MIT Latest News

Subscribe to MIT Latest News feed
MIT News is dedicated to communicating to the media and the public the news and achievements of the students, faculty, staff and the greater MIT community.
Updated: 1 day 3 min ago

Powered by idealism and pragmatism

Thu, 10/11/2018 - 9:00am

When they first met as graduate students in 2012, Samuel Shaner SM ’14, PhD ’18 and Mathew Ellis PhD ’17 realized they shared a common passion.

“Sam was one year ahead of me, and as my official buddy during orientation weekend, he took me to the MIT Energy Conference,” recalls Ellis. “That first night, we began sharing ideas about what we wanted to see happen in the nuclear industry.”

Adds Shaner: “We were both really interested in the innovative side of the industry and doing something entrepreneurial with nuclear reactor development.”

The connection sparked at the start of their acquaintance is now generating dividends. In June, Yellowstone Energy, the company launched by the duo in 2016, received $2.6 million from the Department of Energy's Advanced Research Projects Agency-Energy (ARPA-E). This was one of just 10 awards distributed by a new ARPA-E program, Modeling-Enhanced Innovations Trailblazing Nuclear Energy Reinvigoration (MEITNER), which is intended to identify and develop novel technologies to advance safer and more cost-efficient nuclear reactors.

“It was one of our best days, a really big moment for us,” says Ellis. “After working hard on the enabling technology, winning the grant through a selective and rigorous process was a great accomplishment.”

Shaner says it was incredibly gratifying to receive “such significant validation of the idea we had come up with.”

This idea, the culmination of several years of independent research by Shaner and Ellis, is a design for an advanced, modular nuclear reactor integrating a suite of commonsense but forward-thinking features. Yellowstone Energy’s reactor uses conventional, commercially available uranium dioxide fuel (UO2); operates at near-ambient pressure; and deploys a molten nitrate salt coolant that allows the reactor to reach higher operating temperatures than current water-cooled nuclear reactors. At the heart of this design lies a novel control device that is now under patent review, and in the first stages of testing at Oak Ridge National Laboratory.

Shared frustration to shared vision

Yellowstone Energy and its innovative approach was born out of “frustration with the policy, regulatory, and supply chain challenges of bringing new technologies to market,” says Shaner. “Just to make a small tweak, such as feeding more highly-enriched fuel to current reactors, involves tens of millions of dollars and many years,” he says.

“Sam and I are a good mix of dreamers and pragmatists,” says Ellis. “We realized that a lot of advanced reactor concepts faced hurdles to get to market that went beyond nuclear physics, so we started thinking about how to fix that problem.”

The pair set out to identify a set of reactor properties that would leapfrog the hurdles.

“We needed to have a reactor design and technology that would be inexpensive to build and operate, and given the risks in building new reactors, a design that would promise a time- and capital-efficient pathway to market,” says Shaner.

“We figured that the more we leveraged proven technology, the easier it would be to license the reactor,” says Ellis.

Their first decision was to use what Shaner calls “off-the-shelf” fuel: UO2, the industry standard. But to increase operating efficiency with this fuel, they would need heat transfer fluids different from those circulating in current generation reactors. Other advanced reactor designs suggested fluoride and chloride salts, but these fluids prove technically challenging to engineer for reliable, commercial-scale systems. That led to another major design decision: to deploy molten nitrate salts, a high-temperature, ambient-pressure heat transfer fluid already in widespread use in the chemical and concentrated solar power industries.

The challenge then came in bringing together the current fuel and the molten nitrate salt coolant, says Shaner. As graduate students working in Nuclear Science and Engineering with professors Ben Forget and Kord Smith, Ellis and Shaner had developed expertise in analyzing, modeling, and computing the physics of reactor systems. In a matter of months, they had devised a novel control device that would potentially enable their UO2 and molten-nitrate-salt-based reactor to function.

A leg up for entrepreneurs

In the fall of 2016, the team applied for and received a $25,000 grant from the MIT Sandbox Innovation Fund. With this money, they applied for intellctual property protection on their core enabling technology. But they also received valuable non-financial assistance.

“MIT is one of the few places where big, ambitious ideas like a nuclear reactor startup are encouraged,” says Ellis. “The entrepreneurial ecosystem at MIT, specifically the mentoring through Sandbox, was a big inflection point for us, allowing us to get off the ground, move on with our idea, and ultimately make it a business.”

Today, the team is based in Knoxville, Tennessee, working under the auspices of a Department of Energy incubator, and preparing a first round of simulations at the Oak Ridge Laboratory, with the help of nuclear industry and utility partners. Their collaboration has weathered well.

“Sam and I are very aligned with what we want to do, and the impact we want to make, but we’re always willing to challenge each other to improve our ideas,” says Ellis. “We learned each other's abilities, strengths and quirks during five years together at MIT, which allows us to work really efficiently.”

They've faced their share of challenges. “The hardest part has been the uncertainty, which can make things a roller coaster of emotions,” says Shaner. “For instance, when we finished grad school, we didn't know if we would get funding to continue working on our idea.”

With the endorsement and financial backing of the Department of Energy, they are taking a moment to savor their accomplishment. But they never lose sight of the path before them.

“Nuclear has a longer time horizon than most technologies, so we really have to believe in our mission — clean energy and reducing CO2 emissions — in order to get to the finish line,” says Ellis. “If we’re here a decade from now, it will be because people recognize our approach is fundamentally different, that our technology successfully reduced a lot of the risks, and that we can make a major impact in the near term on energy markets.”

Self-healing material can build itself from carbon in the air

Thu, 10/11/2018 - 12:00am

A material designed by MIT chemical engineers can react with carbon dioxide from the air, to grow, strengthen, and even repair itself. The polymer, which might someday be used as construction or repair material or for protective coatings, continuously converts the greenhouse gas into a carbon-based material that reinforces itself.

The current version of the new material is a synthetic gel-like substance that performs a chemical process similar to the way plants incorporate carbon dioxide from the air into their growing tissues. The material might, for example, be made into panels of a lightweight matrix that could be shipped to a construction site, where they would harden and solidify just from exposure to air and sunlight, thereby saving on the energy and cost of transportation.

The finding is described in a paper in the journal Advanced Materials, by Professor Michael Strano, postdoc Seon-Yeong Kwak, and eight others at MIT and at the University of California at Riverside

“This is a completely new concept in materials science,” says Strano, the Carbon C. Dubbs Professor of Chemical Engineering. “What we call carbon-fixing materials don’t exist yet today” outside of the biological realm, he says, describing materials that can transform carbon dioxide in the ambient air into a solid, stable form, using only the power of sunlight, just as plants do.

Developing a synthetic material that not only avoids the use of fossil fuels for its creation, but actually consumes carbon dioxide from the air, has obvious benefits for the environment and climate, the researchers point out. “Imagine a synthetic material that could grow like trees, taking the carbon from the carbon dioxide and incorporating it into the material’s backbone,” Strano says.

The material the team used in these initial proof-of-concept experiments did make use of one biological component — chloroplasts, the light-harnessing components within plant cells, which the researchers obtained from spinach leaves. The chloroplasts are not alive but catalyze the reaction of carbon dioxide to glucose. Isolated chloroplasts are quite unstable, meaning that they tend to stop functioning after a few hours when removed from the plant. In their paper, Strano and his co-workers demonstrate methods to significantly increase the catalytic lifetime of extracted chloroplasts. In ongoing and future work, the chloroplast is being replaced by catalysts that are nonbiological in origin, Strano explains.

The material the researchers used, a gel matrix composed of a polymer made from aminopropyl methacrylamide (APMA) and glucose, an enzyme called glucose oxidase, and the chloroplasts, becomes stronger as it incorporates the carbon. It is not yet strong enough to be used as a building material, though it might function as a crack filling or coating material, the researchers say.

The team has worked out methods to produce materials of this type by the ton, and is now focusing on optimizing the material’s properties. Commercial applications such as self-healing coatings and crack filling are realizable in the near term, they say, whereas additional advances in backbone chemistry and materials science are needed before construction materials and composites can be developed.

One key advantage of such materials is they would be self-repairing upon exposure to sunlight or some indoor lighting, Strano says. If the surface is scratched or cracked, the affected area grows to fill in the gaps and repair the damage, without requiring any external action.

While there has been widespread effort to develop self-healing materials that could mimic this ability of biological organisms, the researchers say, these have all required an active outside input to function. Heating, UV light, mechanical stress, or chemical treatment were needed to activate the process. By contrast, these materials need nothing but ambient light, and they incorporate mass from carbon in the atmosphere, which is ubiquitous.

The material starts out as a liquid, Kwak says, adding, “it is exciting to watch it as it starts to grow and cluster” into a solid form.

“Materials science has never produced anything like this,” Strano says. “These materials mimic some aspects of something living, even though it’s not reproducing.” Because the finding opens up a wide array of possible follow-up research, the U.S. Department of Energy is sponsoring a new program directed by Strano to develop it further.

“Our work shows that carbon dioxide need not be purely a burden and a cost,” Strano says. “It is also an opportunity in this respect. There’s carbon everywhere. We build the world with carbon. Humans are made of carbon. Making a material that can access the abundant carbon all around us is a significant opportunity for materials science. In this way, our work is about making materials that are not just carbon neutral, but carbon negative.”

The research team included Juan Pablo Giraldo at UC Riverside, and Tedrick Lew, Min Hao Wong, Pingwei Liu, Yun Jung Yang, Volodomyr Koman, Melissa McGee and Bradley Olsen at MIT. The work was supported by the U.S. Department of Energy.

Keeping confidence

Wed, 10/10/2018 - 4:50pm

Catalina Romero, a first-year student at MIT, bustles in the kitchen of her dorm, quickly putting the finishing touches on her arepas, or Colombian corn pancakes. She has been making arepas with her mother for years. Tonight, she is making them for her classmates at MIT.   

Growing up in Gurnee, Illinois, Romero was fascinated by outer space and dreamed of becoming an astronaut. Her parents, who emigrated from Colombia before she was born, worked long hours at Medline, a medical supplies company. When Romero was just six years old, her parents saved enough money to bring her to the Kennedy Space Center in Florida, furthering her interest in the cosmos. By seventh grade, she had decided that aerospace engineering — a field where she could build telescopes and satellites that go into space — was way cooler than the astronaut thing.

That same year, she came across the MIT Admissions’ blog and says she fell in love with the Institute, not just for the academics, but for the people and culture she enjoyed reading about. She thought: This place could really be for me.

MIT became Romero’s dream school, but it wasn’t until 2017, when she attended MIT’s Minority Introduction to Engineering and Science (MITES) program, that she started to believe it was within her reach. For six weeks during the summer after her junior year of high school, Romero lived on MIT’s campus and took rigorous courses in math and science. At first she was nervous.

