Graduate Research Highlights

A low student-to-faculty ratio, world-class researchers, collaborative laboratory facilities, and industry partnerships equip Tufts engineering students with the skills to excel in their chosen specialties and improve people's lives through a passion for innovation and a commitment to excellence.

Research Highlights

• Engineering for Sustainability
• Engineering for Human Health
• Engineering for Human Technology Interface

Engineering for Sustainability

Tufts engineers are developing a wide range of technologies to wean us from fossil fuels while providing the energy we need. Researchers are experimenting with novel materials to lower the cost and increase the efficiency of photovoltaics and fuel cells, building computational models to locate the best sites for offshore wind farms, and devising green manufacturing techniques. They're also improving the accuracy of climate change models, implementing innovative methods to clean up polluted watersheds, and working to make the design, monitoring, and maintenance of infrastructure, such as bridges, more eco-friendly.

• [tracking nanopollution]
• [remote sensing, climate change, and water resources]
• [photovoltaics]
• [wind turbines]
• [sustainable energy]
• [fuel cells]

[tracking nanopollution]

Tiny structures of carbon, titanium, and other materials-are revolutionizing everything from medical imaging to stain-resistant and wrinkle-free clothing. Civil and Environmental Engineering Professor Kurt Pennell is interested in understanding a neglected aspect of nanotechnology: what happens when these ultrafine particles make their way into our soil and groundwater systems?

"These particles aren't really regulated right now," says professor Pennell, whose research is funded by the National Science Foundation and the Environmental Protection Agency. As a researcher in Tufts' Integrated Multiphase Environmental Systems (IMPES) laboratory, Pennell is also investigating the neurotoxicity of chronic, low-level exposure to environmental pollutants.

Along with fellow IMPES investigators professors Andrew Ramsburg and Linda Abriola, the dean of the School of Engineering, the research team combines laboratory experiments and computational models to better understand how contaminants are transported in the environment and to develop new technologies to treat and protect water supplies.

[remote sensing, climate change, and water resources]

Most scientific models of climate change predict that the central United States will become drier as the planet warms. However, observations from the past fifty years show that the opposite is happening. "We're trying to solve this particular question, and improve the models," says civil and environmental engineer Shafiqul Islam, whose investigation is supported by the National Science Foundation. "There must be something going on with weather and climate patterns that we don't really understand."

It's one of several water-related research projects Islam is undertaking. Others include his recently launched online repository of global water research, "Aquapedia," and heading up the multi-institutional Water and Environmental Research, Education, and Applications Solutions Network (WE ReASON). Professor Islam is also affiliated with Tufts' interdisciplinary graduate certificate program, Water: Systems, Science, and Society (WSSS). His doctoral student Ali Akanda's work builds upon Islam's international, interdisciplinary research using remote-sensing data to track and predict cholera outbreaks.

"We're not simply interested in creating knowledge, we're interested in creating actionable knowledge," says Islam. "My students don't want to publish papers that just sit in a library."

[photovoltaics]

"Basically anywhere you have heat escaping, there's a potential for energy," says Dante DeMeo, one of the doctoral students working at the Renewable Energy and Applied Photonics (REAP) Lab with electrical and computer engineering professor Tom Vandervelde. "It's about making everything more efficient. Vandervelde's group is focused on thermal photovoltaics, which convert heat into energy.

They are particularly interested in building devices that can harvest waste heat—from industry, cars, computers, and even our bodies—and convert it into energy for things like lights, car radios, air conditioning, or pacemakers.

"Every 72 minutes, enough sunlight reaches the Earth to supply our current global energy demands for an entire year," says chemical and biological engineering professor Matt Panzer, whose research seeks to improve nanostructured, thin-film electrochemical devices. Meanwhile, biomedical engineering professors Fiorenzo Omenetto and David Kaplan, along with postdoctoral researcher Jason Amsden, are exploring an alternative to traditional silicon solar cells—biocompatible, silk-based photovoltaics.

And Jeffrey Hopwood, chair of electrical and computer engineering, is working on a new, cheaper way to manufacture solar cells to make them more competitive with fossil fuels. He's developed a means of coating thin plastics (think potato-chip bags) with a light-absorbing film.

