Numerical Design Study of a Multistable Magnetic Actuator

Electromagnetic actuators are widely used in various application areas, from electrical machines to microsystems. A popular design goal is the development of multistable actuator concepts that enable energy-efficient switching between stable positions. Typically, the finite element method (FEM) is used for optimization, thus minimizing the need for extensive experimental trials. A novel design for a multistable magnetic actuator tailors stable positions using mu-metal rings. This paper details the calibration of a numerical model based on experimental data, as well as a design exploration to examine the impact of ring dimensions on performance characteristics. The results demonstrate that specific actuator requirements can be directly influenced through appropriate variation of ring parameters. Additionally, a simplified modeling approach is prepared, where the force-displacement curve of an actuator with multiple stable positions is approximated by superimposing the individual components' curves. This approach allows for a highly efficient preliminary design optimization compared to a FEM-exclusive approach. Candidate designs can be refined further in a more comprehensive model or experimentally validated.