The ability to 3D print parts that are electrically conductive in select regions would enable a new era in manufacturing by allowing designers to directly print functional parts with in-build conductive pathways for signal processing or sensing. In this research, electrically conductive polymer composites will be fabricated and/ or otherwise assessed using conductive fillers such as stainless steel and /or conductive carbon black or graphene compounded within an insulated polymer matrix. In order to optimise printing conditions the rheological behaviour of the conductive filaments under heat and shear will be investigated and understood before testing optimal design patterns for 3D printing conductive networks. Structure – property – performance relationships for the printed parts will be assessed with respect to printing limits including nozzle requirements, speed, build orientation/raster pattern will be evaluated along with the conductivity of the component.