ShapeForce: Low-Cost Soft Robotic Wrist for Contact-Rich Manipulation

Jinxuan Zhu*1,2, Zihao Yan*1,2, Yangyu Xiao1,2, Jingxiang Guo1, Chenrui Tie1, Xinyi Cao1, Yuhang Zheng1, Lin Shao†1,2
1School of Computing, National University of Singapore
2RoboScience, Shenzhen, China
* Equal contribution    † Corresponding author
Paper arXiv Code

Overview

ShapeForce Overview

Overview of ShapeForce: (A) Mechanical design of ShapeForce, including (i) exploded view, (ii) finite element analysis (FEA) results, (iii) longitudinal section, (iv) cross section; (B) Perception-to-control pipeline. Marker-based pose tracking converts deformation into 6D displacement, producing force-like signals that inform contact-aware policies. Both search-and-control policies and imitation-learning policies are supported, enabling execution of contact-rich tasks.

Video

Abstract

Contact feedback is essential for contact-rich robotic manipulation, as it allows the robot to detect subtle interaction changes and adjust its actions accordingly. Six-axis force-torque sensors are commonly used to obtain contact feedback, but their high cost and fragility have discouraged many researchers from adopting them in contact-rich tasks. To offer a more cost-efficient and easy-accessible source of contact feedback, we present ShapeForce, a low-cost, plug-and-play soft wrist that provides force-like signals for contact-rich robotic manipulation. Inspired by how humans rely on relative force changes in contact rather than precise force magnitudes, ShapeForce converts external force and torque into measurable deformations of its compliant core, which are then estimated via marker-based pose tracking and converted into force-like signals. Our design eliminates the need for calibration or specialized electronics to obtain exact values, and instead focuses on capturing force and torque changes sufficient for enabling contact-rich manipulation. Extensive experiments across diverse contact-rich tasks and manipulation policies demonstrate that ShapeForce delivers performance comparable to six-axis force-torque sensors at an extremely low cost.

BibTeX

@article{zhu2025shapeforce,
  title={ShapeForce: Low-Cost Soft Robotic Wrist for Contact-Rich Manipulation},
  author={Zhu, Jinxuan and Yan, Zihao and Xiao, Yangyu and Guo, Jingxiang and Tie, Chenrui and Cao, Xinyi and Zheng, Yuhang and Shao, Lin},
  journal={arXiv preprint arXiv:2511.19955},
  year={2025}
}