EFRC scientists take advantage of interdisciplinary centers to explore energy problems at the intersection of various fields of science
Timothy D. Courtney

Satiating the demand for energy is one of the world's defining scientific challenges, but the solutions are increasingly complex and beyond the capabilities and resources available to a single researcher. Solving these challenges requires a wide selection of research tools and a broad understanding of the underlying systems at work. These resources can best be realized by bringing together researchers from different fields. 

A researcher's education begins in primary school learning only a small collection of life's most essential skills. From there, they gradually work up to a broad study of art, science, economics, history, mathematics and more. However, for many, this is as diverse as their course of study will ever be. As undergraduates, the rigor of a technical degree narrows their focus, climbing higher into their chosen fields with increasingly less opportunity to explore other areas. This process only intensifies in graduate school with focused study not even within a single discipline, but on a single problem. For many, a Ph.D. requires years of study all focused to a razor's edge.

"This paradigm relies on the assumption that the challenges we face in developing renewable forms of energy are simple enough to be solved by such a linear approach," said Dion Vlachos, who leads the Catalysis Center for Energy Innovation, an Energy Frontier Research Center (EFRC) based at the University of Delaware. "Of course, many of them are not. We've made major advances by simply sharing perspectives and expertise between colleagues with different backgrounds."

Taking a single-discipline approach requires that one field contain all the tools needed to get the job done, or that the problems we seek to address exist in a vacuum, independent from one another. While there are not enough hours in a day for every researcher to master every discipline, this problem can be alleviated in large part by bringing together scientists and engineers from different disciplines.

"Building a team around the different disciplines – chemistry, computational sciences, biology, physics, materials, etc. – is absolutely necessary for us to design materials capable of mimicking Mother Nature's ability to build fuels using only abundant metals, water and sunlight," said Morris Bullock, who leads the Center for Molecular Electrocatalysis at Pacific Northwest National Lab.

This is not to say working across disciplines does not have its own obstacles. In the course of our studies, we learn to speak a foreign language – the language of science – and every field has its own dialect. We take different truths for granted and approach difficulties from different angles.

"The talks and journal papers by people in one discipline are almost unintelligible to most people in the other discipline," said MIT's William H. Green, a researcher at the Combustion Energy Frontier Research Center (CEFRC). This is both the greatest challenge and the greatest opportunity present in the collaborations within the EFRCs, and in truth, any collaborations of this nature. As one might expect, the juxtapositions of disciplines at EFRCs are as diverse as the centers themselves.

From Molecules to Motors: In just one example, theoretical chemists and automotive engineers are combining forces to develop next-generation biofuels at the CEFRC, headquartered at Princeton University. Their research is motivated by an understanding that not every renewable fuel will work in an engine. Their cross-disciplinary search is determined to identify biofuels that will. Focusing on fuels compatible with current combustion engines will allow CEFRC's findings to be more rapidly integrated into our economy without a dramatic overhaul of automotive fleets.

Their first test case was butanol, a known biofuel capable of substituting for gasoline. The automotive engineers identified critical fuel properties for optimal performance in gasoline and diesel engines such as the ignition delay and, by extension, the octane number. Combustion experiments were conducted in the laboratory to precisely measure these properties for butanol's several isomers. This enabled CEFRC's computational team to rapidly develop models to predict these properties. As the center prepares to move on to explore other alcohols and diesel substitutes, the engineers wait in anticipation to test the proposed fuels.

The CEFRC's collaboration has enabled the assembly of this model remarkably fast, but Green sees that as only part of the benefit. "It is great educational opportunity for my students, who are learning to see the problem all the way from the molecules through the engines, and of course a better understanding of the macro problem helps one to focus on the most important micro problems," said Green. This ability to see the whole picture is an increasingly essential skill among today's researchers.

An Electric Relationship: Another such collaboration is in the interface of electrical engineers, chemists and other disciplines at the Center for Interface Science: Solar Electric Materials (CISSEM) in the development of optoelectronic devices – electronic instruments that manipulate light. Centered at the University of Arizona, CISSEM draws from many pools of knowledge to understand complex phenomena.

Bernard Kippelen of Georgia Tech is engaged on a CISSEM project developing novel synthesis techniques for the electrode, the component that connects the circuit to the optically active part of the device to collect electrical charges. In the process, Kippelen's team identified a fascinating phenomenon: one of the chemicals used in their synthesis method, thought to only play a supporting role, markedly improved the electrode's performance by itself. This opened new questions however, because the chemical was not electrically conductive. "A lot of our research especially with organic or printed electronics is interdisciplinary in nature," explained Kippelen. "It's difficult to do it all as a single research group."

Kippelen led a broad effort to understand this peculiarity, employing the analytical techniques of other research groups to identify the cause. After a series of revelations from each group, the combined team was able to not only explain the improved performance, but capitalize on the phenomenon to take even more advantage of it. "The frequent communication within EFRCs leaves channels open to confer with colleagues in other disciplines. We could easily call up collaborators at Princeton to get their hypothesis or send them materials to test," said Kippelen.

Not content with stopping here, Kippelen is reaching out to mechanical engineering groups specializing in carbon-based electrodes to see what benefits his synthesis technique can bring to those materials.

A Material Impact on Chemistry: Materials science and chemistry have a long-standing overlap in the study of catalytic surfaces and polymers, but batteries and other energy storage devices have been increasingly important as well.  The Center for Electrical Energy Storage (CEES), centered at Argonne National Lab, has set its sights on improving battery technology through a deeply integrated collection of chemists and materials scientists.

While the energy-storing mechanism of batteries is ultimately chemical, the materials used and their configuration is critical to the performance of the battery. The interdisciplinary approach of CEES is able to design batteries with emphasis on both their chemical and structural properties, leading to continually increasing capability.

Jason Goldman, a University of Illinois graduate student in CEES, embodies the interdisciplinary approach taken by his center. Goldman studied undergraduate mechanical engineering and economics, and worked everywhere from finance to the Johnson Space Center before joining the chemistry department in the research group of Ralph Nuzzo.

Entering a new field was a challenge nonetheless. "I was used to thinking on a completely different scale. I had focused on macroscale projects, such as fluid mechanics for aircraft and design of grid-scale power plants. My first materials science class in grad school, statistical thermodynamics, was a real wake-up call," recalled Goldman. "The guidance of Ralph Nuzzo as well as all of the other professors associated with the EFRC – particularly Andy Gewirth – has not only directed my graduate career but been essential for me to develop the knowledge base I needed."

Goldman remembers a particular instance of applying a debugging methodology he learned working in computer science to his problem. "I broke down the complex system into a simpler problem," he explained. "I still remember taking the results to Ralph Nuzzo and getting amazing guidance on how to further demonstrate the results and then presenting the results in an EFRC subtask meeting."

This interdisciplinary environment is part of a trend that will only expand as time goes on. Future researchers must be able to draw from the backgrounds of each other to solve increasingly challenging problems in meeting our energy demands.

About the author(s):

Tim Courtney is a Ph.D. candidate at the University of Delaware and is a student in the Catalysis Center for Energy Innovation. He is advised by Jingguang Chen and Dion Vlachos. Tim holds a B.S. in Chemical Engineering from the University of Maryland, Baltimore County.