Help for high-school science teaching

New research center focuses on advanced materials and microstructures

A new research center at Brown University focuses on the mechanical behavior of advanced materials in structures as small as a billionth of a meter. The center's research expertise will also support new science and engineering teaching approaches in the nation's junior and senior high schools.

PROVIDENCE, R.I. -- To develop reliable, high-strength materials, sometimes it's best to think small.

A $5.35-million grant will allow Brown to establish a research center to explore the mechanical behavior of materials for structural and electronic uses at the size scale of the microstructural features that determine their mechanical response, especially their strength. The sizes of these features range from microns (one thousandth of a millimeter), for grain sizes and film thicknesses, down to nanometers (one thousandth of a micron or 3 to 5 atomic spacings), for distorted regions around imperfections in atomic lattices.

The five-year grant from the National Science Foundation is one of 13 made in a national competition that drew about 140 proposals. The grant supports an interdisciplinary effort involving 12 faculty in the Division of Engineering. Rod Clifton, professor of engineering and Rush C. Hawkins University Professor, is the principal investigator.

"This grant provides an excellent opportunity for us to combine our strengths in experiments, computer simulation and materials synthesis to provide the basic understanding required for the next generation of advanced materials," Clifton said.

As an example, he cites the need for better understanding of the effects of lattice imperfections, surface waviness and injunior and senior mance and reliability of ever-smaller computer chips.

For a structural example, Clifton cites the need for better understanding of failure mechanisms in highly heterogeneous microstructures, such as titanium-aluminide microlaminates, which have potential for advanced aircraft applications because of their low weight and high strength at high temperatures. However, improvement in their fracture strength at low temperatures is required, he said.

A major component of the grant is educational outreach to students in junior and senior high schools. The purpose is to motivate students to study math and science by introducing them to materials science through enrichment modules involving experiments, projects and videotaped instruction. This outreach will be conducted with the Annenberg Institute for School Reform.

Janet Blume, associate professor of engineering and outreach coordinator for the new center, says that the goal is to develop 15 different modules for use in classrooms across the nation. Brown faculty and students are being paired with Rhode Island science and math teachers to develop the modules and test them in the state's schools.

Blume says the module she is developing deals with materials and mechanics issues in the manufacture of soda cans. The geometry of the can and the alloys used are designed to withstand internal pressure and to prevent dents. Students measure the diameter and wall thickness of the can and determine the allowable pressure for a can of a given material. They learn about forces, experimental errors and other concepts in math and science.

"It's important to involve undergraduates in the development of the modules," Blume said. "They were most recently high-school students, so they're closer to knowing what would catch a student's attention. Their involvement may also get them thinking about careers in teaching and research."

Brown houses a broad range of equipment for materials research, including a high-resolution transmission electron microscope that allows researchers to see atomic lattices. This equipment will be extended and upgraded by acquisitions to be made under the grant. These items are located in shared facilities available for use by everyone on campus as well as by researchers from other universities.

The new research center will be called the Materials Research Science and Engineering Center (MRSEC) on Micro- and Nano-Mechanics of Materials.