 of 48 disciplines ranked by QS, as announced in February of this year.
MIT received a No. 1 ranking in the following QS subject areas: Chemistry; Computer Science and Information Systems; Chemical Engineering; Civil and Structural Engineering; Electrical and Electronic Engineering; Mechanical, Aeronautical and Manufacturing Engineering; Linguistics; Materials Science; Mathematics; Physics and Astronomy; and Statistics and Operational Research.
MIT also placed second in six subject areas: Accounting and Finance; Architecture/Built Environment; Biological Sciences; Earth and Marine Sciences; Economics and Econometrics; and Environmental Sciences.
The Cooper Hewitt, Smithsonian Design Museum announced that MIT D-Lab has won the National Design Award in the Corporate and Institutional Achievement category. Nominations were solicited from leading designers, educators, journalists, cultural figures, corporate leaders, and design enthusiasts from every U.S. state.
“D-Lab’s work in bringing design thinking to under-resourced areas of the globe is a tremendous example of MIT’s mission to serve the world,” comments Anantha Chandrakasan, dean of the MIT School of Engineering. “The D-Lab team deeply understands that designing and developing products and services for people living in poverty is not enough. Teaching people to design solutions to meet their own needs is rich with benefits — a sense of pride and accomplishment, the joy of creation, and an increased sense of agency,” he continued.
One of 11 awards, the Corporate and Institutional Achievement Award is "given in recognition of a corporation or institution that uses design as a strategic tool as part of its mission and has consistently exhibited ingenuity and insight in the relationship between design and quality of life," according to the Cooper Hewitt website.
“It is an incredible honor to have our work recognized by this award,” says Amy Smith, D-Lab founding director and senior lecturer in mechanical engineering. “Design is such an important part of what we do at D-Lab — we believe that both the products and the process of design can have a significant impact in addressing global poverty challenges.”
Comments Thabiso “Blak” Mashaba, of founder of These Hands, GSSE and one of D-Lab’s longtime collaborators in Botswana, “We work with D-Lab because our community members not only learn design skills, they become equal design partners on projects that matter and then design leads as they move projects forward and start others.”
Founded in 2002, D-Lab began as a single course known as The Haiti Class, which sought to apply engineering and design principles to the complex issues faced by people living in poverty. That first course embodied the values of technical expertise and a commitment to deep and respectful collaborations that D-Lab continues to hold at the center of its work today. D-Lab’s programs include more than 20 interdisciplinary courses, six research groups working in collaboration with global partners, as well as field programs focused on social entrepreneurship, inclusive markets, innovation ecosystems, and humanitarian innovation.
“This award is a wonderful recognition of D-Lab’s nearly 20 years of world-leading collaborative design education and research focused on empowering local communities to alleviate the pervasive challenges of global poverty,” says Ian A. Waitz, vice chancellor for undergraduate and graduate education.”
When the National Design Awards were established in 2000 as a project of the White House Millennium Council, the stated intent was to affirm design excellence in the U.S. “Twenty years later, the achievements of this year’s class underscore not just the incredible prowess of American design today, but advance our understanding of the power of design to change the world. From MIT D-Lab’s work to address the daily challenges of poverty through design to Open Style Lab’s functional and stylish wearable solutions for people of all abilities, the 2019 winners join an impressive group of honorees who have made an indelible impact on society,” says Caroline Baumann, director of Cooper Hewitt in a prepared statement.
The other National Design Award winners are Open Style Lab, co-founded by Grace Teo PhD '14 (Emerging Designer); Susan Kare (Lifetime Achievement); Patricia Moore (Design Mind); Thomas Phifer (Architecture Design); Tobias Frere-Jones (Communication Design); Derek Lam (Fashion Design); Ivan Poupyrev (Interaction Design); IwamotoScott Architecture (Interior Design); SCAPE Landscape Architecture (Landscape Architecture); and Tinker Hatfield (Product Design).
National Design Award winners will be invited to participate in public-facing programs at the Cooper Hewitt during National Design Week starting Oct. 12. A gala to celebrate the award winners will be held at the museum on Oct. 17.
David Mindell, Frances and David Dibner Professor of the History of Engineering and Manufacturing in the School of Humanities, Arts, and Social Sciences and professor of aeronautics and astronautics, researches the intersections of human behavior, technological innovation, and automation. Mindell is the author of five acclaimed books, most recently "Our Robots, Ourselves: Robotics and the Myths of Autonomy" (Viking, 2015) as well as the co-founder of the Humatics Corporation, which develops technologies for human-centered automation. SHASS Communications spoke with Mindell recently on how his vision for human-centered robotics is developing and his thoughts about the new MIT Stephen A. Schwarzman College of Computing, which aims to integrate technical and humanistic research and education.
