Most common scanning probe microscope

Name the two most common types of scanning probe microscopes. 

There are different types of scanning optical microscopes here one is interested only in the most common type. In these microscopes the light emitted by the sample is simply collected by the probe as can be seen in Fig. 28. 

Direct visualization of nano- and micrometer-sized objects is the most straightforward way for their analysis in surface and polymer science, biomaterial research, and biology. Rapid progress in engineering and microtechnology has led to numerous techniques that allow observation and mechanical manipulation of microscopic objects of various natures. AFM [52] is the most commonly used of these techniques. In AFM, a sample surface is mechanically scanned with a tiny probe—a sharpened stylus fixed at the end of a flexible cantilever. When the stylus interacts with the samples, the resulting force acts on the stylus and causes deflection of the cantilever. This deflection is detected via an optical lever system, that is, a laser beam reflected from the end of the... 

The scanning electron microscope (SEM) forms an image by scanning a probe across the specimen, and in the SEM the probe is a focused electron beam. The probe interacts with a thin surface layer of the specimen, a few micrometers thick at most. The detected signal commonly used to form the TV-type image is the number of low energy secondary electrons emitted from the sample surface. Scanning electron microscopy is fully described in several texts [22-26], and its use with polymers has been reviewed by White and Thomas [27]. 

It is often useful to image the microscopic structure of the carbon-black- polymer composite. Microscopic images can reveal if the carbon-black and polymer are mixed imiformly, if the carbon-black has flocculated or formed nonrandom structures, if there are voids in the composite, or if there is anything else unusual. The most common imaging techniques are optical microscopy, scanning electron microscopy, and transmission electron microscopy. Viswanathan and I have recently used a new imaging technique, based on scanning probe microscopy, to study the microscopic structure of these composites [4]. 

Atomic force microscopy (AFM) is the most commonly nsed scanning probe microscopy (SPM) technique. It has been demonstrated to be an invaln-able technique for characterization of nanoscale snrface strnctures. In this method, the deflection of a cantilever due to repulsive electronic interactions of an attached sharp tip with the surface is measured. The microscopic movement of the tip creates a force that is measnred to provide an image of the surface. Both contact and tapping mode AFMs have been employed for the investigation of surface topography, the latter avoiding contact of the tip with the surface, which can be a problem if the material is soft. 

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