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News Article | October 23, 2015
Site: news.mit.edu

Twelve new faculty members have been invited to join the ranks of the School of Engineering at MIT. Drawn from institutions and industry around the world, and ranging from distinguished senior researchers to promising young investigators, they will contribute to the research and educational activities of six academic departments in the school and a range of other labs and centers across the Institute. “This year we are welcoming another exceptionally strong group of new faculty to engineering,” says Ian A. Waitz, Dean of the School of Engineering. “They are remarkably accomplished, and their research spans some of the most important and pressing challenges in the world. I can’t wait to see what they do.” The new School of Engineering faculty members are: Mohammad Alizadeh will join the faculty as an assistant professor in the Department of Electrical Engineering and Computer Science in September 2015. He was a principal engineer at Cisco, which he joined through the acquisition of Insieme Networks in 2013. Alizadeh completed his undergraduate degree in electrical engineering at Sharif University of Technology and received his PhD in electrical engineering in 2013 from Stanford University, where he was advised by Balaji Prabhakar. His research interests are broadly in the areas of networked systems, data-center networking, and cloud computing. His dissertation focused on designing high-performance packet-transport mechanisms for data centers. His research has garnered significant industry interest: The Data Center TCP congestion control algorithm has been integrated into the Windows Server 2012 operating system; the QCN algorithm has been standardized as the IEEE 802.1Qau standard; and most recently, the CONGA adaptive load-balancing mechanism has been implemented in Cisco’s new flagship Application Centric Infrastructure products. Alizadeh is a recipient of a SIGCOMM best-paper award, a Stanford Electrical Engineering Departmental Fellowship, the Caroline and Fabian Pease Stanford Graduate Fellowship, and the Numerical Technologies Inc. Prize and Fellowship. Tamara Broderick will start as an assistant professor in electrical engineering and computer science in January 2015. She received a BA in mathematics from Princeton in 2007, a master of advanced study for completion of Part III of the Mathematical Tripos from the University of Cambridge in 2008, an MPhil in physics from the University of Cambridge in 2009, and an MS in computer science and a PhD in statistics from the University of California at Berkeley in 2013 and 2014, respectively. Her recent research has focused on developing and analyzing models for scalable, unsupervised learning using Bayesian nonparametrics. She has been awarded the Evelyn Fix Memorial Medal and Citation (for the PhD student on the Berkeley campus showing the greatest promise in statistical research), the Berkeley Fellowship, a National Science Foundation Graduate Research Fellowship, and a Marshall Scholarship. Michael Carbin will join the Department of Electrical Engineering and Computer Science as an assistant professor in January 2016. His research interests include the theory, design, and implementation of programming systems, including languages, program logics, static and dynamic program analyses, run-time systems, and mechanized verifiers. His recent research has focused on the design and implementation of programming systems that deliver improved performance and resilience by incorporating approximate computing and self-healing. Carbin’s research on verifying the reliability of programs that execute on unreliable hardware received a best-paper award at a leading programming languages conference (OOPSLA 2013). His undergraduate research at Stanford received the Wegbreit Prize for Best Computer Science Undergraduate Honors Thesis. As a graduate student at MIT, he received the MIT-Lemelson Presidential and Microsoft Research Graduate Fellowships. James Collins joined the faculty in the Department of Biological Engineering and as a core member of the Institute for Medical Engineering and Science. Collins received a PhD in mechanical engineering from the University of Oxford and was formerly the William F. Warren Distinguished Professor, university professor, professor of biomedical engineering, and director of the Center of Synthetic Biology at Boston University. He is a world leader in bringing together engineering principles and fundamental biology to make new discoveries and invent systems that can improve the human condition. Collins is among the founders of the field of synthetic biology. Otto X. Cordero will join the Department of Civil and Environmental Engineering as an assistant professor. He received a BS in computer and electrical engineering from the Polytechnic University of Ecuador, and an MS in artificial intelligence and PhD in theoretical biology from Utrecht University. For his dissertation, Cordero worked with Paulien Hogeweg on the scaling laws that govern the evolution of genome size in microbes. While a Netherlands Organization for Scientific Research Postdoctoral Fellow working with Martin Polz, he pursued a study of ecological and social interactions in wild populations of bacteria, and demonstrated the importance of these interactions in generating patterns of diversity and sustaining ecological function. In 2013 Cordero was awarded the European Research Council Starting Grant, the most prestigious career award in Europe, to reconstruct and model networks of ecological interactions that form between heterotrophic microbes in the ocean. Since November 2013, he has been an assistant professor at the Swiss Federal Institute of Technology in Zurich. The main goal of Cordero’s lab is to develop the study of natural microbial communities as dynamical systems, using a combination of experimental and computational approaches. Areg Danagoulian joined the faculty in the Department of Nuclear Science and Engineering (NSE) as an assistant professor in July 2014. He received a BS in physics from MIT and a PhD in experimental nuclear physics from the University of Illinois at Urbana-Champaign. He was a postdoctoral associate at the Los Alamos National Laboratory and subsequently worked as a senior scientist at Passport Systems Inc. Danagoulian’s research interests are focused in nuclear security. He works on problems in the areas of nuclear nonproliferation, technologies for arms-control treaty verification, nuclear safeguards, and nuclear-cargo security. Specific projects include the development of zero-knowledge detection concepts for weapon authentication, and research on monochromatic, tunable sources that can be applied to active interrogation of cargoes. Other areas of research include nuclear forensics and the development of new detection concepts. Danagoulian’s research and teaching will contribute to NSE’s growing program in nuclear security. Ruonan Han joined the electrical engineering and computer science faculty in September as an assistant professor. He is also a core member of the Microsystems Technology Laboratories. He earned his BS from Fudan University in 2007, an MS in electrical engineering from the University of Florida in 2009, and his PhD in electrical and computer engineering from Cornell University in 2014. Han’s research group aims to explore microelectronic-circuit and system technologies to bridge the terahertz gap between microwave