Laroussi Edits Special Journal Issue on New Field of 'Plasma Medicine'

Mounir Laroussi, Old Dominion University professor of electrical and computer engineering and director of the university's Laser and Plasma Engineering Institute (LPEI), is a guest editor of a first-of-its-kind journal issue exploring the new field of "Plasma Medicine."

The special issue of the journal Plasma Processes and Polymers published in August is a collection of the most important articles and other presentations from the First International Conference on Plasma Medicine (ICPM-1) held in Corpus Christi, Texas, last fall. Laroussi was on the scientific organizing committee for the conference.

"This conference brought together plasma physicists and doctors to discuss the applicability of cold plasma in medical procedures," Laroussi said. "This is a big step forward to introduce cold plasmas to the health care and medical community. Biomedical applications include wound healing, sterilization and decontamination."

Nearly eight years ago, Business Week magazine named Laroussi as one of the nation's leading experts in atmospheric-or cold-plasmas and he has been building research momentum ever since, much of it supported by funding from the Air Force's Office of Scientific Research. He explores numerous applications of plasmas, such as in radar shields for aircraft, but many of his innovations have involved biological uses.

Plasmas are highly charged soups that are sometimes called the fourth state of matter, neither a gas, liquid nor solid. Most people know plasmas because of their use in neon lights, or because a field of plasma cells can glow in precise colors to create images on a television set. Vast quantities of plasma are in outer space, but at the Earth's atmospheric pressure they are too hot and aggressive to handle. Therefore, uses in neon lights and television screens must take place in vacuums.

Early in his research career, Laroussi began using ultrafast pulses of electricity to turn gases at normal atmospheric pressure into "cold" plasmas. He quickly moved to the head of the class in his field, and became known for his ability to produce an abundant amount of cold plasma economically.

In the cold plasma, electrons are wildly excited but they are so light in weight that they produce little heat. Heavier ions in this particular soup are relatively unexcited and so they also produce very little heat. Although much less aggressive than conventional plasmas, the cold plasma retains enough potency for many biomedical and industrial tasks, while having a significant ease-of-use advantage over conventional plasma.

In 2005 Laroussi developed a germ-killing cold plasma pencil-a handy device that looks like a small light saber. That invention, whose plume can disinfect without harming normal tissue, got international publicity in professional journals and the popular media.

Still, many questions need to be answered about how plasmas can be harnessed for everyday biomedical applications. The field of plasma medicine "poses numerous technological challenges and brings to the forefront many fundamental questions regarding the mechanisms of interaction between living organisms and plasmas," write Laroussi and the other guest editor, Alexander Fridman of Drexel University, in the special issue of Plasma Processes and Polymers.

The main goals of the ICPM-1 and of their special issue, the editors explained, is "to develop a common language that experts in the various relevant fields can all understand, to better define key challenges and open questions, and to move toward their effective solutions."