HybNetic: A Mobile Hybrid Magnetic Actuation System
Lukas Masjosthusmann, Nicholas Posselli, Sarthak Misra
AI summary
Problem
Existing external magnetic actuation systems struggle to balance field shaping capability with human-scale workspace size, often facing trade-offs between power consumption, heat generation, and clinical integration.
Approach
The system mounts a central electromagnet and four independently rotatable permanent magnets in a C-shaped configuration on a robotic arm, enabling flexible torso positioning and dynamic field shaping through coordinated magnet rotation and coil current control.
Key results
- Validated analytical and FEM field models with under 9% error across all axes
- Demonstrated bidirectional force generation and magnetic sphere levitation
- Successfully steered a magnetic guidewire through a dimensionally accurate abdominal aorta phantom
- Achieved up to 50 mT field strength with a 520 mm C-shaped opening and mobile robotic positioning
Why it matters
It provides a clinically compatible, energy-efficient magnetic actuation platform capable of manipulating both macro- and micro-scale devices across human-scale workspaces for minimally invasive surgery.
Abstract
Magnetic actuation enables contactless control of medical microrobots and instruments and offers the potential for improved safety and effectiveness in robot-assisted mini- mally invasive surgery. While much research is being conducted on the development of surgical devices, there is a lack of external actuation systems that provide the necessary magnetic field shaping capability for in vivo control. Existing magnetic actuation systems often face trade-offs between field shaping capability and workspace size. In this work, we introduce HybNetic, a mobile hybrid magnetic actuation system that combines a single electromagnet with four independently ro- tatable permanent magnets mounted on a robotic arm. The C- shaped configuration of HybNetic has an opening of 520 mm, allowing positioning around the human torso. The mobility of the employed robotic arm extends the effective workspace to the length of a human body. We describe the design and field mod- eling and characterize the magnetic performance by comparing analytical model predictions and finite element simulations with experimental validations. Finally, we demonstrate the versatility of HybNetic by levitating a magnetic sphere and navigating a magnetic guidewire through a dimensionally accurate phantom of the abdominal aorta. The demonstrations highlight the potential of HybNetic as a magnetic actuation system with a workspace that is suitable for in vivo manipulation of macro- and micro-scale magnetic devices.