An emerging selective metallization process utilizes Drop-On-Demand (DOD) inkjet printing, and recent developments in nano-particle fluid suspensions to fabricate fine-line circuit interconnects. The suspensions consist of silver or gold particulates of 1–10 nm in size that are homogeneously suspended in an organic carrier solvent. A piezo-electric droplet generator driven by a bipolar voltage signal is used to dispense 50–70 µm diameter droplets traveling at 1-3 m/s before impacting a compliant substrate. The deposit/substrate composite is subsequently processed at 300°Cfor 15 minutes to allow for evaporation of the solvent carrier and sintering of the nano-particles, thereby yielding a finished circuit product. Test vehicles created using this technique exhibited features as fine as 120–200 µm wide and 1–3 µm thick. The circuitry performed well during environmental conditioning studies. However, repeatability of the results showed sensitivity to the generation of steady, satellite-free droplets. In an effort to generate droplets consistently, it is essential to develop a strong fundamental understanding of the correlation between device excitation parameters and fluid properties, and resolve the microrheological behavior of the conductive ink as it flows through the droplet generator.