Synthesis of Silver Nanoparticle Based Conductive Inks for Additively Manufactured Electronics

Abstract

Printed electronics is an emerging area of study at the forefront of additive manufacturing technology. Additively manufactured electronic devices have many novel application areas, including three-dimensional microbatteries, electrically small antennas, spanning electrodes and printed circuit boards. Conductive features, the backbone of all electronic devices, are typically printed with colloidal solutions of silver nanoparticles. Of the well-studied metallic nanoparticle systems, silver exhibits the highest conductivity and is commonly used in commercially available conductive inks. These inks are typically capped with polymeric ligands that interfere with ink rheology and require high processing temperatures to achieve the desired electrical conductivity. For this reason, there is an impetus to develop conductive inks that can be processed at low temperatures in order to minimize processing costs and improve substrate compatibility. This work explores four methods of synthesizing silver nanoparticle based conductive inks, including polymeric ligand, ligand free, small molecule, and conductive ligand synthesis techniques.