Q: Interdisciplinary programs have proved challenging to sustain, given the differing methodologies and vocabularies of the fields being brought together. How might the MIT Schwarzman College of Computing design the curriculum to educate "bilinguals" — students who are adept in both advanced computation and one of more of the humanities, arts, and social science fields?
A: Some technology leaders today are naive and uneducated in humanistic and social thinking. They still think that technology evolves on its own and “impacts” society, instead of understanding technology as a human and cultural expression, as part of society.
As a historian and an engineer, and MIT’s only faculty member with a dual appointment in engineering and the humanities, I’ve been “bilingual” my entire career (long before we began using that term for fluency in both humanities and technology fields). My education started with firm grounding in two fields — electrical engineering and history — that I continue to study.
Dual competence is a good model for undergraduates at MIT today as well. Pick two: not necessarily the two that I chose, but any two disciplines that capture the core of technology and the core of the humanities. Disciplines at the undergraduate level provide structure, conventions, and professional identity (although my appointment is in Aero/Astro, I still identify as an electrical engineer). I prefer the term “dual disciplinary” to “interdisciplinary.”
The College of Computing curriculum should focus on fundamentals, not just engineering plus some dabbling in social implications.
It sends the wrong message to students that “the technical stuff is core, and then we need to add all this wrapper humanities and social sciences around the engineering.” Rather, we need to say: “master two fundamental ways of thinking about the world, one technical and one humanistic or social.” Sometimes these two modes will be at odds with each other, which raises critical questions. Other times they will be synergistic and energizing. For example, my historical work on the Apollo guidance computer inspired a great deal of my current engineering work on precision navigation.
Q: In naming the company you founded Humatics, you’ve combined “human” and “robotics,” highlighting the synergy between human beings and our advanced technologies. What projects underway at Humatics define and demonstrate how you envision people working collaboratively with machines?
A: Humatics builds on the synthesis that has defined my career — the name is the first four letters of “human" and the last four letters of “robotics.” Our mission is to build technologies that weave robotics into the human world, rather than shape human behavior to the limitations of the robots. We do very technical stuff: We build our own radar chips, our own signal processing algorithms, our own AI-based navigation systems. But we also craft our technologies to be human-centered, to give users and workers information that enables them to make their own decisions and work safer and more efficiently.
We’re currently working to incorporate our ultra-wideband navigation systems into subway and mass transit systems. Humatics' technologies will enable modern signaling systems to be installed more quickly and less expensively. It's gritty, dirty work down in the tunnels, but it is a “smart city” application that can improve the daily lives of millions of people. By enabling the trains to navigate themselves with centimeter-precision, we enable greater rush-hour throughput, fewer interruptions, even improved access for people with disabilities, at a minimal cost compared to laying new track.
A great deal of this work focuses on reliability, robustness, and safety. These are large technological systems that MIT used to focus on in the Engineering Systems Division. They are legacy infrastructure running at full capacity, with a variety of stakeholders, and technical issues hashed out in political debate. As an opportunity to improve peoples' lives with our technology, this project is very motivating for the Humatics team.
We see a subway system as a giant robot that collaborates with millions of people every day. Indeed, for all their flaws, it does so today in beautifully fluid ways. Disruption is not an option. Similarly, we see factories, e-commerce fulfillment centers, even entire supply chains as giant human-machine systems that combine three key elements: people, robots (vehicles), and infrastructure. Humatics builds the technological glue that ties these systems together.
Q: Autonomous cars were touted to be available soon, but their design has run into issues and ethical questions. Is there a different approach to the design of artificially intelligent vehicles, one that does not attempt to create fully autonomous vehicles? If so, what are the barriers or resistance to human-centered approaches?
A: Too many engineers still imagine autonomy as meaning “alone in the world.” This approach derives from a specific historical imagination of autonomy, derived from Defense Advanced Research Projects Agency sponsorship and elsewhere, that a robot should be independent of all infrastructure. While that’s potentially appropriate for military operations, the promise of autonomy on our roads must be the promise of autonomy in the human world, in myriad exquisite relationships.
Autonomous vehicle companies are learning, at great expense, that they already depend heavily on infrastructure (including roads and traffic signs) and that the sooner they learn to embrace it, the sooner they can deploy at scale. Decades of experience have taught us that, to function in the human world, autonomy must be connected, relational, and situated. Human-centered autonomy in automobiles must be more than a fancy FitBit on a driver; it must factor into the fundamental design of the systems: What do we wish to control? Whom do we trust? Who owns our data? How are our systems trained? How do they handle failure? Who gets to decide?
