NANOINDENTATION OF SOFT MATERIALS. ANALYSIS OF THE EXPERIMENTAL FACTORS IN CONSTRUCTING A MATHEMATICAL MODEL

Abstract

The authors call for attention to the specifics of conducting experiments on nanoindentation of soft materials (elastomers, polymers), the features of the experimental setup, the material itself, the interaction of the material under study with the scanning elements of the setup, and environmental conditions. The paper shows which of them require to be taken into account in mathematical models, and which can be neglected, or can be almost completely compensated for by others. The following topics are considered: influence of cantilever bending and its inclination, humidity, plasticity, and viscosity, probe jump to the surface, determining the radius of the probe tip curvature, plastics, destruction of the sample during double indentation, size (scale) effect, sample drift, preservation of the probe shape before and after the experiment, time-varying surface properties, and surface energy during contact formation. This work is intended both to simplify further research and to focus efforts on solving acute problems.