Using plasma to kill harmful bacteria has long been a dream of many in the medical field. Produced in electrical discharges, plasma has been shown to “destroy pathogens, help heal wounds, and selectively kill cancer cells.” The problem, however, is that plasma devices need a large external power source to generate enough kilovolts for the electrical discharge. A power supply like this is difficult to come by in hospitals, and almost impossible to supply in situations like emergency calls, natural disasters, or military operations.
Now a group of researchers at the Huazhong University of Science and Technology, led by engineer Xinpei Lu, believe they have created a device that can discharge plasma powered only by a 12-volt battery. The portable prototype is called a plasma flashlight and “it generates the plasma even being disconnected from wall power, using very low power,” explains group member Kostya Ostrikov of CSIRO Materials Science and Engineering in Australia.
In order to solve the setbacks of current plasma devices, the researchers used a DC booster to increase the voltage of the plasma flashlight to 10 kilovolts and “ballast” resistors to ensure someone holding the flashlight wouldn’t feel the discharge’s current. They tested the device on films of bacteria that are resistant to heat and antibiotics, and found that shining the plasma flashlight for 5 minutes at a distance of 5 millimeters killed almost all of the bacterial cells. The results of the test were published April 4, 2012 online in the Journal of Physics D: Applied Physics.
Scientists hail the portability and meager voltage of the device as a big advance for science. The plasma flashlight will have to go through rigorous clinical testing, but besides making it smaller and more efficient, Ostrikov believes that it is basically a commercial device already.