Enhanced aerosol-jet printing using annular acoustic field for high resolution and minimal overspray

Aerosol jet printing has the potential to fabricate fine features on various substrates due to its large stand-off distance. However, the presence of overspray and instability, particularly at high printing resolutions, has limited its widespread application. In this study, we introduce an efficient approach called annular acoustic focusing for aerosol jet printing. By determining the optimal focusing frequency (5.8 MHz) for silver nanoparticles using a particle ejection model, we achieve precise and stable printing. We also propose a modified print nozzle geometry, resulting in ultrafine traces (line width < 6 μm, overspray < 0.1 μm). Compared to printing without acoustic focusing, the line width of the traces decreases to 60 ± 5% while their conductivity increases to 180 ± 5%. Additionally, several 8 h experiments demonstrate excellent printing stability. This research opens up possibilities for the fabrication of conformal electronics with high precision and improved conductivity using aerosol jet printing.