Planes, trains and automobiles: faster, stronger, lighter

New technique advances carbon-fiber composites.

Postdoc Stephen Steiner (right) and graduate student Richard Li are part of the research team. Photo: David Castro-Olmedo/MIT

These days, aerospace engineering is all about the light stuff: building airplanes with lighter wings, fuselage and landing gear in an effort to reduce fuel costs. Advanced carbon-fiber composites have been used in in aircraft like the Boeing 787 and Airbus A380, reducing their weight by 20 percent.

Carbon fibers coated with nanotubes.

For the next generation of commercial jets, researchers are looking to even stronger and lighter materials, such as composites made with carbon fibers coated with carbon nanotubes — tiny tubes of crystalline carbon. But a significant hurdle to achieving such composites lies at the nanoscale: Scientists who have tried growing carbon nanotubes on carbon fibers have found that doing so significantly degrades the underlying fibers, stripping them of their inherent strength.

Now a team from MIT has identified the root cause of this fiber degradation, and devised techniques to preserve the fibers’ strength. “Up until now, people were basically improving one part of the material but degrading the underlying fiber, and it was a trade-off, you couldn’t get everything you wanted,” says Brian Wardle, an associate professor of aeronautics and astronautics at MIT. “With this contribution, you can now get everything you want.”

A paper detailing the results by Wardle and his colleagues is published in the journal ACS Applied Materials and Interfaces. Co-authors are postdoc Stephen Steiner, who contributed to the research as a graduate student, and Richard Li, a graduate student who was an undergraduate in Wardle’s lab. Read more at the MIT News Office.

Robert C. Armstrong named director of MIT Energy Initiative

Outgoing director Ernest Moniz confirmed as U.S. Secretary of Energy.

Robert C. Armstrong will be the new director of the MIT Energy Initiative. Photo: Justin Knight

May 16, 2013
MIT announced today that Robert C. Armstrong will be the new director of the MIT Energy Initiative (MITEI), as outgoing director Ernest Moniz leaves the Institute to head the U.S. Department of Energy. Moniz was confirmed as Secretary of Energy today by the U.S. Senate, 97-0. Moniz was nominated on March 4.

Armstrong has served as the deputy director of MITEI since its founding six years ago. He was co-chair (with Moniz) of the Energy Research Council that laid the groundwork for MITEI and set its guiding principles. Armstrong has since played a leading role in the Initiative’s development, alongside Moniz. He is the Chevron Professor of Chemical Engineering, and has been a member of the MIT faculty since 1973.

Read more at the MIT News Office.

Team observes real-time charging of a lithium-air battery

Imaging reveals what happens during charging; could lead to improved batteries for electric cars.

David L. Chandler, MIT News Office
May 13, 2013

MIT graduate researchers Robert Mitchell and Betar Gallant connect a Li-air battery used to prepare the samples for in-situ Transmission Electron Microscope (TEM) characterization. Photo: Jin Suntivich

One of the most promising new kinds of battery to power electric cars is called a lithium-air battery, which couldstore up to four times as much energy per pound as today’s best lithium-ion batteries. But progress has been slow: The nature of the electrochemical reactions as these batteries are charged remains poorly understood.

Researchers at MIT and Sandia National Laboratories have used transmission electron microscope (TEM) imaging to observe, at a molecular level, what goes on during a reaction called oxygen evolution as lithium-air batteries charge; this reaction is thought to be a bottleneck limiting further improvements to these batteries. The TEM technique could help in finding ways to make such batteries practical in the near future.

The work is described in a Nano Letters paper by Robert Mitchell, who recently received a PhD in materials science and engineering from MIT; mechanical engineering PhD student Betar Gallant; Carl Thompson, the Stavros Salapatas Professor of Materials Science and Engineering; Yang Shao-Horn, the Gail E. Kendall Associate Professor of Mechanical Engineering and Materials Science and Engineering; and four other authors. Read more at the MIT News Office.

Funding clean-energy solutions

MIT’s Clean Energy Prize awards more than $300,000 to support green startups and technologies.

The sixth annual MIT Clean Energy Prize (CEP) competition, held Monday, May 6, awarded a total of $320,000 to five teams that have developed clean-energy startups and innovations.

The contest, co-sponsored by Massachusetts utility NSTAR and the U.S. Department of Energy (DOE) and open to teams from any American university, is the nation’s leading student-run energy business-plan competition. Past participants have gone on to raise a total of $130 million in funding.

One team, Picasolar, took home both grand prizes: the DOE Energy Efficiency and Renewable Energy Clean Energy Prize, worth $100,000, and the NSTAR MIT Clean Energy Prize, worth $150,000. Read more at the MIT News Office.

Steelmaking, a major emitter of climate-altering gases, could be transformed by a new process developed at MIT.

