dielectricbarrier

Dielectric barrier discharge (DBD) is a method for generating plasma at atmospheric pressure by applying an alternating high voltage between two electrodes, at least one of which is separated from the other by a dielectric barrier. The barrier prevents rapid current growth and arcing, so the discharge occurs as many small, short-lived microdischarges across the gas gap. This non-thermal or cold plasma can be produced in air or other gases and at room temperature.

Typical voltages are on the order of several kilovolts, with frequencies from a few to several tens of kilohertz. The plasma produced is non-thermal, meaning the electron temperature is high while the bulk gas remains near ambient temperature. The discharge can operate under various gas compositions and is commonly used at atmospheric pressure, making it versatile for practical applications.

DBD configurations vary and include parallel-plate, coaxial, and recessed geometries. Dielectric barriers are often made from glass, ceramic, quartz, or coated polymers, while electrodes are metal or conductive films. The dielectric thickness, material, and surface area influence discharge uniformity, power handling, and longevity.

Applications are diverse and include surface treatment and adhesion enhancement for polymers and textiles, sterilization and disinfection, ozone generation for air and water treatment, and plasma-assisted catalysis or thin-film deposition. In electronics, DBD concepts underpin some plasma display technologies and related microfabrication processes.

Advantages of DBD include operation at atmospheric pressure, simplicity, and compatibility with temperature-sensitive substrates. Limitations involve energy efficiency, generation of UV and ozone by-products, potential dielectric surface degradation, and challenges achieving uniform plasma over large areas without careful design and control.