Prospective industrial applications of the one atmosphere uniform glow discharge plasma

Abstract

The majority of industrial plasma processing is conducted with glow discharges at pressures below 10 torr. This tends to limit plasma processing applications to high value workpieces as a result of the high capital cost of vacuum systems and the production constraints of batch processing. It has long been recognized that glow discharges would play a much larger industrial role if they could be generated at one atmosphere, and in ambient air. The one atmosphere uniform glow discharge plasma (OAUGDP) has these capabilities. The OAUGDP is a nonthermal, 'cold' RF glow discharge plasma that operates on displacement currents and has the time-resolved characteristics of a classical low pressure DC normal glow discharge. Exploratory tests have been conducted on a variety of prospective industrial applications of the OAUGDP, all at one atmosphere using air as the working gas. These applications include subsonic plasma aerodynamic effects, including flow acceleration and flow re-attachment and the electrohydrodynamic (EDH) flow control of neutral working gas; increasing the surface energy and wettability of fabrics, films, and solid surfaces; sterilizing medical equipment and air filters; stripping of photoresist and directional etching of possible microelectronic relevance and plasma deposition.