The purpose of this research is to clarify the effect of wing veins of a butterfly on a passive deformation of the wing and a flight performance. As a new tool making it possible to experiment with arbitral vein structures at constant flapping motion, we have developed a MEMS (Micro Electro Mechanical Systems) artificial butterfly wing mounted on an ultra-light rubber powered ornithopter. The artificial butterfly wing consists of a thin polymer membrane supported by plastic veins of rectangular cross-section of which thickness and width can be changed as designed. Cross-sectional sizes of the veins are a few hundred micrometers like an actual butterfly’s veins. Its planar shape and venation is the same as those of a swallowtail butterfly, Papilio karna. Other major parameters are in the same range of an actual butterfly; a total mass of the ornithopter including the wings is 0.39 g, and a flapping frequency is around 10 Hz. The ornithopter with artificial butterfly wings successfully flew forward by setting an appropriate center of gravity. Unlike an experiment with an actual butterfly, we can extract only the effect of veins on flight by exchanging wings for different ones, since the flapping motion of the ornithopter is a mechanically constant.

References :
Hiroto Tanaka, Kiyoshi Matsumoto, Isao Shimoyama, “Butterfly Ornithopter with Micromolded Wings Having Wing Vein Structure,” Proceedings of the 20th Bioengineering Conference, pp. 75-76, Tokyo, Japan, January 25-26, 2008.

Hiroto Tanaka, Kiyoshi Matsumoto and Isao Shimoyama, ”Design and performance of micromolded plastic butterfly wings on butterfly ornithopter,” Proceedings of 2008IEEE/RSJ International Conference on Intelligent Robots and Systems(IROS2008), pp. 3095-3100, Nice, France, Sep 22-26, 2008.

Hiroto Tanaka, Kiyoshi Matsumoto and Isao Shimoyama, ”Defromation and aerodynamic performance of a flapping artificial butterfly wing in free flight,” Proceedings of SEB at Marseille 2008, S53-54, Marseille, France, July 6-10, 2008.