Integrated microendeffector for micromanipulation

Micromanipulation is needed for assembly and maintenance of micromachines and their parts. If the handled objects are miniaturized, interactive forces, such as the van der Waals force, surface tension force, and electrostatic force between microobjects and gripper surface become dominant in the air, and they act as adhesive forces. We cannot neglect such adhesive forces in micromanipulation. Considering the physical phenomena in the microworld, we propose reduction methods for adhesive forces. Surface roughness of the endeffector surface is effective to reduce the van der Waals force. We propose making the micropyramids on the endeffector surface by micromachining techniques. We designed and made a prototype of the microgripper with a microendeffector, the gripping surface of which is formed to have several micropyramids. Experimental results show effectiveness of the micropyramids for reduction of the adhesive force. We also made a semiconductor strain gauge at the end of the microendeffector for grasping force measurement. Both micropyramids and integrated piezoresistive force sensor are fabricated on the microendeffector by the micromachining techniques. Performance of this force sensor is shown