“I grew up in Philadelphia building houses with my father,” says Richard Superfine-yes, that is his real name. “That has led me to always appreciate experimental work and using my hands and getting tangible results.”
Superfine is an associate professor of physics at the University of North Carolina in Chapel Hill. He is best known for participating in the development of a new technique called the “nano-Manipulator” that allows anyone to use a sophisticated microscope called an “atomic force microscope” to manipulate molecules and even individual atoms with a microscopic probe.
The atomic force microscope (AFM) contains a probe at its very tip that is so small it can actually move around and grab individual atoms.
“Now I still have fun building things, but at the molecular level,” he adds.
NanoManipulator demonstration at local high school.
The AFM is hooked up to a computer mouse that mimics the motion of the probe. The mouse is called a “pen,” although it has nothing to do with writing. The pen contains motors that push back on the user’s hand, creating the sensation that the user is “touching” and “feeling” the atom.
Using this device, Superfine and his students discovered that under certain circumstances, it is possible to induce certain kinds of carbon molecules to roll along a flat surface that is also made of carbon. The specific kind of carbon molecules are called “nanotubes.” These are just long chains of carbon atoms that have been created in a separate procedure. The nanotubes are long tubes, resembling a drinking straw or a pencil.
These nanotubes are then carefully placed on a flat surface called a “substrate.” The substrate can also be made of carbon atoms that are arrayed in an extended sheet. Such a sheet of carbon is called graphite. (Graphite is the same substance that comprises the “lead” in pencils.")
Once the carbon nanotubes have been placed on the graphite substrate, it is possible under certain circumstances to "roll" the nanotubes along the graphite surface. It is similar to what you would find if you carefully pushed a round pencil on a tabletop. However, the contact between the nanotubes and the graphite atoms must be just right for this to happen. They have found that the nanotubes roll only when the atoms on the outside of the nanotube mesh with the atoms of the graphite surface. The atoms are acting like tiny gear teeth!
AFMs are not cheap- they cost anywhere from $80,000 to $100,000 each- their technological applications extend far beyond merely “feeling” atoms or “rolling” tubes of carbon.
“Any one can do this. They don’t need to know how the microscope works. This means that scientists from other disciplines who are not experts in microscopy can use this device,” Superfine says. “This has widespread biological applications, too.”
For instance, a biologist can use this technique to “touch” and “feel” a virus, mapping out various properties of a virus. Among these properties are optical, chemical, mechanical and magnetic properties.