An overview on bio-inspired UAVs: State-of-the art, challenges and opportunities

Unmanned Aerial Vehicles (UAVs) have been used for a variety of applications in different fields such as engineering, military, and entertainment. Bio-inspired and insect-like UAVs are the two major types of UAVs that have attracted significant attention over the years due to their characteristics. This rapid adoption has led different companies and universities to collaborate on designing flapping wings with optimized characteristics and appropriate mechanisms. In particular, insect-like and bird-like UAVs have demonstrated a huge potential for developing new aerial vehicles, with high efficiency and versatility to be employed in different tasks. Despite their advantageous characteristics, their small size involves several challenges mainly in terms of design, low autonomy and control. Some of the current challenges are being investigated using combined control strategies and alternative energy sources, including the integration of solar cells on the bio-inspired surface, which can increase the stability and flight duration of the UAV. This article presents an overview on the main aspects of flapping wing UAVs, including aerodynamic effects, controller strategies and project and design aspects. The current applications and challenges are introduced and the state-of-art pointed out a possible future for these type of UAVs.