A bioinspired Separated Flow wing provides turbulence resilience and aerodynamic efficiency for miniature drones Smallscale drones have enough sensing and computing power to find use across a growing number of applications. However, flying in the lowxe2x80x93Reynolds number regime remains challenging. High sensitivity to atmospheric turbulence compromises vehicle stability and control, and low aerodynamic efficiency limits flight duration. Conventional wing designs have thus far failed to address these two deficiencies simultaneously. Here, we draw inspiration from naturexe2x80x99s small flyers to design a wing with lift generation robust to gusts and freestream turbulence without sacrificing aerodynamic efficiency. This performance is achieved by forcing flow separation at the airfoil leading edge. Water and wind tunnel measurements are used to demonstrate the working principle and aerodynamic performance of the wing, showing a substantial reduction in the sensitivity of lift force production to freestream turbulence, as compared with the performance of an Eppler E423 lowxe2x80x93Reynolds number wing. The minimum cruise power of a custombuilt 104gram fixedwing drone equipped with the Separated Flow wing was measured in the wind tunnel indicating an upper limit for the flight time of 170 minutes, which is about four times higher than comparable existing fixedwing drones. In addition, we present scaling guidelines and outline future design and manufacturing challenges.

Design and TakeOff Flight of a SamaraInspired RevolvingWing Robot Motivated by a winged seed, which takes advantage of a wing with high angles of attack and its associated leadingedge vortex to boost lift, we propose a powered 13.8gram aerial robot with the maximum takeoff weight of 310 mN (31.6 gram) or thrusttoweight ratio of 2.3. The robot, consisting of two airfoils and two horizontally directed motordriven propellers, revolves around its vertical axis to hover. To amplify the thrust production while retaining a minimal weight, we develop an optimization framework for the robot and airfoil geometries. The analysis integrates quasisteady aerodynamic models for the airfoils and the propellers with the motor model. We fabricated the robots according to the optimized design. The prototypes are experimentally tested. The revolvingwing robot produces approximately 50% higher lift compared to conventional multirotor designs. Finally, an uncontrolled hovering flight is presented.