Introduction
Typically, when we think of microscopes, we think of optical or electron microscopes. Such microscopes create a magnified image of an object by focusing electromagnetic radiation, such as photons or electrons, on its surface. Optical and electron microscopes can easily generate two-dimensional magnified images of an object's surface, with a magnification as great as 1000X for an optical microscope, and as large as 100,000X for an electron microscope. Although these are powerful tools, the images obtained are typically in the plane horizontal to the surface of the object. Such microscopes do not readily supply the vertical dimensions of an object's surface, the height and depth of the surface features.
The atomic force microscope (AFM), developed in the mid 1980's, uses a sharp probe to magnify surface features. With the AFM, it is possible to image an object's surface topography with extremely high magnifications, up to 1,000,000X. Further, the magnification of an AFM is made in three dimensions, the horizontal X-Y plane and the vertical Z dimension. As acknowledged by Binnig and Rohrer1, the inventors of the tunneling microscope, such a powerful technique has its origins in the stylus profiler.
|
