The capsule robot features multiple independent chambers, each equipped with a specially designed magnetic valve. The key innovation lies in the fact that these valves' activations are only sensitive to magnetic forces from specific directions. By applying magnetic fields with different directions of gradients, a target chamber can be opened selectively - like using different keys for different locks - while others remain securely closed. In addition, this "selective opening" function would not be influenced by the magnetic torque, allowing the rotating magnetic field to drive the capsule rolling to the target site. In addition, the robot employs a modular design, allowing the number of chambers to be flexibly adjusted as demand requires.
"It's like the robot is equipped with multiple independently controllable switches," explained co-corresponding author Prof. Qingsong Xu. "The medical doctor could direct the robot rolling to a target site, then 'command' a single chamber to open for sampling the bodily fluid, and later 'command' another chamber to release drugs at the same site or a different site. These operations can be completed after a single oral intake, which significantly enhances the comfort and efficiency of diagnosis and treatment."
Furthermore, the research team successfully validated the robot's functionality in ex vivo porcine stomach models. Under the guidance of real-time ultrasound imaging, the robot can precisely navigate to target sites. Furthermore, the robot performed liquid sampling and drug release at different sites. The team also demonstrated the in situ generation of a shape-adaptive hydrogel drug patch at the target site by storing the polymer and crosslinker in different chambers. This offers a new strategy for sustained drug release.
"Our work provides an integrated platform for the precise diagnosis and treatment of gastrointestinal diseases, which is a significant direction for the development of minimally invasive medical devices," said another co-corresponding author, Prof. Yang Lu. "It not only reduces the discomfort associated with multiple procedures for patients. But also, thanks to its multichamber design, it supports some instances involving combination drug therapy and multiple lesion sites."
The researchers believe that this multifunctional capsule robot holds substantial potential for clinical applications, paving the way for a new approach to diagnosing and treating gastrointestinal diseases, such as inflammatory bowel disease.
Wu Z, Wang X, Lu Y, Xu Q.
Multichamber magnetic capsule robot for selective liquid sampling and drug delivery.
Natl Sci Rev. 2025 Sep 19;12(11):nwaf400. doi: 10.1093/nsr/nwaf400