Antoine Allanore, left, and Donald Sadoway. Photo: M. Scott Brauer

The new process even carries a couple of nice side benefits: The resulting steel should be of higher purity, and eventually, once the process is scaled up, cheaper. Donald Sadoway, the John F. Elliott Professor of Materials Chemistry at MIT and senior author of a new paper describing the process, says this could be a significant “win, win, win” proposition.

The paper, co-authored by Antoine Allanore, the Thomas B. King Assistant Professor of Metallurgy at MIT, and former postdoc Lan Yin (now a postdoc at the University of Illinois at Urbana-Champaign), has just been published in the journal Nature.

Physics and Chemistry of Ionically-Active Solids

Sergei V. Kalinin

Sergei V. Kalinin, senior research staff member at Oak Ridge National Laboratory, will deliver a Nuclear Science and Engineering Faculty Seminar at MIT on Monday, May 13, about high-resolution studies of vacancy dynamics in simple oxides. His talk, "Physics and Chemistry of Ionically-Active Solids: 
from Mesoscopic to Atomic Scales," will be held at 12 p.m in Building 4, Room 159. (Pizza and refreshments start at 11:45 a.m.)

Properties and functionality of correlated oxides are intrinsically controlled by the oxygen and cation stochiometries that directly couple to the oxidation state of a transition metal, induce structural and metal-insulator transitions, and govern magnetic and transport properties. Both structural and electronic aspects of these behaviors are currently of interest for energy generation and storage applications, and are uniquely accessible through high-resolution probe-based studies. Kalinin will discuss several examples of high-resolution studies of the mechanisms of coupled electronic (metal-insulator, superconductive) and ferroic (ferro- and antiferroelastic, ferro and antiferroelectric) transitions from atomistic to mesoscopic scales enabled by combination of the ex-situ and in-situ Pulsed Laser Deposition growth with atomic resolution Scanning Tunneling Microscopy and Spectroscopy.

Kalinin is theme leader for Electronic and Ionic Functionality at the Center for Nanophase Materials Sciences at Oak Ridge National Laboratory, adjunct faculty at Pennsylvania State University and Sung Kyun Kwan University (South Korea) and professor at the Bredesen Center for Interdisciplinary Research and Education at the University of Tennessee, Knoxville. He received his Ph.D. in materials science at the University of Pennsylvania in 2002.

Driving Technological Surprise: An Enduring Mission in a Changing World

DARPA Director Arati Prabhakar

Dr. Arati Prabhakar, the director of the U.S. Defense Advanced Research Projects Agency (DARPA), will speak at MIT on Thursday, May 9, about the need to protect research spending and the agency’s role in national security. Her talk will be held from 1:45 to 2:45 p.m. in Building 54, Room 100, at MIT.

DARPA’s efforts to stay on the leading technological edge can create projects that sound more like science fiction than reality, leading to cyclical criticism about the advisability of specific projects from lawmakers. But it may be that approach is what differentiates the agency and has made it so successful.

Dr. Prabhakar first joined DARPA as a program manager in 1986, and initiated and managed programs in advanced semiconductor technology and flexible manufacturing, as well as demonstration projects to insert new semiconductor technologies into military systems. As the founding director of DARPA’s Microelectronics Technology Office, she led a team of program managers whose efforts spanned these areas, as well as optoelectronics, infrared imaging and nanoelectronics.

Dr. Prabhakar received her Ph.D. in applied physics and M.S. in electrical engineering from the California Institute of Technology, and is a Fellow of the Institute of Electrical and Electronics Engineers, a Texas Tech Distinguished Engineer and a Caltech Distinguished Alumna. Her talk at MIT is sponsored by CSAIL, MTL and RLE.

MIT Physicist Liang Fu receives federal research award

LIANG FU

Liang Fu, Assistant Professor in the MIT Physics Department, is receiving an Early Career Research award for his work on topological insulators, the U.S. Department of Energy’s Office of Science announced Tuesday.

Nationally, 61 scientists will share in awards totaling $15.3 million, but specific awards for individual researchers are still to be negotiated. Fu is expected to receive a total of $750,000 over five years.

DOE’s Science Office will fund Fu’s research on “Predictive Theory of Topological States of Matter.” The Materials Processing Center at MIT will manage the award. Read more.

‘The place I needed to be’

An early passion for mechanical engineering drew first‑generation student Madeline Salazar to MIT.

Last fall, Madeline Salazar and her teammates developed an ocean rescue device called SkyBeacon as part of mechanical engineering course 2.009 (Product Engineering Processes). Photo: Allegra Boverman

During her free time back in high school, Madeline Salazar was often surrounded by piles of balsa wood in her house in East Los Angeles, sanding down her carefully designed bridges for engineering competitions.

“I remember being a real nerd about my bridges; I had this whole rack with all the supplies to make bridges,” she laughs. “It was a mess in my house in those days.”

