A photo from open sources
A group of scientists from Australia and China built a prototype portable cold plasma generator that runs from 12 volt battery and does not require any gas supply or external high voltage power. As shown last year plasma brush, a new device designed for disinfection, for example hands. The system generates electrical discharges 100 ns long and with a repetition rate of 20 kHz. These discharges create plasma in ordinary air with a temperature of only 20-23 ° C (and the device is equipped with a fuse that does not allow temperature rise above). The jet of such a plasma does not cause no harm to the skin, but effectively fights bacteria. For device verification, its authors have grown on the substrate almost 30-micrometer dense film of Enterococcus faecalis bacteria. She totaled 17 layers of microbes. 
Photos from open sources For five minutes of exposure plasma penetrated the lowest layers of this film and successfully inactivated all microorganisms. And for some of their species, developers add a “flashlight”, a few dozen would be enough seconds of the generator. (Details are in the ARTICLE in Journal of Physics D: Applied Physics.)
