Printability and performance of 3D conductive graphite structures

Direct ink writing (DIW) of graphite-epoxy composites has gained significant importance in a number applications fabricating highly conductive free-standing 3D structures. Processing the composite inks, which consist loaded graphene nanoplatelets, first involves detailed understanding underlying rheological properties. However, little is known about effect processing/print parameters, e.g., print speed on orientation such 2D particles during printing process and how this subsequently influences macroscopic properties final cured composite. In work, inks with solid loadings 7−18 wt% were dispersed into low viscosity epoxy resin (EPON 862) to form shear thinning, viscoelastic material. The optimal GNP loading for determined through measurements, electrical are measured as function particle concentration speed. results show sharp increase conductivity by factor ten increased from 5 40 mm/s, all printed samples had conductivities higher than 10−3 S/cm. We attribute change stresses generated deposition ink, resulting shift platelet-like fillers. Such showcase ability tune structure constant filler. present work helps develop design rules processing graphene-based structures enhanced (electrical) using additive manufacturing. envision use thermal interface materials, shielding materials electronic devices, light-emitting name few.