Aerosol Jet Printed plasma actuators: Optical and electromechanical characteristics

We present a novel promising fabrication technique for Surface Dielectric Barrier Discharge (SDBD) plasma actuators based on Aerosol Jet Printing (AJP) technology of conductive inks on dielectric surfaces and characterize the AJP-SDBDs optical and electromechanical performance. Linear SDBD designs, with ultra-smooth electrode edges of micrometer thickness have been fabricated, which when driven by AC, High Voltage waveforms, present stable plasma operation and reproducible features. We measure the electromechanical characteristics in terms of ink-related electrical properties (through Van der Pauw-resistivity and Hall measurements), plasma properties through electrical diagnostics, time-resolved imaging and optical emission spectroscopy (OES), while we perform Particle Tracking Velocimetry (PTV) measurements of the induced wall-jet flow. The printed electrodes show a clear metallic behavior, with their electronic properties comparing very favorably to other printable materials. The AJP-SDBDs show similar electromechanical characteristics with conventional SDBDs fabricated via conventional methods, good robustness, and more intense nature indicating lower breakdown voltage requirements. The emission spectra from the discharge show dominant formation of excited N 2 and N 2 + species. Based on high-resolution OES, an estimation of rotational and vibrational temperatures of the N 2 (C) state is performed, showing the strong non-equilibrium nature of the discharges produced. This helps in maintaining the average gas temperature in the positive and negative AC voltage phase at low levels (below 350 K) indicating its minimal impact on the gas dynamics. In terms of induced flow and electrohydrodynamic (EHD) forcing, the AJP-SDBD resulted in wall-jet flows with a maximum velocity achieved of approximately 5 m/s and a wall-jet height of approximately 3 mm at 7 mm from the exposed electrode edge for the 30 kV 3 kHz case. At the same conditions, the EHD force reached more than 27.5 mN/m. The obtained values and trends are in good agreement with literature values of conventional AC driven SDBD actuators, showcasing AJP potential as a promising fabrication technique for robust and efficient plasma actuators and related applications. • First time application of Aerosol Jet Printing (AJP) technology in the fabrication of Surface Dielectric Barrier Discharge (SDBD) plasma actuators. • Silver ink electrodes present perfect alignment, great adhesion, ultra-fine and ultra-smooth edges, micrometer thickness and low resistivity. • Optical and electromechanical characterization show similar characteristics with SDBDs fabricated via conventional methods, good robustness, and enhanced discharge ignition and intensity characteristics. • Measured maximum induced flow velocities of about 5 m/s and total EHD body force more than 27.5 mN/m. • AJP-SDBDs show great promise as a fabrication technique for next generation of robust, efficient and novel plasma actuators.