Computational modeling of structure formation during dielectrophoresis in particulate composites

In this paper a novel numerical model is proposed for qualitative simulation of the structure formation during dielectrophoresis in a medium of dielectric particles suspended in a liquid between parallel-plate electrodes. Upon application of an electric field particles reorient with respect to the imposed electric field, followed by rotational and axial displacement of particles interaction until chains are formed. The performance of the model is illustrated in a number of fundamental cases. The influence of parameters such as size, aspect ratio and heterogeneity of the particles is studied for the purpose of obtaining insight in the ideal conditions required to obtain the desired structure. In a multi-particle system, the relative particle size is shown to be a key parameter in chain evolution process. The quality of the structure evolution is investigated using a set of geometric parameters. A new topological parameter, chain perfection degree, relating the microstructure to the overall performance of the piezoelectric composite, is proposed and calculated for the fundamental case-studies.