Room-temperature atmospheric pressure plasma plume for biomedical applications

TLDR

Low‑temperature nonequilibrium plasmas are increasingly used in biomedical settings, but practical sources must be reliable, hand‑held, operate at atmospheric pressure, stay near room temperature, avoid arcing, and produce minimal ozone. This letter introduces a device that satisfies all those stringent requirements. The device generates a centimeter‑scale cold plasma plume using helium as a carrier gas, maintaining room‑temperature gas and negligible ozone production even after prolonged operation. It operates at low power, as shown by its current‑voltage characteristics, and can be safely touched and manually directed onto delicate tissues such as skin and dental gum without causing heating or pain.

Abstract

As low-temperature nonequilibrium 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. In this letter, we present a device that meets exactly such requirements. This device is capable of generating a cold plasma plume several centimeters in length. It exhibits low power requirements as shown by its current-voltage characteristics. Using helium as a carrier gas, very little ozone is generated and the gas temperature, as measured by emission spectroscopy, remains at room temperature even after hours of operations. The plasma plume can be touched by bare hands and can be directed manually by a user to come in contact with delicate objects and materials including skin and dental gum without causing any heating or painful sensation.