The current crisis over the Boeing 737 MAX control systems show these questions are hard to get right, even in aviation. There we have a great deal of regulation, formalism, training, and procedure, not to mention a safety culture that evolved over a century. For autonomous cars, with radically different regulatory settings and operating environments, not to mention non-deterministic software, we still have a great deal to learn. Sometimes I think it could take the better part of this century to really learn how to build robust autonomy into safety-critical systems at scale.
Editorial and Design Director: Emily Hiestand
Interview conducted by writer Maria Iacobo
Anne White, associate professor of nuclear science and engineering and associate director of the Plasma Science and Fusion Center at MIT, has been named the new head of the Department of Nuclear Science and Engineering, effective July 1.
“Professor White is a brilliant researcher who has had a tremendous impact on students at MIT,” says Anantha Chandrakasan, dean of the MIT School of Engineering and the Vannevar Bush Professor of Electrical Engineering and Computer Science. “As a tireless ambassador and advocate for the potential of nuclear fusion as an energy source, she inspires our students and our research community. I look forward to working with her on the school’s leadership team.”
An international leader in assessing and refining the mathematical models used in fusion reactor design, White and the members of her research group develop diagnostic techniques that allow for simultaneous measurements of fluctuations in plasma density, and temperature in the core and edge of tokamak reactors, which are large toroidal devices in which plasmas reach temperatures higher 100 million degrees. She and her team hope to improve the understanding of how turbulence is suppressed and how the turbulent-transport of particles, energy, and momentum can be separated from one another — essential data in the development of fusion reactors.
White has taught a variety of courses at MIT, including graduate plasma physics, undergraduate electronics, and an advanced graduate course on the principles of plasma diagnostics, which attracts students from across the Institute and other local universities. She also helped team-teach the first offering of a new undergraduate course, 22.061 (Fusion Energy). Recently, White and a team of faculty led the development of a new MOOC on MITx covering nuclear science and engineering, 22.011x (Nuclear Science: Energy, Systems and Society), which was jointly offered online and on campus in spring 2019 as the new first-year seminar in NSE.
A past winner of the U.S. Department of Energy (DoE) Early Career Award, the American Physical Society Katherine E. Weimer Award, and the Fusion Power Associates Excellence in Fusion Engineering Award, White received a DoE ORISE Fusion Energy Science Fellowship, won the Marshall N. Rosenbluth Outstanding Doctoral Thesis Award, and was named a DoE Fusion Energy Postdoctoral Research Program Fellow and an APS Division of Plasma Physics distinguished lecturer. She is a member of the Division of Plasma Physics at the American Physical Society, and the American Nuclear Society. White is also a past recipient of the Junior Bose Award for Excellence in Teaching from the MIT School of Engineering and the PAI Outstanding Faculty Award, presented by the student chapter of the American Nuclear Society. She currently serves on the DoE Fusion Energy Sciences Advisory Committee and the advisory board for the Princeton Plasma Physics Laboratory.
A member of the MIT faculty since 2009, White earned her BS in physics and applied mathematics at the University of Arizona in 2003, and her MS and PhD in physics at the University of California at Los Angeles, in 2004 and 2008.
White succeeds Dennis Whyte, who has been department head since 2015 and will remain director of MIT’s Plasma Science and Fusion Center. “Under Dennis’s leadership, NSE has implemented a range of innovative strategies to accelerate growth and development in recruiting, education, and research,” Chandrakasan noted in his email to the nuclear science community. “He has been a remarkable and committed leader for the department.”
Over a century ago, a visitor to Henry Ford’s new assembly line in Highland Park, Michigan, could watch workers build automobiles from interchangeable parts, and witness a manufacturing revolution in progress.
Today, someone who wants to glimpse the future of manufacturing should make a visit to John Hart’s lab. Through projects including next-generation 3-D printers, carbon nanotube fibers for use in electric motors and lightweight composites, and printing flexible materials for medical devices, Hart and his research group are developing technologies to reimagine the way things are made, from the nanoscale to the scale of the global economy.
Hart, an associate professor of mechanical engineering at MIT and the director of the Laboratory for Manufacturing and Productivity and the Center for Additive and Digital Advanced Production Technologies, is an expert in 3-D printing, also known as additive manufacturing, which involves the computer-guided deposition of material layer by layer into precise three-dimensional shapes. (Conventional manufacturing usually entails making a part by removing material, for example through machining, or by forming the part using a mold tool.)
Hart’s research includes the development of advanced materials — new types of polymers, nanocomposites, and metal alloys — and the development of novel machines and processes that use and shape materials, such as high-speed 3-D printing, roll-to-roll graphene growth, and manufacturing techniques for low-cost sensors and electronics.
