Emerging technology in flexible circuit fabrication has transformed how designers think about device design, development, and miniaturization, particularly for the healthcare industry in wearable and point-of-care diagnostic devices. Looking beyond traditional microfabrication, screen printing, inkjet printing, and aerosol jet printing (AJP) provide a more cost-effective option and a shorter fabrication process which is attractive for the growing commercial market. As with any new technology, there needs to be a firm understanding of the process limitations, optimization procedures, and the mechanical and functional reliability of the products.

The focus of this work considers the characterization techniques necessary to support optimization of printed circuits with AJP. The simplicity of the AJP process (i.e., design, print, and cure) addresses the complexity and higher costs of traditional microfabrication as well as the hazardous chemicals and limited materials options for substrates due the lower curing temperature of the metallic inks. While many papers in literature discuss characterization options for understanding the functional and the mechanical behavior of the printed structures, few have looked at the optimization process and how to tie together the data to achieve a preferred parameter set with a given ink and substrate material combination. Work presented will help to close this gap by discussing an experimental design and methods to examine the ink, substrate, and printed structure for optimization using microscopy, profilometry, electrical measurements, and static mechanical testing. The presentation will include investigation of silver precursor and nanoparticle inks printed on polyimide thin sheet, Taguchi design, and software for data and image analysis.