Beetle inspired deployable structures

Foldable hindwings in beetles are one of the ultimate deployable structures. They have sufficient strength and stiffness to tolerate 20-1000 beats per second in the flight position, although they can be folded and unfolded nearly instantly depending on the situation. This study focuses on the hindwing in ladybird beetles and aims to reveal their wing-folding/unfolding mechanisms. These beetles use their wing elasticity for deployment and can therefore quickly take off. First, on the basis of the reports of entomologists, the authors describe the factors related to the actuation of insect wing folding and unfolding. Then, the detailed motions involved in take-off and wing storing in ladybird beetles are observed by a high-speed camera. The analysis of these movies reveals the detailed processes of wingunfolding and folding. Next, the crease patterns and the transformations of the veins are clarified by using the paper model. Wing-folding/unfolding mechanisms in these insects have various unique capabilities which will provide new possibilities for designing deployable structures.