Hi,
Can anyone suggest a formula/method/technique to calculate the spring constant and also resonance frequency of an AFM cantilever after metal deposition?
Thanks in advance,
You could ask someone for FEM calculations:
Article Accuracy of the Spring Constant of Atomic Force Microscopy C...
Article Simulation of vibrational resonances of stiff AFM cantilever...
You can do it inside AFM using a standard calibration routine, which should be described in a manual. There are two common methods: (1) acquire a force-distance curve on a hard substrate - calculate optical lever sensitivity (nm/mV) - aquire thermal spectra for the resonance frequency and spring constant (Article Calibration of Atomic-Force Microscope Tips
) or (2) use the Sader method (Article Calibration of Rectangular Atomic Force Microscope Cantilevers
).
In principle, you can connect the piezo-signal-input of your free-standing cantilevel with an oscilloscope and tune only the frequencies. By measuring the amplitude you can find the peak position, which is the resonance frequency you seek for. The spring constant can be estimated as suggested by other experts above.
Hello, Sergey.
For rectangular consoles, I use a simple approximation:
f0=[sqrt(kc/mc)]/pi,
kc- cantilever stiffness [N/m], it's mass [kg].
More details You can find here: https://www.ntmdt-si.ru/resources/spm-theory/theoretical-background-of-spm/2-scanning-force-microscopy-(sfm)/21-cantilever/216-effective-mass-and-eigenfrequency-of-the-cantilever
A. V. Ankudinov Hello. I usually use it when I see topography artifacts and want to estimate whether a tip is broken (lower mass - higher frequency) or contaminated (additional mass - lower frequency).
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