and infrared domains. They focus on high-power generation, sensitive detection and energy-efficient systems. Han is the recipient of the Electrical Computing and Engineering Director’s Best Thesis Research Award and Innovation Award from Cornell, the Solid-State Circuits Society Pre-Doctoral Achievement Award and Microwave Theory Techniques Society Graduate Fellowship Award from IEEE, as well as the Best Student Paper Award from IEEE Radio-Frequency Integrated Circuits Symposium. Juejun (JJ) Hu joined the faculty in the Department of Materials Science and Engineering in January 2015 as an assistant professor and as the Merton C. Flemings Career Development Professor of Materials Science and Engineering. He comes to MIT from the University of Delaware, where he was a tenure-track assistant professor. Previously, he was a postdoc in MIT’s Microphotonics Center. As the Francis Alison Young Professor, Hu initiated and led research projects involving environmental monitoring, renewable energy, biological sensing, and optical communications. He received the 2013 Gerard J. Mangone Young Scholars Award, which recognizes promising and accomplished young faculty and is the University of Delaware’s highest faculty honor. His research is in three main areas: substrate-blind multifunctional photonic integration, mid-infrared integrated photonics, and 3-D photonic integrated circuits. Hu’s group has applied photonic technologies to address emerging application needs in environmental monitoring, renewable energy harvesting, communications, and biotechnology. He earned a BS in materials science and engineering from Tsinghua University, and a PhD from MIT. Rafael Jaramillo will join the materials science and engineering faculty as an assistant professor and the Toyota Career Development Professor in Materials Science and Engineering in the summer of 2015. He has a BS summa cum laude and an MEng, both in applied and engineering physics, from Cornell University. He also holds a PhD in physics from the University of Chicago. Jaramillo is currently a senior postdoctoral fellow at MIT in the Laboratory of Manufacturing and Productivity (LMP). His interests in renewable energy and accomplishments in developing materials systems and techniques for energy applications led to him receiving the Energy Efficiency and Renewable Energy Postdoctoral Research Fellowship from the U.S. Department of Energy. Prior to his appointment in LMP, Jaramillo was a postdoctoral fellow at the Harvard University Center for the Environment. His research interests lie at the intersection of solid-state physics, materials science, and renewable energy technologies. Stefanie Jegelka joined the faculty in the electrical engineering and computer science in January 2015. Formerly a postdoctoral researcher in the Department of Electrical Engineering and Computer Science at the University of California at Berkeley, she received a PhD in computer science from the Swiss Federal Institute of Technology in Zurich (in collaboration with the Max Planck Institute for Intelligent Systems in Tuebingen, Germany), and a diploma in bioinformatics with distinction from the University of Tuebingen in Germany. During her studies, she was also a research assistant at the Max Planck Institute for Biological Cybernetics and spent a year at the University of Texas at Austin. She conducted research visits to Georgetown University, the University of Washington, the University of Tokyo, the French Institute for Research in Computer Science and Automation, and Microsoft Research. She has been a fellow of the German National Academic Foundation and its College for Life Sciences, and has received a Google Anita Borg Fellowship, a Fellowship of the Klee Foundation, and a Best Paper Award at the International Conference on Machine Learning. Jegelka organized several workshops on discrete optimization in machine learning, and has held three tutorials on submodularity in machine learning at international conferences. Her research interests lie in algorithmic machine learning. In particular, she is interested in modeling and efficiently solving machine-learning problems that involve discrete structure. She has also worked on distributed machine learning, kernel methods, clustering, and applications in computer vision. Aleksander Madry is a former assistant professor in the Swiss Federal Institute of Technology in Lausanne (EPFL) School of Computer and Communication Sciences and started as an assistant professor in electrical engineering and computer science in February 2015. His research centers on tackling fundamental algorithmic problems that are motivated by real-world optimization. Most of his work is concerned with developing new ideas and tools for algorithmic graph theory, with a particular focus on approaching central questions in that area with a mix of combinatorial and linear-algebraic techniques. He is also interested in understanding uncertainty in the context of optimization — how to model it and cope with its presence. Madry received his PhD in computer science from MIT in 2011 and, prior to joining EPFL, spent a year as a postdoctoral researcher at Microsoft Research New England. His work was recognized with a variety of awards, including the Association for Computing Machinery Doctoral Dissertation Award Honorable Mention, the George M. Sprowls Doctoral Dissertation Award, and a number of best paper awards at Foundations of Computer Science, Symposium on Discrete Algorithms, and Symposium on Theory of Computing meetings. Xuanhe Zhao joined the Department of Mechanical Engineering faculty in September 2014 as an assistant professor. Before joining MIT, he was an assistant professor in the Department of Mechanical Engineering and Materials Science at Duke University. He earned his PhD at Harvard University in 2009. Zhao conducts research on the interfaces between solid mechanics, soft materials, and bio-inspired design. His current research goal is to understand and design new soft materials with unprecedented properties for impactful applications. His current research projects are centered on three bio-inspired themes: artificial muscle (dielectric polymers and electromechanics), tough cartilage (tough and bioactive hydrogels and biomechanics), and transformative skin (functional surface instabilities and thin-film mechanics). Zhao’s discovery of new failure mechanisms of dielectric polymers in 2011 and 2012 can potentially enhance electric energy densities of dielectric elastomers and gels by a factor of 10. In 2012, he designed a new synthetic biocompatible hydrogel with hybrid crosslinking, which achieved fracture toughness multiple times higher than articular cartilage — unprecedented by previous synthetic gels. With fiber reinforcements, Zhao further controlled the modulus of the tough hydrogel over a wide range from a few kilopascals to over 10 megapascals in 2013 and 2014. By harnessing surface instabilities such as wrinkles and creases in 2014, he dynamically varied both surface textures and colors of an electro-mechano-chemically responsive elastomers to achieve the dynamic-camouflage function of cephalopods. This work was highlighted by Nature News, reported by the The Washington Post, and featured on the MIT homepage: “How to hide like an octopus.” Xuanhe is a recipient of the National Science Foundation CAREER Award, Office of Naval Research Young Investigator Program Award, and the Early Career Researchers Award from AVS Biomaterial Interfaces Division.