Now a senior at MIT, Salazar always excelled in school: Her parents, who emigrated from Mexico in search of greater opportunity for their family, encouraged her. “Although I’m a first-generation student, my parents really valued education,” Salazar says. “From the moment we started school, there were very high expectations for me and my younger sister.”

But the dropout rate in her high school was 60 percent; many of Salazar’s own friends didn’t graduate. “I want to say that I wasn’t influenced by that, but I was; it was really hard,” she says. “There are some opportunities that others may have had that I just didn’t.”

Salazar took advantage of the opportunities that were available to her, including the Women’s Technology Program at MIT during the summer after her junior year.

That first experience at MIT solidified Salazar’s dream. “It just felt so good; it was the place I needed to be,” she says. “I knew I wanted to be a mechanical engineer.” Read more at the MIT News Office.

Glass Lab Mother's Day Sale May 6-7

The MIT Glass Lab's 2013 Mother's Day Sale will be held on Monday, May 6, from 10 a.m. to 8 p.m., and Tuesday, May 7, from 10 a.m. to 5 p.m., in Lobby 10.

The sale will feature a variety of items (everything except pumpkins) made by students and instructors in the Glass Lab. A portion of the proceeds goes towards supporting the lab.

Payment by cash and check. Help conserve resources and protect the environment by bringing a reusable shopping bag with you. (Newspaper or plastic shopping bags donations also welcome. Read more at MIT Glass Lab.

Cheaters Lessen Colony Survival Under Stress in Yeast Experiment

MIT researchers study freeloaders in first lab demonstration of an evolutionary-ecological feedback loop in a social microbial population

Yeast study chart shows spiraling effect of mixed strains of cooperators and cheaters moving either toward extinction or equilibrium. Image: Gore Lab/PLOS Biology

In the first laboratory demonstration of an evolutionary-ecological feedback loop in a social, or cooperative, microbial population, MIT Postdoctoral Associate Alvaro Sanchez and MIT Assistant Professor of Physics Jeff Gore found that as the percentage of consumers grew relative to producers, they followed a spiral path toward equilibrium. Each single-celled yeast organism of the variety they studied – Saccharomyces cerevisiae or baker’s yeast – consumes only about 1 percent of the glucose it produces and releases the other 99 percent, creating creates an opportunity for cheater cells, which lack the invertase gene, to consume the glucose. The cheater cells reproduce at a faster rate than cooperator cells and soon outnumber them. But the study showed in the majority of cheater-dominated yeast colonies a sudden shock to the system led to rapid extinction, while all of the pure cooperator populations survived. The findings are published in the PLOS Biology article, “Feedback between population and evolutionary dynamics determines the fate of social microbial populations.”

“The experiments of Sanchez and Gore beautifully illustrate the central dilemma in the evolution of cooperation. The yeast society depends on cooperation, but if cooperation is plentiful, ‘cheaters’ can exploit the generosity of others. This leads to cycles of cooperation and exploitation,” co-author Benjamin Allen, Assistant Professor of Mathematics at Emmanuel College, said in  an accompanying paper in PLOS Biology. Read more.

Unleashing oxygen

The MIT team used a scanning tunneling microscope (STM) to study the electrical activity of a superlattice material composed of two different compounds of the elements strontium, lanthanum and cobalt. At bottom, a diagram of how they "sliced" the material on an angle to expose wider bands of the thin layers of material. The center two images show the resulting measurements of the surface topography of the material, and the activity of electrons moving through it. At top, a diagram of the molecular structures of the two compounds. Graphic courtesy of Chen et al

‘Superlattice’ structure could boost  oxygen reaction in fuel cells, increasing potential power.

New research at MIT could dramatically improve the efficiency of fuel cells, which are considered a promising alternative to batteries electronic devices, cars and homes. Fuel cells make electricity by combining hydrogen, or hydrocarbon fuels, with oxygen. But the most efficient types, called solid oxide fuel cells (SOFC), have drawbacks such as high operating temperatures above 700 degrees Celsius (roughly 1,300 degrees Fahrenheit). Now, MIT researchers have unraveled the properties of a promising alternative material structure for a key component of these devices.

The new structure, a “superlattice” of two compounds interleaved at a tiny scale, could serve as one of the two electrodes in the fuel cell. The complex material – LSC113/214 – is composed of two oxides of the elements lanthanum, strontium and cobalt. While one of the oxides was already known as an especially good material for such electrodes, the combination of the two is far more potent in promoting oxygen reduction than either oxide alone. The interfaces between these two oxides were thought to be the key, but until now, no one had been able to observe the LSC113/214 interface properties in operation, at sufficiently high resolution, to figure out why it worked so well.

Oxygen reduction is one of two main reactions in a fuel cell, and the one that has limited their overall performance — so finding improved materials for that reaction could be a key advance for fuel cells, the researchers say. The new findings are published in the journal Advanced Energy Materials in a paper co-authored by graduate student Yan Chen, professors Harry Tuller and Bilge Yildiz, and three other researchers at MIT. Read more at the MIT News Office.

