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. Results are published in Nano Letters.

PROVIDENCE, R.I. [Brown University] — 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.

Tripping the light fantastic Each plasmonic interferometer -thousands of themper 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

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 surface 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.

“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.

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 (biology), 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

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Brown School of Engineering to Host a One-Day Planetary MicroRover Workshop

On February 16, 2012, MicroRover will be hosted by the Brown University School of Engineering (Barus and Holley Room 190). MicroRover continues our Space Horizons series of intense one-day workshops, this year bringing planetary researchers together with engineering innovators to discuss the design and application of microvehicles to planetary science missions.

The majority of rovers sent to other planets have offered significant mission utility by deploying multiple-instrument packages.  On the other hand, rovers are becoming increasingly large and complex with longer development times and higher engineering costs. This leads directly to greater risk-aversion that easily spirals into even higher costs and increasing risk-aversion.  With so much riding on each mission, 'safe' landing sites must be selected with exceeding care and ongoing operations undertaken with ever-greater caution at every juncture -- thereby limiting exploration opportunities.

Smaller rovers may offer less capability individually, yet may also provide this utility with far less cost and risk exposure, particularly if large numbers are deployed.  In particular, advantages may include:

• Unit costs that are lower due to simpler designs and the economies of higher production volumes.
• More than one point of interest can be studied simultaneously.
• Instruments may be distributed among specialized vehicles that work together.
• Spare rovers can be kept in reserve during a mission, allowing consideration of higher risk operations.
• A larger rover might act as a "mother ship" to transport families of microrovers to new sites of interest.

Through formal presentations, presenter Q & A, expert panels and informal venues, our workshop will stimulate a wide variety of discussions on topics relevant to the subject of microrover development and mission applications.

Participation is limited to 50. There is no formal registration process or fee for students and faculty of Brown University, and we ask only that you contact us ahead of time to ensure that there will be sufficient space.  Planetary researchers and robotics engineers from other institutions are invited to register online. Student sponsorship for overnight accommodation is available to student from other universities with sponsorship from the NASA Rhode Island Space Grant Consortia.

For additional information, please contact: Kenneth_Ramsley@brown.edu  or visit the workshop website at:
http://www.brown.edu/Departments/Engineering/Workshops/Microrover

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Christian Franck wins Haythornthwaite Research Initiation Grant from ASME Applied Mechanics Division

Christian Franck, an assistant professor in the School of Engineering at Brown University, has received a Haythornthwaite Research Initiation Grant, a new divisional award presented by the Applied Mechanics Division (AMD) of the American Society of Mechanical Engineers (ASME).

This new grant targets university faculty that are at the beginning of their academic careers engaged in research in theoretical and applied mechanics. Professor Franck was one of three recipients of the 2011 awards, along with Dennis Kochmann of CalTech and Xuanhe Zhao of Duke. 

“This is a well deserved award for Professor Franck,” said Dean Larry Larson, “and this grant reflects the potential impact of his research program. The mechanics program has been an area of historic strength at Brown and it is one that continues to remain vibrant with bright, young professors such as Professor Franck.”

Professor Franck specializes in biomechanics and new experimental mechanics techniques at the micro and nanoscale. He received his B.S. in aerospace engineering from the University of Virginia in 2003, and his M.S. and Ph.D. from the California Institute of Technology in 2004 and 2008. His doctoral research was on the development of a quantitative three-dimensional experimental technique for applications in soft biomaterials and cellular traction investigations. Dr. Franck held a post-doctoral position at Harvard investigating brain and neural trauma before beginning his appointment at Brown in 2009.

The Robert M. and Mary Haythornthwaite Foundation has been a generous supporter of the ASME Applied Mechanics Division (AMD).  The Foundation supports scientific research, primarily research in the field of theoretical and applied mechanics. Robert Haythornthwaite was founder and first President of the American Academy of Mechanics.

Robert Haythornthwaite, who grew up in England, also had a Brown connection. In 1950, he was award a Commonwealth Fund Fellowship and spent a year studying at Brown. After obtaining his Ph.D. from London University in 1952, he returned to Brown in 1953 to join the Division of Engineering at Brown before moving on to positions at Michigan, Penn State, and Temple.