“I thought maybe we had to prove a point,” she says. “There was a fear of keeping up and asking questions.”

She quickly realized that everyone at MITES was there to learn and help each other, and that, she says, was “really comforting.” Sunday evenings during MITES were “family meeting” times, where students could share personal experiences in a safe space.

“You could just feel the environment was really inviting and everyone was accepting,” she recalls.

She learned an important life skill during those gatherings — how to openly discuss her feelings and confide in others. It wasn’t easy, Catalina says, because she came to MITES with a secret: She and her family were once homeless when she was in middle school. She had never been able to open up to anyone about that experience because of the shame she felt from it.

“But at MITES, other people were sharing similar struggles they’d been through,” she says. “Just being able to talk about it was a huge release.”

Four short months after MITES ended, there was lots of screaming and yelling and tears — the celebratory kind— when Romero, her parents, and her little brother found out that she was accepted to MIT’s class of 2021. Looking back, the road to her dream school has sometimes felt long, but now that Romero is on campus, she looks forward to learning as much as she can while still making time for the things she loves, like cycling.

She also plans to volunteer for MITES so that she can help others, like herself, find a way to MIT, no matter where they started from. “It really skyrocketed my confidence,” she says.

After she breaks bread (or arepas) with her suitemates, She sits in the quiet of her dorm room and reflects on her journey.

“After so many years of telling people MIT is my dream school, all my hard work has paid off,” she says. “I am here, I made it.”

Prior Art Archive aims to improve patent process

Wed, 10/10/2018 - 4:40pm

Imagine you have invented a device that could save millions of lives around the world. But instead of profiting from the invention yourself, you decide to share the design online, to allow others to make their own version at low cost.

Two years later, a company applies for a patent on your invention. Once the application is granted, the company not only begins profiting from your device, but launches a lawsuit against you, the inventor, for infringing their patent.

This is the danger faced by researchers and developers alike, because the limits of existing content repositories means it is often a struggle for patent examiners to find what they call prior art — evidence that an invention is already known — relating to an application. That means that some applications that should be rejected are wrongly approved.

Now an open-access archive is aiming to make prior art much more accessible. Developed as a collaboration between the MIT Media Lab, Cisco, and the U.S. Patent and Trademark Office (USPTO), the Prior Art Archive is an MIT-hosted database open to both patent examiners and the wider public.

"The archive has the potential to significantly improve patent quality while reducing the number of bad patents issued," says Kate Darling, a research specialist at the MIT Media Lab. Darling and Media Lab research scientist Travis Rich have been involved in building the archive in collaboration with Cisco.

“The Prior Art Archive provides a method for people to better ensure that their prior art is considered by patent examiners,” Darling says. “We have worked closely with the USPTO, so the archive is well-integrated with the search tools that the examiners use.”

The archive, launched at an event at the American Academy of Arts and Sciences earlier this month, is open to universities, companies, and individuals, who can use it to upload or search for files in a range of formats, including Word documents, web pages, Excel spreadsheets, images, and videos.

“It is going to be accessible to anyone who wants to use it to upload files or to access information,” Darling says.

Cisco has already uploaded 165,000 documents into the archive, and a number of companies have committed to take part in the initiative, including Dell, Intel, AT&T, Amazon, Microsoft, and Salesforce. Google has also assisted the project with classification technology that will be used in the system.

"The Prior Art Archive project is an important step in addressing one of the main challenges to the current patent system — the way the Internet and the explosion of information have made it nearly impossible for examiners to review all of the prior art related to new patent applications," says Joi Ito, director of the MIT Media Lab.

Ito references a 2012 poll of Media Lab faculty members, which found that many wanted to patent their inventions, not to commercialize them, but simply to prevent others from doing so by ensuring patent examiners had access to the prior art.

"By making information available to patent examiners in a form that's easy for them to access and search, the Prior Art Archive can significantly improve the functioning of the patent system, and enhance the quality of the patents being issued," Ito says. "This benefits academia, industry and individuals; helps prevent frivolous law suits and ambiguous risk; and encourages inventors and researchers to talk about and publish their work."

While the Prior Art Archive is hosted at MIT, in the future the database may also be replicated at other public institutions to ensure redundancy and performance.

Testing new drugs with “ALS-on-a-chip”

Wed, 10/10/2018 - 2:00pm

There is no cure for amyotrophic lateral sclerosis (ALS), a disease that gradually kills off the motor neurons that control muscles and is diagnosed in nearly 6,000 people per year in the United States.

In an advance that could help scientists develop and test new drugs, MIT engineers have designed a microfluidic chip in which they produced the first 3-D human tissue model of the interface between motor neurons and muscle fibers. The researchers used cells from either healthy subjects or ALS patients to generate the neurons in the model, allowing them to test the effectiveness of potential drugs.

“We found striking differences between the healthy cells and the ALS cells, and we’ve been able to show the effects of two drugs that are in clinical trials right now,” says Roger Kamm, the Cecil and Ida Green Distinguished Professor of Mechanical and Biological Engineering at MIT and the senior author of the study.

MIT postdoc Tatsuya Osaki is the lead author of the paper, which appears in the Oct. 10 issue of Science Advances. Sebastien Uzel, a former MIT graduate student, is also an author of the paper.

3-D junctions

Scientists began developing tissue models of the connections between motor neurons and muscle cells, also called neuromuscular junctions, decades ago. However, these were limited to two-dimensional structures, which do not fully replicate the complex physiology of the tissue.

Kamm and his colleagues developed the first version of their 3-D neuromuscular junction model two years ago. The model consists of neurons and muscle fibers that occupy adjacent compartments of a microfluidic chip. Once placed in the compartments, the neurons extend long fibers called neurites, which eventually attach to the muscles, allowing the neurons to control their movement.

The neurons are engineered so that the researchers can control their activity with light, using a technique called optogenetics. The muscle fibers are wrapped around two flexible pillars, so when the neurons are activated by light, the researchers can measure how much the muscle fibers contract by measuring the displacement of the pillars.

In the 2016 version of the model, the researchers used mouse cells to grow the neurons and muscles, but differences between species can affect drug screening. In the new study, they used induced pluripotent stem cells from humans to generate both the muscle cells and the neurons. After demonstrating that the system worked, they began to incorporate neurons generated from induced pluripotent stem cells from a patient with sporadic ALS, which accounts for 90 percent of all cases.

This ALS model showed significant differences from the neuromuscular junctions created from healthy cells. The neurites grew more slowly and seemed to be unable to form strong connections with the muscle fibers, Kamm says.

“You can see that the healthy neurites are going directly to the individual myotubes and then activating them. However, the ALS neurons don’t seem to be able to connect very well,” he says.

This translated to weaker muscle control: After two weeks, the muscles innervated by ALS motor neurons were generating only about one-quarter the force produced by muscles controlled by healthy neurons. This also suggested that ALS motor neurons attacked healthy skeletal muscle tissues.

“The use of human-derived neuronal cells from ALS patients, combined with stem cell derived muscle cells — and the formation of a functional neuromuscular junction — is a major advance in the field of tissue models on a chip,” says Rashid Bashir, a professor of electrical and computer engineering and bioengineering at the University of Illinois at Urbana-Champaign, who was not involved in the research.

Promising drugs

The researchers then used their model to test two drugs that are now in clinical trials to treat ALS — rapamycin and bosutinib. They found that giving both of the drugs together restored most of the muscle strength that had been lost in the ALS motor units. The treatment also reduced the rate of cell death normally seen in the ALS motor unit.

Working with a local biotech company, Kamm and his colleagues hope to collect induced pluripotent stem cells from 1,000 ALS patients, allowing them to perform larger-scale drug studies. They also plan to scale up the technology so they can test more samples at a time, and to add more types of cells, such as Schwann cells and microglial cells, which play supportive roles in the nervous system.

This tissue model could also be used to study other muscular diseases such as spinal muscular atrophy, which affects nerve cells found in the spine.

The research was funded by the National Science Foundation through the Science and Technology Center on Emergent Behaviors of Integrated Cellular Systems.

Helping small science make big changes

Tue, 10/09/2018 - 5:10pm

Farnaz Niroui SM '13, PhD '17 is returning to MIT for the third time, following her stints as an undergraduate intern, a master’s and PhD student, and now as a professor in the electrical engineering department and researcher in the new MIT.nano facilities. What’s kept her coming back? Generally, she says, it’s the collaborative nature of MIT. “You can easily approach researchers from any department or research field to ask for their advice and to collaborate with them. Such an interdisciplinary environment is very important for me and my research” says Niroui, who is thrilled to be part of the new nano facilities.  

“My research is heavily focused on nanotechnology and greatly benefits from the state-of-the-art characterization and fabrication tools. Part of my research also focuses on developing new tools and techniques related to nano,” says Niroui, who feels confident that MIT.nano will provide a very exciting platform to pursue such research.

As Niroui prepares to settle in again at MIT— her position officially starts on Nov. 1 — she looks forward to another source of inspiration: Her office will be what was once the office of world-renowned scientist Mildred Dresselhaus, the late “queen of carbon science.” “The fact that I was offered Millie’s office was very inspirational,” says Niroui. “I knew Millie as a grad student since our offices were very close to each other and I always looked up to her as a mentor (even though our interactions were quite limited). Being able to be in her office as I start my own independent academic career is extremely inspiring and very valuable to me.”

Niroui was first introduced to nanotechnology through a high school project focused on carbon nanotubes, which made her curious about “how and why small things can matter so much.” That’s just one of the things she says that she loves about nanotechnology, which uses new techniques, processes, and tools to address a variety of fields, including medicine, electronics, environment, consumer goods, and more. “The interesting point, is that the potential of nano is so broad that it can have implications in many fields and some that cannot necessarily even be envisioned currently without further research and exploration,” she says.

Niroui earned her undergraduate degree in nanotechnology engineering at the University of Waterloo, during which time she completed an internship at MIT in Robert Langer’s group doing bionanotechnology research, exploring gene delivery.

“The nano engineering undergraduate program I completed covered courses and concepts from electrical engineering, chemistry, and materials science — a very interdisciplinary program that focuses on both the fundamentals and the emerging technologies that are related to nanotechnology. Once you have the broad multidisciplinary background, it is important to seek further, more specialized expertise to be able to effectively contribute to the rapidly evolving field,” says Niroui, who chose MIT to do a master’s/PhD program in electrical engineering, with a focus on device physics and nanoelectronics.

