Graduate Research

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

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 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.

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.