Investigation of sterilization by a microwave-generated low-temperature atmospheric pressure plasma jet

Abstract

An investigation of sterilization by a low-temperature microwave-generated atmospheric pressure plasma jet (MAPPJ) is presented. Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and yeast Saccharomyces species (Saccharomyces sp.) at 1.0 × 10³ and 1.0 × 10⁴ cfu/mL dilutions are investigated and fungi tested experimentally. The MAPPJ is generated by several watt continuous-wave microwaves and Ar gas, and direct treatment of the bacteria by a programmable planar XY motorized translation stage. After several minutes of plasma treatment, the number of bacterial colonies was sufficiently reduced and found to be nearly zero, and bare ozone and nitrogen dioxide were observed. This investigation shows that plasma sterilization would be a novel application for solid-state microwave power sources.

Keywords:

• Atmospheric pressure plasma jet
• sterilization
• solid-state microwave power sources

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Key Research and Development Program of China under 2019YFA0210202, and the National Natural Science Foundation of China under Grant 61971097.

Notes on contributors

Wenjie Fu

Wenjie Fu received the B.S., M.S. and Ph.D. degrees from the University of Electronic Science and Technology of China. He is currently a Professor at the School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, China. His currently research interests include high power microwave and millimeter sources and applications.

Chaoyang Zhang

Chaoyang Zhang received the B.S. degree from the University of Electronic Science and Technology of China in 2016, where he is currently working toward the Ph.D. degree in physical electronics. His current research interests include microwave power application, microwave plasma jet, microwave power source, microwave circuits, and the application of the plasma jet in material modification and biomedical applications.

Xiaotong Guan

Xiaotong Guan received the B.S. and Ph.D. degree from the University of Electronic Science and Technology of China in 2012 and 2018. He is currently a Postdoctoral Researcher in University of Electronic Science and Technology of China. His currently research interests include high power vacuum electronics devices and their applications.

Xiaoyun Li

Xiaoyun Li graduated from the Tsinghua University, China, in 1979. Currently, he is a Senior Research Engineer at the School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, China. His major research interests are microwave power applications and systems, especially in microwave oven.

Yang Yan

Yang Yan received the B.S., M.S. and Ph.D. degrees from the University of Electronic Science and Technology of China. He is currently a Professor at the School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, China. His currently research interests include high power vacuum electronics devices.