A group of Chinese and Australian scientists have developed a handheld, battery-powered plasma-producing device that can rid skin of bacteria in an instant. The device could be used in ambulance emergency calls, natural disaster sites, military combat operations and other remote locations. The plasma flashlight is driven by a 12 V battery and doesn't require any external generator or wall power. In the experiment, the plasma flashlight effectively inactivated a thick biofilm of one of the most antibiotic- and heat-resistant bacteria, Enterococcus faecalis, which often infects root canals during dental treatments. The biofilms were around 25 micrometres thick and consisted of 17 different layers of bacteria. Each one was treated for five minutes with the plasma flashlight and then analysed to see how much of the bacteria survived. Results showed that the plasma not only inactivated the top layer of cells, but penetrated deep into the very bottom of the layers to kill the bacteria.