Semiconductor-free, monolithically 3D-printed logic gates and resettable fuses

Additive manufacturing has the potential to enable the inexpensive, single-step fabrication of fully functional electromechanical devices. However, while the 3D printing of mechanical parts and passive electrical components is well developed, the fabrication of fully 3D-printed active electronics, which are the cornerstone of intelligent devices, remains a challenge. Existing examples of 3D-printed active electronics show potential but lack integrability and accessibility. This work reports the first active electronics fully 3D-printed via material extrusion, i.e. one of the most accessible and versatile additive manufacturing processes. The technology is proof-of-concept demonstrated through the implementation of the first fully 3D-printed, semiconductor-free, solid-state logic gates, and the first fully 3D-printed resettable fuses. The devices take advantage of a positive temperature coefficient phenomenon found to affect narrow traces of 3D-printed copper-reinforced, polylactic acid. Although the reported devices don’t perform competitively against semiconductor-enabled integrated circuits, the customisability and accessibility intrinsic to material extrusion additive manufacturing make this technology promisingly disruptive. This work serves as a steppingstone for the semiconductor-free democratisation of electronic device fabrication and is of immediate relevance for the manufacture of custom, intelligent devices far from traditional manufacturing centres.