While completing her PhD, working with Jeffrey Lang and Vladimir Bulović, Niroui observed some of the limitations in her field. “I started realizing how many challenges there are wanting to work on things that are in the extreme nanoscale dimensions while trying to solely rely on techniques that are currently available. At very small dimensions, you get limited by many factors, for example, even the smallest amount of roughness on surfaces or the slightest vibration or interference from the environment can matter. I realized that there is a need to develop new techniques.”

Addressing this issue is one of Niroui’s main research goals and something that will be a key objective of MIT.nano as well. “I’m so excited to be part of the beginning of MIT.nano and all the excitement that comes with it, not just in terms of the tools and techniques it’s going to bring, but also focusing as an Institute on bringing in more intellectual contribution to nanotechnology and initiating dialogue between different institutes.”

The design of the facility is unique, she says, and will offer increased opportunities for collaboration. “It’s providing a very central facility that is not restricted to just a particular discipline or conventional design and fabrication concepts. It allows researchers to bring in new materials, new techniques, and most importantly also provides us with a platform to work collectively to develop what is going to be needed to push the frontiers of nanotechnology to reach the dimensions and study the science that otherwise wouldn’t be possible.”

A recipe for health

Tue, 10/09/2018 - 3:30pm

Last week Padma Lakshmi launched her appointment as a visiting scholar in the Center for Gynepathology Research by immersing herself in MIT labs and classrooms before delivering an evening talk.

“I went around and tried to learn as much as I could from people who are doing amazing and beautiful things. I know what I’ve learned will inform my work in the future,” she told a packed auditorium at MIT’s Open Endoscopy Forum, which features TED-style talks from leading gynecology surgeons and MIT technology pioneers.

Lakshmi is the host and executive producer of Bravo’s Top Chef; she’s also an author, an actress, a spokesperson for the American Civil Liberties Union, co-founder of the Endometriosis Foundation of America, and a vocal activist in the realm of women’s health. When MIT launched the Center for Gynepathology Research in 2009, she delivered the keynote address. Since then, Lakshmi has returned to MIT on multiple occasions to discuss women’s health issues and raise awareness about endometriosis among MIT students.

“I never expected to be holding a microphone at MIT,” said Lakshmi, who was hosted by a leading expert in endometriosis, Linda Griffith, an MIT School of Engineering Professor of Teaching Innovation, Biological Engineering, and Mechanical Engineering.

Lakshmi told students about how endometriosis had negatively impacted her life and career, until a treatment breakthrough at age 36 addressed the monthly pain, cramping, nausea, headache, fatigue, and excessive blood flow that the condition triggers. Her decision to speak openly about her condition was complicated, she said, emphasizing the power of connecting to other women via storytelling. “If we don’t listen and we don’t share, we cannot understand. We spend too much time sequestered in our own worlds. We need to share our stories because empathy fuels progress.”

Earlier in the day, Lakshmi met with MIT Chancellor Cynthia Barnhart and dean of engineering Anantha Chandrakasan, the Vannevar Bush Professor in the Department of Electrical Engineering and Computer Science.

“Your advocacy work for targeted research and increased awareness around women’s health issues has been tremendous,” Chandrakasan told her. “The Center for Gynepathology Research is at the forefront in exploring new frontiers in the diagnosis and treatment of gynecology diseases. Your insight and creativity will be tremendous assets.”

During her tour, Lakshmi discussed food and nutrition with MIT students working on “Engineering the Human Gut,” a three-year project to build a highly instrumented model of a tissue-engineered human gut complete with microbiome as part of the New Engineering Education Transformation. “Nothing is done in a vacuum and nothing can be accomplished by staying isolated, whether it’s in cooking or the microbiome,” she told the students. “I really think it’s cool that at your age you’ve found that out — but I guess that’s why you’re at MIT.”

Lakshmi also visited with research scientists to discuss new developments in the diagnosis and treatment of gynecology diseases, including endometriosis, adenomyosis, and preterm birth. She toured the MIT Center for Microbiome Informatics and Therapeutics to learn more about MIT’s work studying and controlling the gut microbiome.

Her evening talk about the power of storytelling was a hit. “When are you going to run for office?” asked one audience member. Another captured the mood in the room with a deeply felt statement: “Thank you for what you’re doing for women.”

A new path to solving a longstanding fusion challenge

Tue, 10/09/2018 - 3:06pm

A class exercise at MIT, aided by industry researchers, has led to an innovative solution to one of the longstanding challenges facing the development of practical fusion power plants: how to get rid of excess heat that would cause structural damage to the plant.

The new solution was made possible by an innovative approach to compact fusion reactors, using high-temperature superconducting magnets. This method formed the basis for a massive new research program launched this year at MIT and the creation of an independent startup company to develop the concept. The new design, unlike that of typical fusion plants, would make it possible to open the device’s internal chamber and replace critical comonents; this capability is essential for the newly proposed heat-draining mechanism.

The new approach is detailed in a paper in the journal Fusion Engineering and Design, authored by Adam Kuang, a graduate student from that class, along with 14 other MIT students, engineers from Mitsubishi Electric Research Laboratories and Commonwealth Fusion Systems, and Professor Dennis Whyte, director of MIT’s Plasma Science and Fusion Center, who taught the class.

In essence, Whyte explains, the shedding of heat from inside a fusion plant can be compared to the exhaust system in a car. In the new design, the “exhaust pipe” is much longer and wider than is possible in any of today’s fusion designs, making it much more effective at shedding the unwanted heat. But the engineering needed to make that possible required a great deal of complex analysis and the evaluation of many dozens of possible design alternatives.

Taming fusion plasma

Fusion harnesses the reaction that powers the sun itself, holding the promise of eventually producing clean, abundant electricity using a fuel derived from seawater — deuterium, a heavy form of hydrogen, and lithium — so the fuel supply is essentially limitless. But decades of research toward such power-producing plants have still not led to a device that produces as much power as it consumes, much less one that actually produces a net energy output.

Earlier this year, however, MIT’s proposal for a new kind of fusion plant — along with several other innovative designs being explored by others — finally made the goal of practical fusion power seem within reach. But several design challenges remain to be solved, including an effective way of shedding the internal heat from the super-hot, electrically charged material, called plasma, confined inside the device.

Most of the energy produced inside a fusion reactor is emitted in the form of neutrons, which heat a material surrounding the fusing plasma, called a blanket. In a power-producing plant, that heated blanket would in turn be used to drive a generating turbine. But about 20 percent of the energy is produced in the form of heat in the plasma itself, which somehow must be dissipated to prevent it from melting the materials that form the chamber.

No material is strong enough to withstand the heat of the plasma inside a fusion device, which reaches temperatures of millions of degrees, so the plasma is held in place by powerful magnets that prevent it from ever coming into direct contact with the interior walls of the donut-shaped fusion chamber. In typical fusion designs, a separate set of magnets is used to create a sort of side chamber to drain off excess heat, but these so-called divertors are insufficient for the high heat in the new, compact plant.

One of the desirable features of the ARC design is that it would produce power in a much smaller device than would be required from a conventional reactor of the same output. But that means more power confined in a smaller space, and thus more heat to get rid of.

“If we didn’t do anything about the heat exhaust, the mechanism would tear itself apart,” says Kuang, who is the lead author of the paper, describing the challenge the team addressed — and ultimately solved.

Inside job

In conventional fusion reactor designs, the secondary magnetic coils that create the divertor lie outside the primary ones, because there is simply no way to put these coils inside the solid primary coils. That means the secondary coils need to be large and powerful, to make their fields penetrate the chamber, and as a result they are not very precise in how they control the plasma shape.

But the new MIT-originated design, known as ARC (for advanced, robust, and compact) features magnets built in sections so they can be removed for service. This makes it possible to access the entire interior and place the secondary magnets inside the main coils instead of outside. With this new arrangement, “just by moving them closer [to the plasma] they can be significantly reduced in size,” says Kuang.

In the one-semester graduate class 22.63 (Principles of Fusion Engineering), students were divided into teams to address different aspects of the heat rejection challenge. Each team began by doing a thorough literature search to see what concepts had already been tried, then they brainstormed to come up with multiple concepts and gradually eliminated those that didn’t pan out. Those that had promise were subjected to detailed calculations and simulations, based, in part, on data from decades of research on research fusion devices such as MIT’s Alcator C-Mod, which was retired two years ago. C-Mod scientist Brian LaBombard also shared insights on new kinds of divertors, and two engineers from Mitsubishi worked with the team as well. Several of the students continued working on the project after the class ended, ultimately leading to the solution described in this new paper. The simulations demonstrated the effectiveness of the new design they settled on.

 “It was really exciting, what we discovered,” Whyte says. The result is divertors that are longer and larger, and that keep the plasma more precisely controlled. As a result, they can handle the expected intense heat loads.

“You want to make the ‘exhaust pipe’ as large as possible,” Whyte says, explaining that the placement of the secondary magnets inside the primary ones makes that possible. “It’s really a revolution for a power plant design,” he says. Not only do the high-temperature superconductors used in the ARC design’s magnets enable a compact, high-powered power plant, he says, “but they also provide a lot of options” for optimizing the design in different ways — including, it turns out, this new divertor design.

Going forward, now that the basic concept has been developed, there is plenty of room for further development and optimization, including the exact shape and placement of these secondary magnets, the team says. The researchers are working on further developing the details of the design.

“This is opening up new paths in thinking about divertors and heat management in a fusion device,” Whyte says.

“All of the ARC work has been both eye-opening and stimulating of new ways of looking at tokamak fusion reactors,” says Bruce Lipschultz, a professor of physics at the University of York, in the U.K., who was not involved in this work. This latest paper, he says, “incorporates new ideas in the field with the many other significant improvements in the tokamak concept. … The ARC study of the extended leg divertor concept shows that the application to a reactor is not impossible, as others have contended.”

Lipschultz adds that this is “very high-quality research that shows a way forward for the tokamak reactor and stimulates new research elsewhere.”

The team included MIT graduate students Norman Cao, Alexander Creely, Cody Dennett, Jake Hecla, Brian LaBombard, Roy Tinguely, Elizabeth Tolman, H. Hoffman, Maximillian Major, Juan Ruiz Ruiz, Daniel Brunner, and Brian Sorbom, and Mitsubishi Electric Research Laboratories engineers P. Grover and C. Laughman. The work was supported by MIT’s Department of Nuclear Science and Engineering, the Department of Energy, the National Science Foundation, and Mitsubishi Electric Research Laboratories.

Five from MIT earn Simons Foundation Postdoctoral Fellowships in Marine Microbial Ecology

Tue, 10/09/2018 - 12:45pm

Four current and former MIT-Woods Hole Oceanographic Institution Joint Program students (MIT-WHOI) and one postdoc from the Department of Civil and Environmental Engineering (CEE) have been awarded Simons Foundation Postdoctoral Fellowships in Marine Microbial Ecology, bringing the total of MIT awardees to five out of the nine fellowships granted nationally in 2018.

