Fabrication of High-Density, High-Resolution Interconnects via Acoustic Field Assisted Aerosol Jet Printing

The additive manufacture of production-grade flexible, large-area electronics is of intense interest to rapidly design, prototype, and fabricate electronics without reliance upon traditional electronics fabrication pathways. Such additive processes enable the direct integration of electronics on arbitrary, non-planar surfaces, expanding the potential form factors and application spaces. Of particular interest is Aerosol Jet Printing (AJP) owing to the capacity to fabricate high-resolution printed interconnects with design geometries not possible via other additive manufacturing technologies. AJP is a process by which the controlled deposition of an aerosolized, liquid ink enables the conformal printing of electronic traces. However, several key challenges, such as overspray and process drift, which restrict broad deployment of AJP and limits the feature resolution of printed interconnects. To address these challenges, we report a new type of AJP print process to control and architect aerosolized ink. Termed acoustic focusing aerosol jet printing (AF-AJP), we utilize acoustic forces (AF) to control the width of printed material by focusing the jetted material to a narrower region than what would be possible with a physical orifice alone. As the acoustic focusing effect is dependent on the ink droplet size, the utilization of acoustic focusing provides a means to “refine” the jet (especially if not material-rich) such that the deposited material has a smaller line width and exhibits a reduction in the typically observed particle overspray. We report a typical 30% reduction in trace width, sharp reduction in overspray, and an overall enhancement in print quality via this novel printing technique. We also demonstrate the utilization of AF-AJP to enable the printing of high-resolution traces with electronic materials such as graphene and MXene Ti₃C₂T_x, in order to fabricate highly conductive traces with conformal and 3D geometries.