Enhanced Electrical and Mechanical Properties of a Printed Bimodal Silver Nanoparticle Ink for Flexible Electronics

Abstract

Electrical patterns that can be formed with high electrical conductivity and mechanical robustness under mild conditions are critical for developing flexible electronics with heat-sensitive substrates. Here, the authors synthesize bimodal Ag nanoparticle (AgNP) inks by mixing two sizes of AgNPs (10 and 50 nm) and sintering them at room temperature in air on photopaper without any heat or chemical treatment. The optimized particle size ratio, sintered microstructures, and properties of the bimodal inks are systematically investigated and compared with those of the unimodal inks. These inks are printed and sintered at room temperature in air using accurate and controllable washing processes. An optimized resistivity as low as 3.66Â10 À6 Ω cm is obtained when the ratio of the 10 nm AgNPs to the 50 nm AgNPs is 2:1. The bimodal ink could be printed in a short time and exhibited good bending performance with reduced coffeering defects. The enhanced performance indicates that even just by matching the particle sizes and using the appropriate cleaning process, the bimodal AgNPs ink could be sintered with uniform morphologies throughout the repeated printing process to achieve a remarkably low resistivity. The proposed water-based bimodal AgNP ink will enable one-step inkjet printing and sintering for the first time with improved properties and convenience for developing highly sensitive flexible substrates and devices.

MODs vs. NPs: Vying for the Future of Printed Electronics

“…Other synthetic methods to improve Ag metal film deposition at low temperature than just altering capping agents have been reported, by Liu et al in 2018. [65] This study investigated the effect of bimodal inks composed of two sizes of Ag NPs (10 and 50 nm). The Ag NPs were synthesised using a modified reduction method based on that by Carey Lea, [61] with the synthesis of the larger 50 nm NPs requiring a higher temperature, a lower AgNO 3 solution concentration and the absence of ferrous sulphate, for a slower reduction process.…”

“…Other synthetic methods to improve Ag metal film deposition at low temperature than just altering capping agents have been reported, by Liu et al. in 2018 [65] . This study investigated the effect of bimodal inks composed of two sizes of Ag NPs (10 and 50 nm).…”

Alternative Materials for Printed Circuit Board Production: An Environmental Perspective

“…The goal of this study was not to compare different conductive inks. AgNP was selected as the ink, since experimental results from the literature and other studies in the ongoing research project showed the feasibility of using AgNP as the printing ink [18][19][20][21]. This study adopted silver nanoparticles (Ag NPs) and thermoset polyurethane as the ECA and screen printing as the deposition method.…”

Effect of Immiscible Secondary Fluid on Particle Dynamics and Coffee Ring Characteristics during Suspension Drying

“…Large particles or aggregates might also mediate resistance to evaporation-driven flows during drying operations [ 30 , 31 ]. Further, the heterogeneous particles in multimodal suspensions can be a reasonable alternative [ 32 , 33 ] for regulating coffee ring formation.…”