AFM indentation - force constant

[elsva]

Anyone have any reference or experience as to in which range the force constant of the cantilever should be for carrying out AFM indentation on CNT? (in UVH).

Thanks,
E.S

 

[Lateralis]

AFM in UHV... You don't have one of those really fancy UHV STM/AFM heads, do you? =P

Anyway, in contact mode the typical forces exerted are of the order 10nN. If you know the area of the tip that is making contact you can then work out what the pressure exerted is. Similarly, you can work backwards; if you know what the bulk modulus of the CNTs is, you can work out what sort of force you need to apply in order deform it. If you guess what the final tip radius might be you can work out roughly what contact force you need to apply to get roughly the right pressure.

... Maybe!

 

[charng]

.

The force constant of the cantilever used for AFM indentation on CNT can vary depending on the specific properties of the CNT being studied and the desired indentation depth. Generally, a higher force constant will allow for deeper indentations, but may also increase the risk of damaging the CNT. A lower force constant may be more suitable for softer CNTs or when studying surface properties rather than indentation depth. It is recommended to consult previous literature or conduct preliminary experiments to determine an appropriate force constant for your specific experimental setup and goals. Additionally, it is important to ensure that the force constant is consistent across all measurements to ensure reliable and accurate results.