Princeton Weekly Bulletin May 24, 1999
PMI knows what's the matter
By Ken Howard
In the 1967 movie The Graduate, a young man just out of college is given one word of advice toward a promising career: "plastics." Today, that word might be "composites"--or "silicon" or "biomaterials."
"In order to make a building work, you have to understand the material -- concrete," says chemistry professor Robert Cava. "On a smaller scale, the material of computer chips -- silicon -- makes electronics work. From the very tiny to the very large, materials are the building blocks that make it all happen."
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Microscope images of buckled gold films on elastomers |
Materials science and engineering grew out of metallurgy and ceramics. As Cava points out, "You took the stuff out of the ground and turned it into the technology of the day, including steel and concrete. Now materials are changing as technology is changing. People are looking for more sophisticated, more complicated types of materials. With these materials, scientists have to worry about more things--electronics, biological structure, physics. They need to be expert in various areas and reach out into other disciplines."
The multidisciplinary approach is characteristic of the research and curriculum at the institute, including a new graduate program that begins in the fall. Both research and course work are coordinated among seven affiliated departments: chemical, civil, electrical, and mechanical and aerospace engineering; chemistry; physics; and molecular biology. Faculty have joint appointments in PMI and a department, and undergraduates and graduate students are based in a home department while fulfilling core PMI course requirements.
Breaking the borders
"It's often the nature of a department to look inward," says Cava. "We're trying to break the borders between fields, to create a group of people who look both in and out. PMI faculty are like representatives who reach into their home departments, looking for expertise that may be of interest to someone else. They bring people together, making a professional connection and teaching students how to do so."
Materials research at universities now relies heavily on partnerships with industry, according to PMI director Anthony Evans, Sir Gordon Wu Professor of Mechanical and Aerospace Engineering.
"For three or four decades, much of the research in materials at universities was funded by the Department of Defense," Evans says. "But 10 years ago, with the end of the Cold War, military funding decreased. Funding for this kind of research is now being provided by the commercial sector, which always needs new materials, but they're more cost-conscious than the military. Now, from an academic point of view, there's a need not only to invent materials and determine how they would benefit a system but also to evaluate them in terms of cost and utility."
Light-weight energy conversion
Some projects are still funded by the Department of Defense. Mechanical and aerospace engineering professor Frederick Dryer, for instance, came up with an idea that could lead to the production of a lighter energy-conversion device to replace the 40 or more pounds of batteries typically carried by infantry soldiers.
His approach converts liquid hydrocarbon fuels to thermal energy and then uses piezo electric membranes and thermoelectric materials to convert the thermal stresses directly into electrical energy. These techniques permit electrical energy generation from chemical sources at very small scale and from energy sources that are much more concentrated than conventional electrochemical batteries.
When Dryer came to PMI with this idea, "It became a multidisciplinary effort involving chemical, mechanical and civil engineers and PMI as facilitator," says Ilhan Aksay, professor of chemical engineering and PMI. "We worked as a team, similar to the way companies work when they tackle a problem." There is a high degree of likelihood, Aksay says, that commercial applications from the research will be developed and brought to market even before military applications.
Mutually beneficial
The scope of the work at PMI embraces many different industries, including aerospace, automotive, communications, electronics, energy and pharmaceutical. Materials for the pharmaceutical industry, for example, include biomaterials for implants and tissue regeneration. Research partnerships reflect various PMI faculty specialties, including materials synthesis, property analysis, reliability, cost evaluation and computer modeling.
"Working with industry is a mutually beneficial arrangement," Cava believes. "It allows us to make the contacts to find out what the real world needs, while it enables companies to embrace a long-term research view outside their short-term mandate to produce."
As PMI bridges the gap between fundamental science and applications and between academia and industry, it also educates students by giving them the tools to think broadly about a problem, uncovering solutions that a single focus may not provide. In doing so, perhaps the next round of graduates will not have to be told about the current equivalent of plastics; they will have designed it.