Lehigh University
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In materials science, there are no boundaries to success

Pittsburgh’s Byham Theatre was announcing an upcoming performance of the contemporary ballet “Complexions” when Harmer and his students were in town.

Like the teachers of younger students, says Martin Harmer, college professors often face a challenge motivating their students to study science.

Harmer, a professor of materials science and engineering, has addressed this challenge by taking a cue from his wife, Andrea Harmer, who recently studied sixth-graders who investigated a hazardous waste site in Pennsylvania.

“The idea of energizing students by giving them a real-world research project intrigued me,” said Martin Harmer.

This past spring and fall, Harmer enlisted his students in a venture that has consumed much of his own time in the last few years—the study of grain boundaries, which are the tiny material interfaces that often determine a material’s chemical, electrical and other properties.

In Mat 214: The Processing and Properties of Ceramics, Harmer and Shuailei Ma set up lab projects that required students to investigate problems whose answers were not yet known. Ma, a Ph.D. candidate in chemical engineering, is a teaching assistant in the class.

The students responded by winning half a dozen prizes at the MS&T (Materials Science and Technology) 2009 Conference in Pittsburgh, Pa., in October. The prizes were awarded in competitions sponsored by the American Ceramic Society for poster presentations and for use of electron microscopy.

Finding new complexions in titania

Harmer, who directs Lehigh’s Center for Advanced Materials and Nanotechnology (CAMN), assigned the Mat 214 students to explore the existence of grain boundary “complexions” in titania (TiO2), a compound that is used in paints, sunscreens and anti-bacterial soaps.

In 2007, Harmer coined the term “complexions” when he and his former Ph.D. student Shen Dillon identified six complexions, or grain boundaries with distinct rates of grain growth, in the ceramic alumina (Al2O3). Scientists had previously believed there were only two or three different types of grain boundaries in alumina, says Harmer. Harmer and Dillon were able to control the complexions they found by making changes in chemistry and temperature. The discovery, he says, could make it easier for engineers to control the rate of growth at grain boundaries, which play a key role in the creation of ceramic solids from powders.

Last spring, the students in Mat 214 conducted separate investigations to determine how the grain-boundary structure of TiO2 changed when the temperature of firing, the composition of the compound and other variables were altered.

“One group added copper to the titania and the result was huge grain structures,” said Harmer. “Another group found that boron produced a needle-like structure. A third group found that zinc also affected the structure of the titania. The students ended up discovering things that I didn’t know.

“This reminded me of a saying I heard once about the three phases of learning that faculty members go through,” said Harmer. “During the first stage you learn from your graduate adviser. During the second you learn from your academic colleagues. During the third, you learn from your students.

“I’m at stage three.”

Prizes for posters and presentations

After obtaining their lab results, the students worked with Harmer and Ma to prepare posters for the MS&T conference. The following students received prizes:

  • Ma and Wu Zhou, a Ph.D. candidate in materials science and engineering, won first place in the TEM (transmission electron microscopy) category in the ACerS Ceramographic Competition for a poster titled “Why is it so colorful?” Faculty advisers for the project were Harmer; Christopher Kiely, professor of materials science and engineering; and Hugo Caram, professor of chemical engineering.
  • Ma and Zhou also won second place in the Combined Techniques category in the ACerS Ceramographic Competition for a poster titled “Abnormal Grain Growth in Yttria” with Harmer, Kiely and Caram as faculty advisers.
  • Taek Bo Kim, a summer student in Lehigh’s materials science and engineering department who is enrolled at Imperial College in London, won first place in the undergraduate studies category in the ACerS Ceramographic Competition for a poster titled “An Unexpected Microstructure.” Kim’s advisers were Profs. Helen Chan and Rick Vinci in the materials science and engineering department, and Sreya Dutta, a postdoctoral research scientist in the department.
  • George Ferko ’10 won third place in the same category for a poster titled “Controlling Grain Morphology in Titania Viewed in 3-D.” Ferko was advised by Ma and Harmer.
  • Stephanie Bojarski ’10 won an honorable mention in the ACerS undergraduate student poster contest for a poster titled “Effect of Doping Element in TiO2 Grain Boundary Complexions.” Bojarski’s advisers were Ma and Harmer. Bojarski helped to coordinate Lehigh’s entry in the ACerS undergraduate poster contest.
  • Abigail Lawrence ’10 advanced as far as the semifinal round in the Material Advantage Student Speaking Contest. Lawrence gave a presentation titled “The Effect of Copper, Boron and Zinc Doping on Microstructure Development in Sintered TiO2.”

Ferko, Bojarski and Lawrence are all materials science and engineering majors.

Real-world inspiration

In a related matter, two of Ma’s posters have been published as the back cover of the monthly Journal of the American Ceramic Society. Huikai Cheng, who earned a Ph.D. in chemical engineering from Lehigh and is now a postdoctoral researcher here, has had one poster published as the journal’s back cover.

The February 2010 issue of the journal will feature as its lead article a lecture that Harmer gave last year when he received the Robert B. Sosman Award from the American Ceramic Society. The lecture traced developments in ceramics research and in the importance of electron microscopy and other observational techniques to improving the understanding of ceramics.

Andrea Harmer was inspired to use real-world problems to motivate students to study science after she conducted research into a class of sixth-graders who investigated the EPA (U.S. Environmental Protection Agency) Superfund Site in Palmerton, Pa. Harmer, an assistant professor of library science and instructional technology at Kutztown University, is also director of web-based instruction with Lehigh’s CAMN.

Harmer asked the sixth-graders what they had gained from the opportunity to create, contribute, collaborate and communicate outside the classroom on cutting-edge topics. She later asked the same questions of the Lehigh students in Mat 214. She compared both sets of student responses and presented the results at the Materials Research Society conference earlier this month (December 2009). The results will be published next year.


Photo by Animesh Kundu

Story by Kurt Pfitzer

Posted on Friday, December 18, 2009

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