Practical characterisation of the friction force for the positioning and orientation of micro-components

This paper deals with the description of a method for the measurement of friction force between a very small object (80 to 300 mum) and a support. The goal is to design a feeder based on controlled mechanical vibrations in order to drive microcomponents by breaking the friction force. The contact model is based on the Hertz theory and the Greenwood-Williamson multi-asperity model. The amplitude of the static friction force is measured in a clean environment with an AFM (atomic force microscope) whose cantilever is placed in the vertical position. Using this setup and the modeling, we have estimated the interfacial shear stress between the microcomponent and the support.