News Article | March 29, 2016
Site: news.mit.edu

“I’ve never experienced this!” The researcher from Mexico was referring to the 7 degrees Fahrenheit weather outside Building 39 at MIT last month, but his comment might also apply to the outright excitement he and seven colleagues conveyed in recent interviews about their stay at the Institute. The eight faculty and postdocs are here as part of the Tec de Monterrey and MIT Program, a formal relationship established between MIT and the Tecnológico de Monterrey in 2014 and launched in early 2015. The program aims to foster exchanges and collaborations among researchers at both institutions focused on the general area of nanotechnology and nanoscience with the ultimate goal of supporting the Tec in its quest to become a research university. Tecnológico de Monterrey, founded by MIT Class of 1914 graduate Eugenio Garza Sada in 1943 and initially directed by León Álvalos y Vez '29, is one of the largest universities in Latin America with more than 90,000 students. The Tec de Monterrey and MIT Program was established by a gift from the Garza family to honor the 100th anniversary of Eugenio Garza Sada’s graduation from MIT’s Department of Civil and Sanitary Engineering. The exchange program is housed at MIT’s Microsystems Technology Laboratories (MTL), under the leadership of Professor Jesús del Alamo of the Department of Electrical Engineering and Computer Science. A primary goal of the program is to pair professors and postdocs from Monterrey Tec with host faculty at MIT, creating opportunities for them to collaborate on world class-research at the leading edge of their fields. “We are hoping to get really smart, driven and enthusiastic young people,” said del Alamo, with “fruitful collaboration” as the benefit for both schools. As del Alamo described it, the program covers engineering of systems and structures at any scale, with initial emphasis on nanoscience and nanotechnology, “broadly construed.” The inaugural cohort of participants in the Monterrey Tec program includes three faculty and five postdocs who have come to MIT for visits ranging from a semester to the full academic year. In 2016, the program will expand to include graduate students. At the end of five years the program’s focus on nanotechnology will be reviewed, with modifications made as needed, del Alamo said. The visiting Monterrey Tec faculty and postdocs bring expertise in diverse fields, including telecommunications, biotechnology, chemical engineering, mechatronics, molecular biology, microfluidics, acoustics engineering, and more, but in separate interviews they described having similar goals. Many came with a desire to learn more about how their MIT peers think, how they use tools and logic, while others wanted to expand the reach of their own research and that of their home university; in a word, to “grow.” Most emphatically, the visitors expressed a strong desire to forge permanent connections between people at both institutions and to demonstrate the mutual value of these research collaborations. The researchers are working on a range of projects at MTL and MTL-affiliated labs and centers, and talked about their work with unqualified excitement. For example, acoustics engineer David Isaac Ibarra-Zarate described his experience working with Brian Anthony and others in the Medical Electronic Device Realization Center as “since the beginning wonderful.” The researcher’s main goal is to develop a micro-electric system that can deliver acoustic therapies to the ear, and he has been working with a Mexico City hospital to develop protocols for this therapy. Drawn to the project in part for personal reasons (his father has tinnitus), Ibarra-Zarate intends to develop a device, standards, and protocol, and perhaps bring it to market. While at MIT he hopes to complete the first step, which is constructing a prototype. With his signal processing experience, the researcher was also invited to join a project to devise an ultrasound pill that can be swallowed to yield an image of the intestines, and he is hopeful of reaching the prototype stage with this pill as well. Beyond these efforts, he is interested in exploring the brain-computer interface, he said, and in correlating encephalography signals with acoustic sensation and binaural sounds. José González-Valdez vividly described his work in Professor Scott Manalis’s lab at the Koch Institute in a similarly enthusiastic vein. The group is “measuring the weights of exosomes “at a very precise, attogram, scale,” in order to characterize different exosome populations, he said. Exosomes are extracellular vesicles or tiny sacs filled with liquid. The intent is to link one of the exosome populations with the symptoms of patients who have what's known as vestibular schwannoma, a cancer of the cerebellum that can leave people blind or deaf. González-Valdez explained that a group he works with in Mexico has been using chromatography to separate molecules. “There’s a protocol,” he said, “but it’s not that efficient — it’s quite tough to do.” His hope, he continued, is to connect the “exosome people” (in Cambridge) and the “bio-separation people” in Mexico, to continue and broaden this critical effort. Biotechnologist Grissel Trujillo-de Santiago, whose PhD focused on biomaterials, described her work on tissue engineering in Professor Ali Khademhosseini’s lab at the Brigham and Women’s Hospital as “a very powerful experience.” The researcher used the analogy of homespun ingredients — milk and coffee — to explain how she is making use of chaotic flows to develop microstructures that become small pieces of tissue. Trujillo-de Santiago hopes to set up her own group for biomaterials and tissue engineering when she returns to Mexico. “The applications would be infinite — it’s a matter of imagination,” she exclaimed, opening a tablet computer and displaying slides of pink and green fluorescent particles in a polymer solution to illustrate these microstructure platforms. Professor Mario Moisés Alvarez, trained in chemical and biological engineering, is also working in the Khademhosseini Lab, focusing on biotechnology and on biomedical technology projects. His research group at Tecnológico de Monterrey had developed proteins that can be used to detect the Ebola virus, and he spoke of how elated he is to be part of a team here leveraging the use of those protein molecules, in combination with nanoparticles and a microfluidic chamber, to detect and capture Ebola viral particles from a patient’s circulating blood — “at the point at which you can still save a life!” A “microfluidics device designer” is how José Israel Martinez-López describes himself. Trained in electrical engineering and biotechnology and with a PhD in mechatronics and advanced materials, he is working with Professor Jongyoon Han’s group in the Research Laboratory of Electronics (RLE). The large-group environment allows him to “get a glimpse” of topics in related fields, and is proving “very helpful for professional growth,” he said. Martinez-López is helping to devise rapid microfabrication methodologies that will enable developing countries to manufacture devices for disease detection close to the site where the devices are needed, using off-the-shelf materials. The goal is “functionality at low cost,” he stated, stressing the enormous need for these tools. All program participants used high praise to describe their experience working with MIT mentors and lab mates. Daniel Olvera Trejo, a mechatronics engineer specializing in machine processes, vibrations, and tools, is working on projects in the MTL lab of Luis Fernando Velásquez-Garcia. Experienced in conventional microfabrication, the researcher is now exploring even more accurate technologies, such as 3-D printing and stereophotography, to design new devices; for example, tools to control drug release. “People always make time to get you what you need,” he said. One important aspect of his experience in the program has been to see how people at MIT work together across disciplines, said Olvera Trejo. Once home, he hopes to increase collaboration between researchers with expertise in mechanics, chemistry, and manufacturing, and the physicians in Monterrey’s hospital who have applications for new devices. The researchers will return to Mexico by the end of this semester, and they spoke eagerly of what they expect to bring back. “People here are very committed, they are very connected,” said Monterrey Tec Professor Rodrigo Balam Muñoz Soto of his experience in the RLE lab of Professor Joel Voldman, working with pairing-cell devices. A molecular biologist, Muñoz Soto noted that these devices have many potential diagnostic uses, and said that his microfluidics and microsystems work here will have “immediate application” in the molecular diagnostics and immunology courses he is teaching next semester. Monterrey Tec Professor Gerardo Antonio Castañón Avila, a telecommunications engineer by training, has been working on silicon photonics in the research laboratory of Professor Rajeev Ram, using concepts of electronics to design wave guides at the nano level. Researchers at MIT “are working with very relevant problems — and that is difficult to find,” he remarked. There are advantages in coupling photonics with electronics such as is being done here, Avila said, and he plans to set up a nanophotonics lab at Monterrey Tec, where fabrication can be done more easily and products can be tested. Researchers outlined many more goals, such as publishing journal articles on their work here; devising new courses in areas like silicon photonics; increasing the number of point-of-care applications in their work; and translating the experience of MIT’s cross-disciplinary thinking to Monterrey. Several said they plan to invite MIT faculty to Monterrey Tec to lecture on microsystems-related work, and to send ambitious Monterrey graduate students to MIT. Perhaps the most commonly mentioned plan was a human one. As Muñoz Soto emphatically said, “My next goal is to keep the relationship [with MIT] alive!”


