Piezoelectric Inkjet Printed Aluminum Bismuth (III) Oxide: The Effects of Printing Parameters on Burning Rate

This thesis presents work on the deposition of nanothermite using a piezoelectric inkjet printer, focusing on the effects of printing parameters and sample geometry on burning rate. The ability of the printer to produce consistent droplet size and spacing was shown to have repeatable droplet size and sub-millimeter precision in droplet spacing. The droplet-droplet interaction of the nanothermite ink was examined, and a printing frequency of 10 Hz was shown to produce smooth and consistent geometry in the printed samples. The primary printing parameter varied in this study was the pixel pitch (i.e., the distance between printed droplets). As pixel pitch decreased (i.e., the droplets are printed closer together) in both directions (x- and y-directions), the burning rate increased, and as sample width increased the burning rate increased. A significant number of samples (476) were printed and demonstrated consistent, energetic performance; this indicated favorable high-volume production capabilities. A thermal model was developed based on an energy balance for the printed nanothermite samples. The model accurately predicted the burning rate trends observed in the experimental results. This result indicated that the increase in heat generation in both the thicker (pixel-pitch studies) and wider samples decreased the significance of heat loss to the environment. The statistically significant results presented in this work, along with a descriptive thermal model, increase the fundamental understanding of the effects of printed geometry and droplet spacing on nanothermite energetic performance.