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The full article is here at sciencemag.org
The above article is a bit generic about how this technique actually works, so here is a link to an applied physics letter detailing some very interesting results in the treatment of cancerous tumors and it's ability to not damage non-cancerous cells.
A group led by engineer Xinpei Lu at the Huazhong University of Science and Technology in China believes it has a device with none of these drawbacks [ed. see full article for previous drawbacks]. Powered by a normal 12-volt battery and operating in open air without a gas supply, the prototype, which they call a plasma flashlight, should be portable enough to take anywhere. "It generates the plasma even being disconnected from wall power, even using very low power," says group member Kostya Ostrikov of CSIRO Materials Science and Engineering in Lindfield, Australia.
The flashlight's battery is far too small to create a plasma on its own, so the researchers use a common electronic device known as a DC booster to step up the voltage to 10 kilovolts. One output of the booster is wired to the device's shell—or "grounded," in technical speak—while the other goes to an array of 12 fine, stainless steel needles that create a rapidly pulsing electrical discharge. The circuit has several "ballast" resistors that limit the discharge's current so that the flashlight is safe to touch.
To test the device, Lu's group grew thick films of Enterococcus faecalis, bacteria that are well-known to infect root canals in the mouth and are highly resistant to both heat and antibiotics. The researchers used some of the so-called biofilms as control samples and subjected the others to the plasma flashlight for 5 minutes at a distance of 5 millimeters. Afterward, they marked all the samples with two fluorescent solutions: a green one that flagged living cells, and a red one that flagged dead cells.
The team found that the control samples stayed green, while the treated samples had turned almost completely red—even at the bottom of the biofilms, which were about 17 cells deep. The results, which are published online today in the Journal of Physics D: Applied Physics, were even better than a nonportable plasma device that Lu's group had tested previously.
The above article is a bit generic about how this technique actually works, so here is a link to an applied physics letter detailing some very interesting results in the treatment of cancerous tumors and it's ability to not damage non-cancerous cells.
From above link said:This paper describes a flexible microplasma jet device using a Tygon® S-54-HL tube as a
biocompatible tube and its potential in developing cancer therapies. The optical and physical
properties of the plasma jets and preliminary apoptosis data of cultured murine tumor cells and
nontumor fibroblast cells treated with these plasma jets are presented. Microplasma jets were
observed to induce apoptosis in cultured murine cells in a dose-dependent manner. The murine
melanoma tumor cells were more sensitive to plasma treatment than fibroblast cells. These features
allow the direct and precise application of this microplasma jet device to tumor cells. © 2010
American Institute of Physics.