Magnetic Shielding of a High-Tech Actuator
Magnetic fields generated by actuators can interfere with nearby sensors, electronics and other sensitive components. In high-tech systems, controlling these stray magnetic fields can therefore be an important part of the actuator design. Electromagnetic simulation can be used to investigate the magnetic field distribution, evaluate shielding concepts and optimize the design before hardware is built. At MECAL (Eindhoven, Netherlands) actuators are used to stabilize frames for machines in the chip industry. Multiphysics Finite Element Method simulations are used to simulate the actuators and determine which parts have the most influence on the magnetic shielding. The simulations concern both static and dynamic magnetic fields. The interest in MECAL lay mainly in the low frequency region of magnetic shielding, typically between stationary behavior and a few kHz.
Electromagnetic FEM Simulation of the Actuator.
The current design was entered into the Finite Element Method (FEM) model, and the stationary fields were determined. Very important are the non-linear input data of the materials from the supplier. An optimal design of the shielding was determined by Physixfactor, which allowed immediate savings on material costs for this part.
Magnetic shielding for actuators protects sensitive electronics from stray magnetic fields or contains the actuator’s field to prevent interference, typically using high-permeability materials (like soft iron) to redirect field lines, often in thin, custom shapes with holes for specific designs, crucial in precision systems like chip manufacturing or robotics. This shielding reduces magnetic cross-coupling between closely spaced actuators, improving system stability, though modeling it accurately can be complex
Magnetic field damping with radial distance
As the distance from the actuator increases, the magnetic field decreases. The radial distribution of the magnetic field provides a direct measure of how effectively the actuator and its shielding contain the magnetic field and limit stray fields in the surrounding high-tech system.
The figure to the left shows the calculated magnetic field strength as a function of radial distance from the actuator.
For high-tech applications, this decay can be particularly important when sensitive sensors, electronics or other electromagnetic components are located close to the actuator. By comparing the magnetic field at different radial positions, the effectiveness of different shielding designs can be evaluated and the required shielding distance or material configuration can be optimized.
The COMSOL simulation therefore provides more than a visualization of the magnetic field: it can be used to quantify stray magnetic fields and assess the effectiveness of magnetic shielding as a function of distance.