Surface stress in the self-assembly of alkanethiols on gold probed by a force microscopy technique

The extreme sensitivity of scanning force microscopy allows its application to be extended well beyond the probing of surfaces. We discuss micromechanical force microscope cantilevers, with a thin Au receptor layer on one side, as sensors for gas-phase adsorption of alkanethiols, which self-organize into well-ordered, densely packed films. Quantitative data show that surface stress develops during the self-assembly process for alkanethiols of different chain lengths. In particular, we present an analysis of the kinetics of the replacement process of adsorbates by butanethiol molecules, details of the acquisition analysis, and a quantitative calibration technique.