BRAINGATE - Brown University

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Collaborations across the campus and beyond strengthen our development of technological advances that address challenges of vital importance to us all.
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Engineering Magazine Summer 2012

Biochip measures glucose in saliva, eliminates the need to draw blood Professor Huajian Gao elected to National Academy of Engineering Brown President-Elect Christina Paxson visits with professors and students Professor Barrett Hazeltine named one of “Best 300 Professors” in the country

BRAINGATE

Using robotic arms controlled directly with brain activity

INSIDE THIS ISSUE Message from the Dean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Letter from the Editor:

People with paralysis control robotic arms using brain-computer interface . . . . . . . . . . 2 Biochip measures gluscose in saliva, not blood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Single nanomaterial yields many laser colors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Bats save energy by drawing in wings on upstroke. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Nanowrinkles, nanofolds yield strange hidden channels. . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Novel device removes heavy metals from water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Senator Reed, federal and state officials tour Brown’s Superfund Lab . . . . . . . . . . . . . . . 14 Faculty Awards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Brown University President-Elect Paxson visits School of Enginering. . . . . . . . . . . . . . . . 18 Barrett Hazeltine named one of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 America’s “Best 300 Professors” by Princeton Review Brown Engineering in Moscow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Hear me Now? Computers can now recognize individual speakers . . . . . . . . . . . . . . . . . 22 Brown’s Engineers Without Borders working in the Dominican Republic . . . . . . . . . . . . . 23 Advisory Council / Alumni Involvement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Comments, suggestions or address changes may be mailed to: Brown School of Engineering Box D 182 Hope Street Providence, RI 02912 USA Tel: 401-863-2677 Fax: 401-863-1238 [email protected] Learn more about Brown Engineering at www.brown.edu/academics/engineering

School of Engineering Magazine Editorial Gordon Morton ’93 Manager of Communications, School of Engineering Design Amy Simmons Photography Gordon Morton ’93, Mike Cohea, Frank Mullin, Lauren Brennan, Dingyi Sun ’12, Alex Grosvenor ’12 Printed in the USA

Connect with Brown Engineering

BROWN School of Engineering

In our last issue, we brought you the story of four women – Amanda Kautz ’12, Natalie Serrino ’12, Farzanah Ausaluth ’14 and Lizzie Costa ’14 - who were inspired to start SPIRA, a free four-week summer engineering camp for rising tenth grade girls. Last summer the camp was funded through a grant from the National Science Foundation (NSF) through Brown’s Materials Research Science and Engineering Center (MRSEC). This year, the program was without funding – until an alumnus saw the SPIRA story in the School of Engineering Magazine and offered to help. Mike Strem ’58 P’97, founder and president of Strem Chemicals, stepped up with a generous gift of $22,000 to fund the program for Mike Strem the upcoming year. Kautz and Serrino were also honored at Commencement with the George H. Main ’45 Award. This issue is equally inspiring – from the cover story on BrainGate to the biochip that measures glucose in saliva, Brown engineers are working to solve real problems that impact millions of people. Our students are doing their part as well to contribute. Our Engineers Without Borders group has offered their skills and expertise – both in Providence and in the Dominican Republic (page 26). As they travel to the Dominican Republic to assist the local community, they need our support. If you would like to help with this project, or other engineering fundraising efforts, please contact Rick Marshall (Richard_ [email protected] or 401-863-9877) in the Brown Advancement Office. We look forward to bringing you more of these exciting and inspirational stories throughout the year, so please stay in contact with us online – on Twitter, Facebook, LinkedIn, YouTube, ITunes, Flickr, blogs, or the web – whatever your preferred method of communication, Brown Engineering is there. Gordon Morton ’93 Editor and Publisher

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M ess a g e f r o m the de a n

Lawrence Larson Why Engineering at Brown?

As I finish off my first year at Brown, I reflect on the trajectory that engineering has taken since it became a true School of Engineering in July 2010. These last two years have been incredibly exciting, and we are just beginning the journey toward a reinvigorated engineering program at Brown. Under the inspiring leadership of my predecessor Dean Rod Clifton, the School took off like a rocket; we hired four new faculty in 2010-2011, we had significant fundraising success and we began the planning for expanded graduate and undergraduate programs. Since I arrived in July of 2011, we have raised an additional $20M toward new programs and a new building for engineering, hired two additional faculty, significantly expanded our master’s enrollment, and under the leadership of Associate Dean Kenny Breuer we are developing exciting new engineering courses that will be available to the entire campus community. Even greater developments for engineering here at Brown are just around the corner. I also want to help the broader community understand that engineering at Brown is a unique and deep intellectual experience, designed for ambitious and broad thinkers who want to make a difference in the world. I’ve been an engineer for over thirty years, and I honestly can’t imagine doing anything else. “Engineers create the future”

is a well-known saying, and what could be more fun and fulfilling than that? I wonder: why isn’t everyone an engineer?

An engineering degree is not a narrowing of possibilities; instead, it gives our students the opportunity to take the superb analytical skills they acquire here, and head in many different directions.

One of the areas we have focused on in the last year is improved mentoring of our students at all levels. Almost every student in engineering faces a crisis at some point in their studies. Engineering has a lot of challenging required courses that leaves less room than is desirable for the wide ranging intellectual exploration that students come to Brown for. How is a young person supposed to figure out areas of interest and, yes, passion if there is limited freedom to explore? Many students get discouraged by all the requirements.

The good news for Brown students is that the engineering curriculum here is more flexible than that at most other universities. In fact, the opportunity to explore a wide range of subjects is built into our curriculum. We have plans in place for students who might not start engineering until sophomore year, allowing for wider exploration as a first-year. Finally, if there’s an interest to explore even further outside of the traditional engineering curriculum, an AB in engineering is an option for all of our students. The actual practice of engineering can be utterly thrilling. In my own field of electrical and computer engineering, there are many beautiful intellectual constructs - like Maxwell’s Equations, Shannon’s Coding Theorems, and modern solid-state physics - that are so simple and elegant, and yet have a profound impact on our everyday lives. Every branch of engineering has similar fundamental results, whose creative application touches the lives of every person in the modern world. Engineering is not just for the math or science genius; it is a field most open to intensely curious learners who strive to work hard, create new innovations and make a difference in the world. Brown is the perfect place for the engineer who wants to explore the broader intellectual feast that our curriculum provides.

Brown University’s School of Engineering educates future leaders in the fundamentals of engineering in an environment of world-class research. We stress an interdisciplinary approach and a broad understanding of underlying global issues. Collaborations across the campus and beyond strengthen our development of technological advances that address challenges of vital importance to us all.

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SUMMER 2012

FRO M T H E L A B s

Leigh Hochberg

People with paralysis control robotic arms using brain-computer interface A new study in Nature reports that two people with tetraplegia were able to reach for and grasp objects in three-dimensional space using robotic arms that they controlled directly with brain activity. They used the BrainGate neural interface system, an investigational device currently being studied under an Investigational Device Exemption. One participant used the system to serve herself coffee for the first time since becoming paralyzed nearly 15 years ago. On April 12, 2011, nearly 15 years after she became paralyzed and unable to speak, a woman controlled a robotic arm by thinking about moving her arm and hand to lift a bottle of coffee to her mouth and take a drink. That achievement is one of the advances in brain-computer interfaces, restorative neurotechnology, and assistive robot technology described in the May 17 edition of the journal Nature by the BrainGate2 collaboration of researchers at the Department of Veterans Affairs, Brown University, Massachusetts General Hospital, Harvard Medical School, and the German Aerospace Center (DLR). A 58-year-old woman (“S3”) and a 66-year-old man (“T2”) participated in the study. They had each been paralyzed by a brainstem stroke years earlier which left them with no functional control of their limbs. In the research, the participants used neural activity to directly control two different robotic arms, one developed by the DLR Institute of Robotics and Mechatronics and the other by DEKA Research and Development Corp., to perform reaching and grasping tasks across a broad three-dimensional space. The BrainGate2 pilot clinical trial employs the investigational BrainGate system initially developed at Brown University, in which a baby aspirin-sized device with a grid of 96 tiny electrodes is implanted in the motor cortex — a part of the brain that is involved in voluntary movement. The electrodes are close enough to individual neurons to record the neural activity associated with intended movement. An external computer translates the pattern of impulses across a population of neurons into commands to operate assistive devices, such as the DLR and DEKA robot arms used in the study now reported in Nature. BrainGate participants have previously demonstrated neurally based two-dimensional BROWN School of Engineering

point-and-click control of a cursor on a computer screen and rudimentary control of simple robotic devices.

toward improving the quality of life for veterans and others who have either lost limbs or are paralyzed.”

The study represents the first demonstration and the first peer-reviewed report of people with tetraplegia using brain signals to control a robotic arm in three-dimensional space to complete a task usually performed by their arm. Specifically, S3 and T2 controlled the arms to reach for and grasp foam targets that were placed in front of them using flexible supports. In addition, S3 used the DLR robot to pick up a bottle of coffee, bring it to her mouth, issue a command to tip it, drink through a straw, and return the bottle to the table. Her BrainGate-enabled, robotic-arm control during the drinking task required a combination of two-dimensional movements across a table top plus a “grasp” command to either grasp and lift or tilt the robotic hand.

