A Novel Approach on Dielectric Barrier Discharge using Printed Circuit Boards

TL;DR

This study evaluates six PCB-based dielectric barrier discharge plasma sources for sterilization, analyzing their electrical, optical, and biocidal performance, and identifies design features that optimize pathogen inactivation.

Contribution

It introduces a novel PCB-based plasma source design and provides comprehensive analysis of its electrical, optical, and microbiological characteristics for sterilization applications.

Findings

Achieved a Log-4 bacterial reduction within one minute.

Discovered that electrode geometry significantly affects plasma behavior.

Identified a saturated ozone production at 435 ppm.

Abstract

Drug resistant bacteria, prions and nosocomial infections underline the need of more effective sterilizing technologies. The cold plasma technology is expected to bring a benefit in this context. Six different plasma sources, based on printed circuit boards, were evaluated fourfold. This include measurements of the power consumption, the ignition behavior by an ICCD-camera and ozone formation by absorption spectroscopy at 254 nm. To evaluate the biocidal effect, four bacterial test series were performed with Escherichia coli. The entirety of the tests analyze the plasma inactivation process from the input parameters to the desired biocidal effect. The discharge current and time resolved ignition behaviors indicated a simultaneous formation of filaments at the beginning of the negative half-cycle. The dynamics of the ozone production showed a saturated exponential growth upon a maximum value of 435 ppm. Additionally, the microbiological test series unveiled differences between the plasma source concepts. A total reduction rate of Log-4 within a minute was achievable. An air flow through slits within the plasma sources destabilized the plasma. Minor changes of the electrode geometry changed all measured parameters. Hence, to develop a pathogen inactivating plasma source, these results recommend a comb-shaped electrode design, which is laminated on a dielectric.