HIGH PERFORMANCE ROBOTS MAGNETS

Permanent Magnets in Robotic Applications

With the rapid progress of artificial intelligence, intelligent robots are becoming essential partners in our lives and work. These robots rely on a critical component: high-performance rare-earth magnets. Acting like the “muscles” and “nerves” of robots, they provide powerful propulsion and precise control. Our advanced magnet technologies empower critical systems including servo motors, magnetic sensors, and electromagnetic clamping mechanisms. Nowhere is this expertise more vital than in robotic core technologies, where our magnet components enable breakthroughs in precision motion control and operational efficiency, setting new benchmarks for intelligent automation.In industries such as manufacturing, automotive, aerospace and electronics, the performance of magnetic components directly affects product quality and bottom line. As a leading magnet supplier, TOPMAG is committed to designing, manufacturing and customizing high-performance NdFeB magnets and other magnetic solutions for our customers’ unique project needs. With ISO 9001:2015 and IATF 16949 certifications, we provide full support from conception to production to ensure that your application is optimal.

Why are magnets the "power heart" of robot joints?

Magnets play an important role in enabling precise perception and motion control. Most notably is motion sensors, it need to meet stringent requirements for parameters such as magnetic flux density, coercivity, and dimensional tolerances. These sensors rely on the Hall effect, when magnetic flux density exceeds a preset threshold, it generates a measurable Hall voltage that translates into real-time data on speed, position, and distance. This technology extends beyond robotics to automotive systems. The backbone of magnetic sensor systems lies in engineered magnetic assemblies, which include not only basic magnet components but also precision-machined couplings and custom-designed subassemblies.

To achieve human-like dexterity, the real power comes from the frameless motors hidden deep in the joints. From fine object manipulation to dynamic balance in bipedal locomotion, these robots use high-energy-density servo motors embedded with permanent magnets. The coercivity is increased to 1500kA/m through grain boundary diffusion technology, and the distributed winding design produces an amazing torque density in a space of 80mm in diameter. This performance breakthrough allows the Boston Dynamics Atlas robot to complete a backflip at a speed of 1.5 meters per second, and its joint output power density is 5 times that of a hydraulic system.

When magnets are combined with novel materials, the boundaries of robotic capabilities are further expanded. Advanced surface treatments such as diamond-like carbon (DLC) coatings further enhance the wear resistance of continuously rotating joints. This magnetic foundation enables humanoid platforms to perform complex tasks with sub-10 millisecond response times, from assembling electronic components to performing synchronized dance moves with 98% motion fidelity.

Magnetic encoder: the "perception cornerstone" of robot movement

In the technical details of the Optimus Prime robot recently released by Tesla, the magnetic encoder, as the core sensor element, supports the robot’s precise movement with a unique electromagnetic induction principle. This technical solution, which is different from the photoelectric encoder, captures position and angle signals by detecting changes in the magnetic field of the magnetic ring. When the code disk moves with the joint, the magnetic sensor converts the periodic changes in the magnetic field distribution into electrical signals, which are resolved by the signal processor to form a position data stream. This non-contact measurement method enables it to maintain stable output under complex working conditions, becoming a key link for the robot to achieve high-precision motion control.

In the rotation execution module of Optimus Prime, 14 independent units are equipped with a dual encoder system. Each module integrates a frameless torque motor, a harmonic reducer, a torque sensor, and a dual encoder, the magnetic encoder of which is responsible for real-time monitoring of the joint rotation angle and speed. According to Tesla’s technical documents, the system can achieve an angle resolution of 0.1°, and with the backlash compensation algorithm of the harmonic reducer, the joint repetitive positioning error is controlled within ±0.05°. This design enables the robot arm to maintain sub-millimetre spatial trajectory accuracy when carrying precision components.

It is worth noting that the application of magnetic encoders in the Optimus Prime system is not isolated. The position signal it outputs, the 6-axis data of the torque sensor, and the posture information of the inertial measurement unit (IMU) together form a motion control closed loop. This multi-source information fusion strategy enables the robot to adjust the torque distribution of each joint in real time when walking dynamically. As humanoid robots move towards practical application, the role of magnetic encoders is being upgraded from basic sensing elements to system-level key technologies.

The Versatile Roles of Rare Earth Magnets in Robotics

In robot motion control, the combination of rare earth magnets and advanced algorithms achieves amazing precision. The “perception” ability of robots also relies on rare-earth magnets. This permanent magnetic material with ultra-high magnetic energy product is redefining the boundary between robot “perception” and “execution” through its unique physical properties.

In the field of industrial robots, the combination of NdFeB magnets and anisotropic magnetoresistive sensors is creating a new record of positioning accuracy. Taking the six-axis robot arm as an example, the magnetic scale built into each joint uses rare earth magnetic rings, and the solution algorithm based on the sliding mode observer compresses the positioning error to ±0.02 mm. This accuracy is equivalent to a deviation of no more than the thickness of an A4 paper at a distance of 10 meters. The core technology is the stable magnetic field provided by rare-earth magnets.

The field of medical robots shows another side of this material. The da Vinci surgical robot achieves 0.05 mm incision control in vascular suture surgery by integrating micro-actuators with SmCo magnets, which is equivalent to the diameter of human red blood cells. Its navigation system can complete six-dimensional posture calculation within 28 milliseconds. Behind it is a high-dynamic response motor supported by rare-earth magnets. This performance enables the robotic arm to complete delicate operations such as tissue peeling in sub-millimetre space.

In the development of innovative morphological robots, the potential of rare earth magnets has been pushed to the extreme. A certain underwater bionic robot project uses dysprosium-doped neodymium iron boron composite materials to drive the tail deformation through an external alternating magnetic field. This design not only allows the robot to obtain a swimming trajectory similar to that of a real fish but also reduces energy consumption in low-speed mode, opening up new possibilities for underwater exploration.

Transmission System Control
Engine Management System
Steering System
Suspension System
Battery Management System

DC Conversion System
Starter Generator System
Throttle Control System
Motor Control
Safety Monitoring

Sustainability and Future Challenges

When humanoid robots begin to enter thousands of households, the sustainability of their core materials will determine the depth of the technological revolution. The unique properties of rare earth magnets not only give robots human-like dexterity and strength, but also build the underlying logic of green development through energy efficiency leaps and material innovation. Despite the environmental pressure of rare earth mining, the recycling technology of magnetic materials is making rapid breakthroughs. Japan’s Daido Industry’s hydrogen treatment method (HD) has achieved a magnet recovery rate of 95%, and the hydrogen-induced grain boundary cracking technology in its process can reduce the energy consumption of separation and purification by 60%. More noteworthy is that the regional recycling network promoted by the EU’s “Critical Raw Materials Act” has reduced the carbon emissions of magnetic materials throughout their life cycle by 42% compared with the traditional model.

As the International Union of Pure and Applied Physics (IUPAP) report pointed out: “The sustainable development of rare earth magnets should not be limited to the materials themselves, but should focus on their improvement of the efficiency of the entire technological ecosystem.” When bionic robots begin to imitate the swarm intelligence of insects and when deep space probes need to maintain magnetic field stability in extreme environments, every evolution of magnetic materials is expanding the possible boundaries of the robot revolution.