Pen-size plasma sterilization device

Prof. Jiunn-Der Liao of Department of Materials Science and Engineering at National Cheng Kung University (NCKU), Tainan, Taiwan, has led Post Doctorate Chih-Chiang Weng and a research team to develop a pen-size plasma sterilization device which can sterilize instruments and wounds by relying on the process of plasma sterilization.

The device can eliminate common bacteria such as Escherichia coli, Staphylococcus aureus and thermophilic bacilli within 90 to 120 seconds and, in the future, it can be applied in various fields such as beauty treatment, wound healing and medical equipment sterilization.

The total elimination of micro-organisms is an important issue during bacterial sterilization process for the reusable medical devices. Common sterilization process will however cause different degrees of damage or degradation on the treated surfaces.

To achieve the best bacterial inactivation effect, plasma reactivity at low temperature was significantly improved by the mixture of oxygen in argon plasma. Thus, the role of oxygen- and nitrogen-based reactive species has been considered to play an important role in the bacterial inactivation process.

The applied working distance of the capillary based oxygen/argon micro-plasma system was influential in the generation of excited species and UV intensity. As the working distance was reduced, the major emission of the reactive species and UV intensity remained. For the case of 3 mm, the required micro-plasma exposure time was reduced within 90 sec. For a gentle working distance, it required within 120 sec. It was consistent with the measurements of combined effect of reactive species and UV intensity.

Prof. Jiunn-Der Liao expressed, "With the developed micro-plasma technology, we can sterilize hard-to-reach places and wounded places, including oral cavities, surgical apparatuses and traumas. Our goal is to replace laser. Currently, we have engaged in an oral sterilization clinical cooperation with NCKU Hospital. The cost of laser charges NT$4,000,000 to NT$5,000,000. However, with the same functions and perhaps better effects, the plasma sterilization pen costs only one-tenth of laser. In the future, body wounds may be sterilized by simply carrying a sterilization pen, replacing alcohol and disinfectant."

Plasma sterilization will not produce toxic substance or create pollution, thus it is suitable to apply to the sterilization of biomedical equipment. In the future, it can replace the current sterilization facilities, provide customized micro-plasma processing system, and adjust plasma array arrangement according to the needs, reaching the goal of a fast, energy-saving and clean sterilization system.

In addition, the by-products after plasma sterilization, such as hydrocarbons, water vapor and residual gases that are not stimulated by plasma, can discharge externally, thus having little threat to the environment and acting in accordance with green technology, which is advocated by the public and the government.

SOURCE National Cheng Kung University