Arcadia Discussion Zone

Portable 'flashlight' kills bacteria

A portable, battery-operated plasma flashlight capable of killing some of the strongest bacteria could be used to treat patients in natural disasters and war zones, researchers say.

The device, developed by Australian and Chinese researchers, resembles a torch and emits reactive plasma particles that can kill bacteria, and potentially treat wounds and even tumours.

Previously, similar devices have often relied on an electricity connection or generators.

This limited their use in natural disaster zones, ambulance call-outs, military operations and other remote locations, said the authors of a study published on Thursday in the Journal of Physics D: Applied Science.

The report's authors, including Kostya Ostrikov from CSIRO's Materials Science and Engineering unit at the Plasma Nanoscience Centre Australia, found the device could successfully penetrate 17 layers of extremely heat-resistant bacteria, called biofilm.

The plasma flashlight was able to penetrate through to the very bottom layers to kill bacteria, while operating at room temperatures of between 20C to 23C, which would prevent damage to the skin.

Biofilm is formed by bacteria to resist treatment and is very difficult to kill, even with intense heat, Prof Ostrikov said.

'That's why alternative approaches like this plasma are sought after,' Prof Ostrikov told AAP.

'In this study we chose an extreme example to demonstrate that the plasma flashlight can be very effective even at room temperature.'

The results could advance techniques to kill biofilms formed by drug and treatment-resistant bacteria.

Reactions between the plasma emitted and air create a cocktail of reactive species believed to be similar to those found in the immune system.

In the experiment, the plasma device was applied to biofilm samples for five minutes.

It is the thickest reported biofilm killed by a room-temperature plasma device, the researchers said.

Prof Ostrikov said the plasma device was easy to make and cost less than $100 to produce.

He said creating a smaller version and different design could make it more appealing to the commercial market.

A team of international researchers from Huazhong University of Science and Technology in China, City University of Hong Kong, University of Sydney and CSIRO Materials Science and Engineering created the device.