Insect-inspired passive wing collision recovery in flapping wing microrobots.

Flying insects have developed two distinct adaptive strategies to minimize wing damage during collisions. One strategy includes an elastic joint at the leading edge, which is evident in wasps and beetles, while another strategy features an adaptive and deformable leading edge, as seen in bumblebees and honeybees. Inspired by the latter, a novel approach has been developed for improving collision recovery in micro aerial vehicles (MAVs) by mimicking the principle of stiffness anisotropy present in the leading edges of these insects. This study introduces a passive, flexible, folding wing design with adaptive leading edges. The impact of these adaptive folding leading edges on the flight performance of flapping-wing MAVs was systematically evaluated. Variations in lift generation and obstacle-crossing capabilities between rigid wings and adaptive deformable wings were quantified. Additionally, the mechanical stiffness of the wings was assessed to validate their functional effectiveness. The proposed mechanism was incorporated into the wings of a dual-layer flapping-wing robot, which demonstrated successful flight recovery after collision. The experimental results indicate that a robot with a 30 cm wingspan can effectively traverse a gap of 16.2 cm during flight, thereby demonstrating its enhanced ability to overcome collision challenges. These findings underscore the potential of adaptive wing designs in enhancing the resilience and performance of MAVs in dynamic environments.