Direct-Writing Flexible Metal Circuit with Polymer/Metal Precursor Ink and Interfacial Reaction

Abstract

In this study, flexible metal circuits are fabricated with polymer/metal precursor ink and an interfacial reaction by direct-writing technology. Poly(vinyl alcohol) (PVA) is selected as one component of ink, which could be a flexible composite in a metal circuit and an adhesive layer to connect the flexible metal circuit with the flexible substrate. Silver nitrate (AgNO 3 ) is added to the ink as a source of metal. After the direct-writing structure was placed in contact with an ascorbic acid (VC) aqueous solution with an adjustable process, silver nanoparticles (AgNPs) with 100−400 nm uniform size could be generated on the direct-writing PVA skeleton. The resistivity of the composite silver layer could reach 10 −6 Ω•m without any postprocessing. Meanwhile, the resistance change could keep within 20% with 180°bending after 10 000 repeat times. Patterned flexible metal circuits could be facilely fabricated by direct-writing technology, which presented excellent electrical conductivity and flexibility.

Recycling of Nanomaterial Ink Waste for Laser Digital Patterning Process

“…Metal complex inks, also referred to as metal precursor inks or metal particle-free inks, are garnering significant interest due to their notable features, including simplicity in synthesis, low viscosity, and the absence of aggregation during preparation and storage. The choice of Cu complex ink over other metal complex inks for the recycling process in this study was motivated by its advantageous attributes: high conductivity, lower sintering temperature, cost-effectiveness, compatibility with flexible substrates, and its recent popularity in flexible printed electronics. − The recycling of Cu complex ink waste was attempted in a similar way to that for the NiO x NP ink using various solvents, including the same solvent as the initial ink solvent (ethanolamine/ethanol with a volume ratio of 1:2) for the washing step, as shown in Figure i–iv. Metallic Cu electrode patterns were successfully generated by the LDP process.…”