The Simons Foundation exists to advance the frontiers of research in mathematics and the basic sciences. Its Life Sciences division supports basic research on fundamental questions in biology, and is currently focused on origins of life, microbial oceanography, microbial ecology and evolution, and support of early career scientists. For the postdoctoral fellowships in marine microbial ecology, the foundation encourages applicants outside of strictly ocean research, seeking researchers interested in using cross-disciplinary experience, modeling, and theory development to explore the interrelationship of microorganisms and ocean processes.

“Postdoctoral fellows bring new ideas and energy to a field, so support for postdocs not only helps launch their careers but also pushes the field forward,” says Marian Carlson, director of life sciences at the foundation.

The awards are for three years and include an annual stipend and $25,000 towards research support.

B.B. Cael

MIT-WHOI Joint Program graduate student B.B. Cael — currently working with Professor Mick Follows of the Department of Earth, Atmospheric and Planetary Sciences at MIT — successfully sought Simons Foundation support for a postdoctoral fellowship to build upon his thesis research on the export of biogenic carbon out of the surface ocean and attenuation of sinking particulate matter (SPM) through the ocean’s interior.

“Phytoplankton living in the sunlit surface ocean mediate the transformation of energy, carbon, and inorganic nutrients within the global marine biosphere,” Cael explains. “In the open ocean, the fraction of SPM that is not ‘remineralized’ or degraded by microbes in the photosynthetic zone becomes sequestered well below the permanent thermocline and is effectively removed from exchange with the atmosphere for decades to millennia. This process is one of many ways in which ocean ecology plays a role in our planet’s climate.”

As a postdoc with Angelique E. White in the Department of Oceanography at the University of Hawai’i, Cael will collect measurements to develop and test plausible and mechanistic theories for SPM flux that might provide an improved understanding for climate and ocean models.

Cael holds a BA in mathematics, human biology, and philosophy, and an MS in applied mathematics, both from Brown University.

Matti Gralka

MIT CEE postdoc Matti Gralka studies microscopic interactions in complex microbial communities on chitin particles in the lab of Otto Cordero, the Doherty Assistant Professor in Ocean Utilization and assistant professor of civil and environmental engineering at MIT. He plans to use the Simons award to investigate the resistance and resilience of marine microbial communities to perturbations.

“I am a physicist broadly interested in applying quantitative experiments and models towards understanding fundamental principles about biological systems and processes,” says Gralka. “At MIT, I will study the interplay of ecology and evolution, i.e., can we predict the assembly and function of microbial communities, their adaptation and response to perturbations, without a full knowledge of all microscopic details?”

Prior to MIT, Gralka completed his PhD in physics at the University of California at Berkeley working with Professor Oskar Hallatschek to study evolutionary dynamics in microbial colonies, investigating how spatial structure affects the action of selection.

Bennett Lambert

With this award from the Simons Foundation, graduate student Bennett Lambert of CEE and the MIT-WHOI Joint Program will be pursuing his postdoctoral fellowship at the University of Washington, working with E. Virginia Armbrust on the behavior of marine microbes and the role diversity plays in survival.

Lambert’s current research in CEE Visiting Associate Professor Roman Stocker’s lab investigates the interactions of individual microbes and how those interactions scale up to affect biogeochemistry in the oceans. Traditional oceanographic techniques cannot be used to investigate the microorganisms, causing Lambert and his colleagues to engineer an in situ chemotaxis assay (ISCA). This allows the investigation of microbial behavior in their natural environment.

“To examine the interactions, I've been working to develop microfluidic techniques that can be applied in both the field and the lab. In the Armbrust Lab, I'll be continuing in the same vein and applying microfluidic techniques to study phenotypic heterogeneity in marine picoeukaryotes,” says Lambert.

Prior to MIT, Lambert completed his BS in civil and environmental engineering at the University of Alberta.

Also receiving 2018 Simons Foundation fellowships in marine microbial ecology are two alumni of the MIT-WHOI Joint Program: Emily Zakem PhD ’17 and Nicholas Hawko PhD ’17. Zakem, herself a former member of the Follows Group at MIT, will explore, “what controls the transition from aerobic to anaerobic microbial activity in the ocean,” in the laboratory of Professor Naomi Levine at the University of Southern California. Also at the University of Southern California, Hawko will be working on, “regional versus phylogenetic inheritance of iron metabolic traits in Prochlorococcus,” with Professor Seth John.

A complete list of the award recipients and their projects is available at the Simons Foundation website.

MIT Campaign for a Better World propels the Institute to best fundraising year on record

Tue, 10/09/2018 - 12:30pm

MIT has announced that the MIT Campaign for a Better World has mobilized record numbers of alumni and friends in support of the Institute’s work on society’s most pervasive global challenges. At the end of fiscal year 2018, MIT had raised $737 million in new gifts and pledges from the highest number of donors in a single year.

This result — the best in the history of MIT — brings the campaign total to $4.3 billion, contributed by more than 96,000 individuals and organizations. From driving the launch of new global research initiatives to providing robust resources for students and reinvigorating physical spaces, the campaign is fulfilling its mission across MIT’s campus and beyond.

“It’s been an incredible year for the Institute,” says Julie Lucas, MIT’s vice president for resource development. “This outcome reflects both the generosity of the MIT community and the outstanding work of our faculty, researchers, and students who are creating a more positive future for all. It’s an extraordinary collective commitment to making a lasting impact on the world. I am proud to work among MIT’s talented advancement professionals, and I am deeply grateful to all of our alumni, friends, and leadership volunteers and ambassadors who have responded to the campaign with energy and vision to help us achieve our aspirations.”

The Institute-wide campaign, publicly launched in 2016, is driven by five problem-solving and discovery priorities that intersect with MIT’s schools, departments, labs, and centers: Discovery Science; Health of the Planet; Human Health, Teaching, Learning, and Living; and Innovation and Entrepreneurship. In addition, the campaign is highly focused on raising funds to support and sustain the people and places at the Institute’s core. 

The impact of the campaign can be seen in the widespread transformation taking place across MIT’s campus

Support for capital initiatives reached a new high this past fiscal year and milestones were attained on a number of projects, including the Harold W. Pierce Boathouse; the Metropolitan Warehouse (the potential future home of the School of Architecture and Planning, as well as a new makerspace for the MIT community); and the Wright Brothers Wind Tunnel, all of which have moved into their design phase.

Initial gifts were also secured for the new Vassar Street undergraduate residence at the heart of campus and the new Innovation and Entrepreneurship Hub. The latter is a cornerstone of the Kendall Square Initiative, which is rapidly transforming this Cambridge innovation neighborhood into a new gateway to the Institute. Kendall Square, also home to a new MIT graduate student residence and a purpose-built MIT Museum, continues to be among the Institute’s highest priorities. 

Adjacent to Kendall Square, MIT.nano, a 214,000-square-footaddition to the campus landscape, opened on Oct. 4. Its advanced nanotechnology and nanofabrication facilities are poised to have a dramatic impact on researchers across the Institute.

Two cross-Institute efforts announced this past year highlight the campaign’s commitment to basic research, human health, and innovation. The Abdul Latif Jameel Clinic for Machine Learning in Health (J-Clinic) aims to create and commercialize high-precision, affordable, and scalable machine learning technologies to revolutionize disease prevention, detection, and treatment worldwide. The MIT Quest for Intelligence, of which J-Clinic is a part, will focus on advancing the science and engineering of human and machine intelligence. 

Meanwhile, donors contributing crucial unrestricted funds to the campaign are fueling MIT’s ability to augment core strengths and invest in daring ideas. Support for undergraduate and graduate financial aid and faculty in the campaign also remains strong, underscoring the MIT community’s dedication to the student and teaching talent that drives the Institute’s education, research, and innovation engines. 

Since the campaign launch, MIT has sought to engage alumni and friends even more deeply in the life of the Institute. A total of 6,178 individuals from Boston to Seattle to Hong Kong to Tel Aviv have experienced the MIT Better World event series in 14 locations across the globe. The tour visited six major regional hubs where MIT alumni live and work during the 2018 fiscal year 2018, attracting 2,715 attendees. 

The 2018 Tech Reunions — MIT’s largest annual gathering of alumni — drew 3,578 alumni and guests, with three classes breaking attendance records and six breaking giving records. Meanwhile, the second MIT 24-Hour Challenge, held on Pi Day (March 14), inspired 8,673 donors to give more than $3.4 million, including a Pi-themed $314,000 challenge gift and a $50,000 bonus gift. The Institute also saw more than 16,000 volunteers offering their services to MIT. 

MIT President L. Rafael Reif says what he has found most striking about the campaign's success “is the enthusiasm for MIT I have witnessed everywhere I have traveled.”

“Our alumni and friends believe deeply in the critical role our community plays in creating and advancing knowledge, in service to the nation and the world. The campaign has strengthened MIT as a magnet for the most talented people on the planet and positioned our brilliant faculty and students to do their best work,” says Reif. “Thanks to the generosity of thousands, and to the time, energy, and dedication of thousands more, MIT’s vision for a better world is a giant step closer to reality.”

For more information about the MIT Campaign for a Better World, visit betterworld.mit.edu and follow #MITBetterWorld. 

Stamp-sized graphene sheets riddled with holes could be boon for molecular separation

Tue, 10/09/2018 - 10:10am

MIT engineers have found a way to directly “pinprick” microscopic holes into graphene as the material is grown in the lab. With this technique, they have fabricated relatively large sheets of graphene (“large,” meaning roughly the size of a postage stamp), with pores that could make filtering certain molecules out of solutions vastly more efficient.

Such holes would typically be considered unwanted defects, but the MIT team has found that defects in graphene — which consists of a single layer of carbon atoms — can be an advantage in fields such as dialysis. Typically, much thicker polymer membranes are used in laboratories to filter out specific molecules from solution, such as proteins, amino acids, chemicals, and salts.

If it could be tailored with pores small enough to let through certain molecules but not others, graphene could substantially improve dialysis membrane technology: The material is incredibly thin, meaning that it would take far less time for small molecules to pass through graphene than through much thicker polymer membranes.

The researchers also found that simply turning down the temperature during the normal process of growing graphene will produce pores in the exact size range as most molecules that dialysis membranes aim to filter. The new technique could thus be easily integrated into any large-scale manufacturing of graphene, such as a roll-to-roll process that the team has previously developed.

“If you take this to a roll-to-roll manufacturing process, it’s a game changer,” says lead author Piran Kidambi, formerly an MIT postdoc and now an assistant professor at Vanderbilt University. “You don’t need anything else. Just reduce the temperature, and we have a fully integrated manufacturing setup for graphene membranes.”