“In my lab, through our partnerships with industry and via the startup companies I’m involved in, we’re seeking to redefine manufacturing at scale and rethink how resources are committed to manufacturing throughout the product life cycle,” Hart says. “One major focus is creating new kinds of 3-D printers. These are printers that are 10 to 100 times faster, more accurate, and process both well-known materials and materials that have never been possible before.”
A focus on applications and scale
Hart grew up in the Detroit area — one of the country’s great manufacturing hubs since Henry Ford’s time — and studied mechanical engineering as an undergraduate at the University of Michigan. He spent summers interning for General Motors, and when he started in the master’s degree program in mechanical engineering at MIT, he thought he would eventually make his way back to the auto industry.
Once he got to Cambridge, though, new horizons opened up. “Coming to MIT, I simply enjoyed the environment, the sense of challenge, learning, and open-mindedness,” he says.
Hart’s work with his advisor, professor of mechanical engineering Alexander Slocum, sparked an interest in nanomaterials manufacturing. He decided to pursue a PhD investigating new ways to build carbon nanotubes, which are long molecules that are stronger than steel and more conductive than copper.
When he returned to MIT in 2013 as a new faculty member, after several years as a professor at the University of Michigan, he started exploring another new frontier: 3-D printing.
As the director of the newly formed MIT Center for Additive and Digital Advanced Production Technologies and the co-founder of two Boston-area 3-D printing startups — Desktop Metal and VulcanForms — Hart is advancing this frontier on multiple fronts, through education, entrepreneurship, and engagement with industry.
Although the research projects in his lab span from the nanoscale to the macroscale, he has an eye trained on the bigger picture. Leveraging advances in computation, digitization, and automation, along with his own expertise with materials processing and machine design, Hart’s group sees the potential for 3-D printing to dramatically streamline and speed up global supply chains. The group is also pursuing a series of projects related to Hart’s longstanding interest in carbon nanotubes, exploring ways to form nanotubes into advanced wires, fibers, and structural composites.
Hart sees this convergence of digitally driven manufacturing technologies as a means of overcoming the logistical hurdles of long lead times, complex supply chains, and steep capital requirements.
And, he is motivated by finding new applications to benefit society at large. “That could be a better medical implant or sensor to measure the health of soil, a wire that is more conductive than copper, or a new business enabled by rapid access to 3-D printing in a dense city or a rural environment,” he says.
“If you want to make a new medical device, or even an automotive part, think of the supply chain you have to figure out and manage. Every part requires a lot of detail, time and investment to design, validate, and eventually produce, whether it’s made locally or overseas. One reason 3-D printing is fundamentally different is that it allows designers and engineers to iterate more quickly, and to, in the near future, produce parts on demand in large quantities without fixed up-front investment.”
Shaping the future
To be sure, “It’s not that 3-D printing will replace all of manufacturing or even a tenth of it in the near future,” Hart says. “It is the cornerstone of a digital transformation in the way we go about designing, producing, and servicing products in a responsive, market-driven manner.”
As these new technologies become more widely used, the resulting changes in industrial manufacturing processes could have profound implications for the workers of the future, and for their training and education. Hart is deeply engaged with those questions, too.
“We also like to think at the system level, in terms of economic modeling of new manufacturing technologies including 3-D printing, and understanding how companies work and what transformations may be needed in product-development processes and in the skills of their employees,” he says.
That research has been inspired by Hart’s involvement in MIT’s Work of the Future initiative, for which he’s assembled a team to examine how demands on workers across the product life cycle — from the designer to the engineer to the production worker — will be influenced by the rise of automation and digitization.
Hart’s own workflow has become ever more diverse, in pace with the rapid developments in the field. But his teaching, research, and work with industry all go hand in hand, he says. “It’s all symbiotic. All these activities and interests feed to and from one another. We also have a prime responsibility to consider the sustainability of the manufacturing technologies that we develop, and the implications of more flexible manufacturing — both positive and negative — on the resource pressures of the planet.”
In addition to his own experience as an entrepreneur — and becoming co-inventor of more than 50 pending and issued patents — Hart gains insights and energy from teaching industry professionals and students alike.
He’s a recipient of the prestigious Ruth and Joel Spira Award for Distinguished Teaching at MIT, as well as the MIT Keenan Award for Innovation in Undergraduate Education, for his work teaching MIT’s flagship undergraduate manufacturing course 2.008 (Design and Manufacturing) and its equivalent as an open online course on edX. As the Department of Mechanical Engineering’s “Maker Czar,” he oversees the design and manufacturing shops used by hundreds of students, working with instructors and various department leaders to make sure facilities have state-of-the-art equipment and capabilities and that students become proficient with both established and emerging technologies.
