In relationship with the demonstrator 1 and the subproject 4, a simulator of capillary forces involved in self-assembly processhave been built by CNRS. It enables to predict the behavior of the capilary self-alignement of the components as shown in the following video. The modeling principle is based on a computation of surface-tension effects, capillary pressure, viscosity of the liquid, and inertia of the objects. An anlythic formulation of this four effects have been proposed in order to easily show the influence of each parameter (surface tension, liquid viscosity, …). The simulator shows a large variety of behavior where the damping factor varies from a high damped behavior to an oscillating behavior. This computation tools consists in a scientific contribution which can be applied to design of self-assembly process.