Design, fabrication, and experiments of an electromagnetic actuator for flapping wing micro air vehicles

The design and construction of a 2.6 gram electromagnetic actuator operated at resonance is presented. This design is based on wedge-shaped electromagnetic coil generating a driving torque on a rotor embedded with permanent magnets. Additional permanent magnets are used to create a virtual spring effect, supply a restoring torque to the rotor and adding nonlinear system stiffness. Flapping wing parameters were varied systematically to generate 16 unique wing profiles, from which wings were fabricated. Independent bench tests for the coil and spring magnets were used to modify analytical models of the actuator, derived in detail in a parallel study. Based on the equations of motion, estimates for the primary mode of resonance and the peak-peak stroke amplitude were determined using an approximate solution. Frequency response tests were conducted on the flapper using the set of test wings at varying supply voltages and spring configurations to verify the predicted resonate frequencies and amplitudes. Wing kinematics and mean lift measurements were performed for the flapper operating at resonance, producing a lift-to-weight ratio for the actuator of over one at 24V.