ABSTRACT
In this chapter, pair interaction between two circular uncharged colloidal particles immersed in an aqueous solution subjected to an external direct current (DC) electric field is numerically investigated taking into account the particle-fluidelectric field interactions under the thin electrical double layer (EDL) assumption. Two nearby particles interact with the external electric field as well as each other when they are close enough, inducing a spatially nonuniform electric field surrounding them. The interaction between the induced nonuniform electric field and the induced electric dipole in each particle arising from the difference in the electrical properties of the particle and the background liquid medium induces a mutual dielectrophoretic (DEP) force exerted on each particle, leading to particle chaining, which has been experimentally observed in the DEP-directed particle assembly process. Particle assembly via DEP force has been recognized as one of the major fabrication tools to assemble novel nanomaterials with superior electric, magnetic, and optical properties for various applications, including photonics, photovoltaic solar cells, electronics, as well as data storage.
