Contact Mode AFM: Measures topography by sliding the probe tip across the sample surface; available for scanning in air and fluids.

• Provides 3D information nondestructively.
  .5 nm resolution laterally
  .05 nm vertical
• Strong repulsive force acts between tip and sample.
• Requires minimal sample preparation.
• Analyzes insulators and conductors easily.
• AFM is not based on conductivity.
• Does not require staining and shadowing.
• Operates in air and fluids environments.
• Fluid controlled environment and hydrated specimens.
• Provides information about physical properties:
  elasticity, adhesion, hardness, friction etc.

TappingMode AFM: Measures topography by "tapping" the surface with an oscillating probe tip. Eliminates shear forces which can damage soft samples and reduce image resolution; available for scanning in air and fluids. TappingMode overcomes problems associated with friction, adhesion, electrostatic forces, and other difficulties that can plague conventional AFM scanning methods. The technique has proven extremely successful for high resolution imaging of a wide variety of samples including:

silicon wafer surfaces
thin films
metals and insulators
photoresist
polymers
biological samples