Chapter 7
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of single atoms at the surface of crystals. This is because the effective diameter of the probe is increased dramatically by the contamination layer on surfaces in ambient air. It is possible, however, to measure atomic structure with an AFM in an ultra high vacuum environment. |
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FIGURE 7-10 Atomic terraces on Strontium Titanate. |
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7.2 Life Sciences |
The AFM has great promise for measuring surface structure of biological material. For example, the AFM is the only microscopy technique that allows making nanometer scale images with the sample submerged in liquid. |
7.2.1 Cells |
An AFM can readily measure images of cells both in ambient air and submerged in a liquid. The cells must be rigidly adhered to a surface for successful imaging. With the AFM it is possible to measure the mechanical activity of a cell by simply placing the probe on the surface of the cell and monitoring the motion of the AFM cantilever. An advantage of the AFM for imaging cells is that the cell does not have to be coated, and in fact can still be alive when imaged. |
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FIGURE 7-11 Breast Cancer Cells 78 x 78 microns. |
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