School Notes: School of Engineering & Applied Science
July/August 2011

Advancements in fuel cells

Fuel cells have been touted as a cleaner solution to tomorrow’s energy needs, with potential applications in everything from cars to computers. But one reason fuel cells aren’t already more widespread is their lack of endurance. Over time, the catalysts used even in today’s state-of-the-art fuel cells break down, inhibiting the chemical reaction that converts fuel into electricity.

“In order to produce more efficient fuel cells, you want to increase the active surface area of the catalyst, and you want your catalyst to last,” says assistant professor of chemical engineering André Taylor. Taylor has teamed up with associate professor of mechanical engineering Jan Schroers to develop a new catalyst system using nanowires made of an innovative metal alloy—known as bulk metallic glass—that incorporates a platinum catalyst. At about one ten-thousandth the width of a human hair, their nanowires provide much more active surface area per mass than current technology, are durable, and are less expensive to process.

A ‘Eureka’ moment

Aerial images of the Deepwater Horizon oil spill in the Gulf revealed long, narrow streaks of oil—like threads on the ocean’s surface. This is an example of “efficient mixing” where an oil slick is repeatedly stretched and folded to expand its periphery and allow diffusion over a large surface area. Although stretching and folding have been qualitatively studied, researchers have never before been able to quantitatively decouple these phenomena. That was until assistant professor of mechanical engineering Nicolas Ouellette happened upon a journal article about a method for modeling glassy solids and realized that it could be applied to fluids. The work, published in the March issue ofNature Physics, provides new and important insights into the details of fluid mixing.

Yale engineers in schools

Doctoral student Sarah Miller was recently honored as a recipient of the Yale Elm-Ivy Award for her outstanding contribution to the education of the next generation of scientists and engineers. As part of a broad portfolio of community outreach work, Miller designed and led a program that has brought 13 Yale engineering doctoral students into New Haven’s Engineering and Science University Magnet School to lead classroom demonstrations and assist middle school teachers in their science and engineering curriculum.