Xspine: Integrating Motion Sensing Capability into Dynamic Structures Using Multi-material FDM 3D Printing

We present Xspine, a design and fabrication method for creating motion-capable, self-sensing structures using multi-material FDM 3D printing with conductive filaments. Our method embeds compliant mechanisms and circuits directly into geometries, enabling the detection of large deformations in a single, assembly-free print. Specifically, we design printable components and circuit layouts aligned with the layer-by-layer nature of FDM 3D printing. Furthermore, we explore physical and digital augmentation strategies to enhance the interactive potential of the structures. To simplify the workflow, we develop an interactive design tool that allows users to configure motion behaviors, preview structural responses, and generate printable circuits. Finally, we demonstrate several application examples that highlight the potential of Xspine for customizable and interactive 3D-printed devices.