Low-voltage electromagnetic actuators for flapping-wing micro aerial vehicles

This paper presents a new type of electromagnetic actuator driven by a low voltage of 5.5 V for potential applications in insect scale Flapping-wing Micro Aerial Vehicles (FMAVs). The actuator can generate vibratory motions via cantilever-beam or cantilever-plate structures to drive artificial wings through flapping motion. The induced magnetic Lorentz force is analyzed by a simplified lumped mass model and the dynamic characteristics including resonant frequency and amplitude are investigated through experimental tests. In the prototype designs and tests, a peak amplitude of 29.8 mm from a 25 mm-long cantilever beam structure has been achieved. Furthermore, a prototype device with the cantilever beam actuator using small magnets of 197.2 mg has demonstrated 5.7 times higher output power density at 0.56 W/Kg as compared with that of another prototype device using larger magnets of 2409.2 mg. This implies the potential for further miniaturized systems toward FMAVs. Under a driving voltage of 5.5 V, a cantilever plate actuator has been shown to drive a pair of artificial wings to achieve 20° flapping amplitude at 101.4 Hz, which results in a high power density of 9.52 W/Kg. By applying AC current to a planar coil, the power density of the actuator can be further enhanced to 48.56 W/Kg. As such, the low-voltage electromagnetic actuators could broaden the driving mechanisms for insect scale FMAVs.