An Energy-Efficient Atmospheric Plasma Jet Line Enabled by a Dielectric Microwave Anapole Source

Cold atmospheric pressure plasmas are crucial for applications in medicine, agriculture, and material processing, where their interaction with ambient air generates reactive oxygen and nitrogen species for disinfection and treatment purposes. Additionally, their ability to alter carbon bonds makes them valuable for processing heat-sensitive materials and etching. Conventional resonant microwave plasma sources generate high electric fields for plasma production but are typically constrained to needle-like plasma configurations. Building on our earlier anapole plasma jet, we demonstrate a 2 cm line plasma jet for large-area surface treatment by leveraging the unique properties of the anapole source. With a uniform electric field of 106 V/m along the entire 2 cm length using just 1 W of input power, this highly efficient and compact PCB-compatible device enables stable plasma operation across a broad range of helium flow rates (1-40 slpm) and power levels (4-27 W). The anapole line plasma jet stands out for its high electron density, low operating temperature, and ease of frequency tunability, making it a promising platform for next-generation plasma applications.