[wind turbines]

The most hazardous ocean conditions sometimes occur well beneath the waves. Eugene Morgan, a civil and environmental engineering doctoral student, is studying underwater landslides along the sloping continental margins, a prime location for wind turbines. He's part of a team analyzing the effects of waves, currents, and other stressors so wind-farm developers can improve the structural design of turbine towers and choose wind-farm sites that maximize their efficiency while minimizing cost and risk. "Offshore winds are steadier, and the sites are far from population centers," says civil and environmental engineer Lewis Edgers, one of the professors leading the research and the associate dean for graduate education. "That's good and bad, because while people don't want to see a 400-foot wind turbine in their back yard, offshore construction is more expensive and the energy distribution is more complicated." Edgers is adapting expertise from three decades of helping oil companies build offshore rigs and platforms.

Joining him are professors Laurie Baise, Richard Vogel, Eric Hines, and Matthew Lackner, a wind-power expert at the University of Massachusetts at Amherst.

[sustainable energy]

Green energy isn't all about renewable sources. Tufts engineers also work on advanced energy materials and catalysts, and investigate less-wasteful energy storage, transfer, and consumption.

Chemical and biological engineering professor Maria Flytzani-Stephanopoulos heads the NanoCatalysis and Energy Laboratory (Nano CEL), where researchers study the activity of gold atoms and clusters, and other metal nanocatalysts in fuel-reforming reactions that produce hydrogen for fuel cell use. NanoCEL researchers also work on desulfurization of fuel gases and on the synthesis of suitable nanocatalyst additives for aviation fuels to improve their combustion efficiency and lower their carbon footprint.

Mechanical engineering professor Luisa Chiesa is investigating the use of superconducting magnets and cables to store and transmit energy from photovoltaics and wind turbines to meet energy demands when the wind stops blowing or after the sun sets. "The students in my lab are doing experiments to study the behavior of superconductors when they are used in large cable configurations and what can be done to improve their performance," says Chiesa.

Meanwhile, Chiesa's colleague, Marc Hodes, is using heat-transfer technologies to reduce energy consumption by power-hungry industries such as telecommunications. Increasingly ubiquitous fiber-optic cables, lasers, and other optical communication networks require precise temperature control to function properly. And that takes lots of energy, says Hodes, who is developing more efficient thermoelectric modules to get the job done. Likewise, along with mechanical engineer and associate provost, Vincent Manno, he is modeling the potential energy savings from using liquid-cooling rather than air cooling for computer server farms.

[fuel cells]

Chemical and biological engineering professor Maria Flytzani-Stephanopoulos collaborates with chemistry professor Charles Sykes to examine the interaction of metals such as gold and copper and adsorption of alcohols and hydrogen on these metal surfaces with atomic resolution using state-of-the-art scanning tunneling microscopes. This research can guide the design of new materials and processes for less expensive catalysts for fuel conversion and fuel cells.

Engineering for Human Health

Tufts is a leader in the development of cutting-edge biodegradable, biocompatible, and biomimetic devices to monitor our environment and safeguard our health. Engineers from multiple disciplines are teaming up to create edible sensors that can detect diseases in our bodies and toxins in our water, robots made entirely of soft tissue that could slither inside bombs to defuse them or repair our internal organs from the inside, and silk-based scaffolding for growing human blood vessels.

• [soft-bots]
• [edible optics]
• [metabolic engineering]
• [tissue engineering]

[soft-bots]

A team of Tufts scientists is inching its way to a major breakthrough in robotics. They are designing robots made entirely of soft, biocompatible, and biodegradable materials—no exoskeletons, no hinges or metal joints, and nothing toxic. The research could lead to robots that can shimmy along wires, crumple their way into tiny crevices to defuse improvised explosive devices, or even explore internal organs and blood vessels to make surgical repairs. Their inspiration is a thumb-sized green caterpillar known as Manduca sexta, or the tobacco hornworm, a creature that has long fascinated the team's leader, neurobiologist Barry Trimmer, a professor of biology who also holds appointments in biomedical engineering and Tufts' Sackler School of Graduate Biomedical Sciences.

