text: The company XeelTech and CK Materials Lab in Korea use magnetorheological fluid to generate the haptic feedback of their HAPTICORE rotary switches. The MR actuators are primarily used as input devices with adaptive haptic feedback to enable new possibilities in user interface design. The HAPTICORE technology functions like a miniature MR brake. By changing the magnetic field created by a small electromagnet inside the rotary knob, the friction between the outer shell and the stator is modified in such a way that the user perceives the braking effect as haptic feedback.
  By modifying the rheological state of the fluid in near real time, a variety of mechanical rotary knob and cam switch haptic patterns such as ticks, grids, and barriers or limits can be simulated. In addition, it is also possible to generate new forms of haptic feedback, such as speed-adaptive and direction-dependent haptic feedback modes. This technology is used, for example, in HMIs of industrial equipment, household appliances or computer peripherals.