The CEMAS Metro Science Enrichment program is a collaboration between the Center for Electron Microscopy and Analysis (CEMAS) at The Ohio State University (OSU) and Metro Early College High School, a unique STEM-oriented secondary school located close to CEMAS with strong pre-existing connections to Ohio State. Over the past three academic years, CEMAS faculty, staff and graduate students worked directly with Metro HS students enrolled in physics and chemistry courses, introducing them to the concept of microscopy-based materials examination. The program received generous support from the Honda-Ohio State Partnership, whose funding in the program’s final two years (2016-2017 and 2017-2018) enabled the project to expand from its pilot stage in 2015-2016.
Visualization of materials using advanced electron microscopy is central to STEM education and research – to be able to “see” on the atomic and molecular scale provides powerful inspiration for students at all levels. Under the CEMAS Metro Science Enrichment Program, a unique collaboration was developed between a world-leading microscopy facility and a local high school. Through the development and incorporation into the high school science curricula of teaching modules introducing students and teachers to the concept of microscopy-based materials examination, this collaboration provided an inspiration to students to pursue STEM studies, and enhanced awareness of microscopy based-materials characterization as a basis for entry to all other STEM fields.
Under this program three separate, but interrelated, high school science topic modules were developed and incorporated into the Metro High School curriculum: 1) material synthesis; 2) material mechanical property measurement; and 3) material microstructure characterization.
The first module on the topic of material synthesis was designed for and presented to the sophomore chemistry class at Metro HS. After receiving an introduction to the basic principles of materials science and background on the optimization of material selection, the chemistry students selected an appropriate Bi-Sn alloy composition, calculated the correct weight of both elemental Bi and Sn to mix for that specific alloy, and then synthesized the alloy. During the synthesis the students weighed out correct amounts of Bi and Sn, melted and mixed them in a bench top furnace, and then cast the alloy into molds for both mechanical test and characterization samples (see Figure 1).
The second module on material mechanical property measurement was designed for and presented to the junior physics class at Metro HS. The students received information about the mechanical properties of materials and how to measure them, as well as an introduction to scanning electron microscopy, microstructure and image quantification. A three-point bend test was conducted by the physics students on each of the mechanical test specimens generated by the chemistry class during their alloy synthesis laboratory (see Figure 2).
The final module on material microstructure characterization was also presented to the junior physics class and was designed to be an extension of their previous module on material mechanical property measurement. This module was conducted at CEMAS and utilized the unique remote microscopy capabilities of the CEMAS digital theater. The digital theater allows up to 30 students to simultaneously participate in the live operation a scanning electron microscopy (SEM), an instrument that normally can accommodate only a single operator, while also presenting relevant lecture content in parallel with the SEM operation (see Figure 3). The physics students used the backscatter electron imaging technique of the SEM to examine the internal microstructure
of each alloy synthesized by the chemistry students and mechanically tested by them in the previous module (see Figure 4). They learned how to identify each constituent phase present in the alloys and how to associate each microstructure with its relevant position in the Bi-Sn phase diagram. They also learned how to use image-processing techniques to quantify the relative amounts of each phase constituent.
In the future, expansion of this program into the chemistry and physics curricula of other high schools is anticipated. High impact STEM programs such as the Honda CEMAS Metro HS science enrichment program have the potential to inspire high school students everywhere to pursue STEM studies.
The 2018 CEMAS Metro Science Enrichment Program was supported by generous funding from Honda R&D Americas, Inc.