‘He was truly one of us’

Thousands of law enforcement officials join the MIT community in honoring fallen officer Sean Collier.

Helicopters fly over as the MIT Police are joined by Vice President Joe Biden, members of the MIT community, and law enforcement officers from across the country to pay respects to MIT Patrol Officer Sean Collier. Photo by Dominick Reuter for MIT. Copyright 2013, Dominick Reuter

April 24, 2013
David L. Chandler, MIT News Office
Thousands of police officers from around the nation and world gathered alongside a similar number of MIT students, faculty and staff today to honor a young MIT Police officer, Sean Collier, who was killed in the line of duty last week.

The memorial service, held at MIT’s Briggs Field on a beautiful spring day, drew a crowd estimated at more than 10,000. It featured remarks by MIT President L. Rafael Reif, MIT Police Chief John DiFava, U.S. Vice President Joe Biden, U.S. Sen. Elizabeth Warren, and a brother of the slain officer.

Reif recalled that Collier, 27, had “a deep, broad, beautiful sense of what his duty involved.

“Officer Collier did not just have a job at MIT — he had a life here,” the president said in solemn, measured remarks. “In just 15 months, he built a life with us that was rich in friendship and shared adventure.”

“MIT is a place that celebrates passionate curiosity,” Reif added. “And Sean Collier fit right in.”

Read more at the MIT News Office.

Congratulations to the 2013 Summer Scholars! This year's Summer Scholar Internship Program will run from June 9 - August 10, 2013.

For more information about the Internship Program please refer to the Summer Scholar Quick Facts, the FAQ portion of our website.

Early warning signs of population collapse

Spatial measurements of population density could reveal when threatened natural populations are in danger of crashing.

MIT physicists studied early signs of population collapse in the yeast Saccharomyces cerevisiae. Image: Wikimedia Commons/Masur

Last year, MIT physicists demonstrated that they could measure a population’s risk of collapse by monitoring how fast it recovers from small disturbances, such as a food shortage or overcrowding. However, this strategy would likely require many years of data collection — by which time it could be too late to save the population.

In a paper appearing in the April 10 online edition of Nature, the same research team describes a new way to predict the risk of collapse, based on variations in population density in neighboring regions. Such information is easier to obtain than data on population fluctuations over time, making it potentially more useful, according to the researchers.

“Spatial data are more accessible,” says Lei Dai, an MIT graduate student in physics and lead author of the study. “You can get them by satellite images, or you could just go out and do a survey.” Read more at the MIT News Office.

Living in a Material World

Report finds materials manufacturers will likely be unable to meet targets for carbon-emissions reductions by 2050.

Image: Christine Daniloff/MIT

A new report by researchers at MIT and elsewhere finds that global makers of steel, cement, paper and aluminum are making great strides in energy efficiency but may be reaching their thermodynamic limits, reducing available options to make them significantly more efficient. As a result, materials manufacturing might be unable to meet the energy-reduction targets implied by the Intergovernmental Panel on Climate Change.

The panel has suggested a 50 percent reduction in carbon-dioxide emissions by 2050 from materials makers as a means of avoiding further climate change, while economists estimate that global demand for materials will double during the same period.

To reduce energy use by 50 percent while doubling the output of materials, the team — led by graduate student Sahil Sahni and Tim Gutowski, a professor of mechanical engineering at MIT — studied whether manufacturing processes could improve in efficiency by 75 percent. Even in the most aggressive scenario, the team found it was only able to reduce energy use by about 50 percent — far short of its 75 percent goal.

Read more at the MIT News Office.

A new understanding of metallic glass

Simulations reveal that the formation of some glassy materials is like the setting of a bowl of gelatin.

In a 50/50 mix of copper and niobium, regions that are richer in copper separate from regions that are richer in niobium. The interface between these two kinds of regions forms an irregular sponge-like surface, shown in this visualization in green. While most of the material is disordered (making it a glass), small collections of atoms at the boundary zone (shown in gray) form a stiff interconnected network, giving the material greater strength. Photo - Image courtesy of the researchers

Gelatin sets by forming a solid matrix full of random, liquid-filled pores — much like a saturated sponge. It turns out that a similar process also happens in some metallic glasses, substances whose molecular behavior has now been clarified by new MIT research detailing the “setting” of these metal alloys.

The research is published this week in the journal Physical Review Letters, in a paper co-authored by assistant professor of materials science and engineering Michael Demkowicz and graduate student Richard Baumer. It addresses one of the “grand challenges” in physics, Demkowicz says: understanding what happens during what is known as the “glass transition” in materials, when their molecular structure settles into a disordered, yet solid, state.

“It was a serendipitous discovery,” Demkowicz says. Read more at the MIT News Office.

