Efficient multipoles modeling for linear magnetized beads manipulations

Many Magnetic MEMS have been recently developed to manipulate spherical diamagnetic or superparamagnetic particles. Magnetic forces can be computed using the dipole method or the semi-numerical integral. However, these methods appear inaccurate or time consuming, respectively. This paper proposes a multipolar approach which provides a satisfying compromise between precision and rapidity to compute the magnetic force on linear magnetized beads. Gain in precision and CPU time will be detailed for water droplets levitating above micromagnets.