He also created and leads an online MITxPro course for professionals, “Additive Manufacturing for Innovative Design and Production,” which has enrolled over 2,500 participants from around the world who have sought to learn the fundamentals and applications of 3-D printing and apply this knowledge to their jobs.
“The experience of teaching and developing courses for industry, both in person and digitally, has been incredibly helpful in shaping my perspective of how we at MIT can contribute to the future of manufacturing,” Hart says.
The formation of air bubbles in a liquid appears very similar to its inverse process, the formation of liquid droplets from, say, a dripping water faucet. But the physics involved is actually quite different, and while those water droplets are uniform in their size and spacing, bubble formation is typically a much more random process.
Now, a study by researchers at MIT and Princeton University shows that under certain conditions, bubbles can also be coaxed to form spheres as perfectly matched as droplets.
The new findings could have implications for the development of microfluidic devices for biomedical research and for understanding the way natural gas interacts with petroleum in the tiny pore spaces of underground rock formations, the researchers say. The findings are published today in the journal PNAS, in a paper by MIT graduate Amir Pahlavan PhD ’18, Professor Howard Stone of Princeton, MIT School of Engineering Professor of Teaching Innovation Gareth McKinley, and MIT Professor Ruben Juanes.
The key to producing uniformly sized and spaced bubbles lies in confining them to a narrow space, Juanes explains. When air or gas is released into a large container of liquid, the dispersal of bubbles is scattershot. When released into liquid that is confined in a relatively narrow tube, however, the gas will produce a stream of bubbles perfectly matched in size, and forming at even intervals. This uniform and predictable behavior, independent of specific starting conditions, is known as universality.
The process of formation of droplets or bubbles is very similar, beginning with an elongation of the flowing material (whether it’s air or water), and eventually a thinning and pinch-off of the “neck” connecting the droplet or bubble to the flowing material. That pinch-off then allows the droplet or bubble to collapse into a spherical shape. Picture blowing soap bubbles: As you blow through the ring, a tube of soap film gradually extends outward in a long pouch before pinching off to form a round bubble that floats away.
Motion of a microbubble in the vicinity of the bubble neck. The microbubble here acts as a tracer showing the flow direction.
“The process of a droplet dripping from a faucet is known to be universal,” says Juanes, who has a joint appointment in the departments of Civil and Environmental Engineering and Earth, Atmospheric and Planetary Sciences. If the dripping liquid has a different viscosity or surface tension, or if the opening of the faucet is a different size, “it doesn’t matter. You can find relationships that allow you to determine a master curve or a master behavior for describing that process,” he says.
But when it comes to what is, in a sense, the opposite process to a dripping faucet — the injection of air through an opening into a large tank of liquid such as a Jacuzzi tub — the process is not universal. “So if you have irregularities in the orifice, or if the orifice is larger or smaller, or if you inject with some pulsation, all of that will lead to a different pinch-off of the bubbles,” Juanes says.
The new experiments involved gas percolating onto viscous liquids such as oil. In an unconfined space, the sizes of the bubbles are unpredictable, but the situation changes when they bubble into liquid in a tube instead. Up to a certain point, the size and shape of the tube doesn’t matter, nor do the characteristics of the orifice the gas comes through. Instead the bubbles, like the droplets from a faucet, are uniformly sized and spaced.
Evolution of the dewetting rim and the ultimate breakup of the bubble in a capillary tube. Courtesy of the researchers
Pahlavan says, “Our work is really a tale of two surprising observations; the first surprising observation came around 15 years ago, when another group investigating formation of bubbles in large liquid tanks observed that the pinch-off process is nonuniversal” and depends on the details of the experimental setup. “The second surprise now comes in our work, which shows that confining the bubble inside a capillary tube makes the pinch-off insensitive to the details of the experiment and therefore universal.”
This observation is “surprising,” he says, because intuitively it might seem that bubbles able to move freely through the liquid would be less affected by their initial conditions than those that are hemmed in. But the opposite turned out to be true. It turns out that interactions between the tube and the forming bubble, as a line of contact between the air and the liquid advances along the inside of the tube, play an important role. This “effectively erases the memory of the system, of the details of the initial conditions, and therefore restores the universality to the pinch-off of a bubble,” he says.
While such research may seem esoteric, its findings have potential applications in a variety of practical settings, Pahlavan says. “Controlled generation of drops and bubbles is very desirable in microfluidics, with many applications in mind. A few examples are inkjet printing, medical imaging, and making particulate materials.”
The new understanding is also important for some natural processes. “In geophysical applications, we often see fluid flows in very tight and confined spaces,” he says. These interactions between the fluids and the surrounding grains are often neglected in analyzing such processes. But the behavior of such geological systems is often determined by processes at the grain-scale, which means that the kind of microscale analysis done in this work could be helpful in understanding even such very large-scale situations.
