Visualization
Two imaging modes, continuous and vibrating, may be used for imaging polymer samples. If the sample is relatively "hard", then "contact" mode may be used. However if the sample is relatively "soft", then it is necessary to use "close contact" mode. The forces placed on the sample surface with "close contact " mode are about 10 - 100 times less than in "contact" mode. Direct visualization of 2-D and 3-D images of polymer surfaces is helpful for understanding the effects in changes in process conditions. Because the AFM does not require conductive samples, there is little or no sample preparation required. Below are three polymer samples prepared from the introduction of polypeptides. In figures 2a, 2b, and 2c, the density of peptides is 1%, 10%, and 100%.  Figure 2: Atomic force microscopes are ideal for visualizing the surface texture of polymer materials. In comparison to a scanning electron microscope, no coating is required for an AFM. Images A, B, and C are of a soft polymer material and were measured with close contact mode. Field of view: 4.85 µm × 4.85 µm.  Figure 3: At the bottom is an illustration of a 3-Dimensional image of a patterned polymer material deposited on silicon substrate. At the top is a 2-Dimensional image of the polymer structure at the top of one of the lines.
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