A two-step method to prepare silver nanoparticles ink for improving electrical and mechanical properties of printed silver wire

摘要

Electrodes and conductors with highly conductive and good mechanical reliability are attracting much attention in the manufacturing of flexible electronics. The printing technology by using nanoparticles conductive ink is one of the promising patterning techniques in flexible electronics manufacturing. In this paper, a two-step method was proposed to prepare the silver nanoparticles (AgNPs) conductive ink, and the electrical and mechanical properties of printed silver wire by the AgNPs ink were investigated. The multi-sized AgNPs ink was obtained by one-step microwave approach, and centrifugal concentration as the second step was applied to improve the AgNPs concentration of the ink. Three types of silver inks, including original ink, one time concentration ink and two times concentration ink with Ag content of 2.1%, 4.3% and 8.7% in weight, were used to print silver wires and their electrical and mechanical properties were investigated by self-designed flexible electronics testing platform. The results shows that silver ink processed by one time concentration can achieve a good balance in electrical conductivity and resistance to deformation and fatigue, while the original ink exhibits good performance in bending fatigue resistance but low electrical conductivity and stability in bending deformation, and the two times concentrated ink can provide excellent electrical conductivity and relatively high stability in bending deformation but its resistance to long-term cyclic bending is extremely low. This work will provide a guide for preparing AgNPs ink to improve electrical and mechanical properties of printed flexible electronics.