Handheld plasma flashlight rids skin of bacteria instantly

Apr 26, 2012

A group of Chinese and Australian scientists, including CSIRO, have developed a handheld, battery-powered plasma-producing device that can rid skin of bacteria in an instant. The handheld plasma flashlight could be used in ambulance emergency calls, natural disaster sites, military combat operations and many other instances where treatment is required in remote locations.

Details of the plasma flashlight have been released today in a study published by the Institute of Physics Publishing's Journal of Physics D: .

The flashlight is driven by a 12 volt battery and doesn't require any external generator or wall power. It also doesn't require any external gas feed or handling system. The device itself is fitted with resistors to stop it heating up and making it safe to touch.

In the study, the plasma flashlight effectively inactivated a thick of one of the most antibiotic and heat-resistant bacteria, Enterococcus faecalis – a bacterium which often infects the root canals during dental treatments.

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.

Co-author of the study CSRIO's Professor Kostya (Ken) Ostrikov, said: "The bacteria form thick biofilms, which makes them enormously resistant against inactivation which is extremely difficult to implement. High temperatures are commonly used but they would obviously burn our skin.

"In this study we chose an extreme example to demonstrate that the plasma flashlight can be very effective even at room temperature. For individual bacteria, the inactivation time could be just tens of seconds."

"The device can be easily made and costs less than 100 US dollars to produce. Of course, some miniaturisation and engineering design may be needed to make it more appealing and ready for commercialisation," Ostrikov added.

The temperature of the plume of plasma in the experiments was between 20-23 degrees C, which is very close to room temperature and therefore prevents any damage to the skin.

The biofilms were created by incubating the bacteria for seven days. 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.

Plasma – the fourth state of matter in addition to solids, liquids and gases – has previously shown its worth in the medical industry by effectively killing and viruses on the surface of the skin and in water.

Although the exact mechanism behind the anti-bacterial effect of plasma is largely unknown, it is thought that reactions between the plasma and the air surrounding it create a cocktail of reactive species that are similar to the ones found in our own immune system.

The researchers ran an analysis to see what species were present in the plasma and found that highly-reactive nitrogen and oxygen-related species dominated the results. Ultraviolet radiation has also been theorised as a reason behind plasma's success; however, this was shown to be low in the jet created by the flashlight, adding to the safety aspect of the device.

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User comments : 14

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antialias_physorg
5 / 5 (1) Apr 26, 2012
Ultraviolet radiation has also been theorised as a reason behind plasma's success; however, this was shown to be low in the jet created by the plasma flashlight, adding to the safety aspect of the device

Ah. good. I was about to ask whether such a device would ceate UV (or even X-rays) since 'cold' plasmas usually require high voltages. If that were the case then the (skin) cancer risk might offset any beneficial effects.
Deathclock
4 / 5 (4) Apr 26, 2012
Just don't start selling them at walmart, the worst thing you can do for your immune system is to attempt to keep yourself sterilized all the time.
typicalguy
5 / 5 (1) Apr 26, 2012
A plasma flashlight. What could possibly go wrong?
PhotonX
not rated yet Apr 26, 2012
Big market in surgery prep also. One more step in the scrub and glove routine.
SWo777
not rated yet Apr 27, 2012
Would this work also for skin conditions which antobiotics such as flufloxacillin treat?
Pattern_chaser
not rated yet Apr 27, 2012
Sounds too good to be true. Is this another process to which bacteria could become resistant, I wonder?
Pattern_chaser
not rated yet Apr 27, 2012
I wonder if you could direct the output from this device down an optical fibre, to treat internal infections, maybe in the lungs or guts?
antialias_physorg
not rated yet Apr 27, 2012
Is this another process to which bacteria could become resistant, I wonder?

Not imposssible, but hard to imagine. A plasma is basically dissociated atoms - which makes the individual components (protons and positively charged nuclei) extremely reactive. The reaction (well, all of chemistry, really) is based on electromagnetic interactions. And there is nothing more electromagnetically active than a loose proton/electron.

