Figure 1. Schematic of the patterned thin-film micromagnet integration, design and magnetization process.

(a) Schematic of the microchip based immunomagnetic assay integrated with micromagnets, and the major forces applied on the cells when they are on the substrate. (b) Concept of the micromagnet design - after being magnetized by the external magnetic field, the ferromagnetic micromagnets generate strong localized field to increase the magnetic force applied on the target cells. (c) Magnetization process of the soft-magnetic micromagnets using the theory of magnetic anisotropy and demagnetizing field.