Handheld plasma instrument for medical professionals
Plasmas are often hot and aggressive. Nevertheless, they are suitable for medical purposes. That is why Mounir Laroussi and XinPei Lu from Old Dominion University in Virginia, USA, have now developed a handy instrument that generates a plasma beam several centimeters wide at room temperature and normal air pressure. They want to use the device to kill bacteria, heal wounds or remove plaque from teeth.
The apparatus developed by Laroussi and Lu consists of a cylinder in which two circular perforated electrodes are placed a few millimeters apart. Helium gas enters the gap from one side of the electrodes and is ionized there. To do this, the technicians apply a short high-voltage pulse to the pinholes. The gas then emerges on the other side as a plasma jet about five centimeters long and can thus be used for medical purposes. By adjusting the helium supply and the voltage pulse, Laroussi and Lu can regulate the length of the plasma stream. At the same time, this remains at room temperature even if the device is used for a long time, so that you can even put your hand in the beam.
When you hear the word plasma, you usually think of the starfire of the sun or nuclear fusion. But plasmas don't have to be hot, which is what you see on plasma television screens or on energy-saving fluorescent tubes. What is new about Laroussi and Lu's instrument is the free-flowing plasma in the form of a kind of lightsaber, similar to that of Luke Skywalker or Darth Vader in the Hollywood film "Star Wars" - only much shorter and colder.
