A Homogeneous Surface Inactivation Device Driven by a Pulse High-Voltage Source

A surface discharge device composed of microns-thick hollow quartz fibers is used to inactivate resistant fungi cells. The homogeneous cold plasmas are generated by using a pulse high-voltage source with the repetition frequency of 150 Hz at atmospheric-pressure. Increasing pulse voltage slightly from 26 to 34 kV leads to an obvious improvement in the inactivation efficiency of fungi cells. The atmospheric-pressure air plasma generated at the pulse voltage of 34 kV is found to kill the fungi cells as much as 99% within a treatment time of 5 min. The inactivation efficiency is systematically investigated as a function of the processing depth of surface plasma. Various measurements indicate that plasma activated derivatives, such as OH, O, O3, and charged species play a key role in this plasma inactivation process.