Design and Characterization of Low Temperature Co-Fired Ceramic Dielectric Barrier Discharge Plasma Arrays for Killing and Removing Bacterial Biofilms

Abstract

Present research at Boise State University (BSU) has demonstrated the ability of low temperature co-fired ceramic (LTCC) Dielectric Barrier Discharge (DBD) cold atmospheric pressure plasma (CAP) devices to remove bacterial biofilms on steel substrates. Although bacteria may easily be inactivated by plasma treatment, the remains of the organism are still present on the substrate. It is shown that single element DBD CAP discharge devices operating at 2100 Vrms with 5 LPM of hydrated argon gas etched P. fluorescens biofilm within a few minutes of exposure. Similarly, using an 8 element array of linear plasma discharges, etch removal of biofilm was demonstrated. After 5 minutes of treatment, the majority of the biofilm was removed leaving only a thin layer ≈ 8 μm) remaining. Incorporating 150 kΩ ballast resistors in multi-discharge arrays greatly reduced variation in discharge channel current. The thermal properties of these devices were also determined in order to find optimal gas flow rates to prevent killing biofilm bacteria by thermal processes. This research shows that feed gas flow rates, power delivered to the plasma, proximity to substrate and flow gas hydration are important factors in etching or removal of bacterial biofilms from surfaces.