Handheld plasma flashlight rids skin of notorious pathogens

Apr 04, 2012
Handheld plasma flashlight rids skin of notorious pathogens

(PhysOrg.com) -- 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 many other instances where treatment is required in remote locations.

The flashlight, presented today, 5 April, in IOP Publishing's Journal of Physics D: is driven by a 12 V battery and doesn't require any external generator or wall power; it also doesn't require any external gas feed or handling system.

In the experiment, 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.

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.

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, Professor Kostya (Ken) Ostrikov, from the Plasma Nanoscience Centre Australia, CSIRO Materials Science and Engineering, 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 , the inactivation time could be just tens of seconds."

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 bacteria 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 plasma flashlight, adding to the safety aspect of the device.

The temperature of the plume of plasma in the experiments was between 20-230C, which is very close to room temperature and therefore prevents any damage to the skin. The device itself is fitted with resistors to stop it heating up and making it safe to touch.

"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 continued.

The device was created by an international team of researchers from Huazhong University of Science and Technology, CSIRO Materials Science and Engineering, The University of Sydney and the City University of Hong Kong.

Explore further: Scientists use plasma shaping to control turbulence in stellarators

More information: Inactivation of a 25.5 µm Enterococcus faecalis biofilm by a room-temperature, battery-operated, handheld air plasma jet, 2012 J. Phys. D: Appl. Phys. 45 165205. iopscience.iop.org/0022-3727/45/16/165205

Related Stories

Plasma-based treatment goes viral

Dec 05, 2011

Life-threatening viruses such as HIV, SARS, hepatitis and influenza, could soon be combatted in an unusual manner as researchers have demonstrated the effectiveness of plasma for inactivating and preventing ...

Safer medical kit by plasma-activated water

Nov 04, 2011

similar to the form created in neon signs, fluorescent tubes and TV displays – to create water that stays significantly antibacterial and can be used as a disinfectant for at least seven days after becoming plasma-active.

Plasma therapy: An alternative to antibiotics?

Dec 15, 2010

Cold plasma jets could be a safe, effective alternative to antibiotics to treat multi-drug resistant infections, says a study published this week in the January issue of the Journal of Medical Microbiology.

Plasma nanoscience needed for green energy revolution

Apr 14, 2011

A step change in research relating to plasma nanoscience is needed for the world to overcome the challenge of sufficient energy creation and storage, says a leading scientist from CSIRO Materials Science and Engineering and ...

Cool plasma packs heat against biofilms

Jun 11, 2009

Though it looks like a tiny purple blowtorch, a pencil-sized plume of plasma on the tip of a small probe remains at room temperature as it swiftly dismantles tough bacterial colonies deep inside a human tooth. But it's not ...

Recommended for you

Cold Atom Laboratory creates atomic dance

2 hours ago

Like dancers in a chorus line, atoms' movements become synchronized when lowered to extremely cold temperatures. To study this bizarre phenomenon, called a Bose-Einstein condensate, researchers need to cool ...

Wild molecular interactions in a new hydrogen mixture

8 hours ago

Hydrogen—the most abundant element in the cosmos—responds to extremes of pressure and temperature differently. Under ambient conditions hydrogen is a gaseous two-atom molecule. As confinement pressure ...

Scientists create possible precursor to life

9 hours ago

How did life originate? And can scientists create life? These questions not only occupy the minds of scientists interested in the origin of life, but also researchers working with technology of the future. ...

User comments : 16

Adjust slider to filter visible comments by rank

Display comments: newest first

pauljpease
5 / 5 (5) Apr 04, 2012
I want a plasma toothbrush!
StarGazer2011
1 / 5 (1) Apr 04, 2012
Can I use this to do the dishes? What about shine my shoes?
Awesome device, looking forward to more plasmonic tech!
joefarah
5 / 5 (1) Apr 04, 2012
This is huge!
Lurker2358
2.8 / 5 (4) Apr 04, 2012
This exact same findings have already been known by American plasma physicists for years.

Do a search for "Plasma Pen".

It was even seen on Discovery several years ago in much this same concept, in demonstration being used to kill bacteria on the skin without harming the skin.
J Schmidt
5 / 5 (3) Apr 04, 2012
This could become a billion-dollar product for preventing teenage acne. Companies need to pounce on this NOW.
Pkunk_
5 / 5 (2) Apr 05, 2012
I want a plasma toothbrush!


It needs to be clinically proven first that plasma will not cause mouth cancer. The outer skin is tough and take mild EM radiation.

I doubt the skin cells in the mouth are that tough though.
Mastoras
5 / 5 (2) Apr 05, 2012
This could become a billion-dollar product for preventing teenage acne. Companies need to pounce on this NOW.


What you wrote here, is an idea worthing a billion or more.
-.
axemaster
5 / 5 (2) Apr 05, 2012
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.

The temperature of the plume of plasma in the experiments was between 20-230C

So basically they are poisoning the bacteria to death. If that's the case, then why do they need a plasma in the first place? Why not just use a compressed bottle of the noxious gas instead?

Also, I have worked with these NOx gases in the past and they are really nasty. You really don't want to be breathing that stuff. Using something like this in a closed area is potentially quite dangerous.
Cynical1
not rated yet Apr 05, 2012
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.

Species inactivated by the plasma?
djxatlanta
not rated yet Apr 05, 2012
This exact same findings have already been known by American plasma physicists for years. Do a search for "Plasma Pen". It was even seen on Discovery several years ago in much this same concept, in demonstration being used to kill bacteria on the skin without harming the skin.


The creator of that plasma pencil, Mounir Laroussi, is cited by the authors in this paper in the very first paragraph. The improvement made on Loroussi's design is cordless portability.
Telekinetic
5 / 5 (3) Apr 05, 2012
"The device could be used in ambulance emergency calls, natural disaster sites, military combat operations and many other instances where treatment is required in remote locations."

Bordellos?
djxatlanta
5 / 5 (2) Apr 05, 2012
Species inactivated by the plasma?


'Species' in the chemistry sense, is a term given to atoms/molecules/ions undergoing chemical processes or measurement.
Lurker2358
3 / 5 (2) Apr 05, 2012
Axemaster:

The compounds are being produced in nano-scale quantities.

It's possible it may also be ionizing the atoms in the membranes of the bacteria, destroying the cell membrane.

While this could probably cause damage to human tissue if exposed long enough, it's probably worth it. After all, if you don't kill the bacteria, the human tissue is going to be destroyed anyway as the bacteria grows and consumes the tissues.

Most of your tissue in your mouth and skin grows back pretty quickly once you get rid of bacteria, and while teeth don't grow back, you can at least put a full stop to decay.
Wolf358
Apr 05, 2012
This comment has been removed by a moderator.
MorituriMax
not rated yet Apr 05, 2012
I had to look at the date to make sure it wasn't posted April 1st. Sounds really interesting.
octium8
not rated yet Apr 07, 2012
"The temperature of the plume of plasma in the experiments was between 20-230C,"

I think you meant 20-23C ?

Great artic!e!
Love this site!
210
1 / 5 (2) Apr 10, 2012
"The device could be used in ambulance emergency calls, natural disaster sites, military combat operations and many other instances where treatment is required in remote locations."

Bordellos?

Our deadliest STDs are viruses. How do you kill the dead? Can this device do that?

word-