A new method for the interaction between multiple DEP particles: iterative dipole moment method

Dielectrophoresis for bio-particle manipulation has been drawing much attention in recent years. The equivalent dipole moment has been widely used to calculate dielectrophoretic forces on a particle, but this method falls short to describe the interaction between neighboring particles. The Maxwell stress tensor method (MST) is theoretically rigorous for particle interaction, but it will cost huge computing resource. In this paper, an iterative dipole moment method (IDM) is presented to investigate the interaction between multiple dielectrophoretic particles in a two-dimensional electric field. Without any cumbersome numerical computation, the inter-particle forces and the particle trajectories calculated by the IDM method are found to be in good agreement with those by the MST method for some published results. Furthermore, it is found that the final stable particle chain patterns strongly depend on the initial configuration of the particle distribution. An arbitrary small disturbance to the particle locations may lead to dramatically different motion trajectories and final particle chains.