Integrated micro endeffector for dexterous micromanipulation

Micro manipulation is required for assembly and maintenance of micro machines and their parts. As the objects to be handled are miniaturized, attractive forces such as van der Waals force, surface tension force and electrostatic force between micro objects and grip surface become dominant in the air, and they work as adhesive forces. We cannot neglect such adhesive forces in micro manipulation. Considering the physical phenomena in the micro world, we propose reduction methods of adhesive forces. Surface roughness of the end effector surface is effective to reduce the van der Waals force. We propose to make the micro pyramids on end effector surface by the micromachining techniques. We designed and made a prototype of the micro gripper with a micro end effector whose grip surface is covered with the micro pyramids. Experimental results show effectiveness of the micro pyramids for reduction of the adhesive force. We also made a semiconductor strain gauge at the end of the micro end effector surface for force measurement. Both micro pyramids and integrated piezoresistive force sensor are fabricated on the micro end effector by the micromachining techniques. Performance of this force sensor is shown.