Trimmer heads up the Biomimetic Devices Laboratory, one of six facilities operating in Tufts' Advanced Technology Laboratory (ATL), 40,000 square feet providing lab space for interdisciplinary research. Other research groups there are dedicated to advanced integrated circuits, the mechanics of soft materials, micro and nano fabrication, nanoscale integrated sensors, and tissue engineering. "One of the classic obstacles to interdisciplinary work is the question of which department is going to give up the space," says ATL research coordinator Michael Doire. "This facility is neutral ground, where we don't block everybody off in separate rooms. I like to call it a research Switzerland."

The ATL is the perfect home for the soft-bot project, because all sorts of expertise is needed to mimic the tobacco hornworm—from creating computational models of the caterpillar crawling along various surfaces, to recreating its stretchy skin, to building a central nervous system that can control its complex movements and react to its environment.

This last task fell to Valencia Joyner, a professor of electrical and computer engineering. The caterpillar uses relatively few neurons to produce a wide variety of movements, and Joyner has been building micro-scale circuits to approximate this incredibly flexible natural system.

"I can design a circuit that gives out an action potential that looks the same as that stimulated by the caterpillar muscle, but this requires control to ensure then you have to control that so that you're getting actual movement," she says. Another challenge was incorporating sensory feedback, that tells the caterpillar's brain where its legs are in relation to its body while crawling on different kinds of surfaces. To solve this, Joyner teamed up with mechanical engineer Robert White, who designed hair-like sensors that attach to the robot's feet to detect small displacements and feed this information into Joyner's circuits.

[edible optics]

Biomedical engineers Fiorenzo Omenetto and David Kaplan are developing biocompatible and biodegradable sensors able to detect everything from body temperature to food-borne bacteria to water pollution. The collaboration began, as many do, with the initiative of a graduate student. A student in Kaplan's lab was working on using silk as a replacement cornea and needed to make tiny, precise cuts in thin silk films. He and Kaplan sought out Omenetto, who has expertise in lasers. And Omenetto, in turn, became fascinated by the optical properties of the films.

Unlike the materials used for most current photonics devices, silk is deemed biocompatible by the Food and Drug Administration, so silk-based sensors could be injected into groundwater systems or integrated into food packaging and could detect the presence of pathogens or toxic chemicals by simply changing color. Plus, the devices Omenetto and Kaplan are creating can be stored at room temperature for long periods without losing their biological activity.

"It's a material, with multiple functionality, that you can eat and that will be reabsorbed by your body," says Omenetto. "This gives us a range of possible sensor applications that didn't exist before."

[metabolic engineering]

The goal is to genetically engineer bacteria into tiny factories manufacturing everything from antibiotics to biofuels to anti-cancer drugs. Chemical and biological engineering professors Blaine Pfeifer and Kyongbum Lee are leading the project, along with doctoral student Brett Boghigian, who forged the partnership. It's not just about rearranging a few genetic sequences. Cell metabolism is an interactive web of chemical reactions. Nothing can be changed in isolation.

"Some reactions we want to shut down and some we want to proceed faster," says Lee. "It's analogous to managing traffic in a complex network of streets."

So, the researchers are creating a computational model of a functioning, bioengineered cellular system. This is Lee's end of the project, and he credits Boghigian with seeing the synergy between his systems modeling and Pfeifer's metabolic engineering research.

"He approached us both," says Lee. "This is one of those collaborations that is really driven by a graduate student."

The team now has a working computational model, which Lee calls "a blueprint," for genetically engineering bacteria to produce any number of compounds. "The next step will be to have molecular biologists and molecular engineers follow that blueprint."

[tissue engineering]

Michael Lovett mends broken hearts. Specifically, he's engineering a vascular graft for coronary arteries that become clogged with plaque, causing heart attacks, America's number one killer. It's a project he began as a doctoral student in biomedical engineering and continues as a post-doctoral associate in Tufts' Tissue Engineering Resource Center, funded by the National Institutes of Health.

Lovett developed a method of "gel spinning" silk solution into tubes with diameters of about one millimeter. He seeds these tubes with smooth muscle and vascular endothelial cells, observes their growth, tests them for mechanical strength, and compares their properties with those of native tissue.

This year, a medical student working with Lovett successfully implanted these silk tubes in the aortas of rats. "We had good response, with the rat's smooth muscle and endothelial cells migrating into the tube," says Lovett. The next step will be incorporating different pharmaceuticals into these grafts to better control cell growth. The grafts could be ready for human hearts in about a decade.

