Integration of composite-structure forming and optical fiber sensing using tool-change 3D printing

Using a tool-change 3D printer, this study investigated the integration of structural formation and functional enhancement in 3D printing. Traditionally, single-material printing is the standard, making the combination of mechanically robust structures, such as those using fiber-reinforced composites, and functional enhancements, such as conductive materials, challenging. In this study, a tool-change system was implemented to enable material-specific print-head operation, enabling the simultaneous fabrication of structural and functional elements in a single process. Moreover, to reduce the impact of internal defects in functional enhancement, this study explored printing methods for existing sensors. Focusing on optical fibers for their continuous thread-like structure, they were processed into filaments by combining them with resin. These filamentized optical fibers demonstrated the ability to achieve sub-millimeter precision in printing. Additionally, the optical fibers exhibited measurement accuracy comparable to conventional sensors, highlighting their suitability as high-performance sensing components. By incorporating optical fibers into 3D printing, this study enabled the stable integration of high-quality sensors into printed components. Utilizing a tool-changing approach, it demonstrated the feasibility of combining entirely different materials in a single process. This achievement highlights the potential of tool-change systems to advance multi-material 3D printing, balancing structural formation with functional integration, and laying the foundation for innovative applications in additive manufacturing.