Nanoporosity-induced effects on Ag-based metallic nano-inks for non-lithographic fabrication

The mechanical response of a thermally cured Ag nano-ink comprising silver nanoparticles of 3-7 nm diameter was evaluated and compared to a fully dense electron-beam-evaporated Ag film. Curing the nano-ink for 60 min at 250 degrees C resulted in a 78% dense structure. Nanoindentation of the partially dense nano-ink yielded Young's modulus, E-np = 54.8 +/- 2.2 GPa, consistent with theoretical models predicting the modulus of metallic foams and hardness of H = 1.37 +/- 0.08 GPa. Cross-sectional analysis of individual indents was also performed via focused ion beam milling.