Accurate Modelling of AFM Force-Indentation Curves with Blunted Indenters at Small Indentation Depths.

Autor: Kontomaris, Stylianos Vasileios, Malamou, Anna, Stylianou, Andreas
Zdroj: Micromachines; Oct2024, Vol. 15 Issue 10, p1209, 17p
Abstrakt: When testing biological samples with atomic force microscopy (AFM) nanoindentation using pyramidal indenters, Sneddon's equation is commonly used for data processing, approximating the indenter as a perfect cone. While more accurate models treat the AFM tip as a blunted cone or pyramid, these are complex and lack a direct relationship between applied force and indentation depth, complicating data analysis. This paper proposes a new equation derived from simple mathematical processes and physics-based criteria. It is accurate for small indentation depths and serves as a viable alternative to complex classical approaches. The proposed equation has been validated for ℎ < 3R (where h is the indentation depth and R is the tip radius) and confirmed through simulations with blunted conical and pyramidal indenters, as well as experiments on prostate cancer cells. It is a reliable method for experiments where the tip radius cannot be ignored, such as in shallow indentations on thin samples to avoid substrate effects. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index