Hybrid Eshelby Decomposition analysis of AFM indentation on heterogeneous layered samples

To determine the micromechanical properties of heterogeneous layered samples using atomic force microscope (AFM) indentation, we previously proposed the Hybrid Eshelby Decomposition (HED) analysis that combines a modified homogenization theory and finite element modeling (FEM) to extract layer-specific elastic modulus values. In this study, the HED technique was experimentally validated using bi-layer spin-coated polydimethylsiloxane (POMS) samples, and we dernonstrated its application by characterizing the layer-specific microelastic properties of mouse aortic wall tissue. Our results show that the mechanical properties of surface and sub-surface layers or thin synthetic and biological samples can be accurately deconstructed from the composite material response to AFM indentation. HED analysis offers an approach to study regional micromechanics of heterogeneous multi-layered samples without destructively separating individual components for testing.