An investigation on the mechanical properties of a multi-layer film coated PMMA by nanoindentation

This study investigates the mechanical properties of a novel multi-layer Silane/Indium Tin Oxide (ITO) film based on Polymethyl methacrylate (PMMA). Nanoindentation tests, theoretical analysis, and numerical simulations were employed. Multi-layer and single-layer film specimens, consisting of various formulations of silane and ITO, were fabricated on a plexiglass PMMA substrate. The elastic modulus and hardness of the silane, ITO, and PMMA substrate were determined using nanoindentation tests combined with the Continuous Stiffness Measurement (CSM). Moreover, the load-indentation depth curve obtained from the experiments was utilized to simulate the nanoindentation tests using the commercial finite element calculation software ABAQUS. The power hardening constitutive model was adopted for the film, and parameters were optimized using a MATLAB neural network. The simulation results for each film material agreed with the experimental findings. Furthermore, a correction factor α was proposed for calculating multi-layer film simulation parameters based on parameter analysis of the multi-layer film system. The degree of idealization for each multi-layer film test was characterized and analyzed.