Kidambi’s MIT co-authors are Rohit Karnik, associate professor of mechanical engineering, and Jing Kong, professor of electrical engineering and computer science, along with researchers from Oxford University, the National University of Singapore, and Oak Ridge National Laboratory. Their paper appears today in Advanced Materials.

Pristine defects

Kidambi and his colleagues previously developed a technique to generate nanometer-sized pores in graphene, by first fabricating pristine graphene using conventional methods, then using oxygen plasma to etch away at the fully formed material to create pores. Other groups have used focused beams of ions to methodically drill holes into graphene, but Kidambi says these techniques are difficult to integrate into any large-scale manufacturing process.

“Scalability of these processes are extremely limited,” Kidambi says. “They would take way too much time, and in an industrially quick process, such pore-generating techniques would be challenging to do.”

So he looked for ways to make nanoporous graphene in a more direct fashion. As a PhD student at Cambridge University, Kidambi spent much of his time looking for ways to make pristine, defect-free graphene, for use in electronics. In that context, he was trying to minimize the defects in graphene that occurred during chemical vapor deposition (CVD) — a process by which researchers flow gas across a copper substrate within a furnace. At high enough temperatures, of about 1,000 degrees Celsius, the gas eventually settles onto the substrate as high quality graphene.

“That was when the realization hit me: I just have to go back to my repository of processes and pick out those which give me defects, and try them in our CVD furnace,” Kidambi says.

As it turns out, the team found that by simply lowering the temperature of the furnace to between 850 and 900 degrees Celsius, they were able to directly produce nanometer-sized pores as the graphene was grown.

“When we tried this, it surprised us a little that it really works,” Kidambi says. “This [temperature] condition really gave us the sizes we need to make graphene dialysis membranes.”

“This is one of several advances that will ultimately make graphene membranes practical for a range of applications,” Karnik adds. “They may find use in biotechnological separations including in the preparation of drugs or molecular therapeutics, or perhaps in dialysis therapies.”

A Swiss cheese support

While the team is not entirely sure why a lower temperature creates nanoporous graphene, Kidambi suspects that it has something to do with how the gas in the reaction is deposited onto the substrate.

“The way graphene grows is, you inject a gas and the gas disassociates on the catalyst surface and forms carbon atom clusters which then form nuclei, or seeds,” Kidambi explains. “So you have many small seeds that graphene can start growing from to form a continuous film. If you reduce the temperature, your threshold for nucleation is lower so you get many nuclei. And if you have too many nuclei, they can’t grow big enough, and they are more prone to defects. We don’t know exactly what the formation mechansim of these defects, or pores, is, but we see it every single time.”

The researchers were able to fabricate nanoporous sheets of graphene. But as the material is incredibly thin, and now pocked with holes, alone, it would likely come apart like paper-thin Swiss cheese if any solution of molecules were to flow across it. So the team adapted a method to cast a thicker supporting layer of polymer on top of the graphene.

The supported graphene was now tough enough to withstand normal dialysis procedures. But even if target molecules were to pass through the graphene, they would be blocked by the polymer support. The team needed a way to produce pores in the polymer that were significantly larger than those in graphene, to ensure that any small molecules passing through the ultrathin material would easily and quickly pass through the much thicker polymer, similar to a fish swimming through a port hole just its size, and then immediately passing through a much large tunnel.

The team ultimately found that by submersing the stack of copper, graphene, and polymer in a solution of water, and using conventional processes to etch away the copper layer, the same process naturally created large pores in the polymer support that were hundreds of times larger than the pores in graphene. Combining their techniques, they were able to create sheets of nanoporous graphene, each measuring about 5 square centimeters.

“To the best of our knowledge, so far this is the largest atomically thin nanoporous membrane made by direct formation of pores,” Kidambi says.

Currently, the team has produced pores in graphene measuring approximately 2 to 3 nanometers wide, which they found was small enough to quickly filter salts such as potassium chloride (0.66 nanometers), and small molecules such as the amino acid L-Tryptophan (about 0.7 nanometers), food coloring Allura Red Dye (1 nanometer), and vitamin B-12 (1.5 nanometers) to varying degrees. The material did not filter out slightly larger molecules, such as the egg protein lysozyme (4 nanometers). The team is now working to tailor the size of graphene pores to precisely filter molecules of various sizes.

“We now have to control these size defects and make tunable sized pores,” Kidambi says. “Defects are not always bad, and if you can make the right defects, you can have many different applications for graphene.”

This research was supported, in part, by the U.S. Department of Energy.

Study opens route to flexible electronics made from exotic materials

Mon, 10/08/2018 - 10:59am

The vast majority of computing devices today are made from silicon, the second most abundant element on Earth, after oxygen. Silicon can be found in various forms in rocks, clay, sand, and soil. And while it is not the best semiconducting material that exists on the planet, it is by far the most readily available. As such, silicon is the dominant material used in most electronic devices, including sensors, solar cells, and the integrated circuits within our computers and smartphones.

Now MIT engineers have developed a technique to fabricate ultrathin semiconducting films made from a host of exotic materials other than silicon. To demonstrate their technique, the researchers fabricated flexible films made from gallium arsenide, gallium nitride, and lithium fluoride — materials that exhibit better performance than silicon but until now have been prohibitively expensive to produce in functional devices.

The new technique, researchers say, provides a cost-effective method to fabricate flexible electronics made from any combination of semiconducting elements, that could perform better than current silicon-based devices.

“We’ve opened up a way to make flexible electronics with so many different material systems, other than silicon,” says Jeehwan Kim, the Class of 1947 Career Development Associate Professor in the departments of Mechanical Engineering and Materials Science and Engineering. Kim envisions the technique can be used to manufacture low-cost, high-performance devices such as flexible solar cells, and wearable computers and sensors.

Details of the new technique are reported today in Nature Materials. In addition to Kim, the paper’s MIT co-authors include Wei Kong, Huashan Li, Kuan Qiao, Yunjo Kim, Kyusang Lee, Doyoon Lee, Tom Osadchy, Richard Molnar, Yang Yu, Sang-hoon Bae, Yang Shao-Horn, and Jeffrey Grossman, along with researchers from Sun Yat-Sen University, the University of Virginia, the University of Texas at Dallas, the U.S. Naval Research Laboratory, Ohio State University, and Georgia Tech.

Now you see it, now you don’t

In 2017, Kim and his colleagues devised a method to produce “copies” of expensive semiconducting materials using graphene — an atomically thin sheet of carbon atoms arranged in a hexagonal, chicken-wire pattern. They found that when they stacked graphene on top of a pure, expensive wafer of semiconducting material such as gallium arsenide, then flowed atoms of gallium and arsenide over the stack, the atoms appeared to interact in some way with the underlying atomic layer, as if the intermediate graphene were invisible or transparent. As a result, the atoms assembled into the precise, single-crystalline pattern of the underlying semiconducting wafer, forming an exact copy that could then easily be peeled away from the graphene layer.

The technique, which they call “remote epitaxy,” provided an affordable way to fabricate multiple films of gallium arsenide, using just one expensive underlying wafer. 

Soon after they reported their first results, the team wondered whether their technique could be used to copy other semiconducting materials. They tried applying remote epitaxy to silicon, and also germanium — two inexpensive semiconductors — but found that when they flowed these atoms over graphene they failed to interact with their respective underlying layers. It was as if graphene, previously transparent, became suddenly opaque, preventing atoms of silicon and germanium from “seeing” the atoms on the other side.   

As it happens, silicon and germanium are two elements that exist within the same group of the periodic table of elements. Specifically, the two elements belong in group four, a class of materials that are ionically neutral, meaning they have no polarity.

“This gave us a hint,” says Kim.

Perhaps, the team reasoned, atoms can only interact with each other through graphene if they have some ionic charge. For instance, in the case of gallium arsenide, gallium has a negative charge at the interface, compared with arsenic’s positive charge. This charge difference, or polarity, may have helped the atoms to interact through graphene as if it were transparent, and to copy the underlying atomic pattern.

“We found that the interaction through graphene is determined by the polarity of the atoms. For the strongest ionically bonded materials, they interact even through three layers of graphene,” Kim says. “It’s similar to the way two magnets can attract, even through a thin sheet of paper.”

Opposites attract

The researchers tested their hypothesis by using remote epitaxy to copy semiconducting materials with various degrees of polarity, from neutral silicon and germanium, to slightly polarized gallium arsenide, and finally, highly polarized lithium fluoride — a better, more expensive semiconductor than silicon.

They found that the greater the degree of polarity, the stronger the atomic interaction, even, in some cases, through multiple sheets of graphene. Each film they were able to produce was flexible and merely tens to hundreds of nanometers thick.

The material through which the atoms interact also matters, the team found. In addition to graphene, they experimented with an intermediate layer of hexagonal boron nitride (hBN), a material that resembles graphene’s atomic pattern and has a similar Teflon-like quality, enabling overlying materials to easily peel off once they are copied.

However, hBN is made of oppositely charged boron and nitrogen atoms, which generate a polarity within the material itself. In their experiments, the researchers found that any atoms flowing over hBN, even if they were highly polarized themselves, were unable to interact with their underlying wafers completely, suggesting that the polarity of both the atoms of interest and the intermediate material determines whether the atoms will interact and form a copy of the original semiconducting wafer.

“Now we really understand there are rules of atomic interaction through graphene,” Kim says.

With this new understanding, he says, researchers can now simply look at the periodic table and pick two elements of opposite charge. Once they acquire or fabricate a main wafer made from the same elements, they can then apply the team’s remote epitaxy techniques to fabricate multiple, exact copies of the original wafer.

“People have mostly used silicon wafers because they’re cheap,” Kim says.
“Now our method opens up a way to use higher-performing, nonsilicon materials. You can just purchase one expensive wafer and copy it over and over again, and keep reusing the wafer. And now the material library for this technique is totally expanded.”

Kim envisions that remote epitaxy can now be used to fabricate ultrathin, flexible films from a wide variety of previously exotic, semiconducting materials — as long as the materials are made from atoms with a degree of polarity. Such ultrathin films could potentially be stacked, one on top of the other, to produce tiny, flexible, multifunctional devices, such as wearable sensors, flexible solar cells, and even, in the distant future, “cellphones that attach to your skin.”

“In smart cities, where we might want to put small computers everywhere, we would need low power, highly sensitive computing and sensing devices, made from better materials,” Kim says. “This [study] unlocks the pathway to those devices.”

This research was supported in part by the Defense Advanced Research Projects Agency, the Department of Energy, the Air Force Research Laboratory, LG Electronics, Amore Pacific, LAM Research, and Analog Devices.

