High speed 3D material-jetting additive manufacturing of viscous graphene-based ink with high electrical conductivity

Three-dimensional (3D) printed highly conductive graphene-based nanocomposites have led to a paradigm shift in the development of flexible electronics as well as customized therapeutic devices. This article addresses the deployment and characterization of a piezoelectric-pneumatic material-jetting (PPMJ) additive manufacturing process to print graphene-based nanocomposites with 3D structures. Here, development of a graphene-silicone ink, so-called MJ-3DG, with a high content of graphene (70 wt%) and its adoption for the PPMJ process to 3D print a highly conductive graphene-silicone structure is demonstrated. The robust 3D printed structure from MJ-3DG ink with the surface roughness around 2.99 (μm) has the resistivity as low as 0.41 (Ω.cm). This low resistivity is fairly comparable with the previously reported extrusion-based 3D-printed graphene structures that are the highest among all the carbon-based 3D-printed structures reported to date. Furthermore, in contrast to the extrusion-based systems, the high process speed (up to 500 mm/s) and the drop-on-demand nature of PPMJ provide internal design flexibility for 3D printed structures and make the development of smart graphene-based electronic and biomonitoring devices possible.