Folding Soft Sheet Robot Using Magnetorheological Fluids Achieves Precise Targeted Drug Delivery in Gastrointestinal Tract

Researchers develop a magnetic soft sheet robot using magnetorheological fluids that folds to navigate the GI tract for localized, targeted drug delivery.

By: AXL Media

Published: Mar 14, 2026, 5:58 AM EDT

Source: Information for this report was sourced from Journal Center of Harbin Institute of Technology

Revolutionizing Targeted Therapy in the Digestive System

Gastrointestinal diseases remain a global health challenge, often requiring drug treatments that suffer from low targeting efficiency and systemic side effects. While magnetic soft robots have been proposed as a solution for minimally invasive procedures, traditional designs often struggle with the irregular and confined spaces of the human gut. To address this, researchers from the China University of Mining and Technology, Soochow University, and the Universities of Oxford and Aachen have engineered a fully soft, four-layer sheet robot. By using an untethered magnetic drive, the robot can navigate complex biological environments without the need for rigid components or internal power sources.

The Mechanics of Reconfigurable Magnetization

The core innovation of this robot lies in its use of magnetorheological (MR) fluids. Unlike traditional magnetic robots with fixed magnetic poles, this device is non-magnetized in a zero magnetic field, preventing unintended interference with other medical equipment or biological tissues. When an external field is applied, the internal magnetic particles form chains in milliseconds, allowing the robot’s magnetization direction to be dynamically adjusted in real time. This flexibility enables the robot to execute complex maneuvers, such as flipping and steering, with a high degree of precision that was previously unachievable in soft robotic systems.

Folding Adaptability for Narrow Biological Passages

The ability to change shape is critical for navigating the varying spatial dimensions of the gastrointestinal tract. Driven by a 5-degree-of-freedom magnetic platform, the soft sheet robot can achieve precise multi-angle folding. This reduces its surface area to just one-third of its original size, allowing it to slip through narrow intestinal segments. Once it reaches a larger cavity, such as the stomach, it can unfold to provide a stable platform for movement and drug release. This "origami-like" capability ensures that the robot can adapt its geometry to the specific anatomical constraints of the patient in real time.