MIT alumnus William Nordhaus wins Nobel Prize in economic sciences

Mon, 10/08/2018 - 6:21am

William D. Nordhaus PhD ’67, a scholar known for his work on the long-term interaction of climate change and the economy, will share the 2018 Nobel Prize in economic sciences, the Royal Swedish Academy of Sciences announced today.

Nordhaus, a professor of economics at Yale University, shares the award with Paul M. Romer of New York University's Stern School of Business, who also did graduate work at MIT. The academy announced that the two economists have “significantly broadened the scope of economic analysis by constructing models that explain how the market economy interacts with nature and knowledge.”

In Nordhaus’ case, the academy cited his pioneering development of an “integrated assessment model” representing “the global interplay between the economy and the climate.” Nordhaus has refined multiple iterations of his model. He has also written about climate an economics for a broad audience, as the author of several books.

Nordhaus completed his PhD dissertation at MIT under the supervision of Robert M. Solow, himself the 1987 winner of the Nobel Prize in economic sciences. Multiple Nobel Prize winners, including Nordhaus, Peter Diamond, George Akerlof, and Joseph Stiglitz, have had Solow as their principal advisor.

Nordhaus is the 37th MIT alumnus to win a Nobel Prize and 90th winner with a connection to MIT. Five people have won the Nobel Prize in economic sciences while serving as members of the MIT faculty; another 11 MIT alumni, including Nordhaus, have won the prize. An additional seven former MIT faculty have won the Nobel Prize in economic sciences.

Student insight on the "Future of Nuclear Energy" study

Fri, 10/05/2018 - 2:45pm

Researchers shared findings and recommendations from the new MIT interdisciplinary study, “The Future of Nuclear in a Carbon-Constrained World,” at a series of events and meetings in Washington last week. Study participants from MIT and other institutions involved in the report spoke with a variety of energy stakeholders and discussed nuclear energy's potential to help address climate change — and how industry and government could solve issues of cost and policy currently limiting that potential.

For four of the graduate students from the research team who participated in the events, the Washington visits held additional significance, as they saw their years of work on the study come to fruition. Karen Dawson, a doctoral candidate in nuclear science and engineering, said she found it valuable to participate in the panel and meetings “because it felt like I was moving from the minor leagues to the major leagues.”

“It was also really fulfilling to see industry experts discussing my work — it demonstrated the impact of my contributions to the study,” she said.

The lead researchers on the study repeatedly underscored the value of the students’ work as well. Addressing an audience of approximately 150 people at the American Association for the Advancement of Science, study co-chair Jacopo Buongiorno began by acknowledging the efforts of the study team, composed of MIT and non-MIT researchers and advisors. Buongiorno, the TEPCO Professor of Nuclear Science and Engineering and associate department head, cited the contributions of the graduate students at the event and other students who worked on the report as being a vital part of the team effort.

Another study co-chair, Michael Corradini, echoed Buongiorno’s remarks and credited the students as being “extremely important in doing these analyses.”

Corradini, an emeritus professor of engineering physics at the University of Wisconsin at Madison, told the audience: “When you get to the tough questions, we’ll pass it on to them.”

In addition to taking audience questions on their areas of expertise within the study, the students answered one from event moderator Robert Armstrong, director of the MIT Energy Initiative (MITEI). He asked what had surprised them as they were working on the study.

Amy Umaretiya, a master’s student in the Technology and Policy Program at the MIT Institute for Data, Systems, and Society, said that learning how some public policies didn’t incorporate nuclear energy as a low-carbon solution came as a surprise.

“The fact that clean energy standards are actually focused only on renewable energy as opposed to [a wider portfolio of] clean energy was a big shock for me,” said Umaretiya, who worked with study co-chair John Parsons, a senior lecturer at the Sloan School of Management, to examine policy issues.

Audience members asked why students had chosen to study nuclear science and engineering, and not something “sexier” like battery storage, smart grids, or next-generation solar.

“My interest in nuclear science and engineering really comes down to the amount of energy that’s released when you split an atom apart,” replied doctoral candidate Patrick White. “We’re talking 40 to 50 million times more energy per reaction if you look at the fission of a uranium atom versus the combustion of a carbon atom.”

He said he began to wonder: “What kind of opportunities do you have when you take that kind of energy and apply it in places where solar and wind might not be appropriate? Or even to help complement other technologies?”

Dawson added: “I was amazed that there was this technology that was viable on the grid already and had zero carbon emissions, and nobody really seemed to be talking about it as a solution, at least when I was an undergrad.”

“After a couple of years at MIT, I believed in nuclear being a strong part of the future energy system, and then I got interested in what the obstacles were to its development,” she said. “That’s what brought me to this study.”

On Tuesday and Wednesday, Dawson, Umaretiya, White, and nuclear science and engineering master’s student Patrick Champlin also participated in meetings at the U.S. Department of Energy, at the Center for Strategic and International Studies, on Capitol Hill with legislators and staff members (arranged by the MIT Washington Office), and at a dinner hosted by the Alumni Club of Washington D.C.

“It’s so important that we’re able communicate our report findings to policymakers,” White says about the meetings. “It was a really different experience to explain my research to a member of Congress instead of my advisor, but if we want to make our work matter, it’s a conversation we need to learn to have.”

MITEI, which published the study, sponsored Dawson’s, Umaretiya’s, and White’s travel for the Washington events. MIT’s International Policy Laboratory also provided support for outreach on the study. Other students who worked on the study included undergraduate students Rasheed Auguste, Ze Dong, and Ka-Yen Yau; doctoral candidate Lucas Rush; and PhD candidate Nestor Sepulveda, all of the nuclear science and engineering department.

“The Future of Nuclear Energy in a Carbon-Constrained World” is the eighth in MITEI’s “Future of” series of reports to inform public policy and serve as guides for industry stakeholders on a range of complex and important issues involving energy and the environment. The comprehensive reports are written by multidisciplinary teams of researchers and the research is informed by a distinguished external advisory committee. This study was also supported by foundation, industry, and individual sponsors.

Showcasing solutions for land, sea, space — and everywhere in between

Fri, 10/05/2018 - 2:20pm

Aaron Persad held up a clear cylinder with filled with water. The inconspicuous object had made a trip most people never will experience — orbiting the Earth aboard a space shuttle.

“I’m trying to determine how liquids behave in space,” explained Persad, a postdoctoral fellow working with Rohit Karnik, an associate professor of mechanical engineering. By understanding how liquids move in zero gravity or a near-freefall environment, Persad hopes to make more compact rockets and safer syringes for administering medication to astronauts.

Persad was one of the 44 participants in this year’s MIT Mechanical Engineering Research Exhibition (MERE), which was held on Sept. 28 in Walker Memorial. MERE is hosted by the Graduate Association of Mechanical Engineers (GAME) and MIT’s Department of Mechanical Engineering. Graduate students, postdocs, and Undergraduate Research Opportunities Program (UROP) students who have conducted research in mechanical engineering present their findings at MERE, using posters, live demos, videos, and interactive models.

The event is modeled after a typical poster session which most of the students will encounter throughout their careers at various scientific and engineering conferences.

“The idea with MERE is to empower graduate students and postdocs so they are more confident about their communication skills when it’s time for them to present their work at a conference or in front of potential industry partners,” explained Rashed Al-Rashed, a PhD candidate in mechanical engineering and one of the co-organizers of MERE.

In addition to providing students and early career researchers with valuable practice presenting their work, the event gave the entire mechanical engineering community at MIT an opportunity to learn about research from a variety of disciplines.

“MERE really demonstrates the breadth and diversity of the mechanical engineering research being conducted at MIT,” says Nick Fang, a professor of mechanical engineering and MERE’s faculty advisor. “It’s great at the beginning of the academic year to give these students and postdocs a chance to introduce themselves and share their passion for research to the community.”

The projects presented at this year’s MERE touched upon a diverse array of subjects — from cooling the electronic chips in cell phones to developing ankle-foot prosthetics for rock climbing. Projects were also related to research in various environments. While Aaron Persad was conducting research with applications in space, others focused on research in land and sea environments.

Kristen Railey, a PhD candidate in mechanical engineering, conducted research beneath the surface of the Charles River. She examined the acoustic features of unmanned underwater vehicles and how well she could detect and track them in a realistic environment. Meanwhile graduate student Carolyn Sheline presented a system model for low-cost, solar powered drip irrigation for use in farms located in Northern Africa and the Middle East.

Much of the research presented deals with pressing topics that could have a major global impact.

Graduate student Peter Godart, for example, hopes to help people after natural disasters by harnessing energy from debris. “I want to give people in the immediate aftermath of a hurricane the ability to provide clean water and electricity for themselves using locally sourced materials,” explains Godart. He plans on accomplishing this by making aluminum debris reactive with water using gallium and indium. The steam and hydrogen released from the reaction with water creates enough force to desalinate seawater and provide enough power to charge a phone.

Judges consisting of Course 2 alumni, current mechanical engineering faculty members, and staff listened to all the presentations and voted on which presenters were the best in certain categories. Awards were given to the following presentations:

  • Best Overall: Daniel Gonzalez for “Extra Robotic Legs for Augmenting Human Payload and Positioning Capabilities.”
  • Best Understanding: Chu Ma for “Acoustic far-field subwavelength imaging.”
  • Highest Impact: Mo Chen for “Room-Temperature Quantum Error Correction with Nitrogen-Vacancy Centers.”
  • Most Excitement: Cameron McBride for “Characterizing Resource Demand and Sensitivity in Biological Synthetic Circuits.”
  • Best UROP: Carson Tucker for “Energy Consumption in a Batch Reverse-Osmosis Prototype,”

The runners-up included Tyler Hamer, Nicolas Selby, Aaron Persad, Kiarash Gordiz, Lup Wai Chew, Jerry Wang, Maytee Chanthrayukonthorn, Shuai Li, Shawn Zhang, and James Hermus. Honorable mention was given to Crystal Owens, Nina Petelina, Yoonho Kim, Thomas Toncagne-Dejean, Noam Buckman, Abhinav Gupta, Sara Nagelberg, Yi Xue, Caleb Amy, Peter Godart, and Dhanushkodi Miarappan.

The full-day event concluded with a keynote address by Karl Iagnemma SM ’97, PhD ’01, co-founder of nuTonomy, a company devoted to developing software for driverless cars. Iagnemma recounted his story of starting as an MIT graduate student focused on robotics and not interested in cars at all, to leading a company that has now given passengers in Las Vegas nearly 10,000 rides in autonomous vehicles. Having worked in both academia and industry, Iagnemma also detailed some of the key differences between life in the lab and life at a start-up. 

“Developing planning and decision making technologies for autonomous vehicles is one of the great technical problems of this decade,” he said.

