Study on DC-Driven Air Cold Plasma Brushes Generated Without Airflow Supplement

In this paper, 30-mm-wide cold atmospheric-pressure air plasma brushes are reported. The brushes driven by a direct current power supply are capable of generating air plasma glows with no noble gas addition and no airflow supplement. There is no risk of glow-to-arc transitions, and the plasma glow appears uniform no matter what kinds of material are being processed. The air plasma glow can be scaled up by using the plasma brush arrays. About 30 mm x 30 mm x 5 mm (W, H, and L) homogeneous air plasma glow is generated by merging seven-brush arrays. Current measurements show that the single-brush discharge appears periodically pulsed, while the brush array discharge actually presents either pulsed with about array-number-times frequency of the single one. A further analysis indicates that the charge particles trapped along the dielectric surface may be responsible for the discharges.