Figure 1

Methodology of the measurement of elasticity parameter by means of nanoindentation with an AFM tip A) An optical preview of the sample helps to monitor the experimental conditions and to choose the measurement area over the cell.B) Sample force-distance curves, 1 - reference curve acquired at a control surface (glass), 2 - force-distance curve taken at the cell. C) The indentation curve obtained on the basis of 1 and 2. The value of the elasticity parameter is evaluated for each curve, according to the model proposed by Sneddon for a paraboloidal tip [24]. D) Histogram presenting distribution of the elasticity parameter obtained from the analysis of approx. 1200 indentation curves acquired at a single sample, from multiple cells. The mean value is calculated from the log-normal distribution fit.