Effect of binder–substrate interactions on printable nickel ink performance in high-speed flexographic manufacturing

Abstract Conductive ink development is vital for advancing flexible, lightweight, and cost-effective electronic devices. Flexography printing, known for its high-speed and roll-to-roll capabilities, offers a scalable method for producing such electronic components. However, achieving optimal printability and electrical conductivity in nickel (Ni) nanoparticle inks remains a significant challenge, primarily due to the complex interplay between binder selection, ink formulation and substrate interaction. This study aims to enhance both the printability and electrical performance of Ni nanoparticle inks printed on paper by systematically optimizing the formulation by the binder choice and its content in the ink. Spherical Ni nanoparticles (~ 40 nm) were combined with a range of binders to evaluate their influence on print quality and electrical performance. Post-printing processes, including photonic curing and calendering, were employed to enhance film uniformity and electrical performance, resulting in a notable 99% decrease in resistivity. Notably, the formulation utilized a carboxylated styrene-butadiene binder that achieved a bulk resistivity as low as 3 × 10 -3 Ω·cm. The findings underscore the importance of binder chemistry in developing Ni nanoparticle inks with superior printability and electrical performance. The results show that Ni inks are well-suited for a range of printed electronics applications where moderate conductivity meets performance requirements, such as RFID antennas, touch interfaces, flexible circuit interconnects, temperature detectors, and EMI shielding for flexible electronics.