Practical Implementation of Dynamic Methods for Measuring Atomic Force Microscope Cantilever Spring Constants
S. M. Cook, T. E. Schaffer, K. M. Chynoweth, M. Wigton, Raymond Simmonds, Kristine Lang
Measurement of atomic force microscope cantilever spring constants (k) is essential for many of the applications of this versatile instrument. Numerous techniques to measure k have been proposed. Of these, the thermal noise and Sader methods, stand out as being widely applicable and relatively user-friendly, providing an in situ, non-destructive, fast measurement of k for a cantilever independent of its material or coating. Such advantages recommend these methods for widespread use. An impediment thereto are the significant complications involved in the initial implementation of the methods. Some details of the implementation are discussed in publications, while others are left unsaid. Here we present a complete, cohesive, and practically-oriented discussion of implementation of both the thermal noise and Sader methods of measuring cantilever spring constants. We review relevant theory and discuss practical experimental means for acquiring the required quantities. We then present results which compare measurements of k by these two methods over nearly two orders of magnitude, and we discuss likely origins of both statistical and systematic error for both methods. In conclusion, we find the two methods agree to within an average of 4 % over the wide range of cantilevers measured. Given that the methods originate in distinct physics we find the agreement a compelling argument in favor of the accuracy of both, suggesting them as practical standards for the field.
, Schaffer, T.
, Chynoweth, K.
, Wigton, M.
, Simmonds, R.
and Lang, K.
Practical Implementation of Dynamic Methods for Measuring Atomic Force Microscope Cantilever Spring Constants, Nanotechnology, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=32139
(Accessed November 30, 2023)