The bubble formation in such geological formations can be a blessing or a curse, depending on the context, Juanes says, but either way it’s important to understand. For carbon sequestration, for example, the hope is to pump carbon dioxide, separated out from power plant emissions, into deep formations to prevent the gas from getting out into the atmosphere. In this case, the formation of bubbles in tiny pore spaces in the rock is an advantage, because the bubbles tend to block the flow and keep the gas anchored in position, preventing it from leaking back out.
But for the same reason, bubble formation in a natural gas well can be a problem, because it can also block the flow, inhibiting the ability to extract the desired natural gas. “It can be immobilized in the pore space,” he says. “It would take a much greater pressure to be able to move that bubble.”
“This is a very nice and careful piece of work,” says Jens Eggers, a professor of applied mathematics at the University of Bristol, in the U.K., who was not involved in this research. “It almost goes without saying that a large part of the success of this paper is that it is backed up by careful and quantitative experiments.”
These findings, he says, reflect the fact that “there is a lot more complexity
to problems like pinch-off than previously thought.” Eggers adds that “Of course, understanding this complexity is crucial for applications, where one does not have a choice to pick a particularly simple part of the problem, but has to face all the complications.”
The Abdul Latif Jameel Water and Food Systems Lab (J-WAFS) has announced the selection of their third cohort of graduate fellows. Two students will each receive one-semester graduate fellowships as part of J-WAFS’ Rasikbhai L. Meswani Fellowship for Water Solutions and J-WAFS Graduate Student Fellowship Programs. An additional student was awarded “honorable mention.” J-WAFS will also support the three students by providing networking, mentorship, and opportunities to showcase their research.
The awarded students, Sahil Shah and Peter Godart of the Department of Mechanical Engineering and Mark Brennan of the Department of Urban Studies and Planning, were selected for the quality of their research as well as its relevance to current global water challenges. Each of them demonstrates a long commitment to water issues, both in and outside of an academic setting. Their research projects focus on transforming water access opportunities for people in vulnerable communities where access to fresh water for human consumption or for agriculture can improve human health and livelihoods. From developing a way to use aluminum waste to produce electricity for clean water to making significant improvements to the energy efficiency of desalination systems, these students demonstrate how creativity and ingenuity can push forward transformational water access solutions.
2019-20 Rasikbhai L. Meswani Fellow for Water Solutions
Sahil Shah is a PhD candidate in the Department of Mechanical Engineering. He spent his childhood in Tanzania, received his undergraduate education in Canada, and worked in Houston as an engineering consultant before being drawn to MIT to pursue his interest in mechanical design and hardware. As a PhD student in Professor Amos Winter’s lab, he is now working to decrease the cost of desalination and improve access to drinking water in developing countries.
His PhD research focuses on new methods to decrease the cost and energy use of groundwater treatment for drinking water. Currently, he is exploring the use of electrodialysis, which is a membrane-based desalination process. By improving the design of the control mechanisms for this process, as well as by redesigning the devices to achieve higher desalination efficiency, he seeks to decrease the cost of these systems and their energy use. His solutions will be piloted in both on-grid and off-grid applications in India, supported through a collaboration with consumer goods maker Eureka Forbes and infrastructure company Tata Projects.
The 2019-20 J-WAFS Graduate Student Fellow
Peter Godart is a PhD candidate in the Department of Mechanical Engineering, and also holds BS and MS degrees in mechanical engineering and a BS in electrical engineering from MIT. From 2015 to 17, Godart also held a research scientist position at the NASA Jet Propulsion Laboratory (JPL), where he managed the development of water-reactive metal power systems, developed software for JPL’s Mars rovers, and supported rover operations.
Godart's current research at MIT focuses on improving global sustainability by using aluminum waste to power desalination and produce energy. Through this work, he aims to provide communities around the world with a means of improving both their waste management practices and their climate change resiliency. He is creating a complete system that can take in scrap aluminum and output potable water, electricity, and high-grade mineral boehmite. This suite of technologies leverages the energy available in aluminum, which is one of the most energy-dense materials to which we have ready access. The process enables recycled aluminum to react with water in order to produce hydrogen gas, which could be used in fuel cells or internal combustion engines to generate electricity, heat, and power for desalination systems.
Mark Brennan is a PhD candidate in the Department of Urban Studies and Planning (DUSP). He studies the supply chains behind public programs that provide goods to vulnerable communities, especially in water- and food-insecure areas. His ongoing projects include studying which firms shoulder risk in irrigation supply chains in the Sahel, and how American federal assistance programs are structured to provide relief after disasters.
