Abstract: Investigation of a DBD Plasma Helium Jet for Medical Applications

Plasma-based healing and sterilization techniques are gaining attention due to their simplicity and effectiveness. Rapid healing of chronic wounds will benefit millions of patients across the USA. Several plasma jet designs are proposed and are being investigated by many researchers. In this study a multielectrode DBD (Dielectric Barrier Discharge) plasma jet device was designed and was tested for its suitability for medical applications. Helium due to its low ionization potential was used as a working gas. Information on plasma input power was extracted from VI characteristics that were experimentally obtained for various input voltages (4kV to 6kV at ~40kHz). Two 1000:1 high-voltage probes were employed to generate VI graphs while plasma was on. Plasma plume gas temperatures along its length were measured using a k-type thermocouple. Plasma plume lengths at various operating conditions were also monitored. An Ocean Optics spectrometer was used to capture the emission spectroscopic signature of the plasma plume in which various emission lines were identified. A maximum plasma plume length of about 50 cm was observed whereas the plasma gas temperature varied from 25 degrees to about 50 degrees centigrade near the plasma exit. For an input operating voltage from 4.0 kV to 6.0 kV, the measured input power varied from 2.0 W to 6.1 W respectively. Multiple lines including second positive nitrogen system, OH, and various He-I and Oxygen lines were identified in the emission spectra of the plasma. The information obtained from this work will be used to find the optimized plasma conditions for effective bacterial mitigation in future studies.