Nano-sized particles have received considerable interest in the past two decades. The filtration of nanoparticles is becoming an important issue as they are produced in large numbers from material synthesis or combustion emission, and their effect on human health is relatively high. Dielectrophoresis (DEP), phenomenon that induces spatial movement of particles placed in nonuniform electric field, depending on the dielectric properties of the particles and the surrounding medium, the geometry of the electrodes, and the amplitude and frequency of the applied signal, proved to be the most adequate tool in order to manipulate particles at submicron scale. First, this work presents an overview of the various applications of the dielectrophoresis. Next, the theoretical description of the main forces implied in the spatial control of submicron particles is given. Finally, a mathematical model describing the filtration of nanoparticles suspended in flue gas by a combination of dielectrophoretic and electrohydrodynamic forces, and a set of numerical results obtained by simulations performed in the frame of this model are presented. The dielectrophoretic force and the nanoparticles concentration profile in a DEP-based separation micro system consisting of a micro channel are numerically investigated using the COMSOL Multiphysics finite element code. The performances of the filtration device are analyzed in terms of a specific quantity related to the separation process, called Filtration rate. The simulations provide the optimal set of values for the control parameters of the separation process in order to obtain a desired performance, and represent a useful tool in designing of microfluidic devices for separating nanoparticles from flue gas.