Brennan is currently collaborating with a team of researchers at the MIT Sloan School of Management, MIT D-Lab, and DUSP on a J-WAFS-funded project that is investigating ways to increase the accessibility of irrigation systems to small rural sub-Saharan African farmers, with a specific focus on Senegal.
Nearly every time you open up a secure Google Chrome browser, a new MIT-developed cryptographic system is helping better protect your data.
In a paper presented at the recent IEEE Symposium on Security and Privacy, MIT researchers detail a system that, for the first time, automatically generates optimized cryptography code that’s usually written by hand. Deployed in early 2018, the system is now being widely used by Google and other tech firms.
The paper now demonstrates for other researchers in the field how automated methods can be implemented to prevent human-made errors in generating cryptocode, and how key adjustments to components of the system can help achieve higher performance.
To secure online communications, cryptographic protocols run complex mathematical algorithms that do some complex arithmetic on large numbers. Behind the scenes, however, a small group of experts write and rewrite those algorithms by hand. For each algorithm, they must weigh various mathematical techniques and chip architectures to optimize for performance. When the underlying math or architecture changes, they essentially start over from scratch. Apart from being labor-intensive, this manual process can produce nonoptimal algorithms and often introduces bugs that are later caught and fixed.
Researchers from the Computer Science and Artificial Intelligence Laboratory (CSAIL) instead designed “Fiat Cryptography,” a system that automatically generates — and simultaneously verifies — optimized cryptographic algorithms for all hardware platforms. In tests, the researchers found their system can generate algorithms that match performance of the best handwritten code, but much faster.
The researchers’ automatically generated code has populated Google’s BoringSSL, an open-source cryptographic library. Google Chrome, Android apps, and other programs use BoringSSL to generate the various keys and certificates used to encrypt and decrypt data. According to the researchers, about 90 percent of secure Chrome communications currently run their code.
“Cryptography is implemented by doing arithmetic on large numbers. [Fiat Cryptography] makes it more straightforward to implement the mathematical algorithms … because we automate the construction of the code and provide proofs that the code is correct,” says paper co-author Adam Chlipala, a CSAIL researcher and associate professor of electrical engineering and computer science and head of the Programming Languages and Verification group. “It’s basically like taking a process that ran in human brains and understanding it well enough to write code that mimics that process.”
Jonathan Protzenko of Microsoft Research, a cryptography expert who was not involved in this research, sees the work as representing a shift in industry thinking.
“Fiat Cryptography being used in BoringSSL benefits the whole [cryptographic] community,” he says. “[It’s] a sign that the times are changing and that large software projects are realizing that insecure cryptography is a liability, [and shows] that verified software is mature enough to enter the mainstream. It is my hope that more and more established software projects will make the switch to verified cryptography. Perhaps within the next few years, verified software will become usable not just for cryptographic algorithms, but also for other application domains.”
Joining Chlipala on the paper are: first author Andres Erbsen and co-authors Jade Philipoom and Jason Gross, who are all CSAIL graduate students; as well as Robert Sloan MEng ’17.
Splitting the bits
Cryptography protocols use mathematical algorithms to generate public and private keys, which are basically a long string of bits. Algorithms use these keys to provide secure communication channels between a browser and a server. One of the most popular efficient and secure families of cryptographic algorithms is called elliptical curve cryptography (ECC). Basically, it generates keys of various sizes for users by choosing numerical points at random along a numbered curved line on a graph.
Most chips can’t store such large numbers in one place, so they briefly split them into smaller digits that are stored on units called registers. But the number of registers and the amount of storage they provide varies from one chip to another. “You have to split the bits across a bunch of different places, but it turns out that how you split the bits has different performance consequences,” Chlipala says.
Traditionally, experts writing ECC algorithms manually implement those bit-splitting decisions in their code. In their work, the MIT researchers leveraged those human decisions to automatically generate a library of optimized ECC algorithms for any hardware.
Their researchers first explored existing implementations of handwritten ECC algorithms, in the C programming and assembly languages, and transferred those techniques into their code library. This generates a list of best-performing algorithms for each architecture. Then, it uses a compiler — a program that converts programming languages into code computers understand — that has been proven correct with a proofing tool, called Coq. Basically, all code produced by that compiler will always be mathematically verified. It then simulates each algorithm and selects the best-performing one for each chip architecture.
Next, the researchers are working on ways to make their compiler run even faster in searching for optimized algorithms.
There’s one additional innovation that ensures the system quickly selects the best bit-splitting implementations. The researchers equipped their Coq-based compiler with an optimization technique, called “partial evaluation,” which basically precomputes certain variables to speed things up during computation.
In the researchers’ system, it precomputes all the bit-splitting methods. When matching them to a given chip architecture, it immediately discards all algorithms that just won’t work for that architecture. This dramatically reduces the time it takes to search the library. After the system zeroes in on the optimal algorithm, it finalizes the code compiling.
