Inkjet printing controllable footprint lines by regulating the dynamic wettability of coalescing ink droplets.

Inkjet printing lines with controllable footprints is the prerequisite of fabricating high-quality patterns. However, achieving precise footprints of lines by inkjet printing is still a challenge because of the difficulty in controlling coalescences of ink droplets. Here, controllable footprint lines were fabricated by adjusting the ink droplets' dynamic wettability which is depended on the ink droplets' surface tension difference. The experimental surface tension difference of 0.77-1.50 mN/m leads to appropriate surface dynamic wettability to ink droplets and the formation of straight lines, which agrees well with the theoretical results. These results will pave the way for printing electronics and patterns.