Autonomous top-perching with an asymmetric bistable claw

Long-duration in situ observation in constrained natural environments (e.g., caves and dense arboreal canopies) is crucial for ecological monitoring. While unmanned aerial vehicles (UAVs) provide cross-terrain access, their operational feasibility is limited by substantial power demands and acoustic disturbance from sustained hovering. Here, we present an autonomous top-perching UAV system that leverages overhead structures for stable suspension and enhanced adaptability in confined spaces. The system features a foldable, asymmetric bistable mechanism. By modulating the structural asymmetry to tailor its energy landscape, it maintains a compact flight configuration (8:1 folding ratio), while achieving rapid, low-energy deployment (0.16 s) into a strong load-bearing state for stable perching. Indoor and outdoor experiments demonstrate the system's ability to perch on diverse natural structures, including trees, drilling holes, cavities, and rock wall gaps. These capabilities demonstrate how mechanical intelligence can simplify aerial interaction tasks, extending the operational scope of autonomous aerial systems in unstructured environments.