Inkjet printing of metal nanoparticles offers design flexibility and rapid processing, enabling 3D printing of functional electronic devices. However, the performance, particularly electrical conductivity, is lower than traditional methods. This study reveals that anisotropic electrical conductivity in printed metal nanoparticles stems from organic residuals in inks. Using silver nanoparticles, electrical resistivity tests, morphological analysis, and 3D nanoscale chemical analysis demonstrate that the polymer stabilizer polyvinylpyrrolidone (PVP) concentrates between nanoparticle layers and at dielectric/conductive interfaces. Understanding this behavior suggests strategies for improving nanomaterial ink formulations in printed electronics.

Gustavo F. Trindade, Feiran Wang, Jisun Im, Yinfeng He, Adam Balogh, David Scurr, Ian Gilmore, Mariavitalia Tiddia, Ehab Saleh, David Pervan, Lyudmila Turyanska, Christopher J. Tuck, Ricky Wildman, Richard Hague, Clive J. Roberts