Principle of a submerged freeze gripper for micro-assembly.

International audienceThe development of reliable and repeatable strategies to manipulate and assemble microobjects lies in the efficiency, reliability and precision of the handling processes. In this paper, we propose a thermal based microgripper working in an aqueous medium. Manipulating and assembling in liquid surroundings can indeed be more efficient than in dry conditions. A comparative analysis on the impact of dry and liquid media on surface forces, contact forces and the miniaturization of the system. hydrodynamic forces is shown. In addition, ice grippers represent flexible manipulation solutions. Nevertheless, when micromanipulation tasks are performed in air, capillary forces can drastically perturb the release. Our submerged freeze microgripper exploits the liquid surroundings to generate an ice droplet to catch microobjects, and to avoid capillary forces during the release. The thermal principle, the first microgripper prototype, an ice generation simulation, and the first tests are presented. The main objective is to validate the manipulation principle. Further works will be focused on control and optimization of the ice generation an