Gore wins $1.13 million NIH grant

Award will fund study into evolution of antibiotic-resistance in bacteria

The research addresses the rise in antibiotic resistance among bacteria to the most widely used class of antibiotic medicines, called beta-lactam antibiotics. Bacteria can develop resistance to antibiotics like penicillin by expressing an enzyme, beta-lactamase, which inactivates the antibiotic.

“We hypothesize that a tightly integrated combination of experiment and modeling will provide novel insight into how the cooperative nature of bacterial growth in beta-lactam antibiotics influences the evolution of antibiotic resistance,” Gore said in his NIH application. “The proposed studies will provide insight into the evolution of antibiotic resistance and cooperative behaviors more generally.”

The Research Project Grant (R01) is the oldest NIH grant program. The first-year allocation of $283,311 for the NIH R01 award begins April 1, 2013. Read more

Jarillo-Herrero, Lu named ONR Young Investigators

Two assistant professors at MIT are among 16 recipients nationwide.

The Navy’s Office of Naval Research (ONR) has named two assistant professors at MIT among its 16 new Young Investigators: Pablo Jarillo-Herrero, the Mitsui Career Development Assistant Professor in Contemporary Technology in the Department of Physics, and Timothy Lu, the Henry L. and Grace Doherty Assistant Professor in Ocean Utilization in the Department of Electrical Engineering and Computer Science.

Jarillo-Herrero and Lu were selected from among hundreds of applicants for the honor, which includes a three-year research grant worth up to $510,000. Jarillo-Herrero’s work under the program will be on “Quantum Transport and Optoelectronics in Atomically Layered Materials;” his funds will be managed by the Materials Processing Center at MIT. Read more at the MIT News Office.

New solar-cell design based on dots and wires

MIT researchers improve efficiency of quantum-dot photovoltaic system by adding a forest of nanowires.

Scanning Electron Microscope images show an array of zinc-oxide nanowires (top) and a cross-section of a photovoltaic cell made from the nano wires, interspersed with quantum dots made of lead sulfide (dark areas). A layer of gold at the top (light band) and a layer of indium-tin-oxide at the bottom (lighter area) form the two electrodes of the solar cell. Image courtesy of Joel Jean, et. al./Advanced Materials

Using exotic particles called quantum dots as the basis for a photovoltaic cell is not a new idea, but attempts to make such devices have not yet achieved sufficiently high efficiency in converting sunlight to power. A new wrinkle added by a team of researchers at MIT — embedding the quantum dots within a forest of nanowires — promises to provide a significant boost.

A solar cell’s absorbing layer needs to be thin to allow charges to pass readily from the sites where solar energy is absorbed to the wires that carry current away — but it also needs to be thick enough to absorb light efficiently. Improved performance in one of these areas tends to worsen the other, says Joel Jean, a doctoral student in MIT’s Department of Electrical Engineering and Computer Science (EECS). “You want a thick film to absorb the light, and you want it thin to get the charges out,” he says. “So there’s a huge discrepancy.”

That’s where the addition of zinc oxide nanowires can play a useful role, says Jean, who is the lead author of a paper to be published in the journal Advanced Materials. Read more at the MIT News Office.

MPC Director Carl V. Thompson visits Myanmar campus

Presents seminar at Yangon Technological University

MIT Prof. Carl V. Thompson gave a seminar on Materials for Micro- and Nano-Systems at Yangon Technological University in Yangon, Myanmar, March 17, 2013. Photo courtesy of Frontiir

March 18, 2013
Professor Carl V. Thompson, Stavros Salapatas Professor of Materials Science and Engineering and Director of the Materials Processing Center at the Massachusetts Institute of Technology, presented a seminar on Materials for Micro- and Nano-Systems on Sunday, March 17, 2013, at Yangon Technological University in Yangon, Myanmar.

Thompson also spoke about potential collaboration between MIT and Yangon Technological University.

Thompson's visit, likely the first to the Yangon campus by an MIT faculty member since the 1950s, coincided with a ribbon-cutting ceremony for a new WiFi and backhaul network. Read more.

MIT materials engineering top graduate program in U.S.

From left: Postdoc Alexis Grimaud, mechanical engineering graduate student David Kwabi and materials science and engineering graduate student Kelsey Stoerzinger work in the laboratory of Associate Professor Yang Shao-Horn, the Electrochemical Energy Lab. Photo: Jin Suntivich

March 12, 2013
Extending a decades-long run, MIT’s graduate program in engineering has again been ranked No. 1 in the country by U.S. News & World Report. MIT has held the top spot since 1990. U.S. News awarded MIT a score of 100 among graduate programs in engineering, followed by No. 2 Stanford University (95) and No. 3 University of California at Berkeley (87).