Hochberg adds that even after nearly 15 years, a part of the brain essentially “disconnected” from its original target by a brainstem stroke was still able to direct the complex, multidimensional movement of an external arm — in this case, a robotic limb. The researchers also noted that S3 was able to perform the tasks more than five years after the investigational BrainGate electrode array was implanted. This sets a new benchmark for how long implanted brain-computer interface electrodes have remained viable and provided useful command signals.

“Our goal in this research is to develop technology that will restore independence and mobility for people with paralysis or limb loss,” said lead author Dr. Leigh Hochberg, a neuroengineer and critical care neurologist who holds appointments at the Department of Veterans Affairs, Brown University, Massachusetts General Hospital, and Harvard. He is the sponsorinvestigator for the BrainGate2 pilot clinical trial. “We have much more work to do, but the encouraging progress of this research is demonstrated not only in the reach-and-grasp data, but even more so in S3’s smile when she served herself coffee of her own volition for the first time in almost 15 years.” Partial funding for this work comes from the VA, which is committed to improving the lives of injured veterans. “VA is honored to have played a role in this exciting and promising area of research,” said VA Secretary Eric Shinseki. “Today’s announcement represents a great step forward 2

John Donoghue, the VA and Brown neuroscientist who pioneered BrainGate more than a decade ago and who is co-senior author of the study, said the paper shows how far the field of brain-computer interfaces has come since the

The investigational BrainGate neural interface array detects and record brain signals, and has allowing persons who have lost the use of their arms to have point-and-click control of a compute, and to control external devices such as a robotic or prosthetic arm. A BrainGate device has provided useful signals for more than five yearsCredit: Matthew McKee/BrainGate Collaboration

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first demonstrations of computer control with BrainGate. “This paper reports an important advance by rigorously demonstrating in more than one participant that precise three-dimensional neural control of robot arms is not only possible, but also repeatable,” said Donoghue, who directs the Brown Institute for Brain Science. “We’ve moved significantly closer to returning everyday functions, like serving yourself a sip of coffee, usually performed effortlessly by the arm and hand, for people who are unable to move their own limbs. We are also encouraged to see useful control more than five years after implant of the BrainGate array in one of our participants. This work is a critical step toward realizing the long-term goal of creating a neurotechnology that will restore movement, control, and independence to people with paralysis or limb loss.” In the research, the robots acted as a substitute for each participant’s paralyzed arm. The robotic arms responded to the participants’ intent to move as they imagined reaching for each foam target. The robot hand grasped the target when the participants imagined a hand squeeze. Because the diameter of the targets was more than half the width of the robot hand openings, the task required the participants to exert precise control. (Videos of these actions are available on the Nature website.) In 158 trials over four days, S3 was able to touch the target within an allotted time in 48.8 percent of the cases using the DLR robotic arm and hand and 69.2 percent of the cases with the DEKA arm and hand, which has the wider grasp. In 45 trials using the DEKA arm, T2 touched the target 95.6 percent of the time. Of the successful touches, S3 grasped the target 43.6 percent of the time with the DLR arm and 66.7 percent of the time with the DEKA arm. T2’s grasp succeeded 62.2 percent of the time. T2 performed the session in this study on his fourth day of interacting with the arm; the prior three sessions were focused on system development. Using his eyes to indicate each letter, he later described his control of the arm: “I just imagined moving my own arm and the [DEKA] arm moved where I wanted it to go.” The study used two advanced robotic arms: the DLR Light-Weight Robot III with DLR five

One small step. A 58-year-old woman, paralyzed by a stroke for almost 15 years, uses her thoughts to control a robotic arm, grasp a bottle of coffee, serve herself a drink, and return the bottle to the table.

fingered hand and the DEKA Arm System. The DLR LWR-III, which is designed to assist in recreating actions like the human arm and hand and to interact with human users, could be valuable as an assistive robotic device for people with various disabilities. Patrick van der Smagt, head of bionics and assistive robotics at DLR, director of biomimetic robotics and machine learning labs at DLR and the Technische Universität München, and a co-senior author on the paper said: “This is what we were hoping for with this arm. We wanted to create an arm that could be used intuitively by varying forms of control. The arm is already in use by numerous research labs around the world who use its unique interaction and safety capabilities. This is a compelling demonstration of the potential utility of the arm by a person with paralysis.” DEKA Research and Development developed the DEKA Arm System for amputees, through funding from the United States Defense Advanced Research Projects Agency (DARPA). Dean Kamen, founder of DEKA said, “One of our dreams for the Luke Arm [as the DEKA Arm System is known informally] since its inception has been to provide a limb that could be operated not only by external sensors, but also by more directly thought-driven control. We’re pleased about these results and for the continued research being done by the group at the VA, Brown and MGH.” The research is aimed at learning how the DEKA arm might be controlled directly 3

from the brain, potentially allowing amputees to more naturally control this prosthetic limb. Over the last two years, VA has been conducting an optimization study of the DEKA prosthetic arm at several sites, with the cooperation of veterans and active duty service members who have lost an arm. Feedback from the study is helping DEKA engineers to refine the artificial arm’s design and function. “Brain-computer interfaces, such as BrainGate, have the potential to provide an unprecedented level of functional control over prosthetic arms of the future,” said Joel Kupersmith, M.D., VA chief research and development officer. “This innovation is an example of federal collaboration at its finest.” Story Landis, director of the National Institute of Neurological Disorders and Stroke, which funded the work in part, noted: “This technology was made possible by decades of investment and research into how the brain controls movement. It’s been thrilling to see the technology evolve from studies of basic neurophysiology and move into clinical trials, where it is showing significant promise for people with brain injuries and disorders.” In addition to Hochberg, Donoghue, and van der Smagt, other authors on the paper are Daniel Bacher, Beata Jarosiewicz, Nicolas Masse, John Simeral, Joern Vogel, Sami Haddadin, Jie Liu, and Sydney Cash.

By David Orenstein SUMMER 2012

FRO M T H E L A B S

Domenico Pacifici

Biochip measures glucose in saliva, not blood Engineers at Brown University have designed a biological device that can measure glucose concentrations in human saliva. The technique could eliminate the need for diabetics to draw blood to check their glucose levels. The biochip uses plasmonic interferometers and could be used to measure a range of biological and environmental substances.

For the 26 million Americans with diabetes, drawing blood is the most prevalent way to check glucose levels. It is invasive and at least minimally painful. Researchers at Brown University are working on a new sensor that can check blood sugar levels by measuring glucose concentrations in saliva instead. The technique takes advantage of a convergence of nanotechnology and surface plasmonics, which explores the interaction of electrons and photons (light). The engineers at Brown etched thousands of plasmonic interferometers onto a fingernail-size biochip and measured the concentration of glucose molecules in water on the chip. Their results showed that the specially designed biochip could detect glucose levels similar to the levels found in human saliva. Glucose in human saliva is typically about 100 times less concentrated than in the blood. “This is proof of concept that plasmonic interferometers can be used to detect molecules in low concentrations, using a footprint that is ten times smaller than a human hair,” said Domenico Pacifici, assistant professor of engineering and lead author of the paper published in Nano Letters, a journal of the American Chemical Society. The technique can be used to detect other chemicals or substances, from anthrax to biological compounds, Pacifici said, “and to detect them all at once, in parallel, using the same chip.” To create the sensor, the researchers carved a slit about 100 nanometers wide and etched two 200 nanometer-wide grooves

on either side of the slit. The slit captures incoming photons and confines them. The grooves, meanwhile, scatter the incoming photons, which interact with the free electrons bounding around on the sensor’s metal surface. Those free electron-photon interactions create a surface plasmon polariton, a special wave with a wavelength that is narrower than a photon in free space. These sur-

“It could be possible to use these biochips to carry out the screening of multiple biomarkers for individual patients, all at once and in parallel, with unprecedented sensitivity,” Pacifici said.

face plasmon waves move along the sensor’s surface until they encounter the photons in the slit, much like two ocean waves coming from different directions and colliding with each other. This “interference” between the two waves determines maxima and minima in the light intensity transmitted through the slit. The presence of an analyte (the chemical being measured) on the sensor surface generates a change in the relative phase difference between the two surface plasmon waves, which in turns causes a change in

light intensity, measured by the researchers in real time. “The slit is acting as a mixer for the three beams — the incident light and the surface plasmon waves,” Pacifici said. The engineers learned they could vary the phase shift for an interferometer by changing the distance between the grooves and the slit, meaning they could tune the interference generated by the waves. The researchers could tune the thousands of interferometers to establish baselines, which could then be used to accurately measure concentrations of glucose in water as low as 0.36 milligrams per deciliter. The engineers next plan to build sensors tailored for glucose and for other substances to further test the devices. “The proposed approach will enable very high throughput detection of environmentally and biologically relevant analytes in an extremely compact design. We can do it with a sensitivity that rivals modern technologies,” Pacifici said. Tayhas Palmore, professor of engineering, is a contributing author on the paper. Graduate students Jing Feng (engineering) and Vince Siu (bioengineering), who designed the microfluidic channels and carried out the experiments, are listed as the first two authors on the paper. Other authors include Brown engineering graduate student Steve Rhieu and undergraduates Vihang Mehta, Alec Roelke. The National Science Foundation and Brown (through a Richard B. Salomon Faculty Research Award) funded the research. By Richard Lewis

