Architectural design and dual nozzle 3D printing creates carbon thermoplastic multi-materials with enhanced conductivity

Abstract

Electrodes made using a mixture of carbon allotropes has been an effective approach to enhance conductivity. Often such electrodes are made as composites or through layer-by-layer construction. These are time-consuming approaches; however, recently fused filament fabrication (FFF) 3D printing has shown significant potential in rapid manufacturing of conductive materials. To make mixed materials using 3D printing, in-house fabrication of printable filaments has shown significant promise. However, this requires specialised equipment, limiting accessibility. Our study explored the potential of creative electrode design and dual nozzle printing to make carbon thermoplastic mixed material electrodes. We created mixed materials electrodes in a helix design where internal pathways would rotate by 180º. The conductivity, capacitance and charge transfer resistance were monitored. We showed that making mixed materials with various permutations of carbon black, multi-wall carbon nanotubes and graphene outperformed single carbon allotrope materials for conductivity. The helix design provided the scope for making mixed material, as when the degree of rotation was reduced, the conductivity decreased. Our findings highlight that a combination of the helix architecture design and mixing achieved on the boundaries of the two materials from the dual nozzle printing process can generate a simple and accessible strategy for making carbon thermoplastic mixed materials, which can have significant impact in sensing applications and generation of energy storage devices.