Nanomechanical properties studied by atomic force microscopy in combination with an inverse methodology

Abstract

This study presents a method for calculating the applied force during the nanoindentation process using atomic force microscope (AFM The determination of the applied force in the nanoindentation system is regarded as an inverse vibration problem. The conjugate gradient method is applied to treat the inverse problem using available displacement measurements. Initially, the nanoindentation force should be applied and then the nanomechanical properties of the thin film, including the elastic modulus and the hardness, can be obtained using the geometric relationships between the indenter, the applied force, and the penetration depth. Without using the inverse methodology the nanomechanical properties of ultrathin coatings or films are very difficult to be obtained with precision using the nanoindentation equipment or solely using AFM. This proposed method is useful for designing a surface measurement system for nanostructured materials. © 2004 American Institute of Physics.