Minimizing tip-sample forces and enhancing sensitivity in atomic force microscopy with dynamically compliant cantilevers

Minimizing tip-sample forces and enhancing sensitivity in atomic force microscopy with dynamically compliant cantilevers

Keyvani Janbahan, A.
Sadeghian Marnani, H.
Tamer, M.S.
Goosen, J.F.L.
van Keulen, F.

2017

Due to the harmonic motion of the cantilever in Tapping Mode Atomic Force Microscopy, it is seemingly impossible to estimate the tip-sample interactions from the motion of the cantilever. Not directly observing the interaction force, it is possible to damage the surface or the tip by applying an excessive mechanical load. The tip-sample interactions scale with the effective stiffness of the probe. Thus, the reduction of the mechanical load is usually limited by the manufacturability of low stiffness probes. However, the one-to-one relationship between spring constant and applied force only holds when higher modes of the cantilever are not excited. In this paper, it is shown that, by passively tuning higher modes of the cantilever, it is possible to reduce the peak repulsive force. These tuned probes can be dynamically more compliant than conventional probes with the same static spring constant. Both theoretical and experimental results show that a proper tuning of dynamic modes of cantilevers reduces the contact load and increases the sensitivity considerably. Moreover, due to the contribution of higher modes, the tuned cantilevers provide more information on the tip-sample interaction. This extra information from the higher harmonics can be used for mapping and possibly identification of material properties of samples.

NOMI Nano Opto-Mechatronics Instruments Group
High Tech Systems & Materials
Industrial Innovation
Nano Technology
OM - Opto-Mechatronics
TS - Technical Sciences

http://resolver.tudelft.nl/uuid:c8b50fb2-8b93-4763-8fc6-6b0f05c48e0f

770968

American Institute of Physics AIP

0021-8979

Journal of applied physics, 121 (121)

article