Creative Problem Solving Across Disciplines

Veronica Miller has spent the past few years as a University of Pittsburgh graduate student learning the intricacies of fluid dynamics, gaining expertise in concepts such as fluid flow and how turbulence is measured.

But Miller, who is pursing a PhD in mechanical engineering, wasn’t content to simply learn the concepts—she wanted to put her new knowledge to good use. So she also is studying renewable energy at Pitt’s Center for Energy, focusing in particular on hydroelectric turbines that can be dropped onto a riverbed or ocean floor to harness electricity from underwater currents. An expert-in-training in mechanical engineering, Miller is wading into other fields—environmental economics, ecology, electrical engineering, computer modeling—in an effort to make her research connect to real-world energy needs.

“If I want to tackle something as big as clean energy, I can’t just focus on mechanical engineering. In real cases, you have to be more than an expert in just one area,” she says.

Miller is one of more than 500 Pitt PhD students who are gaining expertise in the rapidly changing fields that have grown up in the physical sciences and engineering during the 20th and early 21st centuries. Pitt PhD students are very well grounded in the fundamentals of their chosen fields—chemistry, biology, physics, or a number of engineering specialties—but they are also oriented to addressing problems that are outside of their fields. Their mission to be creative in other areas forces  them to master things at the boundaries of their fields and others, to work or consult with experts in other fields, and to synthesize new solutions to problems with an amalgam of all these resources.

The examples that follow explore the rich variety of questions that current Pitt science and engineering PhD students are addressing.

The Creative Spark

A key component of a Pitt doctoral program—in any field—is the opportunity for students to look at problems creatively, from various vantage points. “Research isn’t just about answering problems at the back of the textbook,” says Provost and Senior Vice Chancellor James V. Maher. “You have to be able to study a problem, look for holes in the data, and wonder from where you might be able to draw a solution. It’s essentially a creative process.”

Peter Koehler, professor and director of graduate studies in physics at Pitt, says research requires scientists to have a certain intellectual fitness to approach a problem from multiple perspectives. For instance, a physicist looks at a CO2 molecule or cancer cell differently than a chemist does. But both approaches can help advance research on the topic.

“A real skill that needs to be developed is how you define a problem,” says Koehler. “You don’t want to be too narrow in your training. You always want to keep an eye out for new horizons in research that may not have even been possible when you started.”

Quite often, the path to becoming a successful researcher will lead to other fields and disciplines, says Mark Redfern, a professor of bioengineering and associate dean for research in the Swanson School of Engineering. The reason is that many of the most-pressing problems don’t fit neatly into intellectual categories.

“Research now often requires combining information and techniques from different fields,” says Redfern. “The problems we’re dealing with are complex and require new and innovative approaches.”

Going Outside a Comfort Zone

Training PhD students to cross disciplinary boundaries is part and parcel of scientific tradition, says David Waldeck, professor and chair in Pitt’s Department of Chemistry. “Chemists have often called chemistry the ‘central science’ because it links physics and math to fields like biology and related sciences.”

In recent years, emerging fields like nanoscience and engineering, biophysics, structural biology, and green chemistry have spurred collaboration, offering novel and different ways for scientists to address problems.

To prepare chemistry PhD students for interfacing with these fields, the program requires them to complete a research proposal outside their areas of concentration. “It’s a way of learning how to be an independent researcher in a controlled environment,” Waldeck says. “How do we know the program works? Because students initially say they hate it. But after they’ve finished, they say they’re glad they did it.”

Stephen Weber, a Pitt professor and director of graduate studies for the chemistry department, says being prepared to move into an alternate research field is critical for research PhDs.

“That’s what a true PhD scientist is—someone who can go into a new field, read about it, learn about it, ask cogent questions about it. That’s what we’re training our students to do,” Weber says. “Being a scientist isn’t like joining a guild, where you acquire a set of skills and go out and repeat those skills over and over again. You have to be able to go out and digest someone else’s scientific understanding and incorporate it into your own line of inquiry.”

In physics, students are encouraged to take courses in related disciplines. In engineering, students should have at least a basic understanding of other disciplines with which they interact, says Laura Schaefer, codirector of the Center for Energy and a professor of mechanical engineering. That means they must know the language of other disciplines: a ‘parameter’ in engineering could be a ‘variable’ in chemistry.

“I’ll encourage students to take a course in other departments or schools; even the same course could be taught totally differently,” Schaefer says.

