Under the new Atomic Force Microscope, a thin film of metal appears as a layer of nanometer-sized crystals.

A NEW ATOMIC FORCE MICROSCOPE (AFM) in the Olin-Rice Science Center provides researchers with amazing images at near-atomic scale.An AFM provides extremely high-resolution images on the order of fractions of a nanometer, more than a thousand times better than an optical microscope. (A nanometer is equal to a billionth of a meter.)

The AFM was developed by German physicist Gerd Binnig, who, along with colleague Heinrich Rohrer, won the Nobel Prize in physics for the invention of the precursor to the AFM.

“This extraordinary instrument provides high resolution— near atomic scale—imaging of the surfaces of materials,” says physics professor and chair Tonnis ter Veldhuis. “The acquisition of a state-of-the-art atomic force microscope is the result of successful collaboration between science division faculty and the college administration.”

Macalester was able to acquire the AFM thanks to a substantial four-year grant for scientific equipment from a private foundation.

The AFM resides in the college’s Keck Laboratory and is available for use by every science department. Ter Veldhuis believes that Macalester’s grant application was successful in part because of this interdisciplinary collaboration among departments, all focused on providing meaningful research and practical learning experiences to Macalester students.

Explaining how the AFM may be valuable in her field, chemistry professor Kathryn Splan says, “One facet of my research focuses on the synthesis of porphyrin dyes that, when subjected to suitable conditions, may form interesting self-assembled structures. Characterization with the AFM will help us to understand and control how molecules organize on a molecular level.”

The new instrument will enhance research at Macalester in other ways as well. Being able to view solar films at this level may help scientists develop more efficient and less expensive semiconductors for solar energy. Looking at graphene and other nano-materials with near-atomic resolution has implications for the future development of technology, from ultrafast computers to thermoelectric generators.

Physics professors James Heyman and Jim Doyle have already received training in its operation. By summer, students doing research also will be able to use this remarkable instrument. Courses that may employ the AFM include Modern Physics, Nanoscience, and Quantum Mechanics and Spectroscopy.

Other imaging instruments included in the grant proposal —a micro X-ray fluorescence system for the existing scanning electron microscope and a confocal microscope—are expected to arrive during the next two years.

April 23 2015

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