Self-Assembly Kinetics of Microscale Components: A Parametric Evaluation

At the microscale, assembly by grasp and release is challenging. Self-assembly (SA) is an alternative component assembly method to significantly reduce assembly equipment costs. However, successful application of SA requires high assembly rates and high yield (few process errors). Prior modeling efforts describe SA process performance (yield and rate) for specific system configurations, but they do not use measurable process parameters and provide limited ability to predict the impact of process changes. In this paper, an experimental SA system was designed that controls process parameters independently while measuring SA outcomes. This system is used to evaluate a simple parameterization model for SA rate. The travel direction of the parts is varied to measure the path dependence of the assembly probability in the limit of low-impact velocity. Moreover, effects from changing part geometry are evaluated and accounted for in the model. Experimental results show a strong part-geometry dependence and minimal dependence on part arrival angle. This information is a key step toward a parametric kinetic model of capillary SA and complements previous SA process modeling efforts.