Atmospheric pressure cold plasmas for biology and medicine

Preliminary research is showing promising possibilities to use low temperature plasmas in medical applications such as wound healing, tissue engineering, surface modification of biocompatible materials, and the sterilization of reusable heat-sensitive medical instruments. These fascinating developments are posing many technological challenges and are bringing to the forefront fundamental questions regarding the mechanisms of interaction between living organisms and plasma. At the same time, as low temperature non-equilibrium plasmas come to play an increasing role in biomedical applications, reliable and user-friendly sources need to be developed. These plasma sources have to meet stringent requirements such as low temperature (at or near room temperature), no risk of arcing, operation at atmospheric pressure, preferably hand-held operation, low concentration of ozone generation, etc. At APTL we are carrying out research on plasma source development and on their biomedical use including decontamination, dental applications, and evaluation of the suitability of plasma for wound treatment. One of our main devices is the “plasma pencil” (see picture). This device is capable of emitting a stable, cold plasma plume several centimeters in length. We have been using the plasma pencil in various biomedical applications of interest.

Using nanoseconds pulses to generate uniform non-equilibrium plasmas

The electron energy distribution in non-equilibrium discharges plays the most important role in defining the chemistry in the plasma. It is through electron impact excitation and ionization that the charged particles, excited species, and radicals are produced. Increasing the electrons number density and their energy translates to an increase in the production of reactive species and UV radiation emission. To achieve this increase of ionization and to extend the electron energy distribution to higher values, short high voltage pulses have been used. Using short duration pulses has the advantages of keeping a low average power and not substantially increasing the gas temperature. At APTL we have been using nanoseconds high voltage pulses for many years to produce large volume atmospheric pressure plasmas and plasma jets. One of our jets, the Plasma Pencil, has been shown to launch very high velocity plasma balls or bullets in room air. These plasma bullets can travel several centimeters to deliver reactive species to the surface of a sample.

 

Barrier Discharges&Their Applications

The physics and chemistry of non-equilibrium high pressure discharges are studied. Both electrical and optical diagnostics are applied. Applications of these type of discharges, including biological ones, are under investigation. 

 

VUV Generation & Applications

The generation of vacuum ultraviolet radiation and its use for various practical processes are the subject of this line of research. One application is microlithography. Here we developed a plasma-based source capable of emitting copious amount of VUV radiation at the hydrogen Lyman-alpha line (121. 6 nm). This work was funded by DARPA. In collaboration with ODU's Department of Ocean, Earth & Atmospheric Science, we used excimer radiation at 222 nm to decontaminate salt and fresh water. The goal of this research was to test the applicability of using UV to decontaminate the ballast water of ships entering the Chesapeake Bay. This work was supported by Virginia Seagrant.

Send e- mail to ekara002@odu.edu with questions or comments about this web site.
Last modified: March 24, 2009