3D printing conductive pastes based on polystyrene/graphite composite

The objective of this work was to modify a commercially available 3D printer with a syringe extrusion system inspired by clay 3D printing systems and, afterward, to print conductive test samples from prepared pastes. The pastes were prepared by dissolving polystyrene insulation foam in acetone and adding electrically conductive graphite powder in various loadings. The pastes were homogenized by ultrasonication. Subsequently, the test samples were printed and rested overnight for evaporation of the acetone solvent. Cuboid samples were used for the measurement of the sheet resistance and volume resistivity, followed by analyses of thermal properties and microscopy. The samples containing 23 wt.% and 33 wt.% of graphite exhibited a significantly increased electrical conductivity. Benefiting from a simple preparation, these materials, in conjunction with modified syringe-based 3D printing, can be used in many applications where electrical conductivity is required, such as electromagnetic shielding or sensors.