Surface charging during disinfection by dielectric barrier discharges

Dielectric barrier discharges (DBDs) have shown effectiveness at disinfecting surfaces due to reactive gas species, UV, electromagnetic fields, and fluxes of charged particles to the surface. A relatively less explored factor is the transfer of charge to the treated surface. Resulting field strengths on the order of 10kV/cm, depending on pulse shape and biological species, can cause ruptured membranes, intracellular damage, and apoptosis. Weaker fields, when not directly damaging, can increase uptake of chemicals from the environment due to membrane electroporation. Plasma treatment provides cytotoxic species, making this a promising avenue for disinfection. In this work, we use a non-contacting voltmeter to measure the transfer of surface charge in treatment by two devices: a flexible printed-circuit device (flex-DBD) and a commercially-available floating-electrode D’Arsonval device. Preliminary results for polyimide film suggest a field of up to 11kV/cm post-treatment. Information on surface charging is valuable in designing novel devices and operating regimes to optimize disinfection.