Electrostatically-assisted direct ink writing with superior speed and resolution

Abstract

Here, the addition of an electrode to the printhead in direct-ink-writing (DIW) generates an electric field (E.F.) between the electrode and the printing nozzle. The extruded ink, as an ionic conductor, is then pulled by the Coulomb force in the direction of printing, resulting in much faster writing speeds and much thinner traces (lines) and smaller widths. Limitations in speed and resolution are practically removed here because the integration of an electrode into the printhead allowed successful prints at 13.2 m/s, ~13 times faster than in other published works, as to our knowledge, and almost ~30 times faster than in most commercial printers, which are limited to 0.5 m/s. A print speed of 13.2 m/s is reached in the present work, which unlocks the speed restrictions associated with DIW and holds great promise for new design opportunities. In addition, by means of E.F., an improved resolution up to 35 μm line width has been achieved here. It should be emphasized that the high printing speed and fine resolution demonstrated in this work are still not the physical limits of the method but rather only the restrictions imposed by the present experimental setup.