This type of cross-fertilization is a critical component of graduate education. While a student still needs to be an expert in a specific field to get a PhD, each student realizes that no branch of science exists in a vacuum. Increasingly, students need to work outside their disciplines to find new lines of inquiry and stay on the leading edge of discovery.

The Search for Energy Solutions

The emergence of research centers in energy, nanoscience, and computer simulation and modeling has accelerated this trend. Gerald Holder, the U.S. Steel Dean of the Swanson School of Engineering, says one of the Center for Energy’s purposes is to encourage collaboration between faculty and their graduate students from a variety of disciplines, schools, and departments. The energy question permeates all levels of global society, Holder says, adding that it makes sense to pull as many bright minds into energy research  as possible.

“Society’s interested in this, and so are the students. What we’re trying to do with the center is to focus on creating new technologies by bringing people from around the University together to tackle the big issues,” Holder says.

The prospect of working in the alternative energy field attracted Miller to Pitt, where she is trying to determine which turbine designs can harvest the most energy with the least impact on the aquatic environment. The devices work a lot like submerged water wheels or windmills. Because the devices are in water, they are propelled by drag or lift, the same forces that make airplanes fly. The flow of water propels the turbine’s blades, which turn a shaft that generates electricity. Using computer-modeling software, Miller is analyzing how a series of turbine designs would impact the aquatic environment.

“If we know how water flows through the turbine device, we can estimate how fish will swim around them, and whether they’ll get stuck in the turbine blades,” says Miller, whose research could also lead to the development of a tidal turbine that would generate electricity from currents at the bottom of the ocean floor or tidal estuary.

She’s also working on a research proposal with David Sanchez, a graduate student in Pitt’s civil and environmental engineering department, to create a remote sensor for pollution in rivers that would measure electrical current fluctuations caused by certain kinds of pollutants. In addition, Miller is working with a Pitt mechanical engineering grad student on a project to install river turbines in Ghana.

“Pitt really fosters an environment where we’re thinking about working with people in other fields: I’m not a civil engineer or an electrical engineer, but in order to solve some of these energy problems, I need to be able to work with these kinds of researchers.”

Miller enjoys working on a problem that has a solution with an immediate real-world impact. “It’s one thing to do all these things on paper; it’s another to be able to generate clean, renewable electricity for people who really need it.”

Florian Zink, another mechanical engineering PhD student, is researching thermoacoustic refrigeration—using sound waves as a component of cooling systems. Zink needs to understand the physics of acoustic waves in addition to the intricate science of heat transfer and fluid thermodynamics. Zink says his research at Pitt has opened his eyes to the possibilities for research in alternative energy, a rapidly developing field that is attracting experts in engineering, chemistry, physics, and ecology.

Solutions From the Nano Toolbox

Interdisciplinary research also is prominent in nanoscience at Pitt. The Petersen Institute for NanoScience and Engineering involves dozens of faculty members from various Pitt schools, including the Schools of Arts and Sciences, Engineering, Medicine, Public Health, and Pharmacy. Students from those schools have been able to tap a wide array of tools and faculty collaborations through the center.

Among these faculty members is Jeremy Levy, a professor of physics, who studies “nanostructures at the interface between insulating materials”—popularly termed ‘nanowires.’ These are thin layers of materials one molecule wide that can conduct electricity. Scientists think these structures could lead to increasingly smaller computers that can be implanted in a variety of places or devices. Levy, who collaborates with materials scientists and chemists, thinks his research is an example of how interdisciplinary approaches are needed in emerging fields like nanoscience.

“These nanomaterials are an area I didn’t know anything about two years ago,” Levy says. “Because I’m collaborating with other people, I don’t know how to make these materials, but I don’t have to. I still have to understand what they’re doing, but I can concentrate on another side of the equation.”

Physics PhD students are still expected to have expertise in their field—they must know advanced electromagnetism, classical mechanics, and condensed matter physics. But when they go into fields like nanoscience, they’ll also need to know how to cover ground in chemistry, biology, medicine, and materials science, Levy says.

“It’s important to be an expert in your own domain: The core task of training students in physics is still important. But you also have to learn how to learn, to learn what is needed to interface with collaborators in other disciplines. It’s a matter of becoming aware of what the possibilities are in research. When you’re working with experts in other disciplines, you don’t have to be the expert in their fields, but you do have to know a little bit about what they do.”