From that, the researchers then amassed a library of best ways to split ECC algorithms for a variety of chip architectures. It’s now implemented in BoringSSL, so users are mostly drawing from the researchers’ code. The library can be automatically updated similarly for new architectures and new types of math.
“We’ve essentially written a library that, once and for all, is correct for every way you can possibly split numbers,” Chlipala says. “You can automatically explore the space of possible representations of the large numbers, compile each representation to measure the performance, and take whichever one runs fastest for a given scenario.”
When MIT research scientist Christopher Carr visited a green sand beach in Hawaii at the age of 9, he probably didn’t think that he’d use the little olivine crystals beneath his feet to one day search for extraterrestrial life. Carr, now the science principal investigator for the Search for Extraterrestrial Genomes (SETG) instrument being developed jointly by the Department of Earth, Atmospheric and Planetary Sciences (EAPS) at MIT and Massachusetts General Hospital, works to wed the worlds of biology, geology, and planetary science to help understand how life evolved in the universe.
“Our history revealed by science is a truly incredible story,” Carr says. “You and I are a part of an unbroken chain of 4 billion years of evolution. I want to know more about that story.”
SETG was initially proposed by professor of genetics at Harvard Medical School Gary Ruvkun, and since 2005 has been led by Maria Zuber, the E. A. Griswold Professor of Geophysics in EAPS and vice president for research at MIT.
As the science principle investigator of SETG, Carr, along with a large team of scientists and engineers, has helped develop instrumentation that could withstand radiation and detect DNA, a type of nucleic acid that carries genetic information in most living organisms, in spaceflight environments. Now, Carr and his colleagues are working to fine-tune the instrumentation to work on the red planet. To do that, the team needed to simulate the kinds of soils thought to preserve evidence of life on Mars, and for that, they needed a geologist.
Angel Mojarro, a graduate student in EAPS, was up for the task. Mojarro spent months synthesizing Martian soils that represented different regions on Mars, as established by Martian rover data.
“Turns out you can buy most of the rocks and minerals found on Mars online,” Mojarro says. But not all.
One of the hard-to-find components of the soils was olivine from the beach Carr had visited as a child: “I called up my folks and said, ‘Hey, can you find the olivine sand in the basement and send me some of that?’”
After creating a collection of different Mars analog soils, Mojarro wanted to find out whether SETG could extract and detect small amounts of DNA embedded in those soils as it would do on a future Mars mission. While many technologies already exist on Earth to detect and sequence DNA, scaling down the instrumentation to fit on a rover, survive transport from Earth, and conduct high fidelity sequencing in a harsh Martian environment is a unique challenge. “That’s a whole bunch of steps, no matter what the sequencing technology is right now,” Carr says.
The SETG instrumentation has evolved and improved since its development began in 2005, and, currently, the team is working to integrate a new method, called nanopore sequencing, into their work. “In nanopore sequencing, DNA strands travel through nano-sized holes, and the sequence of bases are detected via changes in an ionic current,” Mojarro says.
By themselves, Mojarro’s Mars analog soils didn’t contain microbes, so to test and develop nanopore sequencing of DNA in Mars analog soils, Mojarro added known quantities of spores from the bacterium Bacillus subtilis to the soils. Without human help on Mars, SETG instrumentation would need to be able to collect, purify, and enable the DNA to be sequenced, a process which usually necessitates about a microgram of DNA on Earth, Mojarro says.
The group’s results using the new sequencing and preparation method, which were reported in Astrobiology, pushed the limits of detection to the parts-per-billion scale — which means even the tiniest traces of life could be detected and sequenced by the instrument.
“This doesn’t just apply to Mars … these results have implications in other fields, too,” Mojarro says. Similar methods of DNA sequencing on Earth have been used to help manage and track Ebola outbreaks and in medical research. And further, improvements to SETG could have important implications for planetary protection, which aims to prevent and minimize Earth-originating biological contamination of space environments.
Even at the new detection limit for the SETG instrumentation, Mojarro was able to differentiate between human DNA and the Bacillus DNA. “If we detect life on other planets,” Mojarro says, “we need a technique that can tell apart hitchhiking microbes from Earth and Martian life.”
In their publication, Mojarro and Carr suggest that these developments may fill in some of the missing gaps in the story of life on Earth. “If there’s life on Mars, there’s a good chance it’s related to us,” Carr says, citing previous studies describing the planetary exchange of materials during the Late Heavy Bombardment period (4.1 to 3.8 billion years ago).
If SETG detects and sequences DNA on Mars in the future, Carr says the results could “rewrite our very notion of our own origins.”