Active adhesion improves adaptive flight for feathered wings

Abstract

Birds change the shape of their wings to adapt to dynamic environments, such as dense cities and forests. Engineers have explored using avian-informed designs with feather-based wing morphing to achieve similar capabilities with small aircraft. Unlike engineered systems, natural feathers prevent separation during morphing with microscopic features. Without a fastening mechanism, gaps can form throughout the wing, reducing the transverse force generation necessary for rapid change in flight path, thus impairing maneuverability. Here we show how active feather fastening adapts wing force and moment generation to improve maneuverability, efficiency, and stability over inactive feathers. Further, the active feathers offer a desirable relationship between velocity and these metrics, improving on, or maintaining comparable performance to, baseline rigid wings. As small aircraft are expected to fly faster, further, and with advanced aerobatic capability, feathered morphing wings incorporating electrostatic adhesion will advance aircraft adaptability for successful operation in complex environments.