Energy-Efficient Resonant Microwave Plasma Jet Architectures

Cold atmospheric plasmas are enabling technologies across diverse fields including plasma medicine, environmental remediation, and propulsion. However, conventional plasma sources often rely on high-voltage pulses or high-power RF systems, limiting their portability, scalability, and energy efficiency. There is a growing need for compact plasma sources capable of ignition and sustainment at drastically reduced power levels.

Microwave resonant structures offer a promising solution by concentrating electromagnetic energy into small volumes, enabling gas breakdown and plasma sustainment at significantly lower input power. Prior to ignition, these high-Q resonators provide strong field enhancement, facilitating efficient plasma initiation. Post-ignition, the presence of plasma alters the resonator’s impedance and acting as a built-in ballast. This self-regulating mechanism helps stabilize the discharge and suppresses undesirable transitions such as glow-to-arc and streamer formation.

In this talk, we present recent advances in our resonant microwave plasma (RMP) technologies utilizing two high-Q architectures: evanescent-mode cavities and dielectric anapole resonators. We demonstrate stable and continuous atmospheric plasma jets sustained with input powers as low as a few hundred milliwatts, achieving energy conversion efficiencies exceeding 80%. Furthermore, we showcase scalable implementations including jet arrays and lines, highlighting their potential for portable, high-throughput, and energy-efficient plasma systems. These results point toward a new class of low-power, compact plasma devices with broad implications for scientific and industrial plasma applications.