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Microscopy

Recent Developments In Microscopy

There have been numerous variations on the types of microscopy outlined so far. A sampling of these is: acoustic microscopy, which involves the reflection of sound waves off a specimen; x-ray microscopy, which involves the transmission of x rays through the specimen; near field optical microscopy, which involves shining light through a small opening smaller than the wavelength of light; and atomic force microscopy, which is similar to scanning tunneling microscopy but can be applied to materials that are not electrically conducting, such as quartz.

An atomic force micrograph of the surface of a thin copolymer film. The atomic force microscope (AFM) is capable of atomic-scale resolution, and works by drawing a very fine probe across the surface of the sample. The vertical motion of the probe is converted into electronic signals which are then processed to give the type of surface map seen here. The advantage the AFM has over the scanning tunneling microscope is that it works for samples that are not electrical conductors. Photograph by Philippe Plailly. National Audubon Society Collection/Photo Researchers, Inc. Reproduced by permission.

One of the most amazing recent developments in microscopy involves the manipulation of individual atoms. Through a novel application of the STM, scientists at IBM were able to arrange individual atoms on a surface and spell out the letters "IBM." This has opened up new directions in microscopy, where the microscope is both an instrument with which to observe and to interact with microscopic objects. Future trends in microscopy will most likely probe features within the atom.


Resources

Books

Burgess, Jeremy, Michael Marten, and Rosemary Taylor. Microcosmos. Cambridge: Cambridge University Press, 1987.

Giancoli, Douglas. Physics. Englewood Cliffs, NJ: Prentice Hall, 1995.

Slayter, Elizabeth and Henry. Light and Electron Microscopy. Cambridge: Cambridge University Press, 1992.

Periodicals

Eigler, D.M., and E.K. Schweizer. "Positioning Single Atoms with a Scanning Tunneling Microscope." Nature 344 (1990): 524-526.

Taylor, D., Michel Nederlof, Frederick Lanni, and Alan Waggoner. "The New Vision of Light Microscopy." American Scientist 80 (1992): 322-335.


Kurt Vandervoort

KEY TERMS

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Compound microscope

—A light microscope which uses two or more glass lenses to produce an image.

Electron

—A negatively charged particle, ordinarily occurring as part of an atom. The atom's electrons form a sort of cloud about the nucleus.

Glass converging lens

—A circular disk with one or two convex curved surfaces used in focusing (converging) light or producing magnified images.

Magnetic lens

—A magnet used to focus an electron beam for producing magnified images in an electron microscope.

Micrometer

—0.000001 meter (one millionth of a meter) or 0.001 millimeter (one thousandth of millimeter).

Refraction

—The bending of light that occurs when traveling from one medium to another, such as air to glass or air to water.

Wavelength

—The distance between two consecutive crests or troughs in a wave.

X ray

—Short wavelength light between wavelengths of 0.01 and 0.00001 micrometer.

Additional topics

Science EncyclopediaScience & Philosophy: Methane to Molecular clockMicroscopy - The Light Microscope, History Of Light Microscopy, Electron Microscopy, Scanning Tunneling Microscopy, Recent Developments In Microscopy