Abstract:

In this work, we develop an artificial foldable wing that mimics the hind wing of a beetle (Allomyrina dichotoma). In real flight, the beetle unfolds forewings and hind wings, and maintains the unfolded configuration unless it is exhausted. The arti-ficial wing has to be able to maintain a fully unfolded configuration while flapping at a desirable flapping frequency. The arti-ficial foldable hind wing developed in this work is based on two four-bar linkages which adapt the behaviors of the beetle’s hind wing. The four-bar-linkages are designed to mimic rotational motion of the wing base and the vein folding/unfolding motion of the beetle’s hind wing. The behavior of the artificial wings, which are installed in a flapping-wing system, is observed using a high-speed camera. The observation shows that the wing could maintain a fully unfolded configuration during flapping motion. A series of thrust measurements are also conducted to estimate the force generated by the flapping-wing system with foldable artificial wings. Although the artificial foldable wings give added burden to the flapping-wing system because of its weight, the thrust measurement results show that the flapping-wing system could still generate reasonable thrust.

Key words: four-bar linkage configuration, thrust measurement, beetle’s hind wing, folding/unfolding motion, flapping-wing system, foldable wing