Trends and Advances in 3D Printing of Flexible Carbon-Based Nanocomposites

3D printing of flexible carbon-based nanocomposites has become an important research area due to its relevance for flexible electronics, wearable sensing, soft devices, and electrochemical energy systems. This study examines the scientific development of the field through a bibliometric and science-mapping analysis based on records retrieved from Scopus and Web of Science. After applying a structured SAAS and PRISMA-based selection process, 1491 peer-reviewed articles published between 2000 and 2025 were retained for analysis. Scientific production has grown markedly, with an annual growth rate of 8.58% and an international co-authorship rate of 27.77%. Geographically, research output is dominated by China, followed by the United States and South Korea, while international collaboration networks connect research groups across Asia, North America, and Europe. The results confirm the central role of graphene and carbon nanotubes and show a progressive shift from the formulation of printable conductive composites toward flexible and stretchable sensors, wearable and textile-integrated devices, soft functional systems, and deformable energy-storage architectures. The thematic structure also points to the increasing relevance of MXenes, hydrogels, direct ink writing, strain sensing, and sensitivity-related applications. The conceptual analysis indicates that current research is increasingly organized around the interaction between material composition, printing strategy, mechanical compliance, electrical performance, and device functionality. The field is therefore moving toward more complex multifunctional architectures capable of combining sensing, wearability, energy storage, and mechanical adaptability within the same printed system.