News Article | August 22, 2016
Site: news.mit.edu

Duane Boning has been named the Clarence J. LeBel Professor of Electrical Engineering. The chair is named for Clarence Joseph LeBel '26, SM '27, who co-founded Audio Devices in 1937, and was a pioneer in recording discs, magnetic media for tapes, and in hearing aids and stethoscopes. “Boning’s teaching is recognized as outstanding at both the undergraduate and graduate levels, and he is a leader in the field of manufacturing and design,” said Anantha Chandrakasan, the Vannevar Bush Professor of Electrical Engineering and head of the Department of Electrical Engineering and Computer Science (EECS). “This is fitting recognition of his outstanding contributions to research, teaching, mentoring, and service.” Boning’s research focuses on manufacturing and design, with emphasis on statistical modeling, control, and variation reduction in semiconductor, MEMS, photonic, and nanomanufacturing processes. His early work developed computer integrated manufacturing approaches for flexible design of IC fabrication processes. He also drove the development and adoption of run-by-run, sensor-based, and real-time model-based control methods in the semiconductor industry. He is a leader in the characterization and modeling of spatial variation in IC and nanofabrication processes, including plasma etch and chemical-mechanical polishing (CMP), where test mask design and modeling tools developed in his group have been commercialized and adopted in industry. Boning served as editor in chief for the IEEE Transactions on Semiconductor Manufacturing from 2001 to 2011, and was named a fellow of the IEEE for contributions to modeling and control in semiconductor manufacturing in 2005. In addition to creating the graduate-level course 6.780J/2.830J (Control of Manufacturing Process), he has lectured in several core EECS subjects, including 6.003 (Signals and Systems) and 6.001 (Structure and Interpretation of Computer Programs), and is also an outstanding recitation and laboratory instructor. His teaching has been recognized with the MIT Ruth and Joel Spira Teaching Award. Boning won the Best Advisor Award from the MIT ACM/IEEE student organization in 2012 and the 2016 Capers and Marion McDonald Award for Excellence in Mentoring and Advising in the School of Engineering. Boning served as associate head from Electrical Engineering in EECS from 2004 to 2011. He has previously and presently serves as associate director in the Microsystems Technology Laboratories, where he oversees the information technology and computer-aided design services organization in the laboratories. He is a long-standing and active participant in the MIT Leaders for Global Operations program. Since 2011, he has served as the director for the MIT/Masdar Institute Cooperative Program, fostering many joint activities between MIT and Masdar Institute. From 2011 through 2013, he served as founding faculty lead in the MIT Skoltech Initiative, working to launch the Skolkovo Institute of Science and Technology (Skoltech). Within MIT, Boning has served on several Institute committees, including as chair of the Committee on Undergraduate Admissions and Financial Aid (CUAFA) in 2007, and he will serve as chair of the Committee on the Undergraduate Program (CUP) in 2016-2017.


