Design and Development of a Novel Tesla Coil-Based Cold Plasma Device for Plasma Medicine: Decoupling the Effect of Plasma-Generated Species

A novel Tesla coil-based cold atmospheric pressure plasma (CAPP) device has been developed from the first principle for biomedical applications. This device has been characterized by electrical and optical diagnostics to determine its efficacy for biological applications. These characterization results showed that eight-LPM Ar plasma at 16.5-W operating power produces stable plasma with low discharge current. The device was then tested as bactericide on Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. While E. coli could be completely annihilated after 120 s of plasma treatment at a 2-mm distance from plasma tip; inactivation of S. aureus starts after 60 s due to its thicker cell wall and complete annihilation requires 240 s of plasma exposure. Potent bactericidal plasma emission bands, such as OH (~309 nm), N2 (SPS) (~337 nm), and OI (~777.4 nm), have been observed and electron microscopy analysis of bacteria supports cell damage post-plasma treatment. The study indicates that ~4–6 mm away from the plasma tip, the effect of charged particles vanishes but emitted UV and reactive oxygen species (ROS) from CAPP still eradicates bacteria in short exposure time (<8 min). Demonstrating microbial inactivation at a distance underscores the potential for noncontact, remote sterilization applications. This innovative capability opens doors to industries where the maintenance of pristine, germ-free environments is of paramount importance.