Plasmas are electrically charged gases that can produce light, radio waves, X-rays and even gamma rays. They are studied in the broad academic field of plasma science or plasma physics and can be generated by high-power lasers or by collisions between solids.
Plasma devices are used commercially for various purposes in the areas of sterilisation, waste gasification, and spacecraft propulsion. A patented plasma process called SPARC uses the electronically-excited oxygen plasma afterglow to attack and kill harmful pathogens on contaminated surfaces. It has been successfully used to sterilise cellulose nitrate filter papers contaminated with E. coli K-12, Staphylococcus epidermidis and Geobacillus stearothermophilus spores.
Another commercial application of plasmas is the use of plasma-assisted combustion in industrial burner systems. CUA has developed a novel device referred to as the Cyclotronic Arc Plasma Actuator (CAPA), which is intended to be used as a mechanism for boundary layer flow control in unmanned aerial vehicles. This device operates by the breakdown of a plasma filament between two coaxial electrodes with a magnetic field placed transverse to the current path. The plasma filament is then ionised with a stream of molecular iodine to pump atomic iodine into the high-efficiency laser cavity and extract laser power at 1315 nm (near-infrared).
In the late 1990s, Plasma TVs became popular as an alternative to LCD flat panel displays for HDTVs, because of their deeper blacks, wider viewing angles, higher resolution and more extensive colour spectrum. However, plasma display sales declined after improvements in VLSI fabrication allowed LCDs to match the size, weight and price of Plasma TVs.
