Discussion on hybrid approach to determination of cell elastic properties

Abstract

This study discusses the application of a hybrid experimental-numerical approach to analyze nano-indentation curves of a biological membrane acquired with an Atomic Force Microscope. The proposed procedure combines experimental measurements, FEM analysis and numerical optimization and is completely general. Variations of estimated Young modulus of the membrane are determined when attributing different constitutive laws to the sample and in the case of progressive blunting of the AFM tip during the measurement. Since traditional analysis of Atomic Force Microscope indentation curves relies on an inappropriate application of the classical Hertz theory, a comparison between the hybrid approach and the Hertzian model in the determination of the elastic properties of the sample is presented. In particular, it is found that large errors occur in the derivation of the Young modulus when the Hertzian model is used for the analyis of experimental data.