BROWN School of Engineering

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Tripping the light fantastic. Each plasmonic interferometer -thousands of them per square millimeter - consists of a slit flanked by two grooves etched in a silver metal film. The schematic shows glucose molecules “dancing” on the sensor surface illumniated by light with different colors. Changes in light intensity transmitted through the slit of each plasmonic interferometer yield information about the concentration of glucose molecules in solution. Credit: Domenico Pacifici

Biochip

Control Button

LCD Panel

Indicator Light

LCD Camera

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Above: Sketch of prototype employing Surface Plasmon Interferometric Technology for non-Invasive glucose Testing (SPIT’nIT). Right: Top view image of a portable glucose sensor prototype showing the lab-on-a-chip gold layer containing thousands of plasmonic interferometers, coupled to a CMOS sensor.

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SUMMER 2012

FRO M T H E L A B s

Arto Nurmikko

Single nanomaterial yields many laser colors Engineers at Brown University and QD Vision Inc. have created nanoscale single crystals that can produce the red, green, or blue laser light needed in digital displays. The size determines color, but all the pyramid-shaped quantum dots are made the same way of the same elements. In experiments, light amplification required much less power than previous attempts at the technology. The team’s prototypes are the first lasers of their kind. Red, green, and blue lasers have become small and cheap enough to find their way into products ranging from BluRay DVD players to fancy pens, but each color is made with different semiconductor materials and by elaborate crystal growth processes. A new prototype technology demonstrates all three of those colors coming from one material. That could open the door to making products, such as high-performance digital displays, that employ a variety of laser colors all at once. “Today in order to create a laser display with arbitrary colors, from white to shades of pink or teal, you’d need these three separate material systems to come together in the form of three distinct lasers that in no way shape or form would have anything in common,” said Arto Nurmikko, professor of engineering at Brown University and senior author of a paper describing the innovation in the journal Nature Nanotechnology. “Now enter a class of materials called semiconductor quantum dots.” The materials in prototype lasers described in the paper are nanometer-sized semiconductor particles called colloidal quantum dots or nanocrystals with an inner core of cadmium and selenium alloy and a coating of zinc, cadmium, and sulfur alloy and a proprietary organic molecular glue. Chemists at QD Vision of Lexington, Mass., synthesize the nanocrystals using a wet chemistry process that allows them to precisely vary the nanocrystal size by varying the production time. Size is all that needs to change to produce different laser light colors: 4.2 nanometer cores produce red light, 3.2 nanometer ones emit green light and 2.5 nanometer BROWN School of Engineering

ones shine blue. Different sizes would produce other colors along the spectrum.

“We have managed to show that it’s possible to create not only light, but laser light,” Nurmikko said. “In principle, we now have some benefits: using the same chemistry for all colors, producing lasers in a very inexpensive way, relatively speaking, and the ability to apply them to all kinds of surfaces regardless of shape. That makes possible all kinds of device configurations for the future.”

The cladding and the nanocrystal structure are critical advances beyond previous attempts to make lasers with colloidal quantum dots, said lead author Cuong Dang, a senior research associate and nanophotonics laboratory manager in Nurmikko’s group at Brown. Because of their improved quantum mechanical and electrical performance, he said, the coated pyramids require 10 times less pulsed energy or 1,000 times less power to produce laser light than previous attempts at the technology. 6

Quantum nail polish When chemists at QDVision brew a batch of colloidal quantum dots for Brown-designed specifications, Dang and Nurmikko get a vial of a viscous liquid that Nurmikko said somewhat resembles nail polish. To make a laser, Dang coats a square of glass — or a variety of other shapes — with the liquid. When the liquid evaporates, what’s left on the glass are several densely packed solid, highly ordered layers of the nanocrystals. By sandwiching that glass between two specially prepared mirrors, Dang creates one of the most challenging laser structures, called a verticalcavity surface-emitting laser. The Brown-led team was the first to make a working VCSEL with colloidal quantum dots. The nanocrystals’ outer coating alloy of zinc, cadmium, sulfur and that molecular glue is important because it reduces an excited electronic state requirement for lasing and protects the nanocrystals from a kind of crosstalk that makes it hard to produce laser light, Nurmikko said. Every batch of colloidal quantum dots has a few defective ones, but normally just a few are enough to interfere with light amplification. Faced with a high excited electronic state requirement and destructive crosstalk in a densely packed layer, previous groups have needed to pump their dots with a lot of power to push them past a higher threshold for producing light amplification, a core element of any laser. Pumping them intensely, however, gives rise to another problem: an excess of excited electronic states called excitons. When there are too many of these excitons among the quantum dots,

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Vertical-cavity surface-emitting laser Colloidal quantum dots — nanocrystals — can produce lasers of many colors. Cuong Dang manipulates a green beam that pumps the nanocrystals with energy, in this case producing red laser light. Credit: Mike Cohea/Brown University

energy that could be producing light is instead more likely to be lost as heat, mostly through a phenomenon known as the Auger process. The nanocrystals’ structure and outer cladding reduces destructive crosstalk and lowers the energy needed to get the quantum dots to shine. That reduces the energy required to pump the quantum dot laser and significantly reduces the likelihood of exceeding the level of excitons at which the Auger process drains energy away. In addition, a benefit of the new approach’s structure is that the dots can act more quickly, releasing light before Auger process can get started, even in the rare cases when it still does start. “We have managed to show that it’s possible to create not only light, but laser light,” Nurmikko said. “In principle, we now have some benefits: using the same chemistry for all

colors, producing lasers in a very inexpensive way, relatively speaking, and the ability to apply them to all kinds of surfaces regardless of shape. That makes possible all kinds of device configurations for the future.” In addition to Nurmikko and Dang, another author at Brown is Joonhee Lee. QD Vision authors include Craig Breen, Jonathan Steckel, and Seth Coe-Sullivan, a company co-founder who studied engineering at

Schematic of a vertically pump CQD-VCSEL with a long pass filter to remove any residual pump excitation beam. CQD gain medium is placed inside a wedge cavity for a variable cavity length. The wedge angle is 1.2 × 10−3 rad, and two DBRs have reflectivity higher than 99%.

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Brown as an undergraduate. The US. Department of Energy, the Air Force Office for Scientific Research, and the National Science Foundation supported the research. Dang is a Vietnam Education Foundation (VEF) Scholar.

By David Orenstein

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SUMMER 2012

FRO M T H E L A B s

Kenneth Breuer

Bats save energy by drawing in wings on upstroke Bat wings are like hands: meaty, bony and full of joints. A new Brown University study finds that bats take advantage of their flexibility by folding in their wings on the upstroke to save inertial energy. The research suggests that engineers looking at flapping flight should account for wing mass and consider a folding design.

Whether people are building a flying machine or nature is evolving one, there is pressure to optimize efficiency. A new analysis by biologists, physicists, and engineers at Brown University reveals the subtle but important degree to which that pressure has literally shaped the flapping wings of bats. The team’s observations and calculations show that by flexing their wings inward to their bodies on the upstroke, bats use only 65 percent of the inertial energy they would expend if they kept their wings fully outstretched. Unlike insects, bats have heavy, muscular wings with hand-like bendable joints. The study suggests that they use their flexibility to compensate for that mass.

The physics of flexed flapping The team originally set out to study something different: how wing motions vary among bats along a wide continuum of sizes. They published those results in 2010 in the Journal of Experimental Biology, but as they analyzed the data further, they started to consider the intriguing pattern of the inward flex on the upstroke.

“If you have a vehicle that has heavy wings, it would become energetically beneficial to fold the wings on the upstroke,” said Sharon Swartz, professor of ecology and evolutionary biology at Brown. She and Kenneth Breuer, professor of engineering, are senior authors on the paper.

The team fed the data in to a calculus-rich model that allowed them to determine what the inertial energy costs of flapping were and what they would have been if the wings were kept outstretched. Bergou, a physicisist, said he was surprised that the energy savings was so great, especially because the calculations also showed that the bats have to spend a lot of energy — 44 percent of the total inertial cost of flapping — to fold their wings inward and then back outward ahead of the downstroke. “Retracting your wings has an inertial cost,” Bergou said. “It is significant but it is outweighed by the savings on the up and down stroke.”