Unless bacterai start to develop membranes coated with halogens this method should be fool-proof.
Origin
not rated yet Apr 27, 2012
The problem is, the cold plasma doesn't kill the bacteria instantly. The complete disinfection of larger areas of skin would be very time consumptive and you're not still guaranteed, this treatments is completely safe (induced cancer and melanoma risks). On the picture bellow the top Petri dish is control; bottom Petri dishes were treated for (left) 30 s and (right) 120 s. http://www.ece.od...coli.gif
antialias_physorg
not rated yet Apr 27, 2012
The complete disinfection of larger areas of skin would be very time consumptive
Such a procedure isn't very quick using current methods, either (and you need a lot of material - swabs, alcohol/peroxide ... Not to mention that it's pretty painful.)

(induced cancer and melanoma risks)

Melanoma is the same as cancer (it's malignant skin cancer to be exact). If the procedure is as low in UV as claimed then that risk may be negligible. In order to mutate DNA (necssary for cancer) you have to hit it with photons that carry enough energy to ionize it.
Though there may be indirect ways to get enough energy there (e.g. chemically, via induced reactions or mutagenic byproducts of proton/electron interaction with proteins)

(BTW: This is why gauging mutagenic effects of cell phone is so hard. The photons aren't energetic enough and secondary effects are extremely hard to measure)
Origin
not rated yet Apr 27, 2012
In order to mutate DNA (necessary for cancer) you have to hit it with photons that carry enough energy to ionize it.
IMO the accelerated ions from cold plasma could break it as well. After all, their destructive mechanism to bacteria is based on their mechanical effects as well.
The photons aren't energetic enough and secondary effects are extremely hard to measure
Your deductions are just plain silly. The long molecules of DNA can be ripped off with microwaves.
http://www.techno...v/24331/
For example, even small kids can break the long bridge, if they make a sufficiently intensive ripples on it with resonance. Analogously, even mild radiowaves can break the water molecules into hydrogen and water peroxide. http://www.youtub...lIm5a1Lc Peroxide radicals can induce the cancer in healthy cells. Sometimes I can't believe, how the proponents of mainstream physics are ignorant and half-educated. They can understand just their math (if at all)
antialias_physorg
not rated yet Apr 27, 2012
IMO the accelerated ions from cold plasma could break it as well.

To break hydrogen bonds you need energies in the UV range. This dvice does supply those - but it seems not much of it.

The long molecules of DNA can be ripped off with microwaves.

This is a resonance effect which requires that 'emitter' and 'receiver' be at a constant distance and the energy being pumped in over time at a constant frequency and in phase.
This is true for a microwave emitter in a microwave oven (which isn't going anywhere) and a DNA moleule ( the 'receiver' - which is also not going anywhere) - or for a kid and a bridge.

But the plasma here creates photons all over the place, not in a manner that lends itself to resonance (i.e. there is no continuous, harmonic oscillation involved but a chaotic flurry of photons which are uncorrelated as to direction, phase and frequency).
antialias_physorg
5 / 5 (1) Apr 27, 2012
Peroxide radicals can induce the cancer in healthy cells.

Well, reading comprehension seems to be on the decline. If you look at my posting you may notice the following sentence:
Though there may be indirect ways to get enough energy there (e.g. chemically, via induced reactions or mutagenic byproducts of proton/electron interaction with proteins)

...which is exactly what can happen with peroxide (or alcohol for that matter) - though chances are pretty low.

So look before you leap (or better "read before you blurb stuff like this"):
Sometimes I can't believe, how the proponents of mainstream physics are ignorant and half-educated.

Makes you look exceedingly foolish.

And BTW: What is a proponent of 'mainstream' science? That's some media buzzword. There is no such thing as 'mainstream' science (or 'alternative' science). There's stuff that is science and there's stuff that isn't.
Graeme
not rated yet Apr 29, 2012
I would expect the plasma to burn skin. After all O- or N are highly reactive. They would form superoxides and ozonides. At least skin has more thickness than the bacteria, so bacteria die first.

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