Measuring Tip Shape for Instrumented Indentation Using Atomic Force Microscopy

Published

October 12, 2021

Author(s)

Mark R. VanLandingham, John S. Villarrubia, R M. Camara

Abstract

Atomic Force Microscopy (AFM) was used to determine the three-dimensional shape of probe tips used for instrumented indentation. AFM images were taken for three probe tips with several different image sizes. The geometry obtained directly from the images was assumed to be an outer bound on the true geometry due to the influence of the AFM probe shape during the imaging process. To account for this artifact, mathematical morphology algorithms were applied first to AFM images of a tip shape characterizer to estimate the three-dimensional geometry ofthe AFM probe, and second to AFM images of the indentation tips to remove the AFM probe artifact. However, uncertainties associated with the use of an open-loop AFM system were more significant than the uncertainty due to the AFM probe artifact. Comparisons of cross-section area as a function of distance from the tip apex for data generated from AFM imaging to that determined from indentation of fused silica revealed a potential problem with determining tip shape area functions using indentation of reference samples. Comparisons of AFM-generated tiparea functions compared to that from indentation of fused silica revealed potential problems with current reference sample indentation procedures that might be linked to the artificially high modulus values often measured for polymers using indentation techniques.

Citation

Journal of Materials Research

Pub Type

Journals

Keywords

Atomic Force Microscopy, Characterization, Modulus, Nanoindentation, Probe, Tip-shape

Citation

VanLandingham, M. , Villarrubia, J. and Camara, R. (2021), Measuring Tip Shape for Instrumented Indentation Using Atomic Force Microscopy, Journal of Materials Research (Accessed May 8, 2025)