News Article | October 7, 2016
Site: www.biosciencetechnology.com

Microencapsulation, in which a tiny particle of one material is encased within a shell made from another, is widely used in pharmaceuticals manufacturing and holds promise for other areas, such as self-repairing materials and solar power. But most applications of microencapsulation require particles of uniform size, and that’s something that existing fabrication techniques don’t reliably provide. In products with a high profit margin, such as pharmaceuticals, it can be cost effective to mechanically separate particles of the proper size from those that are too large or too small, but in niche or small-margin products, it may not be. In the latest issue of the journal Lab on a Chip, researchers from MIT’s Microsystems Technology Laboratories report a new microencapsulation technique that yields particles of very consistent size, while also affording a high rate of production. Moreover, the devices used to produce the spheres were themselves manufactured with an affordable commercial 3-D printer. The ability to 3-D print fabrication systems would not only keep manufacturing costs low but also allow researchers to quickly develop systems for producing microencapsulated particles for particular applications. “When you print your microsystems, you can iterate them very fast,” says Luis Fernando Velásquez-García, a principal research scientist in the Microsystems Technology Laboratories and senior author on the new paper. “In one year, we were able to make three different generations that are significantly different from one another and that in terms of performance also improve significantly. Something like that would be too expensive and too time consuming with other methods.” Velásquez-García is joined on the paper by Daniel Olvera-Trejo, a postdoc at Mexico’s Tecnológico de Monterrey who was a visiting researcher at MIT under the auspices of a new nanoscience research partnership between the two universities. The researchers’ new system adapts the same core technology that Velásquez-García’s group has previously explored as a means for depositing material on chip surfaces, etching chips, generating X-rays, spinning out nanofibers for use in a huge range of applications, and even propelling nanosatellites. All of these applications rely on dense arrays of emitters that eject fluids, electrons, or streams of ions. The emitters might be conical, cylindrical, or rectangular; etched microscopically or 3-D printed; hollow, like nozzles, or solid. But in all instances, Velásquez-García’s group has used electric fields — rather than, say, microfluidic pumps — to control their emissions. The new emitters are a variant on the hollow 3-D-printed design. But instead of having a single opening at its tip, each emitter has two openings — a hole and a concentric ring. The openings are fed by separate microfluidic channels. If the viscosity and electrical conductivity of the fluids fed through the channels, the strength of the electric field that draws them up, and the length and diameter of the channels are precisely calibrated, the emitters will produce tiny spheres in which the material drawn through the outer ring encases the material drawn through the center hole. According to Velásquez-García, the physics describing the relationship of forces that produces the microcapsules is only around a decade old. Other researchers have built individual emitters that can produce microcapsules, but Velásquez-García’s group is the first to arrange the emitters in a monolithic array — 25 emitters packed onto a chip that’s less than an inch square — while maintaining both efficiency and uniformity. The arrays are also modular in design, so they can be tiled together to produce larger arrays. Pharmaceuticals manufacturers use microencapsulation to protect drugs from degradation before they reach their targets. But researchers have also explored microencapsulation as a way to make self-healing materials: The same stress that causes a material to crack would break the capsules, releasing an epoxy that would patch the crack. There, uniformity of capsule size is crucial to ensure that distributing the capsules throughout the material doesn’t compromise its structural integrity. Dye-sensitized solar cells, another potential application for the new technique, are potentially a cheap alternative to silicon solar cells. They use tiny particles of dye-coated metal suspended in some other material, often a fluid. The dye converts light to electricity, which the metal transmits to electrodes. Preserving an exact ratio of dye-covered surface area to volume of metal maximizes the efficiency of the cell. In their initial experiments, Velásquez-García and Olvera-Trejo used water and sesame oil as their fluids, and the emitters were made from plastic. The resulting microspheres were around 25 micrometers in diameter. There are, however, 3-D printers that use metal or ceramics, which could produce emitters able to tolerate hotter or harsher fluids. To pack the emitter arrays into the smallest possible volume, the researchers used helical fluid channels, which spiral around the interiors of the emitters, minimizing their height. To control the rate of emission, the channels also taper, from 0.7 millimeters at their bases to 0.4 mm at their tips. Such small and complex devices would be virtually impossible to manufacture using standard microfabrication processes, Velásquez-García says. “These devices can only be made if you print them,” Velásquez-García says. “We’re not doing printing because we can. We’re doing printing because it enables something that didn’t exist before that brings very exciting possibilities.” “The full implications of this are so large that it’s not easy to fully appreciate what this could do,” says Roger Howe, a professor of electrical engineering at Stanford University and faculty director of the Stanford Nanofabrication Facility. “It has the possibility of revolutionizing the making of very sophisticated large-area devices. This would be the kind of technology that would allow you to do the Internet of things, to build functionality into structures at much, much lower cost than you could by gluing a silicon chip on. And you could actually have higher performance because the sensing is built into the physical structure.” “My group would be users of this,” he adds. “And many of the faculty using the [Stanford nanofabrication] facility would be very excited to get their hands on this.”


News Article | October 23, 2015
Site: news.mit.edu

Nanofibers — polymer filaments only a couple of hundred nanometers in diameter — have a huge range of potential applications, from solar cells to water filtration to fuel cells. But so far, their high cost of manufacture has relegated them to just a few niche industries. In the latest issue of the journal Nanotechnology, MIT researchers describe a new technique for producing nanofibers that increases the rate of production fourfold while reducing energy consumption by more than 90 percent, holding out the prospect of cheap, efficient nanofiber production. “We have demonstrated a systematic way to produce nanofibers through electrospinning that surpasses the state of the art,” says Luis Fernando Velásquez-García, a principal research scientist in MIT’s Microsystems Technology Laboratories, who led the new work. “But the way that it’s done opens a very interesting possibility. Our group and many other groups are working to push 3-D printing further, to make it possible to print components that transduce, that actuate, that exchange energy between different domains, like solar to electrical or mechanical. We have something that naturally fits into that picture. We have an array of emitters that can be thought of as a dot-matrix printer, where you would be able to individually control each emitter to print deposits of nanofibers.” Nanofibers are useful for any application that benefits from a high ratio of surface area to volume — solar cells, for instance, which try to maximize exposure to sunlight, or fuel cell electrodes, which catalyze reactions at their surfaces. Nanofibers can also yield materials that are permeable only at very small scales, like water filters, or that are remarkably tough for their weight, like body armor. The standard technique for manufacturing nanofibers is called electrospinning, and it comes in two varieties. In the first, a polymer solution is pumped through a small nozzle, and then a strong electric field stretches it out.  The process is slow, however, and the number of nozzles per unit area is limited by the size of the pump hydraulics. The other approach is to apply a voltage between a rotating drum covered by metal cones and a collector electrode. The cones are dipped in a polymer solution, and the electric field causes the solution to travel to the top of the cones, where it’s emitted toward the electrode as a fiber. That approach is erratic, however, and produces fibers of uneven lengths; it also requires voltages as high as 100,000 volts. Velásquez-García and his co-authors — Philip Ponce de Leon, a former master’s student in mechanical engineering; Frances Hill, a former postdoc in Velásquez-García’s group who’s now at KLA-Tencor; and Eric Heubel, a current postdoc — adapt the second approach, but on a much smaller scale, using techniques common in the manufacture of microelectromechanical systems to produce dense arrays of tiny emitters. The emitters’ small size reduces the voltage necessary to drive them and allows more of them to be packed together, increasing production rate. At the same time, a nubbly texture etched into the emitters’ sides regulates the rate at which fluid flows toward their tips, yielding uniform fibers even at high manufacturing rates. “We did all kinds of experiments, and all of them show that the emission is uniform,” Velásquez-García says. To build their emitters, Velásquez-García and his colleagues use a technique called deep reactive-ion etching. On either face of a silicon wafer, they etch dense arrays of tiny rectangular columns — tens of micrometers across — which will regulate the flow of fluid up the sides of the emitters. Then they cut sawtooth patterns out of the wafer. The sawteeth are mounted vertically, and their bases are immersed in a solution of deionized water, ethanol, and a dissolved polymer. When an electrode is mounted opposite the sawteeth and a voltage applied between them, the water-ethanol mixture streams upward, dragging chains of polymer with it. The water and ethanol quickly dissolve, leaving a tangle of polymer filaments opposite each emitter, on the electrode. The researchers were able to pack 225 emitters, several millimeters long, on a square chip about 35 millimeters on a side. At the relatively low voltage of 8,000 volts, that device yielded four times as much fiber per unit area as the best commercial electrospinning devices. The work is “an elegant and creative way of demonstrating the strong capability of traditional MEMS [microelectromechanical-systems] fabrication processes toward parallel nanomanufacturing,” says Reza Ghodssi, a professor of electrical engineering at the University of Maryland. Relative to other approaches, he adds, there is “an increased potential to scale it up while maintaining the integrity and accuracy by which the processing method is applied.”


