Thinking Small Led ASU to Better Fuel Cells

After UNLV, my university-hopping trip through the Southwest took me to Arizona State University (ASU). My principle reason for stopping at ASU was to visit with Professor Jonathan Posner, who went to school with me about a thousand years ago at UC Irvine.

Professor Posner now directs ASU’s Micro/Nanofluidics Laboratory, and he is among the most accomplished young microfluids researchers in the country. He recently won the National Science Foundation CAREER Award to study the fluid dynamics of colloidal crystals. Dr. Posner’s work extends into many different areas, including electro-kinetics and bio-sensors. However, the research area that got me fired up was fuel cells.

Many energy conversion processes are limited by flow phenomena occurring at extremely tiny length scales. For example, ion transport through semi-permeable membranes governs rates of energy generation in proton exchange membrane fuel cells (PEMFCs). Membrane hydration is critical to PEMFC performance. However, over-hydration causes liquid build-up in the fuel cell cathode, reducing oxygen transport to reaction sites, which hinders performance.

Professor Posner and his colleagues developed a mechanism to actively pump water away from the fuel cell cathode. In a recent paper on the subject, Posner and his co-authors say “removal of liquid water with a low power, robust, active method should allow PEMFCs to operate in regimes otherwise inaccessible due to flooding.” Not only did they improve performance, but they also extended the effective PEMFC operating range to lower temperatures.

With their well-developed expertise in small-scale fluid flow, ASU’s Micro/Nanofluidics Laboratory is nicely positioned to make an impact in energy generation and other allied industries. Professor Posner is a researcher worth keeping your eye on.