[Journal Article] Robot-assisted multi-axis embedded silicone printing for free-form volumetric model

Overview

Embedded silicone printing (ESP) enables the creation of complex soft structures by extruding silicone inks into a gel support matrix. However, issues such as excess local ink deposition and the staircase effect have historically limited the quality of solid model prints, especially when the gel matrix is immiscible with silicone ink.

This paper presents a systematic multi-axis ESP framework designed specifically for fabricating volumetric silicone models with nearly solid infill and high surface quality.

Key Contributions

• Multi-axis ESP Framework: Introduced a comprehensive framework for free-form volumetric models with spatial toolpath generation and printing direction optimization.
• Field-based Curved Slicing: Developed a novel slicing strategy based on an iteratively optimized scalar field to preserve critical surface features and ensure near-uniform layer heights.
• Boundary-conformal Staggered Toolpaths: Proposed a width-constrained toolpath generation algorithm tailor-made for multi-axis ESP, enabling uniform material distribution and improved infill rates.
• Demonstrated Results: The framework was validated on a robot-assisted multi-axis platform by fabricating customized wearable components, biomedical phantoms, and soft robotic structures. Characterization via surface scanning and X-ray CT confirmed an infill ratio of 99.47% and a surface error below 1.5 mm (1% of the model size).

Impact

Our proposed framework greatly broadens the practical capabilities of ESP, enabling the reliable fabrication of customized and functionally integrated soft devices.