Flexibility-driven aerodynamic performance in a bio-inspired four-wing, eight-segment, dual-actuator flapping mirco-robot

Flapping-wing micro air vehicles (FWMAVs) continue to face significant challenges, including flight control difficulties, high energy consumption, insufficient lift relative to weight, and complex construction. This paper presents the design and performance of a 21-gram "Four-wing, Eight-segment" Flapping-wing Micro Air Vehicle (FWMAV) based on natural wing flapping. It uses an eight-segment wing structure that balances flexibility and stiffness during flapping, rather than the wing membranes commonly fond in previous designs. In terms of mechanism, instead of a single motor per wing used in previous designs, a simple and efficient dual-motor double-crank double rocker system is used, which reduces the number of motors, weight, and power consumption. It can flap the wings at an angle of ±20°, and reduces vibration and torque requirements by up to 25 percent. Using Topology Optimization technology, the wing membranes were removed, reducing the weight to 3.24 grams and improving the lift-to-weight ratio. This research systematically explores the relationship between segmentation-driven flexibility and power efficiency of the wing. The design calculations and hand tests were shown to be in agreement within 8 percent, which is better than the 10 percent difference between the calculations and measurements reported in KUBeetle. In addition, our prototype was able to fly for 10 seconds, demonstrating the validity of the design in real flight.