Simulation of micro-manipulations:: Adhesion forces and specific dynamic models

Aiming at achieving precise micromanipulations using only adhesion forces, the three main sticking effects on a microscale are considered. On the hypothesis that Newton's laws are applicable at this scale, dynamic models of a simple task, consisting in picking up and placing micro-spheres, are proposed. Three models of capture are written, introducing Van der Waals, capillary, electrostatic, rubbing and pull-off forces. A complete model of the release is also proposed. The capture and release tasks were dissociated and simulated. Some strong conclusions guaranteeing the manipulation by adhesion were extracted on materials of each part of the system, on the size of the spheres and on the speed limits applied to the end-effector. (C) 1999 Elsevier Science Ltd. All rights reserved.