Sterilization of conductive and nonconductive surfaces using atmospheric pressure dbd plasma

Abstract

NASA spacecrafts are composed of a variety of conductive and non-conductive materials. For this reason, it is important to study sterilization efficacy of DBD plasma on varying substrates which are conductive, non-conductive, in wet conditions, and in dry conditions. In the experimental setup, “wet” bacteria designates that it is suspended in a 10 µl drop of water and when allowed to dry for 30 minutes, it is designated as “dry”. The bacteria chosen for these experiments are Escherichia coli and Deinococcus radiodurans. Initial results demonstrate an 8-log reduction in wet E. coli deposited on stainless steel after 30 seconds of plasma treatment; a 4-log reduction in dry E. coli deposited on a polyethylene substrate after 30 seconds of plasma treatment; and a 4-log reduction of wet D. radiodurans which was deposited on stainless steel after 15 seconds of plasma treatment. The results will allow NASA researchers to better design spacecraft for higher sterilization efficacy.