Electric field and force on a dielectric particle between two diverging plate electrodes

This paper presents an analysis of the electric field and force on a dielectric particle in a non-uniform field varying in three dimensions. The electric field is calculated by the method of multipole images using fundamental solutions of the Laplaceʹs equation and the multipole re-expansion including multipole rotation. From the electric field, the dielectrophoretic (DEP) force acting on the particle is calculated. The results show that the force attracting the particle to the higher field region depends strongly on the position of the particle. Approximation by an effective dipole gives significantly smaller forces than our results.