Soft-magnetic rotational microwings in an alternating magnetic field applicable to microflight mechanisms

This paper presents microsized soft-magnetic rotational wings in an alternating magnetic field. The wireless power supply as well as control of magnetic microwings are readily applicable to microflight mechanisms. As a magnetic material, soft magnetic material, such as nickel-iron alloy was deposited via electroplating, which is a well-developed MEMS batch process. The magnetization of the soft-magnetic device, however, changes its direction and magnitude during rotation, where the shape magnetic anisotropy of the wings plays a vital role. The principle of the wing rotation in an alternating magnetic field was elucidated theoretically and showed favorable agreement with the experimental results with large-sized models. The aerodynamic performances of soft magnetic rotational wings were evaluated, including the microrotational wings 165 μg in weight consisting of 0.9-mm-long magnetic wings made of electroplated nickel-iron alloy and an axis of wing rotation made of a sharpened glass tube. The micromagnetic rotational wings presented here were utilized for microflight mechanisms, which achieved successful flights.