Micromagnetic Simulation for nanobeads detection using planar Hall sensors

A micromagnetic simulation for the detection of magnetic nanobeads by planar Hall sensors is presented. The calculated dipole field created by the polarized nanobeads shows the strong dependence on the distance from beads to the sense plane. In this simulation, nonuniform dipole field, random configuration of beads, and experimental parameters of device were used. Micromagnetic calculation shows the linear signal response to the bead number. This linear behavior is insensitive to the random distribution of beads, but is sensitive to the bead number, indicating the possible application to quantitative biomolecular recognition.