美国斯坦福大学David Lentink小组的一项最新研究揭示飞行羽毛如何粘在一起以形成连续的变形机翼。这一研究成果发表在2020年1月17日出版的国际学术期刊《科学》上。

研究人员表示，与飞机不同，可变的羽毛重叠使鸟类能够使翅膀变形。其通过结缔组织的弹性顺应性来实现这一壮举，当骨骼运动以改变机翼平面形状时，结缔组织会被动地重新分布重叠的飞行羽毛。独特的微观结构形成“方向性维可牢搭扣”，从而当相邻的羽毛在伸展过程中滑开时，重叠羽毛上成千上万的叶状纤毛与重叠羽毛的钩状拉米（hooked rami）锁定，以防止缝隙。这些结构在屈曲过程中会自动解锁。

研究人员使用一个羽毛状的生物混合空中机器人，演示了两个被动机制如何使变形机翼对湍流具有稳健性。研究人员发现，钩形的微结构将羽毛固定在鸟类物种上，而无声飞行动物除外，后者的羽毛也缺乏相关维可牢搭扣般的噪音。这些发现可能会激发创新的定向扣件和变形飞机。

附：英文原文

Title: How flight feathers stick together to form a continuous morphing wing

Author: Laura Y. Matloff, Eric Chang, Teresa J. Feo, Lindsie Jeffries, Amanda K. Stowers, Cole Thomson, David Lentink

Issue&Volume: 2020/01/17

Abstract: Variable feather overlap enables birds to morph their wings, unlike aircraft. They accomplish this feat by means of elastic compliance of connective tissue, which passively redistributes the overlapping flight feathers when the skeleton moves to morph the wing planform. Distinctive microstructures form “directional Velcro,” such that when adjacent feathers slide apart during extension, thousands of lobate cilia on the underlapping feathers lock probabilistically with hooked rami of overlapping feathers to prevent gaps. These structures unlock automatically during flexion. Using a feathered biohybrid aerial robot, we demonstrate how both passive mechanisms make morphing wings robust to turbulence. We found that the hooked microstructures fasten feathers across bird species except silent fliers, whose feathers also lack the associated Velcro-like noise. These findings could inspire innovative directional fasteners and morphing aircraft.

DOI: 10.1126/science.aaz3358

Source: https://science.sciencemag.org/content/367/6475/293