“Wing mass is important and it’s normally not considered in flight,” said Attila Bergou, who along with Daniel Riskin is co-lead author of the study that appears April 11 in the Proceedings of the Royal Society B. “Typically you analyze lift, drag, and you don’t talk about the energy of moving the wings.” The findings not only help explain why bats and some birds tuck in their wings on the upstroke, but could also help inform human designers of small flapping vehicles. The team’s research is funded by the U.S. Air Force Office of Sponsored Research.

mass by cutting the wing of a bat that had died into 32 pieces and weighing them.

That curiosity gave them a new perspective on their 1,000 frames-per-second videos of 27 bats performing five trials each aloft in a flight corridor or wind tunnel. They tracked markers on the bats, who hailed from six species, and measured how frequently the wings flapped, how far up and down they flapped, and the distribution of mass within them as they moved. They measured the

The conventional wisdom has always been that bats drew their wings in on the upstroke to reduce drag in the air, and although the team did not measure that, they acknowledge that aerodynamics plays the bigger role in the overall energy budget of flying. But the newly measured inertial savings of drawing in the wings on the upstroke seems too significant to be an accident. “It really is an open question whether natural selection is so intense on the design and movement patterns of bats that it reaches details of how bats fold their wings,” Swartz said. “This certainly suggests that this is not a random movement pattern and that it is likely that there is an energetic benefit to animals doing this.” By David Orenstein

BROWN School of Engineering

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1: A Potential Flow model is used to predict the aerodynamic forces on the bat's wings. 2: The accelerations of the center of gravity are used to determine the aerodynamic forces required to sustain flight. 3: The wake circulation distribution illustrates the flow memory of the force generation during flight. 4: Complex vortex structures are present in the wake as a result of the unsteady force generation during flapping flight.

A computer simulation of the unsteady aerodynamics of a bat flying at 3.4 m/s

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D. J. Willissl, M. Kostandovs, D. K. Riskins, J. Perairel, D. H. Laidlaws, S. M. Swartzs & K. S. Breuer 9 Brown University, Massachusetts Institute of Technology

Inertial model Flow model

SUMMER 2012

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Kyung-Suk Kim

Nanowrinkles, nanofolds yield strange hidden channels Wrinkles and folds, common in nature, do something unusual at the nanoscale. Researchers at Brown University and in Korea have discovered that wrinkles on super-thin films have hidden long waves. The team also found that folds in the film produce nanochannels, like thousands of tiny subsurface pipes. The research could lead to advances in medicine, electronics and energy. Results appear in “Proceedings of the Royal Society A”. Wrinkles and folds are ubiquitous. They occur in furrowed brows, planetary topology, the surface of the human brain, even the bottom of a gecko’s foot. In many cases, they are nature’s ingenious way of packing more surface area into a limited space. Scientists, mimicking nature, have long sought to manipulate surfaces to create wrinkles and folds to make smaller, more flexible electronic devices, fluid-carrying nanochannels or even printable cell phones and computers. But to attain those technology-bending feats, scientists must fully understand the profile and performance of wrinkles and folds at the nanoscale, dimensions 1/50,000th the thickness of a human hair. In a series of observations and experiments, engineers at Brown University and in Korea have discovered unusual properties in wrinkles and folds at the nanoscale. The researchers report that wrinkles created on super-thin films have hidden long waves that lengthen even when the film is compressed. The team also discovered that when folds are formed in such films, closed nanochannels appear below the surface, like thousands of super-tiny pipes. “Wrinkles are everywhere in science,” said Kyung-Suk Kim, professor of engineering at Brown and corresponding author of the paper published in the journal Proceedings of the Royal Society A. “But they hold certain secrets. With this study, we have found mathematically how the wrinkle spacings of a thin sheet are determined on a largely deformed soft substrate and how the wrinkles evolve into regular folds.”

BROWN School of Engineering

Wrinkles are made when a thin stiff sheet is buckled on a soft foundation or in a soft surrounding. They are precursors of regular folds: When the sheet is compressed enough, the wrinkles are so closely spaced that they form folds. The folds are interesting to manufacturers, because they can fit a large surface area of a sheet in a finite space. Kim and his team laid gold nanogranular film sheets ranging from 20 to 80 nanometers thick on a rubbery substrate commonly used in the microelectronics industry. The researchers compressed the film, creating wrinkles and examined their properties. As in previous studies, they saw primary wrin-

kles with short periodicities, the distance between individual wrinkles’ peaks or valleys. But Kim and his colleagues discovered a second type of wrinkle, with a much longer periodicity than the primary wrinkles — like a hidden long wave. As the researchers compressed the gold nanogranular film, the primary wrinkles’ periodicity decreased, as expected. But the periodicity between the hidden long waves, which the group labeled secondary wrinkles, lengthened. “We thought that was strange,” Kim said. It got even stranger when the group formed folds in the gold nanogranular sheets. On the

One dimensional ordered wrinkle folding of 50nm thick gold film on a PDMS substrate. From bottom up, initially.

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FRO M T H E l a b Typical surface nanostructures for various functions in nature. Wrinkle folding is expected to create artificially such for various applications.

Nano hairs of water strider X. Gao and L. Jiang, Nature 432, 36 (4 November 2004)

surface, everything appeared normal. The folds were created as the peaks of neighboring wrinkles got so close that they touched. But the research team calculated that those folds, if elongated, did not match the length of the film before it had been compressed. A piece of the original film surface was not accounted for, “as if it had been buried,” Kim said.

Nano rods on lotus (Courtesy of M. -W. Moon, KIST)

Indeed, it had been, as nano-size closed channels. Previous researchers, using atomic force microscopy that scans the film’s surface, had been unable to see the buried channels. Kim’s group turned to focused ion beams to extract a cross-section of the film. There, below the surface, were rows of closed channels, about 50 to a few 100 nanometers in diameter. “They were hidden,” Kim said. “We were the first ones to cut (the film) and see that there are channels underneath.” The enclosed nano channels are important because they could be used to funnel liquids, from drugs on patches to treat diseases or infections, to clean water and energy harvesting, like a microscopic hydraulic pump.

Nano thresholds of sandfish I. Rechenberg et al. Tech. Univ. Berlin Fachgebiet: Bionik und Evolutionstechnik, 2009

Contributing authors include Jeong-Yun Sun and Kyu Hwan Oh from Seoul National University; Myoung-Woon Moon from the Korea Institute of Science and Technology; and Shuman Xia, a researcher at Brown and now at the Georgia Institute of Technology. The National Science Foundation, the Korea Institute of Science and Technology, the Ministry of Knowledge Economy of Korea, and the Ministry of Education, Science, and Technology of Korea supported the research. Nano ribs of sharks D.-Y. Zhao, et al. J. Mat. Proc. Tech. 212, 2012.

By Richard Lewis

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Joseph M. Calo

Novel device removes heavy metals from water Engineers at Brown University have developed a system that cleanly and efficiently removes trace heavy metals from water. In experiments, the researchers showed the system reduced cadmium, copper, and nickel concentrations, returning contaminated water to near or below federally acceptable standards.

The technique is scalable and has viable commercial applications, especially in the environmental remediation and metal recovery fields. Results appear in the Chemical Engineering Journal. An unfortunate consequence of many industrial and manufacturing practices, from textile factories to metalworking operations, is the release of heavy metals in waterways. Those metals can remain for decades, even centuries, in low but still dangerous concentrations. Ridding water of trace metals “is really hard to do,” said Joseph Calo, professor emeritus of engineering who maintains an active laboratory at Brown. He noted the cost, inefficiency, and time needed for such efforts. “It’s like trying to put the genie back in the bottle.”

A proven technique for removing heavy metals from water is through the reduction of heavy metal ions from an electrolyte. While the technique has various names, such as electrowinning, electrolytic removal/recovery or electroextraction, it all works the same way, by using an electrical current to transform positively charged metal ions (cations) into a stable, solid state where they can be easily separated from the water and removed. The main drawback to this technique is that there must be a high-enough concentration of metal cations in the water for it to be effective; if the cation concentration is too low — roughly less than 100 parts per million — the current efficiency becomes too low and the current acts on more than the heavy metal ions.

