Duke assistant physics professor Anna Lin admits she gets fascinated with the beautiful, swirling shapes of the ebbing and flowing Belousov-Zhabotinsky (BZ) chemical reaction. But her primary interest in the reaction is not aesthetic but rather scientific.
The BZ reaction is an example of a system that is "out of equilibrium," meaning that "energy is constantly being put in and energy is being constantly consumed," she explained in an interview. Her scientific interest and expertise in the fundamentals of this reaction has won her a $450,000 National Science Foundation Faculty Early Career Development (CAREER) award for young researchers.
She said her award will allow her to use the well-controlled BZ reaction as a model system to help understand less well characterized facets of instability. She envisions this investigation could also provide insights into how some patterns form in biology.
Chemicals in the BZ reaction are in constant flux. Excited by energy from a beam of light, one ingredient may begin copying itself while consuming supplies of a second chemical. As the second chemical in consumed, the first responds by interacting with a third chemical, furthering shifting the balance of the reaction components.
As concentrations of its chemical constituents shift back and forth, the gelatinous mixture of compounds forms spirals and other geometric patterns. In some cases those patterns, and the timing of the chemical reactions involved in their formation, mimic the evolution of biological shapes. Examples range from bacterial colonies to clumps of fertilized frog eggs.
Biological systems are also out of equilibrium, she said. "We eat every day, so we put energy into ourselves. Then we dissipate energy. That's essentially a non-equilibrium system."
Over the years, scientists and engineers have developed principles and mathematical equations derived from what are known as the laws of thermodynamics to explain how matter should behave in equilibrium, she said. "But we don't have the analogue of that for systems that are out of equilibrium."
So Lin is among groups of scientists doing experiments that they hope will provide "guidelines for the development of a theory of non equilibrium physics," she added.
In the process, her work at Duke will also look for ties to biology. For instance, the spiral waves that form in a BZ reaction show certain similarities to the spirals that form at certain stages during the development of fertilized frog eggs, she noted. And the generation of those biological spirals are tied to changes in the concentrations of certain chemical constituents such as calcium.
"The idea is to study a well-controlled model system - this BZ chemical reaction - and then to apply that knowledge to these intriguing biological systems," she said. "There has to be some physics that's dictating the biology."
Lin said she will use much of her five-year CAREER award grant to fund the work of graduate students and post-doctoral researchers involved in the BZ research. Her current graduate students Karl Martinez, Bradley Marts and Nicholas Perry will be joined by a fourth, Zheng Gao. She now works with two post docs, Eric Monson and Linda Smolka.
In the summary of her CAREER project, Lin wrote that another long-term goal is to contribute to the further development of Duke's multidisciplinary Center for Nonlinear and Complex Systems, which addresses a large range of phenomena that can be described as out of equilibrium.
She also has plans to incorporate such research "into the high school, undergraduate and graduate teaching curriculum." Some of that effort has already started. Last summer she discussed non-equilibrium physics and nonlinear dynamics with area high school teachers attending a class organized by Michael Fitzgerald, a Duke assistant professor of chemistry and biochemistry.
Lin received her undergraduate degree in chemistry, with a concentration in biology, at the State University of New York at Stony Brook. She then earned her Ph.D. in physical chemistry at the University of Michigan at Ann Arbor.
Before joining Duke's faculty, she did postgraduate research at the University of Texas at Austin with Harry Swinney, a leading researcher in nonlinear dynamics and complex systems whose lab has studied BZ reactions.
The CAREER award program recognizes and supports "those teacher-scholars who are most likely to become the academic leaders of the 21st century," according to the NSF.
Anna Lin was one of five Duke young faculty members to win NSF CAREER awards this fiscal year. In addition:
- Alexander Hartemink of computer science will receive $487,000 over five years for a project that will apply new computational inference methods to the study of complex biological systems, and that will develop a series of courses that incorporate computational biology into both the undergraduate and graduate curricula.
- Andrew Schuler of civil and environmental engineering will receive $400,000 over five years for a project studying new strategies for treating wastewater, involving the buoyant densities of biomass in solid separation. The project also includes an educational component, providing environmental engineering coursework and research experiences for high school, undergraduate, and graduate students.
- Adam Wax of biomedical engineering will receive $400,000 over five years for a project studying low coherence light scattering for biophotonics. One of the applications of the work could be determining the structural features of cells and tissues, providing an important approach for diagnosing disease.
- Jun Yang of computer science received $400,000 in funding over the next five years. Yang will use the award to support his research project titled "Techniques and Applications of Derived Data Maintenance." Yang's research interests include database and information management systems.