Dielectric breakdown of high-k epoxy-based anisotropic composites

New polymer-based high permittivity materials often depend on the addition of high-k particles such as BaTiO3. In the present work we propose the use of dielectrophoretically-aligned composites with anisotropic properties in the direction of the applied ac field during the curing process. The results on the dielectric permittivity of epoxy-based BaTiO3 ant SrTiO3 composites show that permittivity is increased for the anisotropic composites. Nevertheless the dielectric strength of such anisotropic composites is lower than the isotropic ones, possibly due to the increased ionic and/or electronic transport along the aligned particle chains.