Design and evaluation of single nozzle with a non-conductive tip for reducing applied voltage and pattern width in electrohydrodynamic jet printing (EHDP)

We investigated the effect of a non-conductive tip inserted into a capillary nozzle (inner diameter of 860 μm) on jet formation and pattern width in electrohydrodynamic jet printing. Simulated and experimental results showed that the non-conductive tip stabilized the jet, and reduced the effective nozzle diameter and the onset voltage needed for the cone-jet mode, by eliminating the backflow near the apex of the liquid cone while a tiny backflow away from the apex of the liquid cone still remained. Silver nanocolloid patterns with an average width of 18.5 μm (standard deviation: 1.5 μm) were obtained with an applied voltage of 2.7 kV, a flow rate of 3 μl min ^-1 and a stage velocity of 200 mm s^-1.