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23 Students Inducted in Tau Beta Pi at Brown

Tau Beta Pi, the engineering honor society, inducted 23 new members into the Rhode Island Alpha chapter at Brown University on Saturday, December 3. Fourteen juniors were inducted along with nine seniors.

Among the 14 juniors elected were: Ross J. Browne ’13, Derek  Croote ’13, Eric C. Greenstein ’13, Kaan T. Gunay ’13, Mia M. Helfrich ’13, Steven I. Klurfeld ’13, Max Y. Liberman ’13, Visarute Pinrod ’13, Patipan Prasertson ’13, Rebecca R. Reitz ’13, Sahar Shahamatdar ’13, Jeremy R. Wagner ’13, Kasey A. Wagner ’13, and Adam D. Wyron ’13.

The eight seniors elected included: Anastassia Astafieva ’12, Natalie E. Bodington-Rosen ’12, Karine Ip Kiun Chong ’12, Kelsey J. MacMillan ’12, Henry H. Mattingly ’12, Emir V. Okan ’12, Alejandro Rivera Rivera ’12, Pablo L. Sanchez Santaeufemia ’12, and Reid T. Westwood ’12.

Tau Beta Pi, founded in 1885, is the second oldest Greek-letter honor society in America; the oldest is Phi Beta Kappa. While Phi Beta Kappa is restricted to students in the liberal arts, Tau Beta Pi is designed to “offer appropriate recognition for superior scholarship and exemplary character to students in engineering.”

In order to be inducted into the prestigious honor society, juniors must rank in the top eighth of their class and seniors must rank in the top fifth of their class. Graduate students who have completed at least 50% of their degree requirements and who rank in the top fifth of their class are also eligible to become candidates for membership.

The Rhode Island Alpha chapter is not only an honor society to pay tribute to outstanding students, it also provides a vehicle for these students to assume a role of leadership at Brown and to be of distinctive service. Tau Beta Pi members are active in engineering student publications, the engineering recruiting project, and in a variety of other organizations.

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Professor Huajian Gao to Receive Rodney Hill Prize from IUTAM

Huajian Gao, Walter H. Annenberg Professor of Engineering at Brown University, will receive the 2012 Rodney Hill Prize from the International Union of Theoretical and Applied Mechanics (IUTAM). The prize, which consists of a plaque and a check for $25,000, is awarded in recognition of outstanding research in the field of solid mechanics and is awarded only once every four years in conjunction with the International Congress of Theoretical and Applied Mechanics (ICTAM). The initial prize was awarded at ICTAM 2008 in Adelaide, Australia. Professor Gao will receive his award during ICTAM 2012 which will be held in Beijing, China, from August 19-24, 2012.

Professor Gao receives the prize for his deep and broad scientific achievements in basic solid mechanics and its bridge to other fields, which has re-defined the modern frontiers of mechanics research. His work includes fundamental theory as well as applications to materials science, nanotechnology, and bioengineering. His highly cited publications appear not only in the major solid mechanics journals but also in many high-profile, cross-disciplinary journals.

"I want to warmly congratulate Professor Gao on this prestigious and well deserved award," said Dean Larry Larson. "His groundbreaking work shows how the field of solid mechanics - an area of historic national leadership at Brown - can have an impact on fields as diverse as health care, the environment and information technology."

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.

About IUTAM and its Congress
The International Union of Theoretical and Applied Mechanics (IUTAM) is an international non-governmental scientific organization belonging to the International Council of Scientific Unions (ICSU), which was formed in 1946 and founded in 1948, with the objectives to form a link between persons and organizations engaged in scientific work in mechanics and related fields, and to promote the development of mechanics, both theoretical and applied, as a scientific discipline.

IUTAM achieves this aim mainly by organizing international meetings to deal with scientific problems. An International Congress on Theoretical and Applied Mechanics (ICTAM), including mini-symposia and pre-nominated sessions, is held every four years. It is organized by the Congress Committee, established by the IUTAM General Assembly.

