Study, modeling and measurement of adhesion forces at the microscale.
The behavior of microsized objects is governed by surface effects. Reliable interaction models between micro-objects and robots end-effectors are required for micromanipulation. Numerous parameters are involved in adhesion forces modeling. The influence of each of these parameters must be determined in order to control forces and especially the one which is required to split to contacting objects: the pull-off force. Moreover, at the microscale, measurements of interaction forces during a manipulation task are complex and are only available in few cases. The general approach of this work can be divided into three main steps. After a presentation of the micromanipulation context, models and measurement tools of the literature are depicted in the first step (chapter 1). Two modeling approaches are highlighted; where strengths and weaknesses of models are focused in chapter 2 in order to develop a new adhesion forces model during the second step (chapter 3). This model highlights coupling between local deformations and adhesion forces and exposes major differences between microscale and nanoscale. Finally, the objective of the third step is the correlation of the proposed model with experiments. The analysis of experimental results is presented in the chapter 4. The results show the difficulties encountered for modeling interactions between real micro-objects and highlights a scale effect on electrostatic forces.