Design and test a pneumatically actuated microgripper based on structural stiffness

In response to the problem that the actual amplification ratio of the compliant motion amplification mechanism cannot be further improved, this paper introduces a two-stage amplification microgripper based on structural stiffness that is driven by pneumatics. The mechanism not only has the advantages of good symmetry, compact structure, and large output displacement but can also reduce the relative error of the theoretical and experimental amplification ratios. The first-stage mechanism selects high-stiffness mechanisms and high-stiffness flexure hinges, and the second-stage mechanism uses low-stiffness mechanisms and low-stiffness flexure hinges. The arrangement order of the mechanism is determined by the working mode analysis. The specific dimensions of the mechanism and flexure hinges are determined through structural size optimization so that the amplification performance of the mechanism will be optimal. The experimental results show that the displacement amplification ratio of both the opening and closing of the microgripper is 41.8.