Bio-Inspired Wing With Bistable Morphing Airfoils for Aquatic-Aerial Robots

The versatile locomotion capabilities of aquatic-aerial robots significantly extend their operational range, opening up a wide array of potential applications. The compatibility of water and air is crucial in the design of aquatic-aerial robots, requiring their wings to possess the ability to deform for enhanced adaptability. However, existing designs have faced challenges in balancing movement efficiency in both environments. Drawing inspiration from the wings of mantas and eagles, we developed a bistable airfoil capable of morphing from a symmetric to an asymmetric shape, driven by pneumatic hinges. Experiments in a water tank and a wind tunnel demonstrate that these two shapes effectively improve the lift-to-drag ratio of the airfoil in water and air environments, respectively, contributing to maintaining high movement efficiency. Building on these results, we designed a bionic manta wing based on this bistable airfoil and confirmed its underwater propulsion and lift-adjusting capabilities through experiments. Outdoor tests further validate the potential of this design for aquatic and aerial robotic applications.