Determination of the spring constants of probes for force microscopy/spectroscopy

TLDR

The method differs from other static‑deflection approaches by exploiting routine features of current instruments. The authors present a direct, accurate, and convenient procedure for calibrating the spring constants of force microscopy/spectroscopy probes. The procedure deflects an unknown cantilever with a precalibrated standard lever and is benchmarked against other static and dynamic calibration methods. The technique achieves absolute and relative accuracies of 30 % and 20 %, respectively, limited mainly by uncertainties in the spring constants of both the standard and unknown levers.

Abstract

A direct, accurate and convenient procedure for calibrating the spring constants of probes used for force microscopy/spectroscopy is described. It amounts to deflecting an `unknown' cantilever with a `standard' lever, where the standard lever has been precalibrated. The absolute and relative accuracies of the procedure are - 30% and - 20%, respectively; the former is limited by uncertainties in the determination of the spring constant for the `standard' lever, as well as that for the `unknown'. The method differs from others of the static deflection variety by its exploitation of the routine features of current instruments. The technique is compared with other static and dynamic methods currently being used.