MIT’s graduate programs led U.S. News lists in seven engineering disciplines, up from four No. 1 rankings last year. Top-ranked programs at MIT this year are:

• aerospace engineering (tied with Caltech);
• chemical engineering;
• materials engineering;
• computer engineering;
• electrical engineering (tied with Stanford)
• mechanical engineering (tied with Stanford)
• nuclear engineering.

The MIT Sloan School of Management ranked first for three programs: information systems, production/operations, and supply chain/logistics among the nation’s top business schools.

Read more at the MIT News Office.

Cutting through the fog

New surface coating for glass could eliminate image distortion caused by condensation and also prevent frost buildup.

A team of MIT researchers has developed such a fog-resistant coating that doesn't distort. Still from video: Melanie Gonick, MIT News Office

Preventing glass from fogging or frosting is a longstanding challenge with myriad applications: eyeglasses, cameras, microscopes, mirrors and refrigerated displays, to name but a few. While there have been many advances in meeting this challenge, so far there has been no systematic way of testing different coatings and materials to see how effectively they work under real-world conditions.

Now, a team of MIT researchers has developed such a testing method, and used it to find a coating that outperforms others not only in preventing foggy buildups, but also in maintaining good optical properties without distortion.

The new approach is detailed in a paper in the journal ACS Nano, written by Michael Rubner, the TDK Professor of Polymer Materials Science and Engineering; Robert Cohen, the Raymond A. and Helen E. St. Laurent Professor of Chemical Engineering; doctoral student Hyomin Lee; and recent MIT graduate Maria Alcaraz.

Read more at the MIT News Office

MIT’s Ernest J. Moniz nominated Secretary of Energy

President Obama’s pick is head of the MIT Energy Initiative and a former undersecretary of energy.

Ernest Moniz, the Cecil and Ida Green Professor of Physics and Engineering Systems and director of the MIT Energy Initiative. Photo: Justin Knight

“President Obama has made an excellent choice in his selection of Professor Moniz as Energy Secretary,” said MIT President L. Rafael Reif.

At MIT, Moniz has also served previously as head of the Department of Physics and as director of the Bates Linear Accelerator Center. His principal research contributions have been in theoretical nuclear physics and in energy technology and policy studies. He has been on the MIT faculty since 1973.

Read more at the MIT News Office.

Allen Family Foundation grants Gore $1.5 million for research

MIT Assistant Professor of Physics Jeff Gore in his lab with Tecan Freedom Evo pipetting robot that will be used to study evolution of cooperative behaviors in single-celled yeast. Photo: Denis Paiste

MIT Assistant Professor of Physics Jeff Gore is getting a $1.5 million awglasard to conduct research into the evolutionary origins of cooperation by applying game theory to how  single-celled yeast make decisions about consuming and sharing sugar, the Paul G. Allen Family Foundation announced Thursday.

Gore’s project, “Microbial studies of cellular decision-making: game theory and the evolutionary origins of cooperation,” will apply game theory to analysis of sugar consumption among yeast as a model biological system.

The work will examine probabilistic or mixed strategies among yeast and the evolution of cooperative behaviors in the consumption of two different sugars, galactose and glucose. “Even genetically identical cells placed in some environment will often not all do the same thing,” Gore said. In particular, some will turn on a particular gene while others will not. Read more.

‘Invisible’ particles could enhance thermoelectric devices

New approach could improve the efficiency of devices that harness power from temperature differences.

This diagram shows one of the core-shell nanoparticles embedded in a host material, as described in a paper in Advanced Materials. The motion of electrons, as shown by brown lines, is bent in such a way that they appear to be unaffected by the presence of the particle, thus allowing them to pass with little resistance. Image courtesy of the researchers

A new way of enhancing the efficiency of thermoelectric devices, developed by researchers at MIT and Rutgers University, could lead to harnessing waste heat from power plants and engines.

The new work, by mechanical engineering professor Gang Chen, Institute Professor Mildred Dresselhaus, graduate student Bolin Liao, and recent postdoc Mona Zebarjadi and research scientist Keivan Esfarjani (both of whom are now on the faculty at Rutgers), has been published in the journal Advanced Materials.

The group’s earlier work showed nanoscale materials could have properties significantly different from larger chunks of the same material, work that involved tiny particles of one material embedded in another, forming nanocomposites. The latest work continues that research, tuning the composition, dimensions and density of the embedded nanoparticles to maximize the thermoelectric properties of the material.

Read more at the MIT News Office.

Duflo, Lander, Lewin to lead spring-semester MITx course

EdX takes stock of last semester’s MITx courses;
data will be used to improve education online and in the classroom.

MIT professors Esther Duflo, Eric Lander and Walter Lewin will lead three new MITx courses this spring, joining three existing MITx courses that will be offered again this semester.

The new MITx courses were announced recently by edX, the free online-education platform created last May by MIT and Harvard University. EdX also said that courses on its platform have now attracted more than 600,000 registrants from around the world.