News Article | December 18, 2015
Site: phys.org

That's because manufacturing MEMS has traditionally required sophisticated semiconductor fabrication facilities, which cost tens of millions of dollars to build. Potentially useful MEMS have languished in development because they don't have markets large enough to justify the initial capital investment in production. Two recent papers from researchers at MIT's Microsystems Technologies Laboratories offer hope that that might change. In one, the researchers show that a MEMS-based gas sensor manufactured with a desktop device performs at least as well as commercial sensors built at conventional production facilities. In the other paper, they show that the central component of the desktop fabrication device can itself be built with a 3-D printer. Together, the papers suggest that a widely used type of MEMS gas sensor could be produced at one-hundredth the cost with no loss of quality. The researchers' fabrication device sidesteps many of the requirements that make conventional MEMS manufacture expensive. "The additive manufacturing we're doing is based on low temperature and no vacuum," says Luis Fernando Velásquez-García, a principal research scientist in MIT's Microsystems Technology Laboratories and senior author on both papers. "The highest temperature we've used is probably 60 degrees Celsius. In a chip, you probably need to grow oxide, which grows at around 1,000 degrees Celsius. And in many cases the reactors require these high vacuums to prevent contamination. We also make the devices very quickly. The devices we reported are made in a matter of hours from beginning to end." For years, Velásquez-García has been researching manufacturing techniques that involve dense arrays of emitters that eject microscopic streams of fluid when subjected to strong electric fields. For the gas sensors, Velásquez-García and Anthony Taylor, a visiting researcher from the British company Edwards Vacuum, use so-called "internally fed emitters." These are emitters with cylindrical bores that allow fluid to pass through them. In this case, the fluid contained tiny flakes of graphene oxide. Discovered in 2004, graphene is an atom-thick form of carbon with remarkable electrical properties. Velásquez-García and Taylor used their emitters to spray the fluid in a prescribed pattern on a silicon substrate. The fluid quickly evaporated, leaving a coating of graphene oxide flakes only a few tens of nanometers thick. The flakes are so thin that interaction with gas molecules changes their resistance in a measurable way, making them useful for sensing. "We ran the gas sensors head to head with a commercial product that cost hundreds of dollars," Velásquez-García says. "What we showed is that they are as precise, and they are faster. We make at a very low cost—probably cents—something that works as well as or better than the commercial counterparts." To produce those sensors, Velásquez-García and Taylor used electrospray emitters that had been built using conventional processes. However, in the December issue of the Journal of Microelectromechanical Systems, Velásquez-García reports using an affordable, high-quality 3-D printer to produce plastic electrospray emitters whose size and performance match those of the emitters that yielded the gas sensors. In addition to making electrospray devices more cost-effective, Velásquez-García says, 3-D printing also makes it easier to customize them for particular applications. "When we started designing them, we didn't know anything," Velásquez-García says. "But at the end of the week, we had maybe 15 generations of devices, where each design worked better than the previous versions." Indeed, Velásquez-García says, the advantages of electrospray are not so much in enabling existing MEMS devices to be made more cheaply as in enabling wholly new devices. Besides making small-market MEMS products cost-effective, electrospray could enable products incompatible with existing manufacturing techniques. "In some cases, MEMS manufacturers have to compromise between what they intended to make, based on the models, and what you can make based on the microfabrication techniques," Velásquez-García says. "Only a few devices that fit into the description of having large markets and not having subpar performance are the ones that have made it." Electrospray could also lead to novel biological sensors, Velásquez-García says. "It allows us to deposit materials that would not be compatible with high-temperature semiconductor manufacturing, like biological molecules," he says. "For sure, the paper opens new technical paths to making gas microsensors," says Jan Dziuban, head of the Division of Microengineering at Wroclaw University of Technology in Poland. "From a technical point of view, the process may be easily adapted to mass fabrication." "But promising results must be proved statistically," he cautions. "Personal experience tells me that plenty of very promising materials for new sensors, utilizing nanostructured materials, which have been published in high-level scientific papers, haven't resulted in reliable products."


