Implications of contact mechanics models for mechanical properties measurements using scanning force microscopy

Considerable effort is aimed at using the scanning force microscope (SFM) t o measure the mechanical properties of surfaces with nanometer-scale resolu tion. The properties of interest include the Young and shear moduli, shear strength, and work of adhesion. The most widely used approach is to extract these properties from the SFM data by simply scaling the results of the ma croscopic continuum mechanics theory of contact to the dimensions-and force s of a SFM contact. This article provides a contemporary overview of contac t mechanics from the perspective of SFM. The discussion is limited to nonsl iding contacts between linear elastic materials. One of its main goals is t o emphasize the assumptions underlying and restricting the application of t he most commonly used models and their implications for SFM measurements. ( C) 1999 American Vacuum Society.