That may be changing. Calo and other engineers at Brown describe a novel method that collates trace heavy metals in water by increasing their concentration so that a proven metal-removal technique can take over. In a series of experiments, the engineers report the method, called the cyclic electrowinning/precipitation (CEP) system, removes up to 99 percent of copper, cadmium, and nickel, returning the contaminated water to federally accepted standards of cleanliness. The automated CEP system is scalable as well, Calo said, so it has viable commercial potential, especially in the environmental remediation and metal recovery fields. The system’s mechanics and results are described in a paper published in the Chemical Engineering Journal. BROWN School of Engineering

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Another way to remove metals is through simple chemistry. The technique involves using hydroxides and sulfides to precipitate the metal ions from the water, so they form solids. The solids, however, constitute a toxic sludge, and there is no good way to deal with it. Landfills generally won’t take it, and letting it sit in settling ponds is toxic and environmentally unsound. “Nobody wants it, because it’s a huge liability,” Calo said. The dilemma, then, is how to remove the metals efficiently without creating an unhealthy byproduct. Calo and his co-authors, postdoctoral researcher Pengpeng Grimshaw and George Hradil, who earned his doctorate at Brown and is now an adjunct professor, combined the two techniques to

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form a closed-loop system. “We said, ‘Let’s use the attractive features of both methods by combining them in a cyclic process,’” Calo said. It took a few years to build and develop the system. In the paper, the authors describe how it works. The CEP system involves two main units, one to concentrate the cations and another to turn them into stable, solidstate metals and remove them. In the first stage, the metal-laden water is fed into a tank in which an acid (sulfuric acid) or base (sodium hydroxide) is added to change the water’s pH, effectively separating the water molecules from the metal precipitate, which settles at the bottom. The “clear” water is siphoned off, and more contaminated water is brought in. The pH swing is applied again, first redissolving the precipitate and then reprecipitating all the metal, increasing the metal concentration each time. This process is repeated until the concentration of the metal cations in the solution has reached a point at which electrowinning can be efficiently employed. When that point is reached, the solution is sent to a second device, called a spouted particulate electrode (SPE). This is where the electrowinning takes place, and the metal cations are chemically changed to stable metal solids so they can be easily removed. The engineers used an SPE developed by Hradil, a senior research engineer at Technic Inc., located in Cranston, R.I. The cleaner water is returned to the precipitation tank, where metal ions can be precipitated once again. Further cleaned, the supernatant water is sent to another reservoir, where additional processes may be employed to

further lower the metal ion concentration levels. These processes can be repeated in an automated, cyclic fashion as many times as necessary to achieve the desired performance, such as to federal drinking water standards. In experiments, the engineers tested the CEP system with cadmium, copper, and nickel, individually and with water containing all three metals. The results showed cadmium, copper, and nickel were lowered to 1.50, 0.23 and 0.37 parts per million (ppm), respectively — near or below maximum contaminant levels established by the Environmental Protection Agency. The sludge is continuously formed and redissolved within the system so that none is left as an environmental contaminant. “This approach produces very large volume reductions from the original contaminated water by electrochemical reduction of the ions to zero-valent metal on the surfaces of the cathodic particles,” the authors write. “For an initial 10 ppm ion concentration of the metals considered, the volume reduction is on the order of 106.” Calo said the approach can be used for other heavy metals, such as lead, mercury, and tin. The researchers are currently testing the system with samples contaminated with heavy metals and other substances, such as sediment, to confirm its operation. The research was funded by the National Institute of Environmental Health Sciences, a branch of the National Institutes of Health, through the Brown University Superfund Research Program. By Richard Lewis 13

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Senator Reed, federal and state officials tour Brown’s Superfund Lab Senator Jack Reed, accompanied by the New England regional director of the U.S. Environmental Protection Agency and the directors of the state’s environmental and health departments, visited Brown University’s Superfund Research Program Monday, April 9, 2012. The Brown program is one of 14 research groups funded by the National Institutes of Health. Brown’s Superfund research group has been in operation since 2005. The program has brought in some $43 million in funding to Rhode Island since then, creating or supporting 45 jobs in the Ocean State. The group is working on the Centredale Manor Superfund site in Providence, the Gorham Manufacturing site in Providence, and the well-publicized soil contamination affecting residential properties in the Bay Street neighborhood in Tiverton. In these cases, scientists and students have tracked the flow of hazardous gases from contaminated sites, identified and tested toxic chemicals, worked with community and neighborhood associations and state and federal agencies to clean up contaminated areas, and offered insights into how chemicals can alter human health and reproduction. “Rhode Island is a small, densely populated state with a proud industrial heritage, yet burdened by a toxic legacy,” said Kim Boekelheide, professor of medical science and a member of Brown’s Superfund research group. “Brown’s Superfund Research Program is a center of technical excellence, where we focus on new scientific approaches to clean up our post-industrial legacy of contaminated sites here in the Ocean State and throughout the nation.” Reed toured the Brown group’s facility in the Laboratories for Molecular Medicine, 70 Ship St. in Providence, at 12:30 p.m. He was accompanied by Gwen Collman, director of extramural research and training, National Institute of Environmental Health Sciences (NIEHS), the program’s primary funder; Curt Spalding, New England administrator for BROWN School of Engineering

“Putting people to work to reduce the negative impacts of abandoned hazardous waste sites is a smart investment to protect public health, the environment, and our economy,” said Reed. “I am pleased that Brown’s federally funded Superfund Research Program is working through targeted research and community outreach to address health concerns and design novel techniques to reduce toxic chemicals

In addition to working on contaminated sites in Rhode Island, the Brown Superfund Research Program connects to Superfund sites nationwide, primarily through research. Specifically, the group has: • Devised a computational model with the Rhode Island Department of Environmental Management to track the flow of contaminant vapors from groundwater and soil into homes and businesses. The model has been tested at the Gorham site in Rhode Island and is currently being tested at a hazardous waste site in Somerville, Mass. • Investigated the potential environmental hazards from consumer products using nanomaterials (dimensions one-billionth of a meter, or 1/50,000th the width of a human hair). Current projects are looking at the release of nanosilver into sewer systems, how nanomaterials break down in landfills and how they infiltrate human lungs. • Studied the effects of chemicals on human sperm and human female reproduction, especially pregnant women and chemically induced premature births.

at Superfund sites in Rhode Island.”

the EPA; Janet Coit, Rhode Island Department of Environmental Management director; and Michael Fine, Rhode Island Department of Health director. Brown Provost Mark Schlissel also toured the facility. 14

The nano-material photo shows a human lung macrophage engulfing a graphene nanomaterial

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Clockwise from left: Ed Dere, Postdoctoral Researcher, Brown University; Curt Spalding, Administrator forEPA’s New England Region (Region1); Steve Hourihan, Governor Lincoln Chafee’s office; Senator Jack Reed. Photography: Mike Cohea/Brown University

The Brown Superfund Program has created innovative ways to connect with local communities and develop the next generation of environmental leaders. The centerpiece of this effort is the Community Environmental College, an eight-week summer leadership program for inner-city youth. Last year, nearly 50 urban high-school students, primarily in Providence and Pawtucket, engaged in various activities to raise community awareness of the environment, ranging from enlisting Latino restaurants to supply used vegetable oil for biodiesel fuel, recycling mattresses, and encouraging convenience stores to stock healthier food. Brown students work with youth and community

groups on myriad projects, including a yearround after-school program called ECO Youth, weatherizing homes and the “Hospitals for a Healthy Environment in Rhode Island” programs, which promotes cost-effective, healthy, and sustainable health-care institutions. “Through our Community Engagement Core, we help local groups clean up contaminated land and work with legislators and regulators to strengthen state policies on brownfields, school siting, and various environmental justice issues,” said Phil Brown, professor of sociology at Brown and a researcher with the Superfund Research Program. “I am excited about our engagement with so many high school students in the Community Environmental College, as they learn so much and apply themselves to the Healthy Corner Store Initiative, weatherization, green transportation, and other critical concerns.”

Postdoctoral Researcher Pengpeng Grimshaw takes samples from a Rhode Island riverbank to assess possible contaminant levels and study novel cleanup processes that have been developed in a Superfund lab at Brown.

The Brown Superfund Research Program is up for renewed funding in 2014. The renewal comes amid a competitive landscape; a decade ago, the federal Superfund Research Program supported 21 such programs nationwide. “Continued funding will allow us to improve the prediction of the health risks associated with complex chemical exposures and devise new remediation strategies for contaminated sites,” Boekelheide said. By Richard Lewis



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Professor Kyung-Suk Kim PhD ’80 to Receive 2012 Engineering Science Medal Brown University School of Engineering Professor Kyung-Suk Kim PhD ’80 will receive the 2012 Engineering Science Medal from the Society of Engineering Science (SES). The prize is awarded in recognition of a singularly important contribution to engineering science. Professor Kim will receive his award during the 49th Annual Technical Meeting of the Society of Engineering Science to be held at Georgia Institute of Technology from October 9-12, 2012. The Society of Engineering Science has only awarded the Engineering Science Medal eight previous times since its inception in 1987.

displacement measurement at the micro and nano-length scales, field projection methods to extract cohesive laws, residual stress measurements via chemical etching, high resolution TEM analysis to extract near atomic resolution constitutive laws and extension of the AFM range to measure the size scaling in contact and adhesion. Professor Kim received his B.S. and M.S. degrees from Seoul National University of Korea in 1974 and 1976, respectively, and his Ph.D. from Brown University in 1980. He worked on the faculty of the University of Illinois at Urbana-Champaign from 1980-1989 before returning to Brown as Professor of Engineering in 1989. He is currently the director of Nano and Micromechanics Laboratory in the Mechanics of Solids and Structures Group in the School of Engineering at Brown University. Founded in 1963, the Society of Engineering Science (SES) was established to promote the free exchange of information on all aspects of engineering science and to provide a forum for discussion, education, and recognition of the talents of the engineering science community. Since its founding in 1963, the SES has established its reputation as the most vibrant and relevant technical society to promote the field of engineering science, where science and engineering meet. The annual technical meetings organized by SES bring leading engineers, scientists and mathematicians from around the world together to tackle some of the most challenging problems at the interface between engineering, sciences and mathematics.

