A Bio-inspired Spherical Soft Magnetic Millirobot for Gastrointestinal Applications
Yulin Li, Zhaorui Hong, Yuhao Zhao, Shuohao Zhang, Xin Zhao, Liu Yang
Abstract
Gastroscopy and colonoscopy have become the fundamental tools for gastrointestinal (GI) tract diagnosis and treatment. Conventional tethered devices usually lead to the use of anesthetic agents and patient discomfort. Capsule endoscopy is becoming an ideal alternative, however, the smooth capsule shape may hinder its active locomotion and retention in the GI tract. Here, we propose a spherical soft magnetic millirobot (S<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>M<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> robot) that integrates a virus-like spherical body with protrusions and an octopus-inspired sucker design for enhanced physical capabilities. The protruding suckers (radius: 2.2-4.8 mm) on its surface enable efficient locomotion performance (maximum angular velocity: 8 r/s, maximum speed: 180 mm/s) with strong adhesive ability (maximum force: 3.5 N). The ex vivo experiments in a swine stomach demonstrate the robot’s motion on the slippery surface of the gastric mucosa and the effectiveness of the pressure-based drug delivery system. The in vitro and ex vivo results highlight the superior mobility and controllability, showcasing its potential as a carrier robot for the next-generation capsule endoscopy.
BibTeX
@inproceedings{iros2025_abioinspiredsphe,
title = {A Bio-inspired Spherical Soft Magnetic Millirobot for Gastrointestinal Applications},
author = {Yulin Li and Zhaorui Hong and Yuhao Zhao and Shuohao Zhang and Xin Zhao and Liu Yang},
booktitle = {IROS 2025},
year = {2025}
}