Selective Actuation for Microrobots Based on Distributed Magnetic Field Design
Kaiwen Fang, Zhen Yang, Lianshuo Wang, Yuezhen Liu, Hui Chen, Yu LIU, Jiangfan Yu
AI summary
Problem
Global magnetic fields used to actuate microrobot swarms inevitably stimulate non-target cells, risking undesired biological effects. There is a need for a method to spatially confine mechanical stimulation to specific areas.
Approach
The authors designed a selective rotating magnetic field using a dual robotic-arm system with four coils, optimized via a swarm intelligence algorithm to maintain field strength above a critical threshold only within a user-defined target region.
Key results
- Chain length and stability governed by magnetic field strength and frequency
- Smooth rotation and longer chains sustained within target zone
- Field fluctuations outside target cause chain fragmentation
- Effective swept area peaks sharply inside target and drops rapidly beyond
Why it matters
This strategy enables precise, spatially confined mechanostimulation for biomedical applications, reducing off-target biological risks and advancing targeted microrobot therapies.
Abstract
Mechanical stimulation is essential for regulating cellular processes such as proliferation, differentiation, and apoptosis. Magnetic microrobot swarms offer a promising platform for delivering targeted mechanical stimulation to cells via remote actuation under rotating magnetic fields. However, magnetic fields globally activate swarms in non-target regions, risking undesired biological effects. To overcome this limitation, we propose a spatially selective magnetic actuation strategy that confines mechanical stimulation to user-defined regions. A dual- robotic-arm magnetic actuation system is developed to generate a selective rotating magnetic field. The field ensures swarms have smooth rotation and longer chain formation within the target area, enabling effective mechanical stimulation, while swarms outside exhibit shortened chains and disordered motion. We further demonstrate that the area swept by the rotating chain of microrobots peaks within the targeted region but drops sharply beyond it. This approach provides a foundation for precise mechanostimulation in biomedical applications with minimal off-target effects.