Esther Duflo, Eric Lander and Walter Lewin. Photos: Peter Tenzer; Rick Friedman; Dominick Reuter

This spring, there will be 15 new courses on edX — including the first offerings in the humanities and social sciences — from MITx, HarvardX and BerkeleyX, in addition to reprises of 10 existing courses from these three universities.

MITx’s new courses this semester are 7.00x (Introduction to Biology: “The Secret of Life”), led by Lander; 8.02x (Electricity and Magnetism), led by Lewin; and 14.73x (The Challenges of Global Poverty), led by Duflo.

Read more at the MIT  News Office.

Related: MIT Materials Science and Engineering offers Semester from Anywhere

A physicist and her neutrinos

MIT senior Christie Chiu has found her focus: the study of tiny particles.

Christie Chiu is currently working with physics professor Janet Conrad on research related to neutrinos. Photo: Allegra Boverman

Quarks, bosons, muons, electrons, neutrinos: This is the stuff the universe is made of, and these particles fascinate MIT senior Christie Chiu.

A physics and math major from Bedford, Mass., Chiu excelled in math and science from an early age and dreamed of attending MIT, her father’s alma mater. As a freshman at the Institute, she found herself drawn to the physics department. “The professors were just so engaged in what they were teaching,” Chiu says. “I felt a lot of energy in the classrooms.”

Now, Chiu channels that same energy as a teaching assistant for Junior Lab, the notoriously challenging lab class for physics majors. “I absolutely fell in love with it, while other people were maybe not liking it so much,” Chiu says. “That’s one of the reasons I became a TA — so that I could get people more excited about this and make them want to go into experimental physics.” Read more at the MIT News Office.

Rare earth oxides make water-repellent surfaces that last

Ceramic forms of hydrophobic materials could be far more durable than existing coatings or surface treatments.

MIT postdoc Gisele Azimi, left, displays three of the 13 different ceramic disks made from oxides of the rare earth elements, with associate professor Kripa Varanasi. Behind them is the furnace used to convert the powdered oxides into solid ceramic form. Photo: David Castro-Olmedo/MIT

Water-shedding surfaces that are robust in harsh environments could have broad applications in many industries including energy, water, transportation, construction and medicine. For example, condensation of water is a crucial part of many industrial processes, and condensers are found in most electric power plants and in desalination plants.

Hydrophobic materials — ones that prevent water from spreading over a surface, instead causing it to form droplets that easily fall away — can greatly enhance the efficiency of this process. But these materials have one major problem: Most employ thin polymer coatings that degrade when heated, and can easily be destroyed by wear.

MIT researchers have now come up with a new class of hydrophobic ceramics that can overcome these problems. These ceramic materials are highly hydrophobic, but are also durable in the face of extreme temperatures and rough treatment.

The work, by mechanical engineering postdoc Gisele Azimi and Associate Professor Kripa Varanasi, along with two graduate students and another postdoc, is described in the journal Nature Materials. Durability has always been a challenge for hydrophobic materials, Varanasi says — a challenge he says his team has now solved.

Read more at the MIT News Office.

Thermal lattices, shown here, are one possible application of the newly developed thermocrystals. In these structures, where precisely spaced air gaps (dark circles) control the flow of heat, thermal energy can be "pinned" in place by defects introduced into the structure (colored areas). Illustration:  Martin Maldovan

How to treat heat like light

New approach using nanoparticle alloys allows heat to be focused or reflected just like electromagnetic waves.

An MIT researcher has developed a technique that provides a new way of manipulating heat, allowing it to be controlled much as light waves can be manipulated by lenses and mirrors.

The approach relies on engineered materials consisting of nanostructured semiconductor alloy crystals. Heat is a vibration of matter — technically, a vibration of the atomic lattice of a material — just as sound is. Such vibrations can also be thought of as a stream of phonons — a kind of “virtual particle” that is analogous to the photons that carry light. The new approach is similar to recently developed photonic crystals that can control the passage of light, and phononic crystals that can do the same for sound.

The spacing of tiny gaps in these materials is tuned to match the wavelength of the heat phonons, explains Martin Maldovan, a research scientist in MIT’s Department of Materials Science and Engineering and author of a paper on the new findings published Jan. 11, 2013, in the journal Physical Review Letters.

“It’s a completely new way to manipulate heat,” Maldovan says. Heat differs from sound, he explains, in the frequency of its vibrations: Sound waves consist of lower frequencies (up to the kilohertz range, or thousands of vibrations per second), while heat arises from higher frequencies (in the terahertz range, or trillions of vibrations per second). Read more at the MIT News Office.

