AFM or Atomic Force Microscope is a device that allows three-dimensional imaging of molecular surfaces with a nanometer resolution.
SEM or Scanning Electron Microscope is an electron microscope that performs the task of imaging sample surface by scanning it, using a high-energy beam of electrons.
Scanning probe microscope, like Scanning electron microscope, magnifies results based on the ratio of raster’s dimensions on the specimen to the raster’s dimension on the display device.
AFM SEM differences:
In comparison to scanning electron microscope (SEM), atomic force microscope (AFM) provides much better function. It furnishes reliable three-dimensional surface profile and doesn’t even require any kind of special treatment (including carbon/metal coatings), which would irreversibly damage or affect the sample.
In addition, unlike scanning electron microscope that requires expensive vacuum environment for normal functioning, atomic force microscope has the ability to function effectively even in a liquid or an ambient air environment. This feature of AFM proves very useful for studying macromolecules and living organisms.
Another AFM SEM difference lies in the resolution quality. It’s a known fact that AFM can offer resolution that is much better in comparison to the resolution offered by an SEM and as good as offered by transmission in an electron microscope and a scanning tunneling microscope.
A major drawback of the atomic force microscope is the size of the image it offers. Unlike SEM, which can image a particular area in terms of square millimeters having a depth of field in terms of millimeters, AFM is capable of imaging only a maximum height in terms of 10-20 micrometers and a maximum scanning area or approximately 150 X 150 micrometers.
Another area in which the SEM scores over AFM is the time taken for the scanning of images. AFM scans images in comparatively less time than SEM. This slow rate, many a time, causes thermal drift in the image.
These were some prominent SEM AFM differences.