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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.

PROVIDENCE, R.I. — 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.”

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.

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.

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.

Novel device removes heavy metals from water from Brown PAUR on Vimeo.

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 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, solid-state 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

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Philippe Fauchet ScM '80 named dean at Vanderbilt School of Engineering

Philippe Fauchet ScM '80 will be the new dean of the school of engineering at Vanderbilt University.

Fauchet, currently chair of the Department of Electrical and Computer Engineering at the University of Rochester, begins work at Vanderbilt July 1, pending approval by the Vanderbilt Board of Trust.

He graduated from Brown University in 1980 with a master’s in engineering. Fauchet earned his Ph.D. in applied physics from Stanford University in 1984.

“This is an important moment of transition for the School of Engineering,” said Vanderbilt Chancellor Nicholas S. Zeppos. “Philippe Fauchet is already well-known and respected at Vanderbilt because of his accomplishments at the University of Rochester, and we anticipate great success as he brings his dynamic leadership to our campus.”

Fauchet will succeed Dean Kenneth Galloway, who is returning to the faculty at the end of the current academic year after serving as dean since 1996.

“The engineering school is getting a visionary leader in Philippe Fauchet to build on the impressive contributions of Dean Ken Galloway,” said Richard McCarty, provost and vice chancellor for academic affairs. “Philippe has broad experience as a researcher and he is a dedicated teacher and university citizen. I look forward to his arrival on campus with great excitement.”

Galloway disclosed to members of the engineering faculty last spring that the 2011-2012 academic year would be his last as dean. Fauchet was named his successor after a national search by a provost-appointed committee.

During Galloway’s tenure, research expenditures from external sources grew from less than $10 million to more than $60 million annually, according to Art Overholser, senior associate dean and professor of biomedical engineering and chemical engineering. The school has also experienced a steady rise in national rankings, facilities have been upgraded and outstanding faculty have been retained and recruited.

“I intend to build on the strong foundation laid by Dean Galloway and help the School of Engineering become a national leader that attracts the very best minds from the United States and abroad,” Fauchet said. “I think Vanderbilt can have important impact on issues including improving health for our aging population, energy production, the environment and security.”

Fauchet, 56, is the founder of Rochester’s Center for Future Health, where engineers and physicians work to develop affordable technology that can be used in the home. He is also the founder of the Energy Research Initiative, a university-wide effort at Rochester to coordinate and expand the university’s research and educational activities in all areas related to energy.

“With his considerable administrative experience and leadership skills, Philippe Fauchet will be a great fit for our School of Engineering and Vanderbilt University,” said M. Douglas LeVan, the J. Lawrence Wilson Professor of Engineering at Vanderbilt and chair of the committee that recommended Fauchet. “The range of his research interests is extraordinary.”

Fauchet has been the primary adviser of Ph.D. students in six different academic disciplines and is the author of 400 technical articles. He became the chair of the Department of Electrical and Computer Engineering at Rochester in July 2010.

“I have known Philippe for some 27 years,” said Dennis Hall, vice provost for research and dean of the Graduate School at Vanderbilt. “His collaborative style, his record as a fine classroom teacher, and his history of personal engagement with productive research related to energy, health care, nanoscience and more, make him an excellent match and catch for Vanderbilt.”

Fauchet and his wife, Melanie, a nurse practitioner, have 13 children ranging in age from 2 to 22. Eight of their children are adopted and five are biological.

The Vanderbilt School of Engineering, founded in 1886, is celebrating its 125^th anniversary. It ranks No. 34 in U.S. News and World Report’s evaluations of engineering programs nationwide. While retaining its strong focus on teaching, leaders at the school have dramatically expanded its research component, with an emphasis on the development of technology that is useful and accessible to the general public.

“I am especially looking forward to working with other academic units at Vanderbilt and also with the federal and state government, industry and our alumni,” Fauchet said. “Together we can develop research and educational initiatives that will contribute to solve the most pressing societal problems the United States and the world are facing.”

- by Jim Patterson/Vanderbilt University News

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