Design Improvements in Dielectric Barrier Discharge Plasma Torches for Medical Applications

Low-temperature dielectric barrier discharge (DBD) plasmas are used for rapid wound healing and sterilization. Plasma temperatures and radicals (reactive nitrogen/oxygen) play a vital role in the healing process. In preliminary designs, plasma was generated in a dielectric tube where plasma characteristics could not be changed without changing the input power or gas flow rates. In a new design a variable outer electrode was used to control the plasma jet characteristics. Another manifestation of this design appeared as a multi-electrode plasma torch where multiple fixed outer electrodes were used. The traditional DBD torches produce plasma jets and are not suitable for bacteria mitigation on larger surfaces. For this purpose, a DBD plasma sheet generator was designed. In this presentation, we analyze the design of multiple plasma troches and measure the gas temperatures and plasma vibrational, rotational, and excitation temperatures. Helium was used as the working gas in all experiments and 20-30 kV/30-50 kHz AC voltage was applied. An Ocean Optics UV-VIS spectrometer was used to conduct spectroscopy and SPECAIR was employed to estimate plasma temperatures. Detailed analysis of the experimental results will be included in this presentation.