Multimodal Locomotion in Insect‐Inspired Microrobots: A Review of Strategies for Aerial, Surface, Aquatic, and Interfacial Motion

Abstract

Aerial–aquatic robots possess a distinctive ability to operate in air, on water, and underwater, requiring designs that function across distinct physical regimes. This review highlights insect‐inspired legged and wing‐driven designs, identifying core design principles that enable propulsion systems to function across air and water. Biological and robotic strategies for multimodal locomotion are examined, followed by methods for air–water transitions. In air, flapping wings generate lift and thrust through unsteady aerodynamic forces. On water surfaces, locomotion relies on surface tension support and sculling strokes. Underwater, movement is dominated by drag‐based rowing or lift‐based flapping. Water entry and exit involve static and dynamic strategies, coordinated with posture and stroke timing. Four key design considerations for multimodal systems are identified: leg design and coordination, body posture control, flapping mechanics, and actuation. Unified legged systems for surface and underwater motion, along with posture strategies that stabilize transitions, represent promising avenues. For winged systems, a deeper understanding of stroke plane and body orientation could enable simpler adaptable control. Challenges in actuation and autonomy also remain central to building aerial–aquatic robots. Leveraging bioinspiration offers a path for microrobots to realize their potential for tasks, such as monitoring, disaster response, and search‐and‐rescue.