Engineering for Human Technology Interface

Engineering is about solving problems. Whether it's creating a computer language with children's building blocks, helping teachers develop hands-on engineering curricula, or managing a new product line for a biotech company, Tufts graduate students are training the problem solvers of tomorrow and getting the real-world skills to be the engineering leaders of today. School of Engineering researchers are working to make computers smarter, too—better able to learn from experience. This could help scientists and doctors make the most of their data or provide users in general with an interface that automatically adjusts to suit their needs.

• [center for engineering education and outreach]
• [machine learning]
• [human-computer interaction]
• [cyber-enabled chemical models]

[center for engineering education and outreach]

In a technology-saturated society confronted by technical challenges such as an addiction to fossil fuels, engineering literacy is increasingly critical. Enter the Tufts Center for Engineering Education and Outreach (CEEO), where pedagogic research, instructional product design, classroom outreach, and workshops improve the teaching of engineering and spark more interest in science and math. Research at the CEEO is driven by students earning doctorates in math, science, technology, and engineering (MSTE) education.

Recent graduate Morgan Hynes developed a middle-school engineering curriculum using a robotics lab developed by LEGO, Tufts, and National Instruments. In another dissertation project, doctoral student Brian Gravel studied how having kids make stop-action movies reinforces their understanding of science and engineering. "Our mission is to motivate people of all ages to understand math, science, and engineering through hands-on, open-ended engineering projects," says CEEO director and mechanical engineering professor Chris Rogers.

One of the core programs at CEEO is the Student Teacher Outreach Mentorship Program (STOMP), in which undergraduate and graduate students work with teachers over several years to incorporate the math and science already in the teachers' curricula into interactive engineering projects, such as using static electricity to create mini-lightning bolts and making ice cream without an ice-cream maker.

[machine learning]

Computer scientist Carla Brodley develops algorithms that allow a computer to learn from experience by recognizing complex patterns and "rules of thumb" in massive data sets. The Machine Learning Group, led by professor Brodley and professors Roni Khardon and Anselm Blumer, teams up on interdisciplinary projects with scientists, engineers, and doctors from various fields who need help sifting, sorting, and mining information.

In one application, Brodley and her team worked with astronomers to detect anomalies in star-light measurements captured over time by huge telescopes to aid in the discovery of unusual astronomical phenomena. In another project, they worked with the evidence-based medicine group at the Tufts School of Medicine to automate the process of sorting through thousands of journal abstracts for relevant research.

[human-computer interaction]

As a graduate student, Mike Horn was in an elementary school on a fellowship, watching a math teacher whose curriculum included some computer programming to help the kids learn geometry. But the teacher just skipped over it and went on to the next lesson, which wasn't surprising to Horn. "He had about 25 kids and he had a handful of aging desktop computers," Horn says. "It made me think, Is there a way for the kids to learn programming without being tethered to a computer?"

So Horn, who earned his Ph.D. in computer science at Tufts in 2009, developed a tangible programming language while working in Tufts' Human Computer Interaction lab. Instead of grappling with complicated coding syntax, kids fit together wooden blocks containing simple commands for a robot, such as "forward" or "spin around." The computer then snaps a picture of the assembled blocks, which have barcodelike symbols on top that feed the robot its program.

The Human Computer Interaction Lab is led by computer science professor Robert Jacob and the belief that if our digital devices could learn a little bit about us, then they could subtly alter their interfaces to be more efficient and user-friendly.

In recent research, Jacob and his graduate students are teaming up with biomedical engineer Sergio Fantini to give computer interfaces the ability to read our minds—if only a little bit. They're using non-invasive techniques to measure mental workload and emotional activation in the brains of computer users. At the same time, they're designing interfaces that can adjust by, say, highlighting only important details on a computer screen or gradually fading extraneous windows when signaled.

[cyber-enabled chemical models]

Pressing problems in biotechnology and biomedicine can be solved using computational, mathematical, and statistical methods. Chemical engineering professor Kyongbum Lee works with computer science professor Soha Hassoun to create metabolic models that could predict potentially harmful side effects of chemicals and discover targets for drug development. Chemical engineering professor Hyunmin Yi teams up with computer scientist Diane Souvaine, professor and chair of the Computer Science Department, to develop models for functional nano-scale architecture manufacturing.