Monolithic Structure of Integrated Coaxial Micro-hollow Dielectric Barrier Discharges: Characterization for Environmental and Biomedical Application

Dielectric barrier discharge (DBD) devices operated at atmospheric pressure are of great uses for varieties of environmental and biomedical applications. Instead of commonly used parallel plate structures we have ever developed an alternative structure of integrated coaxial micro-hollow discharges by stacking two ceramic insulated metal meshes, which can be scaled to any size keeping uniform discharge. Since its new version of monolithic structure became available, we tried in this work to characterize the properties of discharge and production of OH radicals with several gas species using optical emission and laser induced fluorescence (LIF) spectroscopy techniques. Spatiotemporal behavior of DBD showed ring structures at larger hole-diameters than 1 mm but changed to convex structures at 0.6 mm hole-diameter. Large amounts of OH radicals were produced with He and Ar gases but almost none with N$_{2}$ gas. Spatial distribution of OH radicals diagnosed by LIF showed the propagation with the gas flow. Rotational temperature estimated from OH (0-0) band was larger than those from N$_{2}$$^{+}$ (0-0) and (0-1) bands.