News Article | December 18, 2015
Site: news.mit.edu

Microelectromechanical systems — or MEMS — were a $12 billion business in 2014. But that market is dominated by just a handful of devices, such as the accelerometers that reorient the screens of most smartphones. That’s because manufacturing MEMS has traditionally required sophisticated semiconductor fabrication facilities, which cost tens of millions of dollars to build. Potentially useful MEMS have languished in development because they don’t have markets large enough to justify the initial capital investment in production. Two recent papers from researchers at MIT’s Microsystems Technologies Laboratories offer hope that that might change. In one, the researchers show that a MEMS-based gas sensor manufactured with a desktop device performs at least as well as commercial sensors built at conventional production facilities. In the other paper, they show that the central component of the desktop fabrication device can itself be built with a 3-D printer. Together, the papers suggest that a widely used type of MEMS gas sensor could be produced at one-hundredth the cost with no loss of quality. The researchers’ fabrication device sidesteps many of the requirements that make conventional MEMS manufacture expensive. “The additive manufacturing we’re doing is based on low temperature and no vacuum,” says Luis Fernando Velásquez-García, a principal research scientist in MIT’s Microsystems Technology Laboratories and senior author on both papers. “The highest temperature we’ve used is probably 60 degrees Celsius. In a chip, you probably need to grow oxide, which grows at around 1,000 degrees Celsius. And in many cases the reactors require these high vacuums to prevent contamination. We also make the devices very quickly. The devices we reported are made in a matter of hours from beginning to end.” For years, Velásquez-García has been researching manufacturing techniques that involve dense arrays of emitters that eject microscopic streams of fluid when subjected to strong electric fields. For the gas sensors, Velásquez-García and Anthony Taylor, a visiting researcher from the British company Edwards Vacuum, use so-called “internally fed emitters.” These are emitters with cylindrical bores that allow fluid to pass through them. In this case, the fluid contained tiny flakes of graphene oxide. Discovered in 2004, graphene is an atom-thick form of carbon with remarkable electrical properties. Velásquez-García and Taylor used their emitters to spray the fluid in a prescribed pattern on a silicon substrate. The fluid quickly evaporated, leaving a coating of graphene oxide flakes only a few tens of nanometers thick. The flakes are so thin that interaction with gas molecules changes their resistance in a measurable way, making them useful for sensing. “We ran the gas sensors head to head with a commercial product that cost hundreds of dollars,” Velásquez-García says. “What we showed is that they are as precise, and they are faster. We make at a very low cost — probably cents — something that works as well as or better than the commercial counterparts.” To produce those sensors, Velásquez-García and Taylor used electrospray emitters that had been built using conventional processes. However, in the December issue of the Journal of Microelectromechanical Systems, Velásquez-García reports using an affordable, high-quality 3-D printer to produce plastic electrospray emitters whose size and performance match those of the emitters that yielded the gas sensors. In addition to making electrospray devices more cost-effective, Velásquez-García says, 3-D printing also makes it easier to customize them for particular applications. “When we started designing them, we didn’t know anything,” Velásquez-García says. “But at the end of the week, we had maybe 15 generations of devices, where each design worked better than the previous versions.” Indeed, Velásquez-García says, the advantages of electrospray are not so much in enabling existing MEMS devices to be made more cheaply as in enabling wholly new devices. Besides making small-market MEMS products cost-effective, electrospray could enable products incompatible with existing manufacturing techniques. “In some cases, MEMS manufacturers have to compromise between what they intended to make, based on the models, and what you can make based on the microfabrication techniques,” Velásquez-García says. “Only a few devices that fit into the description of having large markets and not having subpar performance are the ones that have made it.” Electrospray could also lead to novel biological sensors, Velásquez-García says. “It allows us to deposit materials that would not be compatible with high-temperature semiconductor manufacturing, like biological molecules,” he says. “For sure, the paper opens new technical paths to making gas microsensors,” says Jan Dziuban, head of the Division of Microengineering at Wroclaw University of Technology in Poland. “From a technical point of view, the process may be easily adapted to mass fabrication.” “But promising results must be proved statistically,” he cautions. “Personal experience tells me that plenty of very promising materials for new sensors, utilizing nanostructured materials, which have been published in high-level scientific papers, haven't resulted in reliable products.”


Home > Press > Nanodevices at one-hundredth the cost: New techniques for building microelectromechanical systems show promise Abstract: Microelectromechanical systems -- or MEMS -- were a $12 billion business in 2014. But that market is dominated by just a handful of devices, such as the accelerometers that reorient the screens of most smartphones. Two recent papers from researchers at MIT's Microsystems Technologies Laboratories offer hope that that might change. In one, the researchers show that a MEMS-based gas sensor manufactured with a desktop device performs at least as well as commercial sensors built at conventional production facilities. In the other paper, they show that the central component of the desktop fabrication device can itself be built with a 3-D printer. Together, the papers suggest that a widely used type of MEMS gas sensor could be produced at one-hundredth the cost with no loss of quality. The researchers' fabrication device sidesteps many of the requirements that make conventional MEMS manufacture expensive. "The additive manufacturing we're doing is based on low temperature and no vacuum," says Luis Fernando Velásquez-García, a principal research scientist in MIT's Microsystems Technology Laboratories and senior author on both papers. "The highest temperature we've used is probably 60 degrees Celsius. In a chip, you probably need to grow oxide, which grows at around 1,000 degrees Celsius. And in many cases the reactors require these high vacuums to prevent contamination. We also make the devices very quickly. The devices we reported are made in a matter of hours from beginning to end." Welcome resistance For years, Velásquez-García has been researching manufacturing techniques that involve dense arrays of emitters that eject microscopic streams of fluid when subjected to strong electric fields. For the gas sensors, Velásquez-García and Anthony Taylor, a visiting researcher from the British company Edwards Vacuum, use so-called "internally fed emitters." These are emitters with cylindrical bores that allow fluid to pass through them. In this case, the fluid contained tiny flakes of graphene oxide. Discovered in 2004, graphene is an atom-thick form of carbon with remarkable electrical properties. Velásquez-García and Taylor used their emitters to spray the fluid in a prescribed pattern on a silicon substrate. The fluid quickly evaporated, leaving a coating of graphene oxide flakes only a few tens of nanometers thick. The flakes are so thin that interaction with gas molecules changes their resistance in a measurable way, making them useful for sensing. "We ran the gas sensors head to head with a commercial product that cost hundreds of dollars," Velásquez-García says. "What we showed is that they are as precise, and they are faster. We make at a very low cost -- probably cents -- something that works as well as or better than the commercial counterparts." To produce those sensors, Velásquez-García and Taylor used electrospray emitters that had been built using conventional processes. However, in the December issue of the Journal of Microelectromechanical Systems, Velásquez-García reports using an affordable, high-quality 3-D printer to produce plastic electrospray emitters whose size and performance match those of the emitters that yielded the gas sensors. Made to order In addition to making electrospray devices more cost-effective, Velásquez-García says, 3-D printing also makes it easier to customize them for particular applications. "When we started designing them, we didn't know anything," Velásquez-García says. "But at the end of the week, we had maybe 15 generations of devices, where each design worked better than the previous versions." Indeed, Velásquez-García says, the advantages of electrospray are not so much in enabling existing MEMS devices to be made more cheaply as in enabling wholly new devices. Besides making small-market MEMS products cost-effective, electrospray could enable products incompatible with existing manufacturing techniques. "In some cases, MEMS manufacturers have to compromise between what they intended to make, based on the models, and what you can make based on the microfabrication techniques," Velásquez-García says. "Only a few devices that fit into the description of having large markets and not having subpar performance are the ones that have made it." Electrospray could also lead to novel biological sensors, Velásquez-García says. "It allows us to deposit materials that would not be compatible with high-temperature semiconductor manufacturing, like biological molecules," he says. For more information, please click If you have a comment, please us. Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.