How to stop leaks — the way blood does

The first stage of blood clotting is the formation of a plug, seen here, which is made up of platelets (seen in gold) and structures called von Willebrand Factor (vWF), seen in red. The vWF structures are normally present in blood in coiled up form, but in the presence of the flow from a bleeding wound they unfurl to form long, sticky strands, which bind the platelets together. Image: Hsieh Chen

When you get a cut, blood starts to flow from the wound. But very quickly, complex biochemical processes spring into action, creating a scaffolding of molecules to block the hole, and then building up an impervious clot to stanch the flow. That process relies on a set of molecules that constantly flow through the body's veins and arteries, just waiting to spring into action when needed. When their job is done, they dissolve back into the blood, awaiting their next repair job. A team of MIT researchers has analyzed the process and found, for the first time, exactly how the different molecular components work together to block the flow of blood from a cut. Now, they are working on applying that knowledge to the development of synthetic materials that could be used to control different kinds of liquid flows, and could lead to a variety of new self-assembling materials. Read more at the MIT News Office.

Video: Melanie Gonick, MIT News; Computer simulations: Hsieh Chen

Chips that can steer light

Because of the interference of the phase-shifted light beams emitted by the antennas, images of the MIT logo appear to hover above the surface of the chip. Photo - Image: Jie Sun

January 9, 2013

If you want to create a moving light source, you have a few possibilities. One is to mount a light emitter in some kind of mechanical housing — the approach used in, say, theatrical spotlights, which stagehands swivel and tilt to track performers.

Another possibility, however, is to create an array of light emitters and vary their “phase” — the alignment of the light waves they produce. The out-of-phase light waves interfere with one another, reinforcing each other in some directions but annihilating each other in others. The result is a light source that doesn’t move, but can project a beam in any direction.

In this week’s issue of Nature, researchers from MIT’s Research Laboratory of Electronics (RLE) describe a 4,096-emitter array that fits on a single silicon chip. Chips that can steer beams of light could enable a wide range of applications, including cheaper, more efficient, and smaller laser rangefinders; medical-imaging devices that can be threaded through tiny blood vessels; and even holographic televisions that emit different information when seen from different viewing angles.

The MIT authors — Michael Watts, an associate professor of electrical engineering, Jie Sun, a graduate student in Watts’ lab and first author on the paper, Sun’s fellow graduate students Erman Timurdogan and Ami Yaacobi, and Ehsan Shah Hosseini, an RLE postdoc — report on two new chips. Both chips take in laser light and re-emit it via tiny antennas etched into the chip surface. Read more at the MIT News Office.

Research update: Jumping droplets help heat transfer

Click here or on image above to watch video. Scalable nanopatterned surfaces designed by MIT researchers could make for more efficient power generation and desalination. Read more at the MIT News Office.

Researchers demonstrate record-setting p-type transistor

In this micrograph of an experimental transistor, blue highlighting indicates areas of "strain," where germanium atoms have been forced closer together than they find comfortable. One of the reasons for the transistor's record-setting performance is that the strain has been relaxed in the lateral direction. Image: Winston Chern and James Teherani

Researchers from MIT’s Microsystems Technology Laboratories (MTL) presented a p-type transistor with the highest “carrier mobility” yet measured at the IEEE’s International Electron Devices Meeting (IEDM) in December.

The new transistor is twice as fast as previous experimental p-type transistors, almost four times as fast as the best commercial ones and features a trigate design.

Judy Hoyt, a professor of electrical engineering and computer science; her graduate students Winston Chern, lead author on the new paper, and James T. Teherani; Pouya Hashemi, who was an MIT postdoc at the time and is now with IBM; Dimitri Antoniadis, the Ray and Maria Stata Professor of Electrical Engineering; and colleagues at MIT and the University of British Columbia achieved their record-setting hole mobility by “straining” the germanium in their transistor — forcing its atoms closer together than they’d ordinarily find comfortable.

Read more at the MIT News Office.

MIT researchers gain insights
into 'stress corrosion cracking'

F. William Herbert of materials science and engineering (left) and Bilge Yildiz of nuclear science and engineering are examining how nanoscale disruptions in the crystalline structure of metals affect those materials’ vulnerability to stress corrosion cracking. Image: Justin Knight

High stresses combined with a corrosive environment can cause critical components inside power plants and other systems to crack and fail, sometimes with little warning. MIT researchers now have new insights into how such "stress corrosion cracking" may be affected by nanoscale disruptions in the crystalline structure of metallic materials.

"Corrosion causes a material to age in a particular manner and speed, and stress causes it to fracture after a certain period of time," says Bilge Yildiz, associate professor of nuclear science and engineering. "But when you have those two processes together, they interact, and both processes are accelerated."

Read more at the MIT News Office.

Young Investigator Award

MIT Professor Bilge Yildiz, left, was presented the Charles W. Tobias Young Investigator Award at the Electrochemical Society meeting this fall in Hawaii. Yildiz is Associate Professor of Nuclear Science and Engineering at MIT and Principal Investigator for the Laboratory for Electrochemical Interfaces at MIT.

Materials Science at the Heart of MIT