AFM Non-contact mode

AFM cantilever can be modeled as a mass- spring system as shown. The air molecules between the tip and sample surface play the role of damping when imaging in air. Damping is provided by viscosity when scanning in liquid.

Atomic Force Microscopy Non-contact mode

A dithering signal is applied and frequency response of the cantilever is swiftly obtained by AraResearch_AFM. Typical of dynamic curve is shown.

Atomic Force Microscopy Non-contact mode

Zoom into the spectrum by drag and drop inside the spectrum

Atomic Force Microscopy Non-contact mode

Typical cantilever used in non-contact mode is NSC 15 with the following characteristics :

Contilever

length

width

Thickness

Resonant FrequencyKHz Typical

Force Constant N/m Typical

 

µ

µ

µ

 

 NC15/AlBS

125

35

4

325

46

Non-contact Atomic Force Microscopy