Nanogrooved carbon microtubes for wet 3D printing of conductive composite structures

Recent advances in 3D printing have enabled the fabrication of interesting structures which were not achievable using traditional fabrication approaches. 3D printing of carbon microtube composite inks allows fabrication of conductive structures for practical applications in soft robotics and tissue engineering. However, it is challenging to achieve 3D printed structures from solution‐based composite inks which requires an additional process to solidify the ink. Here, we introduce a wet 3D printing technique which uses a coagulation bath to fabricate carbon microtube composite structures. We show that through facile nanogrooving approach which introduces cavitation and channels on carbon microtubes, enhanced interfacial interactions with chitosan polymer matrix are achieved. Consequently, the mechanical properties of the 3D printed composites improves when nanogrooved carbon microtubes are used, compared to untreated microtubes. We show that by carefully controlling the coagulation bath, extrusion pressure, printing distance, and printed line distance, we can 3D print composite lattices which are composed of well‐defined and separated printed lines. The conductive composite 3D structures with highly‐customised design presented in this work, provide a suitable platform for applications ranging from soft robotics to smart tissue engineering scaffolds.