Microassembly using a cluster of paramagnetic microparticles

We use a cluster of paramagnetic microparticles to carry out a wireless two-dimensional microassembly operation. A magnetic-based manipulation system is used to control the motion of the cluster under the influence of the applied magnetic fields. Wireless motion control of the cluster is implemented at an average velocity and maximum position tracking error of 144 μm/s and 50 μm, respectively. This control is used to achieve point-to-point positioning of the cluster, manipulation of microobjects, and assembly of microobjects into a microstructure. The control system achieves stable positioning of the cluster, while simultaneously compensating for the planar drag forces on the cluster and the microobject. The presented magnetic-based microassembly technique allows for the selective pushing and pulling of microobjects with specific geometries towards their destinations inside a microstructure in an execution time of 18 s, within a workspace of 1.8 mm × 2.4 mm.