One of Levy’s students, Cheng Cen, is studying the electronic characteristics of these nanowires, specifically how electrical charges influence how nanowires behave. She says the research shows the nanowires have the potential to be manipulated into “single-electron transistors”—the tiniest of computing devices. “It’s like you’re writing on a canvas the width of a couple of nanometers,” says Cen, a fourth-year student. Though she’s in the physics department, Cen uses techniques and tools from chemistry and engineering labs. “We have to learn to use a variety of techniques: If it’s learning a new chemical process, you have to learn it; if it’s using a machine from engineering, you have to do it.”

Like Cen, Matt Kofke studies nanomaterials, but from the perspective of a chemist. Kofke, a second-year chemistry PhD student, is researching the optical transmission capabilities of some nanomaterials. Researchers in the field think the interaction of light on nanomaterials could be the key to developing sophisticated biosensors for certain antibodies, the development of more efficient solar cells, and improved fiber-optic communications.

Kofke has had to learn concepts of wave physics, materials science, and engineering along the way. The research has involved reading a lot of textbooks in other fields, and, when he’s stumped, asking someone for help. “That’s generally the best way to learn, and it’s worked pretty well for me,” he says. “The most important thing to learn in graduate school is how to independently direct your own research, to solve your own problems without relying on someone else doing it for you.”

Brett Allen is studying carbon nanotubes—tiny straw-like structures largely made up of carbon atoms. Scientists think these structures could have widespread use in medicine and energy. Allen, a third-year chemistry PhD student at Pitt, has studied nanotubes’ possible use as a biosensor for a gas that is common in the breath of asthmatics. This could be used as a diagnostic tool. He also is studying the possibilities for nanotubes to be used in carbon sequestration—the process of taking CO2, the most abundant greenhouse gas, out of the atmosphere, to slow the effects of global climate change. The ability to look at a research problem like nanotubes from various disciplines—chemistry, biophysics, materials science—is critical in being ready to follow the research wherever it leads, Allen says.

“Graduate school really focuses you on critical thinking—you’re taught to not just memorize things but to understand all the variables that can go into a problem,” Allen says. “A lot of the research in my field is brand-new. If you don’t have the ability to think through what’s going on, you’re never going to be able to understand what’s happening when you stumble on something new.”

Computer Simulation for Complex Phenomena

In another nascent area of scientific research—computer modeling and simulation—Pitt students also are taking an interdisciplinary approach to solving big scientific questions.

Sam Rothstein, a fourth-year PhD chemical engineering student, is using computer modeling to test ways to deliver drugs to AIDS patients and people with osteoporosis. Currently, many of these drugs require daily or even twice-daily injections. Researchers want to make drugs that require only weekly or monthly injections. Rothstein designed a model that predicts how quickly drugs are released in the body with different types of delivery systems (“vehicles”). Having developed a model that works in the lab, he will soon test the system in a real-world setting.

With computer modeling, Rothstein says, he can make progress solving problems faster than he would using only a lab. “The two problems I’m working on, a sustained-release medication and a single-injection vaccine, have a combined 50 years of research, and no one has come close to creating a better delivery system,” Rothstein says. “Computer modeling is a way to examine more parameters, more possibilities, than the normal benchtop approach.”

Rothstein has taken an interdisciplinary approach to his research—a full semester of medical school courses and sessions with computer-modeling faculty to develop his simulations. The approach works because it allows researchers like Rothstein to make faster progress on the question they’re addressing. Instead of working on one part of the problem, like modeling a drug-delivery system, Rothstein can also take the results from his model and perform an experiment in the lab to take the research to the next level.

“I can talk to people who are experts in modeling, and I can talk to people who are experts in application. Being an inter-disciplinary researcher means I can move the project forward,” Rothstein says.

Looking to the Future

The goal for students like Rothstein, Miller, Cen, and others is to help solve the big scientific problems of the 21st-century. To accomplish this, they have to master the tools and logic of their own disciplines while maintaining the intellectual acuity to understand and collaborate with scientists in other fields. That is what has fueled the great scientific discoveries of the past, and it is what funders like the National Science Foundation are looking for, says Larry Shuman, professor and senior associate dean for academic affairs in Pitt’s Swanson School.

And it’s what Pitt is instilling in its PhD students in the physical sciences and engineering, Shuman says: “You look at the societal problems we’re facing—energy, the environment, health care, and medicine. These are large, complex problems. The teams that tackle them have to be interdisciplinary, because we’re working on problems that are all over the map. We have to find expertise and opportunities at every turn. And for grad students at Pitt, that opportunity can be found throughout the University.”