中文版本

Opportunity  

Magnetic small-scale robots hold significant promise for biomedical applications, such as non-invasive access and remote navigation within hard-to-reach regions of the human body, including the gastrointestinal tract and blood vessels. These robots are typically actuated by external magnetic fields that induce force and torque, enabling them to function as end-effectors for various tasks. However, a critical limitation persists: existing magnetic robots often fail to generate sufficient force and torque output required for demanding real-world biomedical functionalities, such as long-lasting anchoring and tissue penetration. This insufficiency becomes particularly pronounced as robot size decreases and actuating distance increases, where output forces and torques diminish exponentially. Prior attempts to enhance mechanical output through tailored robot structures have not fundamentally increased magnetic interaction forces. Alternative approaches, such as leveraging elastic potential energy stored in deformable elastomers or spring structures, often require additional energy sources for triggering and are typically one-off solutions, lacking the capability for continuous, repeated operations. Meanwhile, pulse-induced kinetic energy methods, like those using free-moving magnets within hollow shells, can generate instantaneous high forces but demand high-frequency switching with substantial energy density and require spacious acceleration gaps incompatible with the constrained onboard space of small-scale robots. Although magnetic collisions between multiple magnetized components at a macro-level, inspired by phenomena like the Gauss gun, can produce high forces, they are generally disposable and irreversible due to strong magnetic coupling, failing to meet the need for continuous, repeatable operations in biomedical settings. Additionally, existing designs are often confined to specific field generators like electromagnetic coil systems or MRI scanners, which involve bulky cooling modules and preprogrammed signals, while commercial permanent magnets like neodymium iron boron are brittle and pose operational risks during collisions. Thus, there is a pressing need for a magnetic robotic system that can deliver high, repeatable impact forces in a compact, wirelessly actuated design suitable for continuous biomedical applications.

Technology  

This patent introduces a magnet impact device centered on a triple-magnet system designed to achieve reversible and repeatable macro-scale magnetic collisions, enabling high-force output for small-scale robots. The device comprises an impacting portion with two permanent magnets (a first and a second permanent magnet, typically spherical) housed within a casing, and a third external permanent magnet (often cubic) that actuates the system. The third magnet rotates via a motor, generating a non-uniform magnetic field that manipulates the internal magnets. Specifically, the first magnet is free to rotate and translate within the casing, while the second magnet rotates but does not translate. As the external magnet rotates, it induces synchronized rotations in the internal magnets initially, creating a magnetic chaining state. Upon reaching a critical angle, the magnetic interaction between the two internal magnets shifts from attractive to repulsive, causing the first magnet to bounce away from the second magnet. Subsequently, as the external magnet continues rotating, the first magnet is pulled back to collide with the casing, producing a striking action along a linear direction. This cycle—comprising aligning, magnetic chaining, pre-bouncing, bouncing-off, and hitting-back states—is repeatable and reversible, allowing continuous impact forces. The impacting portion can be configured as a magnetic impact needle robot (MINRob) by attaching a needle, utilizing the generated impact for tasks like tissue penetration. The system integrates with a teleoperation platform using robotic arms to position the external magnet and cameras for guidance, enabling precise control in biomedical environments. Mathematical modeling and finite element analysis optimize parameters such as magnet sizes and distances to maximize impact force, which can be adjusted by varying the rotation frequency of the external magnet. This innovation essentially transforms magnetic energy into controlled mechanical impact through managed collisions within a compact form factor.

Advantages  

• Generates significantly higher impact forces (e.g., up to 2.92 N) compared to pure magnetic pulling forces, enabling tasks like tissue penetration. 
• Enables reversible and repeatable collisions, allowing continuous operation without disposable components. 
  
• Compact design suitable for small-scale robots, with a total length as low as 17.5 mm, facilitating navigation in confined spaces. 
  
• Wireless actuation via external permanent magnets eliminates tethers, enhancing maneuverability in biomedical applications. 
  
• Adjustable force output by controlling rotation frequency of the external magnet, providing flexibility for different surgical needs. 
  
• Integrates with teleoperation systems for precise remote control, improving accuracy in targeted interventions. 
  
• Reduces reliance on bulky electromagnetic coils or MRI scanners, using portable permanent magnets for actuation. 
  
• Minimizes swinging motions through design optimizations, ensuring stable impact delivery.  
  
  

Applications  

• Minimally invasive surgery, including tissue biopsy and tumor cell sampling in hard-to-reach areas. 
  
• Targeted drug delivery by penetrating tissue barriers to administer therapeutics locally. 
  
• Treatment of conditions like deep vein thrombosis or intestinal obstruction via mechanical disruption or anchoring. 
  
• Capsule endoscopy enhancements, enabling needle-based interventions within the gastrointestinal tract. 
  
• Robotic-assisted diagnostics, such as precise needle insertion for imaging or fluid extraction. 
  
• Biomedical research tools for studying tissue mechanics or simulating surgical procedures. 
  
• Potential use in cardiovascular interventions, such as clearing clots or accessing vascular sites. 
  
• Integration with existing surgical robotic platforms for enhanced functionality in operating rooms.