This Phase-I proposal addresses the need specified in Air Force 18.1 under the Topic Index of AF181-059 Low temperature copper inks for low-cost flexible hybrid electronics manufacturing.In contrast to the current use of silver inks which is high cost and often requires photonic or high-temperature sintering, the electronics developed around copper feature low cost and high conductivity but present major challenges in terms of high-temperature sintering requirement and the oxidation propensity.To address this challenge, Phase I work will develop a new nanoink formulation of air-stable copper nanoparticles and nanowires compatible with ambient temperature sintering processes to enable improved conductive copper for manufacturing flexible electronics.Phase I work will focus on (1) synthesis and processing of copper nanoparticles and nanowires with controlled sizes and surface properties. (2) formulation of the nanoinks to enable printable and ambient-temperature sinterable capability on flexible plastic and paper substrates; and (3) characterization of the electrical properties of the sintered conductive patterns on the flexible substrates. The goal is to demonstrate the feasibility of the copper nanoinks in meeting the specifications in terms of the low temperature sintering and high electrical conductivity for commercial applications in manufacturing flexible electronics.
