Atmospheric Pressure Dielectric Barrier Discharges: A Low-Cost System for Surface Modification

Plasma treatment is a common way for modifying the surface of a material. A simple but effective source for a low‐temperature nonequilibrium plasma is dielectric barrier discharges (DBDs), also referred to as silent discharges. DBDs are characterized by the presence of at least one insulating (dielectric) layer in the discharge gap between two metal electrodes. When a high voltage is applied to the DBD configuration, tiny breakdown channels are formed in the discharge gap. These microdischarges are characterized as a weakly ionized plasma containing electrons with energies up to 10 eV and ions at room temperature. The energetic electrons provide an effective tool for chemical surface modification. Typical setups for DBD treatments consist of vacuum chambers and vacuum equipment, and so are very cost‐intensive. Atmospheric pressure discharges provide a possibility for low‐cost surface chemistry, because the setup consists only of the discharge set‐up in normal air or in a specified inert gas atmosphere and a high‐voltage amplifier coupled with a frequency generator. Silent discharges in air increase the wettability of polymer foils such as PTFE and FEP, sufficient for cell growth and further for surface‐chemical binding of proteins onto the polymer. Thereby a simple and low‐cost process to achieve protein chips for biomedical applications may be envisaged.