Dielectric-barrier discharge (DBD) is the electrical discharge between two electrodes separated by an insulating dielectric barrier. Originally called silent (inaudible) discharge and also known as ozone production discharge or partial discharge, it was first reported by Ernst Werner von Siemens in 1857. On right, the schematic diagram shows a typical construction of a DBD wherein one of the two electrodes is covered with a dielectric barrier material. The lines between the dielectric and the electrode are representative of the discharge filaments, which are normally visible to the naked eye. Below this, the photograph shows an atmospheric DBD discharge occurring in between two steel electrode plates, each covered with a dielectric (mica) sheet. The filaments are columns of conducting plasma, and the foot of each filament is representative of the surface accumulated charge.