Plasma-jet printing is an emerging additive manufacturing technique that enables one-step material deposition and self-sintering, eliminating the need for substrate pretreatment and post-processing steps. This study investigates the adhesion and self-sintering mechanisms of plasma-jet printing using optical emission spectroscopy (OES). A dielectric barrier discharge (DBD) plasma operating at atmospheric pressure (10–20 kV) Page 16 of 20 2025 Spring Symposium Proceedings was used for the directional deposition of ultrasonically atomized metal nanoparticle inks. Wettability and adhesion test results revealed increased surface energy upon plasma treatment, enhancing material-substrate interaction and electrical characterization of printed films demonstrated a significant reduction in the sheet resistance with increasing gas flow and plasma voltage.
While plasma-jet printing has demonstrated enhanced substrate adhesion and self-sintering capabilities, the underlying mechanisms remain unclear. We hypothesize that energetic particles generated within the plasma plume contribute to improved adhesion and electrical performance. To validate this hypothesis, we analyzed plasma emission spectra under varying plasma conditions, including different voltages and gas flow rates while maintaining a constant substrate-to-plasma distance. The collected spectral data were processed and visualized using Origin software, with prominent peaks identified through comparison with the NIST Atomic Spectra Database. Understanding the interactions between reactive plasma species and the substrate surface provides critical insights into optimizing plasma conditions for improved adhesion and sintering.