Haiyan Wang: Thin-film Star

By Kristina Twigg

Texas A&M Engineering Associate Professor Haiyan Wang is a budding superstar in her field, having received three of the top awards given to young faculty for her work in thin films. Her research could lead to more efficient and affordable alternative energy.

It is the Triple Crown of engineering academia: the Presidential Early Career Award for Scientists and Engineers (PECASE), the National Science Foundation CAREER Award, and the Young Investigator Award (YIP).

They are the most prestigious awards bestowed upon young researchers, and Haiyan Wang has received them all in just three years.

Wang most recently received the CAREER Award in 2009, adding it to her 2007 Air Force Research Office’s YIP as well as her Office of Naval Research YIP and PECASE, both awarded in 2008.

The accolades for Wang resulted from her work in thin films, which are composed of layers — some as thin as one atom — deposited on a substrate. Thin films are light, flexible and have unique physical properties that may soon lead to a variety of applications, from more efficient and affordable alternative energy technology to less expensive medical equipment.

The art of laying apples

Imagine perfectly stacking apples layer upon layer. Each would have to fit carefully against the other in a specific pattern.

Wang, associate professor in Texas A&M University’s Department of Electrical and Computer Engineering, is a master at what she calls “the art of laying apples.” Her model is designed to explain the basics of thin-film deposition to her students and the general public.

In Wang’s model, apples are equivalent to atoms deposited layer upon layer onto a flat substrate, but only atoms of the same or similar kind fit together well. Wang, for example, works specifically on nitride and oxide thin films, which she became familiar with during her Ph.D. studies at North Carolina State University and her postdoctoral research at Los Alamos National Laboratory.

“I feel material science is such a versatile, multidisciplinary area. People always have needs for new materials, so you always have fun things to work on.”

“It’s so fun when you sit in the microscope room and watch how the atoms really space or locate in your thin-film sample,” Wang says.

For her, growing thin films is like developing a new creation each time. “There are always some unexpected surprises,” she says.

The advantage of a close fit

Because they have better atomic arrangements, thin films are lighter, are more flexible and have higher efficiency than conventional bulk materials. These properties make them ideal for fabricating solar cells, batteries and solid oxide fuel cells — all alternative energy sources.

“I feel material science is such a versatile, multidisciplinary area. People always have needs for new materials, so you always have fun things to work on,” Wang says.

Thin films can also be applied in high-temperature superconductors (HTS), another of Wang’s research areas. They are a step up from current low-temperature superconductors widely used in devices such as magnetic resonance imaging (MRI) machines, which visualize the inside of the human body.

Because of thin-film technology, HTS-coated conductors can support 10 times more electricity traffic than conventional copper wires, Wang says. Consider an interstate that has only one lane compared with 10. So, HTS-coated conductors are promising for electric power transmission and are already being tested by the Department of Energy. Another advantage of HTS is that they use liquid nitrogen, a far less expensive coolant than the liquid helium that low-temperature superconductors require.

The future of thin films

Although thin-film and HTS technologies are still in their infancy, Wang’s group does fundamental research with future users in mind.

“This doesn’t mean that people will be able to use our new material structures tomorrow, but I foresee that our architectures will be useful in probably 5 or 10 years,” Wang says.

With eight patents and eight awards — including the PECASE, NSF CAREER Award, the Office of Naval Research YIP and the Air Force OSR YIP — Wang is a rising star in Texas A&M Engineering. Her lab, which includes 15 graduate and undergraduate student workers, produces about 20 journal publications every year. Wang attributes their productivity to the extensive collaborations she shares with researchers at Texas A&M, other universities and national laboratories.

Wang also capitalizes on the work done by graduate students she advises.

“I feel it’s so fun to work with graduate students because they generate such interesting ideas,” she says. “The students are really the heart of the research.”