Multi-material embedded 3D printing for one-step manufacturing of multifunctional components in soft robotics

Developing a simple and effective preparation method for integrating functional components into highly flexible and multifunctional soft robotics is challenging. Here, we report a novel method for the integrated manufacturing of silicone-based multifunctional soft robotics components based on multi-material embedded 3D printing. By directly printing diluted platinum catalyst ink within a removable silicone oil matrix, which consists of a base monomer and crosslinker, we achieve one-step and time-unrestricted manufacturing of complex spatial structures (e.g., diamond frame, DNA double-helix structure, tubes, ears). The formed volume presents a high ratio (up to 25) to ink consumption volume. Meanwhile, printing materials and parameters are investigated for strong filament fusion and freeform fabrication of complex structures with high fidelity. Furthermore, a compliant robotic fishtail and pneumatic humanoid hand with seamlessly integrated strain sensors are designed and fabricated using this process. These components demonstrate effective execution, while the integrated sensors exhibit excellent linearity (0.99), repeatability, and stability, further demonstrating the feasibility and superiority of the proposed method for manufacturing soft robotics. These results confirm the enormous potential of this progressive method for flexibility, functionality, and integrated manufacturing of soft robotics.