Despite the technical challenge posed by the problem, the technology  holds tremendous opportunity to have a large positive impact on society, Iagnemma added. He said his main motivation in developing autonomous vehicle technology has been reducing the cost of both money and lives due to vehicle accidents. 

“It’s often the case that hard problems are valuable problems,” he told the student audience. “I think that’s the case with driverless technology and I know that there are at least half a dozen other examples in this room today.”

Student entrepreneurs think inside the box

Fri, 10/05/2018 - 2:05pm

Paramedics must perform rapid assessments when responding to any emergency medical situation. Understanding a patient’s condition is critical to making a more informed decision to improve outcomes, but a high-stress environment and the need to process a lot of information quickly can sometimes lead to a misdiagnosis.

Challenged to reimagine the ambulance of the future, five MIT students — Paolo Adajar, a mathematical economics sophomore; Eswar Anandapadmanaban, an electrical engineering and computer science junior; Jordan Harrod, a PhD candidate studying medical engineering and medical physics; Samuel Salomon, a chemistry, biology, and physics junior minoring in nuclear engineering; and Erica Yuen, a mechanical engineering graduate student — designed a solution they think can help paramedics more accurately identify patients who are in critical condition.

AugMedic is an integrated sensing system that simplifies vital sign monitoring. There are five vital signs that can indicate worsening trends in a patient’s health — heart rate, respiration, blood pressure, oxygen levels, and temperature. With the AugMedic system, the sensors are placed on a stretcher and integrated through a processing unit that displays the patient’s vitals automatically on a portable tablet. The interactive interface also allows for the input of qualitative patient information and provides assistive questioning that offers recommendations to investigate a patient’s conditions based on existing protocols. In addition, the system compiles the paramedic’s entry data and vital signs to automatically fill out post-call reports, saving time and allowing the technician to move more efficiently between calls.

The idea for AugMedic was developed over the course of a four-day span during which time the team ate, slept, and worked together inside a glass cube housed on the MIT campus. Their effort was part of InCube, a global startup competition that took place Sept. 20 to 24. 

The students began the challenge by interviewing over 40 people to understand the problem space.

“Since our team didn’t know much about ambulances, we were completely dependent on the interviews,” says Yuen. “We had paramedics, nurses, medical directors, and EMTs who took time out of their busy schedules to talk about their personal experiences in ambulances. A researcher from DUSP [Department of Urban Studies and Planning] even put together a personalized large packet of research papers outlining how the pollution from ambulances may affect cardiac health. Their contributions made me realize that with an open mind and honest discussion with a diverse group of people with different perspectives, you can learn so much about a new domain.”

Through the interviews, the students were surprised to learn how unintegrated the ambulance system was, which led them to design a more simplified structure.

“If you want paramedics to focus on the patients and on saving their lives, why should they have to reach all over the place? It’s such a small space and the patient is right in the middle,” Solomon says. “They always have to take blood pressure and temperature so why doesn’t it do this automatically for them. If they always have to do it, it’s like a routine. They should be able to focus on the other signs of a patient that may not be as obvious instead.”

InCube invites students to live the full entrepreneurial journey and work towards finding an innovative solution to a societal challenge that could be turned into a successful startup. The notion of doing it while inside a glass cube is intended to draw the public into the process, foster transparency, and provide a platform for interactive engagement. 

Conceived by a Swiss-based student association, the ETH Entrepreneur Club, the appearance of the novel workspace at the Institute marked the second time the InCube experiment has been conducted. After the success of the first edition in Zurich last year, the student organizers brought the idea to host the first U.S.-based cube in Cambridge to the MIT Innovation Initiative, which helped co-organize the event.

On Sept. 20, the five teammates, who had just met for the first time the prior week, stepped into a tiny 270-square-foot cube that was set up with a small workspace on MIT’s North Court to compete against four other teams in Switzerland — two in Zurich, one in Bern, and one in Crans-Montana. Each of the cubes was supported by a private company, institution, or foundation that defined a problem for the team to solve. Stryker, a medical technology company, sponsored the Cambridge cube and unveiled their challenge to design a better ambulance to the students on the first day of the competition.

After four days of working around the clock, the team pitched their idea for AugMedic in front of a camera which was broadcast at the finale event in Zurich on Sept. 24. Based on the quality of their concept and the marketability of their idea, the judges awarded the MIT team second place.

When asked what it was like living and working with people he didn’t know in such close quarters, Solomon says he thought being strangers “kind of helped because we came in with different backgrounds and mindsets.

“It was so much fun,” Solomon says. “I don’t think we would have had such a good experience if we weren’t living together in the cube. It was an intellectual campground. I mean we never stopped seeing each other so we were always connecting and laughing.”

Yuen says hackathons are a great vehicle to collaborate intensively on a project, but most are not long enough to go deep into problem-solving because the limited amount of time doesn’t allow for the validation of ideas.

“InCube was different though because its entire premise was based on design thinking and not just on making technology that works, but technology that can actually be applied and utilized to solve problems,” she says.

InCube was not only an opportunity for the students to apply theory into practice, it was also a chance for them to try their hands at entrepreneurship. The competition required all the teams to develop a prototype and a business model for their concepts and were provided mentors who helped guide them in defining value propositions and revenue streams. “I went into this with an open mind and to learn more about entrepreneurship,” says Solomon. “I have a science background and I really wanted to see how I can take all these equations and theories and turn that knowledge into an invention or into something useful for the world.”

Yuen says it was “really amazing seeing how each one of our team members contributed in different, significant ways, and watching our design evolve over time with each design iteration.”

“In just a few days, my team accomplished so much more than I thought was possible,” she says. “After this experience I feel much more confident in pursuing entrepreneurship since the process was so rewarding.”

With the intellectual property of the design owned by the team, the students are planning to continue working on AugMedic and have plans to try and push a startup forward.

“How exactly we’re going to work through that, we’re still discussing, but it’s going to happen,” says Solomon. “All of us poured our hearts into this for these four days, so we all want to give it go.”

Three MIT researchers win U.S. Air Force Young Investigator Research Program grants

Fri, 10/05/2018 - 2:00pm

Three MIT researchers, representing the departments of Physics, Electrical Engineering and Computer Science, and the Research Laboratory of Electronics (RLE), are among 31 scientists and engineers nationwide who have been awarded three-year, $450,000 research grants by the U.S. Air Force’s Office of Scientific Research (AFOSR).

Selected from a pool of more than 290 proposals, the three MIT grant winners are Riccardo Comin, an assistant professor of physics; Phillip “Donnie” Keathley, a research scientist in the RLE’s Quantum Nanostructures and Nanofabrication group; and Luqiao Lui, an assistant professor of electrical engineering and computer science and an RLE principal investigator.

Awarded by the AFOSR’s Young Investigator Research Program, the grants are intended to foster creative basic research in science and engineering, and support early career development of outstanding young investigators who show exceptional ability and promise for meeting the challenges of science and engineering research related to the Air Force's mission.

Riccardo Comin is an experimental condensed matter physicist whose research explores the rich variety of electronic phases that can be crafted and engineered in the broad class of quantum materials. Comin’s research focuses on unconventional superconductors, where he studies the interplay between superconductivity and other competing electronic orders in pure materials and in nanostructured devices.

For his work using X-ray probes to elucidate the inner anatomy of quantum solids, Comin has received several awards, including a 2018 Sloan Research Fellowship, the 2016 Bryan R. Coles Prize, and the 2015 McMillan Award, among others.

Phillip Keathley PhD '15 develops optical-field-driven electronics, nanoscale free-electron light sources, and nanoscale vacuum-electronic devices for harsh environments. His research experience spans the areas of areas of ultrafast optics, strong-field science, attosecond physics, nanophotonics, and plasmonics. He received a bachelor’s and a master’s degree, both in electrical engineering, from the University of Kentucky in 2009, and a PhD in electrical engineering and computer science.

Luqiao Lui conducts research is in the field of spin electronics; in particular, he focuses on nanoscale materials and devices for spin logic, non-volatile memory, and microwave applications. He received a bachelor’s degree in physics from Peking University and a PhD in applied physics from Cornell University. Before joining MIT, he was a research staffer at IBM’s T.J. Watson Research Center.

Among other honors, he has received the Patent Application Achievement Award from IBM, the Young Scientist Prize in the Field of Magnetism from the International Union of Pure and Applied Physics, and the William L. McMillan Award, which recognizes outstanding contributions by a young condensed-matter physicist, from the Department of Physics at the University of Illinois at Urbana-Champaign. 

Startup uses 3-D printing to reinvent the production of metal parts

Fri, 10/05/2018 - 12:59am

It’s not hard to understand why some of the world’s largest corporations have made huge investments in metal 3-D printing recently. Manufacturing metal parts at scale currently requires companies to navigate complex global supply chains that take an unavoidable chunk out of the bottom line.

However, the cost, complexity, and time associated with metal 3-D printing has ensured the technology’s mark on the multi-trillion-dollar manufacturing industry remains minimal.

Desktop Metal is working to change that. Later this year, the company will begin shipping early versions of its Production System, a 3-D printer that can produce up to 100,000 metal parts at a cost and speed competitive with traditional manufacturing methods. The company’s first product, the Studio System, improved the safety, speed, and price point of 3-D printing prototypes and small batches of metal parts.

“Metal manufacturing is one of the biggest drivers of manufacturing overall, and manufacturing drives the world,” says Desktop Metal co-founder A. John Hart, an associate professor at MIT’s Department of Mechanical Engineering and the director of the Laboratory for Manufacturing and Productivity. “3-D printing is an amazing technology in terms of its capabilities and how it reshapes the product life cycle, but we’re in such early stages that innovative processes are needed to open the floodgates.”

In pursuit of that goal, the founding team, which includes four current MIT professors and an alumnus of the Sloan School of Management, has overseen a remarkable degree of innovation that’s led the company to file or be in the process of filing over 200 patents.

That innovation may help explain why Desktop Metal has enjoyed an unprecedented trajectory since its founding in 2015. The Boston Business Journal reports that last summer it became the fastest company in U.S. history to reach a billion-dollar valuation, on its way to raising $277 million in venture capital.

The centuries-old manufacturing industry may seem like a formidable target for such a young startup, but the investing arms of corporate behemoths such as Google, Ford, BMW, and GE have funded Desktop Metal in bets that the company can disrupt the industry at a scale never before seen in the 3-D printing world.

A golden opportunity

In 2012, Ric Fulop MBA ’06 was a general partner at North Bridge Venture Partners when he saw a business opportunity in the fact that current processes for 3-D printing metal were far too slow for mass production and far too expensive for prototyping. He spent the next three years looking for the right company to tackle those problems before deciding that he should start the company himself.

