In context
By 2023, magnetically actuated micro-robots had emerged as a promising technology for biomedical and industrial applications, driven by their ability to operate in confined spaces wirelessly. However, challenges such as limited workspace, rigid structures, open-loop control, and single-agent operation hindered broader adoption. This review, published in the Chinese journal Robot, systematically examined the state of intelligent control in this field, reflecting a growing focus on autonomy and adaptability in micro-scale robotics.
What was reported
The article, authored by researchers at the Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, surveyed recent progress in intelligent control for magnetically actuated micro-robots. It highlighted four key development trends: transitioning from rigid to flexible structures to improve passage through narrow environments; implementing closed-loop control to enhance precision under disturbances; enabling multiple motion modes for better adaptability in unstructured settings; and scaling from single robots to swarms to increase cargo capacity for targeted drug delivery.
The review detailed various magnetic actuation systems, including static small-space systems using electromagnetic coils (e.g., Helmholtz, Maxwell, and combined configurations) and dynamic large-space systems with moving permanent magnets or electromagnets. It also discussed motion control principles, such as rotating and oscillating fields for helical and surface-rolling robots, and compared open-loop versus closed-loop strategies. The authors noted that intelligent control methods, including model-based and learning-based approaches, are increasingly applied to address nonlinearities and uncertainties in micro-robot dynamics.
Future directions identified included developing magnetic drives for larger workspaces, creating micro-robots with more motion modes, advancing flexible medical micro-robots, achieving autonomous navigation, and improving multi-robot control.
Why it mattered
This review underscored the shift toward intelligent, adaptive control in micro-robotics, which is critical for translating laboratory prototypes into reliable tools for minimally invasive surgery, micromanipulation, and environmental sensing. For industrial automation, the insights on scalable control and flexible designs could inform the development of micro-scale systems for precision assembly and inspection in confined spaces.
"Low-intensity magnetic fields can penetrate biological tissues and are harmless to organisms, making them highly significant for biomedical applications."
Source: 《机器人》期刊 (robot.sia.cn) · Published 2023-09-16 · “磁驱动微型机器人的智能控制发展现状”