Inkjet Printed Fractal-Connected Electrodes with Silver Nanoparticle Ink

The development of a simple and reliable method for nanoparticles-based ink in an aqueous solution is still a challenge for its inkjet printing application. Herein, we demonstrate the inkjet printing of fractal-aggregated silver (Ag) electrode lines on substrates. Spherical, monodisperse Ag nanoparticles have been synthesized using silver nitrate as a precursor, ethylene glycol as a reducing agent, and polyvinyl pyrrollidone as a capping agent. As-synthesized pure Ag nanoparticles were well dispersed in water-ethylene glycol mixture, which was directly used as an ink for inkjet printing. Using this ink, the Ag electrodes of fractal-connected lines were printed on Si/SiO₂, glass, and polymer substrates. The fractal-connected Ag lines were attributed to the diffusion-limited aggregation of Ag nanoparticles and the effect of annealing on conductivity was also examined.