Manipulation of carbon nanotubes and other carbon nanoparticles in liquid media through the application of electric fields has been frequently addressed in literature. For nanoparticles in liquid suspensions, Brownian motion and Van der Waals forces are usually regarded as the relevant driving forces in particle dynamics. Given the high aspect ratio and electrical conductivity of such particles, induced polarisation takes place in the presence of an electric field, leading to dielectrophoresis and Coulombic interactions. This is thought to promote their rotation and chaining due to electric synergies. When performed in polymer composites, this technique could lead to a significant improvement of the electrical properties of the bulk material. There is, as reported in literature and hereby investigated, a strong dependency on the electric field intensity and frequency, as well as on the viscosity of the medium. Experimental setups were developed for investigations of dielectrophoresis in thermoset and thermoplastic composite systems with different kinds of carbon nanoparticles such as single-wall and multi-wall carbon nanotubes (resp. SWCNT and MWCNT) and graphene nanoplatelets (GNP). In-situ current and voltage measurements are performed for studying the dynamic evolution of such electrical processes. Single-walled carbon nanotubes (SWNTs) were dispersed in an epoxy resin as electrically conductive filler. Epoxy/SWNT nanocomposites were produced by curing while applying both DC and AC electric fields to the system in order to improve the through-plane electrical conductivity. Parameters such as electric field strength and frequency, curing temperature and filler concentration were investigated. AC fields enabled values in the through-plane direction lower than 3 kΩ.cm at only 0.01 wt.% loading, representing a reduction of up to around 10 times in comparison with the samples produced without electric field.