Figure shows the profile of the normalized modulus (E/EFF) versus normalized distance (x/aFF) from the sample without an I layer (i.e., λphase = 0) and different tip radii. Since there is no I layer, the inherent modulus of the M layer should be a uniform constant value of unity when divided by its far field value. The increase of the modulus near the substrate (S layer) as x/aFF decreases shows the influence of the substrate on measured modulus from the AFM indentation, i.e., the substrate effect. The master curve of this substrate effect from the FEA simulation is shown as the black line. In our study, we utilized the Johnson-Kendall-Roberts (JKR) model to determine the contact radius. In the JKR model, the contact radius, a, is described as a function of the indentation depth, as shown in equation ( ) and (3),