Robot-assisted multi-axis embedded silicone printing for free-form volumetric model

Hailin Sun1, Yingjun Tian2, Chenyu Xu1, Mahdi Bodaghi3, Fei Gao4, Guoxin Fang1, 5, *

Virtual and Physical Prototyping

1The Chinese University of Hong Kong, China
2The University of Manchester, United Kingdom.
3Nottingham Trent University, United Kingdom.
4Chinese Academy of Sciences, China
5Institute of Intelligent Design and Manufacturing, Hong Kong, China
*Corresponding author: guoxinfang@cuhk.edu.hk

Paper Video(YouTube)

This work presents a multi-axis embedded silicone printing (ESP) framework for fabricating volumetric silicone models with nearly solid infill and high surface quality. A field-based curved slicing strategy is introduced to preserve critical surface features and optimise layer height distribution. A width-constrainted staggered toolpath algorithm further promotes uniform ink deposition. Characterization via surface scanning and X-ray CT confirms an infill ratio of 99.47% and a surface error below 1% of the model size. The proposed framework greatly broadens the practical applications of ESP, enabling the fabrication of customised and functionally integrated soft devices.

Video Presentation

Field-based Curved Slicing

Slicing process visualization

The computational pipeline of our field-based curved slicing. (a) Input Solid model for slicing (b) The process of iteration-based scalar field optimization. (c) The final gradient field and scalar field lead to optimized layer height variation (d) The curved working surfaces are extracted as a set of iso-surfaces. (e) Error convergence of the objective function, which is well reflected in (f) the layer-height distribution after different numbers of iterations

Staggered width-constrained toolpath generation

Slicing process visualization

Staggered toolpath generated on adjacent layers

toolpath generation

An overview of our width-constrained toolpath algorithm. (a) Original isolayer with path-width field. (b) Isolayer after width-based deformation with constant path-width field. (c) Equal-width toolpath generated on deformed iso-layer. (d) Width-constrained toolpath extracted on original isolayer.

Fabrication Result

soroFab

Printed soft robots with different structures and materials (White: EcoFlex 00-30; Pink: DragonSkin 10A; Blue: MoldStar 30A)

membranceFab

The printed variable-thickness chest model can well mimic chest outlines across different body types.

cardioFab

Compared with conventional planar-based ESP, our method shows good surface finishing, high geometry accuracy, and good infill performance.

BibTeX


@article{Sun31122026,
  title={Robot-assisted multi-axis embedded silicone printing for free-form volumetric model},
  author={Hailin Sun and Yingjun Tian and Chenyu Xu and Mahdi Bodaghi and Fei Gao and Guoxin Fang},
  journal={Virtual and Physical Prototyping},
  pages={e2614811},
  year={2026},
  publisher={Taylor \& Francis}},
  doi = {10.1080/17452759.2026.2614811},
  URL = {https://doi.org/10.1080/17452759.2026.2614811}
}