This work presents the design, fabrication, and characterization of a three-dimensional FeCo-based flux-modulator microwinding intended for integration into high-torque axial-flux Vernier micromotors. The proposed micromotor architecture modulates the stator magnetic flux using 12 magnetically isolated FeCo teeth interacting with an 11-pole permanent-magnet rotor. The design requires the manufacturing of complex three-dimensional micrometric parts, including three teeth and a cylindrical core. Such a complex design cannot be manufactured using conventional micromanufacturing lithography or 2D planar methods. The flux-modulator envelope dimensions are 250 μm outer diameter and 355 μm height. It is manufactured using a femtosecond laser-machining process that preserves factory-finished surfaces and minimizes heat-affected zones. In addition, this micrometric part has been wound using 20 μm diameter enamelled copper wire. A dedicated magnetic clamping fixture is developed to enable multilayer microwinding of the integrated core, producing a 17-turn inductor with a 60.6% fill factor—the highest reported for a manually wound ferromagnetic-core microcoil of this scale. Geometric and magnetic characterization validates the simulation model and demonstrates the field distribution inside the isolated core. The results establish a viable micromanufacturing workflow for complex 3D FeCo microwindings, supporting the development of next-generation high-performance MEMS micromotors.

This paper presents a novel rotary electromagnetic actuator designed for high-speed and high-precision positioning with ultra-low power consumption, intended for industrial and scientific applications such as rotary index tables, pick and place robots, or optical systems, among others. The actuator is based on harnessing electromagnetic potential energy and its transformation into kinetic energy to enable accurate and rapid changes between different equilibrium positions of the device. A prototype with an outer diameter of 86 mm and a thickness of 25 mm and a mass of about 0.57 kg has been manufactured and tested. It presents eight equilibrium positions evenly separated to 45 degrees, reachable in just 48 ms with a positioning accuracy of 20 arcmin. Experimental results demonstrate that the device generates a torque of 590 mNm, maximum angular speed and acceleration up to 663 rpm and 14,500 rad/s², respectively, with an input current of ±500 mA and a maximum power consumption of just 6.3 W. This value of power consumption represents a power saving up to 80% when compared to a conventional electromagnetic actuator that reproduces the same motion profile. An energy saving up to 38% is calculated for a change between two adjacent equilibrium positions. This innovative technology provides a new tool for precise positioning in highly dynamic applications with unprecedented energy and power savings.

Micromachines, MEMS and actuators suffer from much more significant relative friction and wear issues than their equivalent macroscopic devices. Active magnetic bearings can be a good option to mitigate friction issues; however, their construction at microscale is still an open research topic. In this work, we have developed a micrometric-size active magnetic bearing with a simple configuration and one vertical degree of freedom. This active magnetic microbearing is composed of a coreless coil with 1 mm outer diameter, 0.3 mm inner diameter and 0.5 mm length that holds a 0.3 mm outer diameter, 0.5 mm length NdFeB N52 micromagnet. Stable magnetic levitation is achieved by regulating the coil current based on precise position measurements of the magnet obtained using the smallest commercially available Hall-effect microsensor. The microprobe integrates between the coil and magnet, reducing the total size of the device. A maximum axial load capacity of 1.16 mN/A has been demonstrated. This micromagnetic bearing is one of the smallest active magnetic bearings developed to date, demonstrating the viability of this kind of system at the micrometric scale.