A Versatile Low Temperature Curing Molecular Silver Ink Platform for Printed Electronics

Abstract

The development and sale of conductive silver flake-based inks remains one of the most profitable areas within the printed electronics (PE) industry. However, the volatility of the silver market is a concern for conductive ink manufacturers, so cost effective alternatives that can minimize the amount of metal used to produce a functional trace are actively being investigated and developed in order decrease costs. Here we present a simple formulation containing a silver compound that provides a screen printable ink capable of producing traces with thicknesses under 1 micometer, linewidths as narrow as 42 μm separated by 38 μm and excellent electrical properties (22 μΩ·cm) following thermal sintering at temperatures of 120 °C on PET substrates. The molecular ink is also quite versatile, enabling the metallization of common textile threads and allowing their incorporation into applications where the threads can serve as wires to power LEDs driven by a wearable electronic platform. The silver traces derived from the silver ink also demonstrate impressive stretchability on both metalized latex/polyester threads and as printed traces on thermoplastic polyurethane (TPU) substrates, where the threads/traces remain conductive up to strains as high as 126%. The ability for the traces produced from the silver molecular ink to maintain conductivity as they are strained/stretched also enables their incorporation into structural and in-mold electronics applications, where conductive 3D traces can be produced through a simple thermoforming process. Together these results represent a significant advance for the PE industry