Modeling and magnetic-based motion control of a cluster of microparticles

We investigate a dynamic model for a cluster of micro particles inside a fluid under the influence of magnetic fields. The drag force of a cluster of micro particles is modeled by estimating its geometry using an ellipsoid with an axis ratio of 8. Point-to-point motion control experiments with a cluster of micro particles are carried out with a maximum average velocity of 327 um/s, and maximum position tracking error of 110 um/s. Our magnetic system has a workspace of 1.8 mm x 2.4 mm, and is capable of generating magnetic field and gradient of the magnetic field squared of 5 mT and 0.4 T2/m, respectively. In order to investigate the feasibility of performing micro assembly tasks using micro particles, a cluster of micro particles is utilized to perform micro manipulation of micro-objects and direct these micro-objects into destinations within a target structure. Micro manipulation experiments are executed with a maximum average velocity and maximum position tracking error of 297 um/s and 150 um respectively. Micro assembly of micro objects using a cluster of micro particles is demonstrated at an average velocity of 193 um/s and an execution time of 18 s.