Plasma Flashlight Destroys Bacteria

This prototype flashlight would be utterly unhelpful in a blackout or in the woods. But the plasma-emitting machine, shaped like a giant crayon, has one useful feature that your Maglite doesn’t. It can kill germs.

Australian and Chinese researchers have built a device that uses a 12-volt battery to create a plasma that could kill one of the most persistent bacterial structures, biofilm. A biofilm is a bacterial group that encases its entire colony with a slimy material. Normally, we encounter biofilms as plaque when we brush our teeth, but they can also grow and thrive in wounds, holding up the healing process. Using a quick blast of plasma to break up biofilms would make it easier for doctors and dentists to deal with infection. The study is published in the Journal of Physics D: Applied Physics.

Plasma is essentially ionized gas, a free-flowing state of matter that is electrically charged, David Graves says. Graves, a professor of chemical and biomolecular engineering at UC Berkeley who has been studying plasma for more than 30 years (but was not involved in this study), says plasma is everywhere: from stars to lightning to those buzzing florescent lights in the office. "The basic idea is very, very simple. If you pass electricity through a gas by applying a high voltage then you get plasma.