The role of dielectric properties of biological substrates in the medical applications of dielectric barrier discharges

Nonthermal plasma (NTP) technology has promising implications for advances in medicine, and understanding the electrical effects of NTP on cells is essential for realizing these implications. For these applications, dielectric barrier discharges (DBDs) are of interest because they treat substrates without causing thermal damage. DBDs are plasmas that are formed when a high voltage is applied between two electrodes, where at least one electrode is covered by a dielectric material. The dielectric properties of the substrate under treatment by a DBD affect the overall load impedance of the power source and the way the discharge interacts with the substrate. In this project, we explore the effect of the dielectric properties of a given substrate on the power delivered to the substrate and on the properties of the plasma discharge. A vector network analyzer is used with a coaxial probe to measure the relative permittivity of different substrates, including cell suspensions. Substrates are treated with NTP produced by a dielectric barrier discharge. Electrical measurements are completed to determine the load impedance for various substrates. The dependence of the power supply and discharge characteristics on substrate material is determined.

This work is supported by the US Department of Energy, contract no. DE-AC02-09CH11466