Recognizing the enormous technical challenges ahead of him, Fulop decided to bring together a team of people who have spent their careers advancing fields related to 3-D printing, including materials science, machine design, automation, and software.

The six people with whom he founded the company include Hart; Kyocera Professor of Materials Science and Engineering Yet-Ming Chiang; materials science and engineering Professor Christopher Schuh; and mechanical engineering Professor Ely Sachs, an early pioneer of 3-D printing who invented the widely used method of binder jet printing. The other co-founders are computer-aided-design software veteran Rick Chin, and Jonah Myerberg, who worked with Fulop at a previous company and currently serves as Desktop Metal’s chief technology officer.

“We got together and said, ‘Let’s start inventing,’ and that was an amazing experience,” Hart recalls. “Desktop Metal didn’t spin out of IP from any of our labs. It was a team founded around an opportunity and a vision that then required rapid invention and innovation in the context of market need.”

Among the team’s breakthroughs was a printing technique called bound metal deposition, which works by extruding metal powder mixed with a binding agent, in a similar fashion to the layer-by-layer process that’s common in plastic 3-D printing. The parts are then placed in a debinder, where a proprietary fluid dissolves the binding agent, before they are sintered and densified in a furnace.

Bound metal deposition works with many of the same alloys as the metal injection molding (MIM) process that has been widely used in manufacturing since the 1980s, including stainless steel, copper, and titanium.

“We turned metal 3-D printing into something office-friendly that you can put anywhere,” Fulop says. “You just plug it in and you can make metal parts.”

The Studio System made 3-D printing practical for office prototyping and low-volume production. But in order for Desktop Metal to contend with the global manufacturing market, the company needed to further reinvent the printing process.

The firm’s Production System leverages another proprietary technique called single pass jetting, a complex but outwardly smooth process in which a print head with powder spreading units on either side slides back and forth across a build area. With each pass, the printer deposits precise layers of metal powder before jetting a binding agent onto the powder. Each layer of powder is as thin as a human hair.

According to the company, the system is the world’s fastest metal 3-D printer, 400 percent faster than the closest binder jet system and 100 times faster than today’s laser printers. 

“A big part of the inaccessibility up to this point has been the cost and speed of printing,” Hart says. “If you’ve ever watched a 3-D metal part being printed … some plants grow faster.”

A bright future

Fulop estimates that two dozen Production Systems will be shipped in 2019 as the company continues to scale. With orders rolling in, many of Desktop Metal’s customers are looking to purchase multiple systems to print at volumes much higher than 100,000 parts.

Still, it remains unclear how much 3-D printing will be disrupting mainstream metal processing in the near future. Traditional manufacturing processes, like casting, do have their advantages for creating relatively simple parts at high volumes.

“When people say that 3-D printing is going to be 20 or 40 percent of manufacturing in some number of decades, I think, ‘Probably not,’ and then, ‘It’s too early to tell,’” Hart acknowledges. “That said, it’s so early that I’m confident the additive manufacturing industry will grow 10- or 100-fold in the next five to 10 years or so.”

Measuring the impact of metal 3-D printing using the sales volume of current machines and materials probably underestimates its true value. The unique capabilities of 3-D printing should uncover novel options for engineers and designers trying to make objects such as more efficient aircraft engines and lighter automotive structures.

“3-D printing lets you transform complexity to simplicity,” Hart explains. “Consider how many products require the concurrent engineering and eventual assembly of many parts, and how the design constraints and logistics of manufacturing shape how we develop products. 3-D printing lets you consolidate assemblies into single parts, and design for optimal performance.  Thinking only about the cost of 3-D printing ignores the incredible value unlocked by new designs, and by speed and flexibility on operations. When you think about those aspects hand in hand, you see the real breakthrough.”

Fujitsu Laboratories and MIT’s Center for Brains, Minds and Machines Broaden Partnership

Thu, 10/04/2018 - 10:00pm

Fujitsu Laboratories Ltd. and MIT's Center for Brains, Minds and Machines (CBMM) has announced a multi-year philanthropic partnership focused on advancing the science and engineering of intelligence while supporting the next generation of researchers in this emerging field. The new commitment follows on several years of collaborative research among scientists at the two organizations.

Founded in 1968, Fujitsu Laboratories has conducted a wide range of basic and applied research in the areas of next-generation services, computer servers, networks, electronic devices, and advanced materials. CBMM, a multi-institutional, National Science Foundation funded science and technology center focusing on the interdisciplinary study of intelligence, was established in 2013 and is headquartered at MIT’s McGovern Institute for Brain Research. CBMM is also the foundation of “The Core” of the MIT Quest for Intelligence launched earlier this year. The partnership between the two organizations started in March 2017 when Fujitsu Laboratories sent a visiting scientist to CBMM.

“A fundamental understanding of how humans think, feel, and make decisions is critical to developing revolutionary technologies that will have a real impact on societal problems,” said Shigeru Sasaki, CEO of Fujitsu Laboratories. “The partnership between MIT’s Center for Brains, Minds and Machines and Fujitsu Laboratories will help advance critical R&D efforts in both human intelligence and the creation of next-generation technologies that will shape our lives,” he added.

The new Fujitsu Laboratories Co-Creation Research Fund, established with a philanthropic gift from Fujitsu Laboratories, will fuel new, innovative and challenging projects in areas of interest to both Fujitsu and CBMM, including the basic study of computations underlying visual recognition and language processing, creation of new machine learning methods, and development of the theory of deep learning. Alongside funding for research projects, Fujitsu Laboratories will also fund fellowships for graduate students attending CBMM’s summer course from 2019 to contribute to the future of research and society on a long term basis. The intensive three-week course gives advanced students from universities worldwide a “deep end” introduction to the problem of intelligence. These students will later have the opportunity to travel to Fujitsu Laboratories in Japan or its overseas locations in the U.S., Canada, U.K., Spain, and China to meet with Fujitsu researchers.

“CBMM faculty, students, and fellows are excited for the opportunity to work alongside scientists from Fujitsu to make advances in complex problems of intelligence, both real and artificial,” said CBMM’s director Tomaso Poggio, who is also an investigator at the McGovern Institute and the Eugene McDermott Professor in MIT’s Department of Brain and Cognitive Sciences. “Both Fujitsu Laboratories and MIT are committed to creating revolutionary tools and systems that will transform many industries, and to do that we are first looking to the extraordinary computations made by the human mind in everyday life.”

As part of the partnership, Poggio will be a featured keynote speaker at the Fujitsu Laboratories Advanced Technology Symposium on Oct. 9. In addition, Tomotake Sasaki, a former visiting scientist and current research affiliate in the Poggio Lab, will continue to collaborate with CBMM scientists and engineers on reinforcement learning and deep learning research projects. Moyuru Yamada, a visiting scientist in the Lab of Professor Josh Tenenbaum, is also studying the computational model of human cognition and exploring its industrial applications. Moreover, Fujitsu Laboratories is planning to invite CBMM researchers to Japan or overseas offices and arrange internships for interested students.

Immune cell variations contribute to malaria severity

Thu, 10/04/2018 - 2:04pm

At least 250 million people are infected with malaria every year, and about half a million of those die from the disease. A new study from MIT offers a possible explanation for why some people are more likely to experience a more severe, and potentially fatal, form of the disease.

The researchers found that in some patients, immune cells called natural killer cells (NK cells) fail to turn on the genes necessary to effectively destroy malaria-infected red blood cells.

The researchers also showed that they could stimulate NK cells to do a better job of killing infected red blood cells grown in a lab dish. This suggests a possible approach for developing treatments that could help reduce the severity of malaria infections in some people, especially children, says Jianzhu Chen, one of the study’s senior authors.

“This is one approach to that problem,” says Chen, an MIT professor of biology and a member of MIT’s Koch Institute for Integrative Cancer Research. “Most of the malaria patients who die are children under the age of 5, and their immune system has not completely formed yet.”

Peter Preiser, a professor at Nanyang Technical University (NTU) in Singapore, is also a senior author of the study, which appears in the journal PLOS Pathogens on Oct. 4. The paper’s lead authors are NTU and Singapore-MIT Alliance for Research and Technology (SMART) graduate students Weijian Ye and Marvin Chew.

First line of defense

In 2010, Chen and his colleagues engineered strains of mice that produce several types of human immune cells and red blood cells. These “humanized” mice can be used to study the human immune response to pathogens that don’t normally infect mice, such as Plasmodium falciparum, the parasite that causes malaria. 

A few years later, the researchers used those mice to investigate the roles of NK cells and macrophages in malaria infection. These two cell types are key players in the innate immune system, a nonspecific response that acts as the first line of defense against many microbes. Chen and his colleagues found that when they removed human NK cells from the mice and infected them with malaria, the quantity of parasites in the blood was much greater than in mice with NK cells. This did not happen when they removed human macrophages, suggesting that NK cells are the most important first-line defenders against malaria.

A natural killer (NK) cell binds to a malaria-infected red blood cell and destroys it. Credit: Weijian Ye

In that study, the researchers also found that in about 25 percent of the human blood samples they used, the NK cells did not respond to malaria at all. In the new paper, they set out to try to find out why that was the case. To do that, they sequenced the RNA of NK cells before and after they encountered malaria-infected red blood cells. This allowed the researchers to identify a small number of genes that get turned on in malaria-responsive NK cells but not in nonresponsive cells.

Among these genes was one that codes for a protein called MDA5, which was already known to be involved in helping immune cells such as NK cells and macrophages recognize foreign RNA. Further studies revealed that malaria-infected red blood cells secrete tiny bubbles called microvesicles that carry pieces of RNA from the malaria parasite. The studies also showed that NK cells absorb these microvesicles. If MDA5 is present, the NK cell is activated to kill the infected blood cell.

Nonresponsive NK cells, which have lower levels of MDA5, fail to recognize and kill the infected cells. NK cells are also responsible for secreting cytokines that summon T cells and other immune cells, so their failure to activate also hinders other elements of the immune response.

Boosting immunity

Chen and his colleagues also showed that they could activate the nonresponsive NK cells by treating them with a synthetic molecule called poly I:C, which is structurally similar to double-stranded RNA. For poly I:C to be effective, the researchers had to package it into tiny spheres called liposomes, which allow it to enter cells just like the RNA-carrying microvesicles do.

The researchers also found a correlation between the levels of MDA5 in the NK cells and the disease severity experienced by the patients who donated the blood samples. Next, they hope to take cells from human patients and use them to further examine this correlation in humanized mice, and also to explore whether treating the mice with poly I:C would have the same beneficial effect they saw in cells grown in a lab dish.

The research was funded by the National Research Foundation of Singapore through the SMART Interdisciplinary Research Group in Infectious Disease Research Program.

Pages