Fine-line conductor manufacturing using drop-on demand PZT printingtechnology

An emerging selective metallization process to fabricate fine-line conductors based on drop-on-demand (DOD) ink jet printing and novel nano-particle fluid suspensions (NPFS) was studied. The suspensions consist of 1-10 nm silver or gold particulates that are homogeneously suspended in an organic carrier. 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 polyimide substrate. The deposit/substrate composite is subsequently processed at 300°C for 15 min to allow for complete evaporation of the carrier and for sintering of the nano-particles, thereby yielding a finished circuit interconnect. Test vehicles created using this technique exhibit features as fine as 120 μm wide and 1 μm thick with resistivities on the order of 3.5×10^-5 Ωcm. The circuitry performed well under environmental conditioning. As expected, repeatability of circuitry fabrication 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 dispensed fluid properties, and to resolve the microrheological behavior of the NPFS when flowing through the droplet generator     

Mg2Si nanocomposite converted from diatomaceous earth as a potential thermoelectric nanomaterial

With recent literature demonstrating enhancement of the thermoelectric performance of nanoscale materials relative to their corresponding bulk materials, methods to synthesize low-dimensional nanomaterials in large scale at low cost are needed. We demonstrate a method for preparing nanostructured dimagnesium silicide (Mg₂Si) thermoelectric materials that are nanocomposites with MgO by the reduction of diatomaceous earth (diatoms) using a gas-displacement solid state reaction with magnesium vapor. The resulting semiconducting Mg₂Si preserves the general morphology of the original diatoms and their nanosized grains at least down to the size of 30 nm. This reaction represents a possible method for the production of large quantities of low-cost nanoscale thermoelectric materials with potential for enhanced thermoelectric performance.