“This is a tremendous and well-deserved honor for Professor Kim,” said Dean Larry Larson. “As both a Brown Engineering alumnus and professor we are extremely proud of his accomplishments and look forward to his continued contributions to the field.” Professor Kim receives the prize for his singularly important contributions to experimental micro and nano-mechanics. These include his inventions of transverse displacement interferometer for high strain rate combined normal and shearing load, stress intensity tracer for time dependent fracture testing, Moiré interferometry for finite

Andrew Peterson named Young Investigator Andrew Peterson, assistant professor of engineering, has won a Young Investigator Award from the U.S. Navy. Peterson, one of only 26 young faculty nationwide to be selected, was recognized for scientific pursuits that show exceptional promise for the Navy and Marine Corps. The award is intended to promote the researcher’s professional development; Peterson will receive three years’ funding for research that could advance naval technology, the Navy announced Tuesday, March 27. Peterson joined the Brown faculty in January. His primary research is devoted to figuring out how to produce carbon-based fuels from renewable sources. A key to such a breakthrough lies in overcoming the steep energy threshold needed to split carbon dioxide molecules into hydrocarbons. Peterson’s approach is to rely on quantum mechanics calculations to design catalysts to make those reactions more efficient and less costly. BROWN School of Engineering

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Professor Huajian Gao Elected to the National Academy of Engineering Huajian Gao, Walter H. Annenberg Professor of Engineering at Brown University, has been elected to the National Academy of Engineering (NAE). Gao, honored for contributions to micromechanics of thin films and hierarchically structured materials, is one of 66 new members and 10 foreign associates elected, and is one of just 2,254 U.S. members and 206 foreign associates in the NAE.

ed 1965), Daniel C. Drucker (elected 1967), James R. Rice (elected 1980), Joseph Kestin (elected 1982), Rush C. Hawkins University Professor Rod Clifton (elected 1989), Professor Emeritus L.B. Freund (elected 1994), Professor Emeritus Alan Needleman (elected 2000), and Vice President for Research and Otis Randall University Professor Clyde Briant (elected 2010). "This is a spectacular professional achievement for Professor Gao and we are extremely happy for him," said Dean Larry Larson. "To have five members of the National Academy within a faculty of 40 also underscores the strength and level of accomplishment of our faculty here at Brown.”

NATIONAL ACADEMY OF ENGINEERING Election to the National Academy of Engineering is among the highest professional distinctions accorded to an engineer. Academy membership honors those who have made outstanding contributions to "engineering research, practice, or education, including, where appropriate, significant contributions to the engineering literature," and to the "pioneering of new and developing fields of technology, making major advancements in traditional fields of engineering, or developing/implementing innovative approaches to engineering education."

Professor Gao received his B.S. degree from Xian Jiaotong University of China in 1982, and his M.S. and Ph.D. degrees in engineering science from Harvard University in 1984 and 1988, respectively. He served on the faculty of Stanford University between 1988 and 2002, where he was promoted to associate professor with tenure in 1994 and to full professor in 2000. He was appointed as Director and Professor at the Max Planck Institute for Metals Research in Stuttgart, Germany between 2001 and 2006. He joined Brown University in 2006. Professor Gao has a background in applied mechanics and

engineering science. He has more than 25 years of research experience and more than 300 publications to his credit. Professor Gao’s research group is generally interested in understanding the basic principles that control mechanical properties and behaviors of both engineering and biological systems. His current research includes studies of how metallic and semiconductor materials behave in thin film and nanocrystalline forms, and how biological materials such as bones, geckos, and cells achieve their mechanical robustness through structural hierarchy.

Professor Gao becomes the ninth member of the Brown School of Engineering faculty to be elected to the National Academy of Engineering. He joins William Prager (elect

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Brown’s Barrett Hazeltine Named one of America’s “Best 300 Professors” by The Princeton Review

Legendary engineering professor Barrett Hazeltine has been recognized by The Princeton Review as one America’s top undergraduate professors in its latest guidebook, The Best 300 Professors. The book profiles professors in 60 fields based on surveys by The Princeton Review and ratings on RateMyProfessors.com, the highest trafficked college professor ratings site in the country. Data from RateMyProfessors.com identified more than 42,000 professors, and was culled down to a base list of 1,000 professors. After obtaining further input from university administrators and students, along with The Princeton Review’s surveys of the professors under consideration, the editors of The Princeton Review made the final choices of the professors. Professor Hazeltine has taught engineering, management, and technology courses at Brown for more than 50 years, and currently teaches Management of Industrial and Non-Profit Organizations, Managerial Decision Making, and Appropriate Technology. He received awards for teaching from thirteen senior classes at Brown, 1972 to 1984, and 1990. In 1985, this award was named after him. “Professor Hazeltine has touched the lives of so many Brown students over the years,” said John Stamler ’98, Brown University alum and investment professional at Wayzata Investment Partners “I always looked forward to attending Professor Hazeltine’s classes knowing they would be thought provoking, interesting and challenging. His passion for his subject and commitment to all of his students made him extra special. He is a true asset to Brown University.”

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M eet the N E W P r esident

President-Elect Paxson Visits School of Engineering On Tuesday, March 20, Dean Larry Larson had the pleasure of leading President-Elect Christina Paxson on a tour of Barus and Holley, Prince Lab, and the Giancarlo Labs. This was the President-Elect’s first extended visit to campus since her selection as the University’s 19th President on March 2. During the visit, Paxson also met with senior administrators and faculty members and toured the libraries. During her tour of the School of Engineering, President-Elect Paxson had the opportunity to meet many professors, graduate and undergraduate students, and staff, and see demonstrations of some of the research that is being conducted at the School. Outstanding faculty members Arto Nurmikko, Gabriel Taubin, Ben Kimia, Rashid Zia, Chris Bull, Kenny Breuer, and Nitin Padture explained some of their ongoing research projects to the President-Elect.

Professor Gabriel Taubin shows President-Elect Paxson the video wall constructed by his group as a prototype platform to develop new computer vision technologies to enable groups of users to interact with large format displays in collaborative environments, as well as remote collaboration of multiple groups across large distances.

She also had the opportunity to sit in on Professor Allan Bower’s freshman EN0040 class, where she was able to see student presentations. “Having the opportunity to present our project to President-Elect Paxson was wonderful, not only because she had a very friendly and amiable demeanor, but also because she showed evident appreciation for our ideas,” said Emily Toomey ’15.

“Although the project at first seems like it has a simple objective, it required a great deal of collaboration, creativity, and application of engineering principles to create a successful result. By asking questions about our thought processes and how the MATLAB functions worked, President-Elect Paxson displayed a genuine interest in our efforts that made the project even more worthwhile,” added Toomey. “What I enjoyed most about President-Elect Paxson's visit was the genuine interest that she showed in understanding our project,” said Maggie Coats-Thomas ’15. “The questions that she asked made it clear that she understood what was going on and appreciated our efforts, which I thought was very rewarding. She was very friendly and I am so pleased I got the opportunity to interact with her so soon after she was elected.” The tour also provided the new President-Elect with the opportunity to see some of the space and facility constraints and challenges that currently exist in Barus & Holley. In an interview with the Brown Daily Herald, Paxson said of engineering, “it is clear that they’ve had a lot of growth, but they’re very tight on space.” Overall, the tour was a great success in showcasing both the exciting work that is happening in the School of Engineering, and the need for expansion and growth.

Left to Right: Wendy Ginsberg ’15, Emily Toomey ’15, President-Elect Paxson, Dean Larry Larson, Selena Buzinky ’15, Professor Rod Clifton, and Omar Nema ’15.



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Brown Engineering in Moscow! My intensive two-week introduction to international spaceflight began with cloudless skies and 95% humidity on the campus of NASA, Houston. There, with Dr. Michael Kezirian ‘89 as guide and host, I was given the full tour of Johnson Space Center facilities including the SAIL (Shuttle Avionics Integration Laboratory), the NBL (Neutral Buoyancy Laboratory), the shuttle docking simulator, Mission Control Center, and numerous other shuttle and space centered projects. We met a few somber souls who were soon to lose their shuttle-related jobs upon shuttle “wheel stop”, uncertain about the future. At the same time, in a brief tour just down the road, we met the hopeful faces of the employees at Ad Astra Rocket Company, looking forward to the future usage of ion propulsion in deep space travel. All of my exposures to U.S. space travel in Houston would turn out to be the perfect preface to the ensuing experience on the Moscow Space Summer Internship Program (MSSIP). I soon met up with the eight other American students accepted into the program, hailing

from USC, UTEP, Rice University, and University of Houston. The MSSIP, founded by the Baker Institute for Public Policy at Rice University, was to send us nine American students to participate in Space Development: Theory and Practice (STDP), hosted by Bauman Moscow State Technical University (BMSTU). This act of public policy was made in part to establish precedence for international space collaboration, and would be the first time SDTP had admitted American students since its beginnings in 1996. Thus, we departed Houston on the 6,000 mile journey to Moscow to join the other 50 student participants from over ten different countries including Switzerland, France, Germany, England, Australia, South Korea, Greece, and of course, Russia. We were met at the Domodedovo Airport by Russian students of BMSTU, with whom we would be spending the next two weeks. After stopping by our dorms and meeting the other participants, we plunged right into the amazing cultural portion of the trip which started off with a quick tour through

Russian Cosmonaut Sergei Krikalev (center) with Nick Helmer, USC, (left) and Alex.

