Baseline correction of AFM force curves in the force-time representation.

This note reports on the proper correction of force data acquired with an atomic force microscope (AFM). The force-time representation is hereby used to obtain the correction factors for the overall offset and slope for a single force-time curve, as the initial force, F-0 = F(t(0)), and the rate of change in the force per unit of time, dF/dt, respectively. The report shows that a complete set of force data, including the approach, delay and retraction regions, can be simultaneously corrected in the force-time representation by subtracting the line CLt = F-0 + dF/dt-t to the experimental data. The method described here outperforms the one commonly employed in the correction of AFM force curves and highlights the convenience of using the force-time representation for force data processing wherein the artifactual behavior can be expressed as a single, differentiable function of time.