Home > Press > Manufacturing microspheres: Technique mass-produces uniform, encapsulated particles for pharmaceuticals, many other uses Abstract: Microencapsulation, in which a tiny particle of one material is encased within a shell made from another, is widely used in pharmaceuticals manufacturing and holds promise for other areas, such as self-repairing materials and solar power. But most applications of microencapsulation require particles of uniform size, and that’s something that existing fabrication techniques don’t reliably provide. In products with a high profit margin, such as pharmaceuticals, it can be cost effective to mechanically separate particles of the proper size from those that are too large or too small, but in niche or small-margin products, it may not be. In the latest issue of the journal Lab on a Chip, researchers from MIT’s Microsystems Technology Laboratories report a new microencapsulation technique that yields particles of very consistent size, while also affording a high rate of production. Moreover, the devices used to produce the spheres were themselves manufactured with an affordable commercial 3-D printer. The ability to 3-D print fabrication systems would not only keep manufacturing costs low but also allow researchers to quickly develop systems for producing microencapsulated particles for particular applications. “When you print your microsystems, you can iterate them very fast,” says Luis Fernando Velásquez-García, a principal research scientist in the Microsystems Technology Laboratories and senior author on the new paper. “In one year, we were able to make three different generations that are significantly different from one another and that in terms of performance also improve significantly. Something like that would be too expensive and too time consuming with other methods.” Velásquez-García is joined on the paper by Daniel Olvera-Trejo, a postdoc at Mexico’s Tecnológico de Monterrey who was a visiting researcher at MIT under the auspices of a new nanoscience research partnership between the two universities. Concentric circles The researchers’ new system adapts the same core technology that Velásquez-García’s group has previously explored as a means for depositing material on chip surfaces, etching chips, generating X-rays, spinning out nanofibers for use in a huge range of applications, and even propelling nanosatellites. All of these applications rely on dense arrays of emitters that eject fluids, electrons, or streams of ions. The emitters might be conical, cylindrical, or rectangular; etched microscopically or 3-D printed; hollow, like nozzles, or solid. But in all instances, Velásquez-García’s group has used electric fields — rather than, say, microfluidic pumps — to control their emissions. The new emitters are a variant on the hollow 3-D-printed design. But instead of having a single opening at its tip, each emitter has two openings — a hole and a concentric ring. The openings are fed by separate microfluidic channels. If the viscosity and electrical conductivity of the fluids fed through the channels, the strength of the electric field that draws them up, and the length and diameter of the channels are precisely calibrated, the emitters will produce tiny spheres in which the material drawn through the outer ring encases the material drawn through the center hole. According to Velásquez-García, the physics describing the relationship of forces that produces the microcapsules is only around a decade old. Other researchers have built individual emitters that can produce microcapsules, but Velásquez-García’s group is the first to arrange the emitters in a monolithic array — 25 emitters packed onto a chip that’s less than an inch square — while maintaining both efficiency and uniformity. The arrays are also modular in design, so they can be tiled together to produce larger arrays. Pharmaceuticals manufacturers use microencapsulation to protect drugs from degradation before they reach their targets. But researchers have also explored microencapsulation as a way to make self-healing materials: The same stress that causes a material to crack would break the capsules, releasing an epoxy that would patch the crack. There, uniformity of capsule size is crucial to ensure that distributing the capsules throughout the material doesn’t compromise its structural integrity. Dye-sensitized solar cells, another potential application for the new technique, are potentially a cheap alternative to silicon solar cells. They use tiny particles of dye-coated metal suspended in some other material, often a fluid. The dye converts light to electricity, which the metal transmits to electrodes. Preserving an exact ratio of dye-covered surface area to volume of metal maximizes the efficiency of the cell. Printing possibilities In their initial experiments, Velásquez-García and Olvera-Trejo used water and sesame oil as their fluids, and the emitters were made from plastic. The resulting microspheres were around 25 micrometers in diameter. There are, however, 3-D printers that use metal or ceramics, which could produce emitters able to tolerate hotter or harsher fluids. To pack the emitter arrays into the smallest possible volume, the researchers used helical fluid channels, which spiral around the interiors of the emitters, minimizing their height. To control the rate of emission, the channels also taper, from 0.7 millimeters at their bases to 0.4 mm at their tips. Such small and complex devices would be virtually impossible to manufacture using standard microfabrication processes, Velásquez-García says. “These devices can only be made if you print them,” Velásquez-García says. “We’re not doing printing because we can. We’re doing printing because it enables something that didn’t exist before that brings very exciting possibilities.” ### Written by Larry Hardesty, MIT News Office For more information, please click If you have a comment, please us. Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.


News Article | December 7, 2016
Site: news.mit.edu

Henry I. Smith, professor emeritus of electrical engineering, has been awarded the 2017 IEEE Robert N. Noyce Medal in recognition of his “contributions to lithography and nanopatterning through experimental advances in short-wavelength exposure systems and attenuated phase-shift masks.” The Noyce Medal honors exceptional contributions to the microelectronics industry, and was established in 1999 in honor of Robert N. Noyce, founder of the Intel Corporation and inventor of the integrated circuit. Recipients are judged on the basis of their leadership in the field, research contributions, originality, breadth and inventive value among other criteria. Smith is known for a number of innovations in nanoscale science and engineering, including: X-ray lithography, the attenuating phase shifter, interference lithography, immersion photolithography, zone-plate-array lithography, graphoepitaxy, and a variety of quantum-effect, short-channel, single-electron and microphotonic devices. Smith founded the NanoStructures Laboratory (NSL) in the Research Laboratory of Elelctronics, and was an affiliate of the Microsystems Technology Laboratories. He held the Joseph F. and Nancy P. Keithley Chair from 1990 to 2005. He is also a fellow of the American Academy of Arts and Sciences, the National Academy of Inventors, the International Society for Nanomanufacturing, the IEEE, and the OSA, and he is a member of the National Academy of Engineering. “Hank’s work with colleagues in the NSL has made a lasting impact in the field of nanofabrication,” says Anantha Chandrakasan, head of the Department of Electrical Engineering and Computer Science. “The Robert N. Noyce Medal is well-deserved recognition of his many contributions to the microelectronics industry.”

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