Magnetic self-assembly of multiple component types: simultaneous and sequential sorting of a heterogeneous mixture

This paper presents completely parallel magnetically-directed self-assembly of multiple types of millimeter scale components. The free floating components from a heterogeneous mixture self-assemble onto pre-defined receptor sites on a fixed substrate using magnetic forces between permanent magnets integrated onto the component surfaces. Heterogeneous assembly is demonstrated in both simultaneous and sequential fashion. Simultaneous heterogeneous assembly is demonstrated using two types of components with 4-fold rotational symmetry with an assembly yield of 93 % in 1 min. Sequential heterogeneous assembly is demonstrated using one component with 4-fold symmetry and the second component with 2-fold symmetry with an assembly yield of 99 % in 3.5 min. This method shows a promise for low-cost, high-throughput parallel assembly of multi-chip modules, stacked die assemblies, system-in-package solutions, etc.