High Yield Automated MEMS Assembly

Heterogeneous assembly of 21/2D or 3D MEMS components is an alternate micromanufacturing route to monolithic integration or other stochastic, self-assembly approaches. This approach is deterministic (directed) and involves using microgrippers mounted on precision robots to pick-and-place microparts. In this context, the use of engineered compliance has been recently proposed as a very practical way to account for positional tolerances of the robot end-effectors and the manufacturing tolerances in the microparts. In this paper, we examine the most important tradeoffs in compliant MEMS assembly and conclude that the use of automation at these scales is qualitatively different than automation at larger scales. Whereas at the meso and macro scales, automation is often undertaken after, and often benchmarked against manual assembly, deterministic automation at the MEMS scale is a more holistic approach. This means that the designs of the assembly cell, part and end-effectors should be considered simultaneously, and that by doing so, we can automate assembly operations without the use of closed-loop feedback. To support our findings, we use several examples of micropart design and experimental results with mu³, a microrobotic workcell configured for high yield MEMS assembly.