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by Alexander Grosvenor ’12

Red Square and Alexander’s Garden. Throughout the rest of our time in Moscow, we visited markets, saw the “Black Swan” performed by the Russian Ballet, indulged in Russian foods, and toured historic sites such as the Kremlin, The Holy Trinity-St. Sergius Lavra, and the Tretyakov Gallery. Our cultural experience was topped off with a night out on popular Arbat Street and a boat trip up and down the Moscow River. These cultural activities were well integrated into the entirety of the trip, but were heavily supplemented with the real focus of the program: the Russian Space Agency, or Roscosmos. Who better to introduce us to Roscosmos than world-renowned cosmonaut, Sergei Krikalev? Having spent more time than any other human in space (800+ days), it was incredible to have the chance to speak with him and shake his hand. The trip continued with tours of multiple space museums and functioning facilities. At Zvezda, a research, development and production enterprise for Roscosmos and the Russian military, we learned about the design and history of Russian space suits and ejection seats. At Mission Control Center in Korolev we were given a unique opportunity to hold a long distance real-time Q&A video conference with the Russian cosmonauts aboard the International Space Station. Every student was extremely curious about life in space and we were truly lucky to hear about it straight from the source. Other learning experiences included visits to the Memorial Museum of Cosmonauts, Monino Air Force museum, and BMSTU’s own University Educational and Experimental Center. Some of these museums offered a unique touchanything policy, giving us a chance, for example, to actually climb into the Russian lunar lander (built in the ’60s but never flown) at the Educational and Experimental Center. At the Gagarin Cosmonaut Training Center in Star City, we were given a tour of cosmonaut training facilities such as the centrifuge

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Touring the Gagarin Space Museum.

trainer, their equivalence of the Neutral Buoyancy Lab, the Soyuz, and other systems mock-ups. Here, the intense pride that the Russians have for their human spaceflight capabilities was very evident.

tile temperatures on Mercury. As a member of the thermal design group, I was personally involved in brainstorming solutions for this untested dilemma. We worked to tackle this problem by using a combination of concentrating parabolic mirrors, solar radiation collectors, excess heat radiators, multi-layer insulation, and of course, teamwork and problem solving skills. The final rover design was presented to the President of BMSTU and directors of SDTP as well as some members of the local media. At the end of this program I realized that the interpersonal experiences and relationships formed with students from all over the globe were some of the most valuable aspects of the trip - and arguably the purpose of this trip. By working and living with international engineering students for almost two weeks I gained life-long friendships and was able to experience and promote the international cooperation that will be necessary as humanity begins to explore deep space. I am very thankful to the students of Bauman University and organizers

CAD model, created in Solidworks, of final rover design includes solar collector and deflector, a camera system and internal scientific instruments, 6-axis robotic arm with various tools attached, and a chassis system.

of Space: Development, Theory and Practice 2011 as well as all those at the Baker Institute of Rice University who made this trip possible. I look forward to seeing the growth of the program within the Brown University School of Engineering, and I’m happy to report that this summer three more Brown students - Ian Brownstein ’13, Brady Casper ’13, and Nathaniel Gilbert ’13 - will have the opportunity to participate in the program.

In addition to our history lessons and visiting of space program exhibits, we were given lectures, usually in Russian and translated to English, by Bauman professors on topics of space flight. These included lessons on robotics, ballistic trajectories, rocketry, and thermal control. We even had the opportunity to build and launch our own model rockets. Three American students, including myself, took first, second and third in the flight duration competition. The culmination of this program of international cooperation was the team project, the goal of which was to design a Mercurial rover that could demonstrate the same capabilities as the currently operable Mars rovers. The entire project was divided into five specialized groups including ballistics, thermal control, robotics, electrical control systems, and general design. One of the main problems was designing a rover that could withstand the extreme radiation and vola



In the pilot’s seat, testing the shuttle simulator for “take-off”.

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Brian Regiannini

Hear me now? If computers could become ‘smart’ enough to recognize who is talking, that could allow them to produce realtime transcripts of meetings, courtroom proceedings, debates, and other important events. In the dissertation that will allow him to receive his Ph.D. at Commencement this year, Brian Reggiannini ‘07 ScM ‘09 PhD ‘12 found a way to advance the state of the art for voice- and speaker-recognition.

Everyone does signal processing every day, even if we don’t call it that. With friends at a sports bar, we peer up at the TV to see the score, we turn our head toward the crashing sound when a waitress drops a glass, and perhaps most remarkably, we can track the fast-paced banter of all the people in our booth, even if we’ve never met some of the friends-of-friends who have insinuated themselves into the scene. Very few of us, however, could ever get a computer to do anything like that. That’s why doing it well has earned Brian Reggiannini a Ph.D. at Brown and a career in the industry. In his dissertation, Reggiannini managed to raise the bar for how well a computer connected to a roomful of microphones can keep track of who among a small group of speakers is talking. Further refined and combined with speech recognition, such a system could lead to instantaneous transcriptions of meetings, courtroom proceedings, or debates among, say, several rude political candidates who are prone to interrupt. It could help the deaf follow conversations in real-time. If only it weren’t so hard to do. But Reggiannini, who came to Brown as an undergraduate in 2003 and began building microphone arrays in the lab of Harvey Silverman, professor of engineering, in his junior year, was determined to advance the state of the art. The specific challenge he set for himself was real-time tracking of who’s talking among at least a few people who are free to rove BROWN School of Engineering

around a room. Hardware was not the issue. The test room on campus has 448 microphones all around the walls and he only used 96. That was enough to gather the kind of information that allows systems – think of your two ears – to locate the source of a sound. The real rub was in devising the algorithms

“We’re trying to teach a computer how to do something that we as humans do so naturally that we don’t even understand how we do it.”

and, more abstractly, in realizing where his reasoning about the problem had to abandon the conventional wisdom. Previous engineers who had tried something like this were on the right track. After all, there is only so much data available in situations like this. Some tried analyzing accents, pronunciation, word use, and cadence, but those are complex to track and require a lot of data. The simpler features are pitch, volume, and spectral statistics (a breakdown of a voice’s component waves and frequencies) of each speaker’s voice. Systems can also ascertain where a voice came from within the room. 22

Snippets, not speaker But many attempts to build speaker identification systems (like the voice recognition in your personal computer) have relied on the idea that a computer could be extensively trained in “clean,” quiet conditions to learn a speaker’s voice in advance. One of Reggiannini’s key insights was that just like a politician couldn’t possibly be primed to recognize every voter at a rally, it’s unrealistic to train a speaker-recognition system with the voice of everyone who could conceivably walk into a room. Instead, Reggiannini sought to build a system that could learn to distinguish the voices of anyone within a session. It analyzes each new segment of speech and also notes the distinct physical position of individuals within the room. The system compares each new segment, or snippet, of what it hears to previous snippets. It then determines a statistical likelihood that the new snippet would have come from a speaker it has already identified as unique. “Instead of modeling talkers, I’m going to instead model pairs of speech segments,” Reggiannini recalled. A key characteristic of Reggiannini’s system is that it can work with very short snippets of speech. It doesn’t need full sentences to work at least somewhat well. That’s important because it’s realistic. People don’t speak in florid monologues. They speak in fractured conversations. No way! Yes, really. People also are known to move around. For that reason position as inferred by the array

S T U D E N T S in the ne w s

Touring the Gagarin Space Museum.

Real-time tracking of who’s talking. With the right algorithms and signal processing software, an array of button-size microphones placed around the perimeter of a room can identify, follow, and record each of several people as they move about, interrupt each other, and converse. Photography: Frank Mullin/Brown University

of microphones can be only an intermittent asset. At any single moment in time, especially at the beginning of a session, position helpfully distinguishes each talker from every other (no two people can be in the same place at the same time), but when people stop talking and start walking, the system necessarily loses track of them until they speak again. Reggiannini tested his system every step of the way. His experiments included just pitch analysis, just spectral analysis, a combination of the two, position alone, and a combination of the full speech analysis and position tracking. He subjected the system to a multitude of voices, sometimes male-only, sometimes female-only, and sometimes mixed. In every case, at least until the speech snippets became quite long, his system was better able to discriminate among talkers than two other standard approaches.

