When Cherry A. Murray, dean of the Harvard’s School of Engineering and Applied Sciences (SEAS), visited the School for her first meet-and-greet in April 2009, she delivered a tribute to materials. The future, she argued, was right below our feet.
The audience responded warmly, but with puzzlement. What about the grand promise of engineering solutions to energy and global health concerns? What about pushing the frontiers of computing and biology? What about cool concepts such as flying cars, time travel, and robots?
After exploring the work of David Clarke, appointed Gordon McKay Professor of Materials in January 2009, her due deference to the elements becomes clearer.
Echoing the ads for chemical giant BASF, while Clarke may not make novel gadgets or rewrite the laws of physics, he does help researchers make the things that they do … better.
British by birth and education, the materials scientist began his career by working on measurement standards at the National Physical Laboratory. While pursuing his Ph.D., he discovered ceramics.
“The word ceramics is often a misleading one, because people think of ‘white wears,’” said Clarke, referring to the ghostly molds lining the shelves of paint-your-own-pottery stores. “I’m interested in high-temperature oxide materials, or compounds that are similar to many minerals. Ceramics are really a materials class of their own, even though their name is not so exciting.”
The ceramics that Clarke deals with can withstand extremely high temperatures, and some varieties even exhibit excellent electrical conductivity akin to metals such as copper.
He points out that such materials are the basis for solid oxide fuels cells, a technology that could transform how automobiles are powered. In fact, many past and present advances in ceramics stem from a desire to improve the efficiency of moving people and information from place to place.
Clarke’s decision to cross the Atlantic to experience a different research environment in the United States may be a prescient example. By looking out the plane’s window at the turbines, he could have seen his future humming back at him.
After a postdoctoral fellowship at the University of California, Berkeley, he ended up at Rockwell International, the aviation and rocket giant.
Clarke and fellow researchers discovered that the hard ceramic with a high-temperature tolerance was ideal for the blades inside aircraft engines because of its featherlike weight and durability.
Materials laid the path, again, for his next venture, as he switched from aviation to information. He landed at IBM Research in the 1970s.
Clarke then left the industrial research sector, going first to Massachusetts Institute of Technology and then to the University of California, Santa Barbara.
He decided to come to SEAS in large part for the opportunity to be amid a small, dedicated community of researchers. The aim now, as Murray pointed out during her initial SEAS visit, is to build on what is already known. For example, the p-n junction (the gap that led to the transistor) discovered in 1939 is still paying dividends. The same approach, said Clarke, also will help to tackle “big problems” such as energy.
“We know a lot about the elements and the bindings of materials. But when we get into the really complex materials, we know very little. This is really the frontier of research,” said Clarke.
To encourage surprises, he teaches a freshman seminar called “Materials, Energy, and Society,” a lab course focused on the nature of materials. He asks students to consider hulking wind turbine towers. Performance and efficiency depend on the size of the blades, which in turn depend on their composition. To have sufficiently large and stiff blades requires composite materials.
The first blades used to capture wind energy were made of basic, lightweight balsa wood. You have everything you need right here, he hints to his students, to make a more efficient turbine. With ingenuity, he suggests, you can transform the way the blade — and hence the world — go round.