Flexible flapping wings with self-organized microwrinkles
Flexible flapping wings with self-organized microwrinkles
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DOI：
10.1088/1748-3190/10/4/046005
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发表时间：
2015-08-01
影响因子：
3.4
通讯作者：
Liu, Hao
中科院分区：
文献类型：
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作者：
Tanaka, Hiroto;Okada, Hiroyuki;Liu, Hao
设计并制作了具有褶皱翼膜的仿生扑翼。翅膀由碳纤维增强塑料框架和聚合物薄膜组成，薄膜上有微尺度的皱纹，灵感来自鸟类的羽毛和昆虫翅膀的波纹。通过改变褶皱的方向和波形，可以控制褶皱薄膜的弯曲和拉伸刚度，从而扩展了微型扑翼飞行机器人柔性翅膀的设计空间。在制造微皱纹的过程中利用了一种自组织现象，从而自发地产生了横跨宽翼区域的微尺度皱纹。将这些自组织皱纹的波浪形用作模具，并在模具上沉积一层对二甲苯膜，形成皱翼膜。从理论、计算和实验三个方面研究了起皱波形对油膜刚度的影响。与平膜相比，弯曲刚度提高了两个数量级，拉伸刚度降低了两个数量级。为了验证褶皱对扑翼实际变形和由此产生的气动力的影响，使用系留电动扑翼机构对所制造的褶皱机翼进行了测试。研究发现，弦向单向皱纹可以防止机翼后缘附近的颤振，并且与平翼或有展向皱纹的机翼相比，可以产生更大的气动升力。我们的结果表明，通过调节微皱纹来实现翼膜的精细刚度控制，可以改善未来扑翼飞行机器人的气动性能。
Bio-inspired flapping wings with a wrinkled wing membrane were designed and fabricated. The wings consist of carbon fibre-reinforced plastic frames and a polymer film with microscale wrinkles inspired by bird feathers and the corrugations of insect wings. The flexural and tensile stiffness of the wrinkled film can be controlled by modifying the orientations and waveforms of the wrinkles, thereby expanding the design space of flexible wings for micro flapping-wing aerial robots. A self-organization phenomenon was exploited in the fabrication of the microwrinkles such that microscale wrinkles spanning a broad wing area were spontaneously created. The wavy shape of these self-organized wrinkles was used as a mould, and a Parylene film was deposited onto the mould to form a wrinkled wing film. The effect of the waveforms of the wrinkles on the film stiffness was investigated theoretically, computationally and experimentally. Compared with a flat film, the flexural stiffness was increased by two orders of magnitude, and the tensile stiffness was reduced by two orders of magnitude. To demonstrate the effect of the wrinkles on the actual deformation of the flapping wings and the resulting aerodynamic forces, the fabricated wrinkled wings were tested using a tethered electric flapping mechanism. Chordwise unidirectional wrinkles were found to prevent fluttering near the trailing edge and to produce a greater aerodynamic lift compared with a flat wing or a wing with spanwise wrinkles. Our results suggest that the fine stiffness control of the wing film that can be achieved by tuning the microwrinkles can improve the aerodynamic performance of future flapping-wing aerial robots.