Advantages and Disadvantages of Contact Mode AFM, TappingMode AFM, and Non-contact Mode AFM
Rev. F
Scanning Probe Microscope Training Notebook
13
6.3
Non-contact Mode AFM
Advantage:
•
No force exerted on the sample surface.
Disadvantages:
•
Lower lateral resolution, limited by the tip-sample separation.
•
Slower scan speed than TappingMode and Contact Mode to avoid contacting the
adsorbed fluid layer which results in the tip getting stuck.
•
Non-contact usually only works on extremely hydrophobic samples, where the adsorbed
fluid layer is at a minimum. If the fluid layer is too thick, the tip becomes trapped in the
adsorbed fluid layer causing unstable feedback and scraping of the sample.
Note:
Due to these disadvantages, applications for non-contact mode AFM imaging
have been limited.