Comment on 'Influence of atomic force microscope cantilever tilt and induced torque on force measurements' [J. Appl. Phys. 103, 064513 (2008)]

摘要

In a recent article, Edwards et al. [J. Appl. Phys. 103, 064513 (2008)] examined the effect of cantilever tilt and induced torque on the effective normal spring constant for both sharp tips and spherical probes, and in contrast to previous studies, they found that induced tip torque can act to either enhance or reduce the effective normal spring constant of the cantilever, which is of great value for force measurement in atomic force microscopy. However, their work is technically limited in application by their nonparallel-force assumption. In this comment, we improve their work to be more applicable by developing a more practical model without the nonparallel-force assumption.