That said, the system sometimes is uncertain and in cases like that it defers assigning speech to a talker until it is more certain. Once it is, it goes back and labels the snippets accordingly. It’s no surprise that the system would err, or hedge, here and there. Reggiannini’s test room was noisy. While some systems are fed very clean audio, the only major concessions that Reggiannini allowed himself were that speakers wouldn’t run or jump across the room and that only one would speak from the script at a time. The ability to filter individual voices out from within overlapping speech is perhaps the biggest remaining barrier between the system remaining a research project and becoming a commercial success. A career in the field While the ultimate fate of Reggiannini’s innovations is not yet clear, what is certain is

that he has been able to embark on a career in the field he loves. Since leaving Brown last summer he’s been working as a digital signal processing engineer at Analog Devices in Norwood, Mass., which happens to be his hometown. Reggiannini has yet to work on an audio project, but that’s fine with him. His interest is the signal processing, not sound per se. Instead he’s applied his expertise to challenges of heart monitoring and wireless communications. “I’ve been jumping around applications but all the fundamental signal processing theory applies no matter what the signal is,” he said. “My background lets me work on a wide range of problems.” After seven years and three degrees at Brown, Reggiannini was prepared to pursue his passion. by David Orenstein



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S T U D E N T S in the ne w s

Brown’s Engineers Without Borders Brings Water to a Village in the Dominican Republic by Karine Ip Kiun Chong ‘12 Since its inception in 2006, Brown Engineers Without Borders (EWB) has been a dedicated group of passionate students intent on building a better world by applying their problem-solving skills and enthusiasm beyond the classroom walls. Our members’ work has impacted people around the world, from Peru, Kenya, and India to the Dominican Republic. Past international projects include setting up a health clinic, aiding Amaranth farming, and setting up a water-harvesting program and a water distribution-filtration system.

a backdrop, serving as decoration and storage due to the scarcity of electricity. Water is a scarce commodity for them as the women walk daily to the nearby stream to wash their clothes and fill their bath tub. Brown EWB felt that this aspect was something we could improve on, hence responded to the community’s call for assistance for setting up a water distribution-filtration system. A typical day in La Tinajita: Work started at 8:00 a.m. for our members to preempt the midday heat, before they would catch the heat of the day later on. Initial investigation and GPS topographical mapping had shown us suitable spring sources which could be tapped. Our engineering team chose a gravity-fed distribution system to take advantage of La Tinajita’s hilly terrain. We journeyed through the grassland looking for the water source and, once found, linked PVC pipes to direct water downhill to the two communal tanks, one of which led to a biosand filter. Because this region was prone to floods during the rainy season, it was essential to build a sustainable strong concrete base for the biosand filter, a task we completed with much help from the men of the village who are used to building their own houses out of bricks and cement, wood and corrugated sheets. At the end of a week’s work, we came away with the memory of the grateful smiles of the community members, the peace of mind that they had working taps near their home, and the assurance that they are empowered to maintain the water supply network and filter. This year, we hope to establish a long term relationship with a barrio in the city of Tireo in Dominican Republic. This summer, we will be sending two representatives to forge relationships with community leaders to truly comprehend the most pressing health needs of each community.

Sharon Makava ‘11, Joy Nkosi ‘11, Karine Ip Kiun Chong ‘12 and Matt Jasmin ‘09 discussing the building of the tank’s concrete base, while the community leader’s daughter (far right) watches on intently.

This year, Brown EWB reached out to the local community of Providence in partnership with the Hub, a community center in downtown Providence, through an after-school program for students from Juanita Sanchez High School. This program has been a rewarding opportunity both for the Brown EWB students-turned-instructors and for our students who gain high-school course credit by learning engineering skills through interactive, fun projects. In the spirit of our mission statement, this program aims at empowering communities through sustainable engineering projects. By sharing our knowledge of sustainable development and by enabling these students to make their own LED cubes and mini wind-turbines, it is our hope that they will come away with a sense that they can change society through passion and dedication.

For more information, please go to: students.brown.edu/ewb To discuss ways you can assist EWB, or make a donation to EWB, please contact [email protected] or 401.863-9877

During spring break in 2011, five of our members went to La Tinajita, Dominican Republic to bring a water distribution and filtration project to fruition, in collaboration with A Mother’s Wish Foundation, a local non-governmental organization (NGO). Our contact with La Tinajita was a humbling and enriching experience. We experienced the vivid contrast between our comfortable campus and the community, the old TVs and refrigerators in their homes are just BROWN School of Engineering

Rita (co-founder of A Mother’s Wish Foundation), Matt Jasmin ‘09, Joy Nkosi ‘11, a community member, Sharon Makava ‘11 and Karine Ip Kiun Chong ‘12: discussing the pipe network from the blue filtration tank to the storage tank and water point.

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Advisory counc il/a lumni involvement School of Engineering Advisory Council Members Sangeeta N. Bhatia ’90 Professor, Investigator, Director: Laboratory for Multiscale Regenerative Technologies MIT Cambridge, MA John Bravman President Bucknell University Lewisburg, PA Seth Coe-Sullivan ’99 Chief Technology Officer QD Vision Lexington, MA Dr. Rick Fleeter ’76 Ph.D.’81 Author/Adjunct Professor Brown University Providence, RI La Sapienza /University of Rome Rome, Italy Thomas F. Gilbane, Jr. ’69 P’97 P’98 P’00 Chairman & CEO Gilbane Building Company Providence, RI D. Oscar Groomes ’82 P’15 Metallurgical Engineer, Physicist and Materials Scientist Groomes Business Solutions Charlotte, NC Deirdre Hanford ’83 - Chair Senior Vice President, Global Technical Services Synopsys, Inc. Mountain View, CA David Hibbitt Ph.D.’72 PMAT’96 Co-Founder ABAQUS, Inc. Providence, RI Alejandro Knoepffler ’82 Principal Cipher Investment Management Co. Coral Gables, FL

Hanford on Alumni Involvement

Peter Lauro ’78 P’11 Partner Edwards Wildman Palmer, LLP Boston, MA JoAnn Lighty Chair, Professor of Chemical Engineering University of Utah Salt Lake City, Utah Andrew Marcuvitz ’71 P’06 Founder, Chairman Alpond Capital, LLC Lincoln, MA James R. Moody ’58 Sc.M.’65 P’97 President Co-Planar, Inc. Denville, NJ Venkatesh “Venky” Narayanamurti Director Science Technology /Public Policy Program Harvard Kennedy School Cambridge, MA James B. Roberto Associate Laboratory Director Oak Ridge National Laboratory Oak Ridge, TN Paul Sorensen ’71 Sc.M.’75 Ph.D.’77 P’06 P’06 Co-Founder ABAQUS, Inc. Providence, RI Donald L. Stanford ’72 Sc.M.’77 Chief Innovation Officer GTECH Adjunct Professor Brown University Providence, RI James E. Warne, III ’78 President WTI, Inc. Phoenix, AZ

School of Engineering Development Committee Charlie Giancarlo ’79 P’08 P’11 Managing Director Silver Lake Partners Menlo Park, CA Theresia Gouw Ranzetta ’90 Partner Accel Partners Palo Alto, CA

Joan Wernig Sorensen ’72 P’06 P’06 Providence, RI Paul Sorensen ’71 Sc.M.’75 Ph.D.’77 P’06 P’06 Co-Founder ABAQUS, Inc. Providence, RI

How did your time at Brown Engineering shape who you are? When I consider this question, my mind floods with examples of how Brown and Brown Engineering helped form me – personally and professionally. My Brown experience gifted me by shaping several personal traits like my work ethic, problem solving skills, global perspective and character. The office hours I spent with professors taught me to seek out experts. The late nights spent working on group projects with peers taught me the value of teamwork. I solidified my work ethic and time management skills when I successfully juggled my academic, extracurricular and social life at Brown. Brown gifted me with many things. Now it is my turn to give back to Brown. I do so financially and directly with my time invested as the chair of the School of Engineering Advisory Council. I am gratified to see how engineering at Brown is forming as we complete our second year as the School of Engineering. The University, our Dean, our faculty and staff, and our current students benefit directly from the time and resources that each of us gives back. How will you give back to Brown? Can you hire a Brown engineering undergrad as a summer intern? Can you interview prospective Brown students in your region? Can you partner with the college and sponsor research? Can you provide financial support with annual giving? No matter how you choose to add value to Brown, Brown will benefit from your engagement, as will you. Deirdre Hanford ’83

Engineering Advisory Council Mission Provide support and advice in the development, execution, and attainment of the School of Engineering’s strategic goals. Ensure the School of Engineering is providing the highest quality educational experience for its students, and is embarking on the highest impact, highest quality, research program. Coordinate with the Engineering Development Committee to ensure that our strategic and financial initiatives are achieved. Work with campus leadership to ensure their continued support of the School of Engineering, and recognition of the key role Engineering plays in the vitality of the entire Brown community.

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School of Engineering Box D 182 Hope Street Providence, RI 02912

C o mmen c ement 2 0 1 2 To view additional pictures from Commencement, please visit: http://tiny.cc/qkytgw