Optimal design of non intuitive compliant microgripper with high resolution

This paper reports on the description of a new high force-resolution microgripper with large jaw displacement, electrostatically actuated by a comb-drive and instrumented with an integrated differential capacitive displacement sensor. This microgripper has been non-intuitively designed using a multi-objective optimization method, to reach the best compromise between chosen performance criteria. It has been modeled and fabricated using silicon micro-technology. The theoretical gripping force resolution obtained is 78 pN along the direction of the mobile tip displacement. This performance is many times of magnitude better than the monolithically fabricated MEMS based grippers mentioned in the literature. First experimental characterization tests have been conducted and show good agreement with the expected theoretical performances.