Tailoring the formulation and curing performance of low-silver conductive ink for flexible circuit applications

With the rapid advancement of flexible and wearable electronics, there is an increasing demand for conductive inks that are low-cost, low-temperature processable, and high-performance. In this study, a particle-free conductive silver ink with a low silver content (22 wt%) was developed using silver acetate as the precursor. The influence of curing conditions on the performance of printed silver electrodes was systematically examined. The ink exhibits excellent low-temperature sintering capability, achieving high electrical conductivity with a resistivity as low as 4.8 × 10 –6  Ω m at temperatures below 100 °C, showing similar properties to those of high-temperature-processed commercial inks. Characterization techniques, including four-point probe measurements, scanning electron microscopy, and X-ray diffraction, revealed that the electrical conductivity of the silver electrodes is highly dependent on annealing temperature and dwell time. At 100 °C for 20 min, silver ions were reduced into continuous conductive networks, achieving a resistivity that, while higher than bulk silver, remains sufficiently low to meet the requirements of low-temperature electronic applications. Extending the annealing duration to 30 min further reduces the resistivity to 4.45 × 10 –6  Ω m. These findings provide both theoretical insights and practical reference for the low-cost manufacturing of flexible electronic applications, including wearable sensors, printed circuits, and bendable displays.