COLLABORATIVE RESEARCH: Structure and Mechanics of the Bat Wing Membrane

所有飞行动物的翅膀都是由外表面的一部分组成的-皮肤，羽毛和/或角质层-但这个翅膀结构的关键组成部分比内部骨骼，肌肉和神经系统研究得少得多。 由于皮肤可以构成翅膀表面的大部分，因此了解飞行动物皮肤的机械性质对于了解动物如何飞行以及动物飞行的进化起源和多样化至关重要。蝙蝠与其他飞行动物和人类制造的飞行器的一个不同之处在于，它们的翅膀在飞行过程中会变形和伸展。该研究项目将专注于蝙蝠皮肤的独特结构和功能，以及它如何有助于蝙蝠的飞行能力。 该项目旨在了解翅膀的皮肤如何有助于控制蝙蝠飞行性能不可或缺的3D机翼形状的动态变化。为了实现这一目标，该合作项目将整合生物学和工程研究，以深入了解蝙蝠翅膀皮肤的性质，这是一种非凡而复杂的生物材料。 首先，蝙蝠自然飞行的高速摄像将被用来记录翅膀皮肤在正常的翅膀运动过程中如何伸展和变形。第二，比较分析的结缔组织和肌肉的结构的多样性翅膀皮肤将进行一组87的1200多个活的蝙蝠物种，选择代表蝙蝠的多样性和进化关系。第三，机翼蒙皮的独特机械试验将通过施加力的方式进行，这是第一次模拟蒙皮在飞行过程中的经历。使用偏振光的特殊技术，将有可能首次量化整个皮肤样本的微观变形。这种新方法将使人们有可能获得基本的见解机翼皮肤作为一种材料和机翼作为翼型。最后，所有这些研究的数据将被纳入蝙蝠皮肤的结构-性能关系的工程模型。 这些模型不仅能提供对皮肤力学的更深入的了解，而且还能预测皮肤功能和动力学，这些预测超出了实验室测试条件下所能观察到的。工程科学越来越多地从生物世界中寻找设计理念，对蝙蝠翅膀结构和材料的研究可以揭示一系列独特的特征，这些特征可以激发新的航空航天材料、机翼设计、和其他尖端技术。此外，理论和建模工具开发高度变形机翼皮肤将适用于组织力学在各种生物和生物医学应用。公众对蝙蝠的迷恋以及蝙蝠形态和动作之美为交流提供了自然的起点;主要研究人员和他们的学生将在当地公立学校和博物馆进行推广，为许多观众创造基于网络的内容，并参与电影和电视节目。研究人员将特别努力从代表性不足的群体中识别、招募和留住本科生和研究生，并让他们作为团队成员参与到各个层面。牙买加金斯顿的NSF-GEMS（工程、数学科学女孩）方案将增加一个生物组成部分，该方案将纳入牙买加的动物飞行和自然历史。 这一增强将扩大该计划的科学范围，为研究生提供外展培训，并让女孩在自己的环境中亲身体验科学。

The wings of all flying animals are composed in part of an outer surface -- the skin, feathers, and/or cuticle -- but this key component of wing structure is much less well studied than the internal skeletal, muscular, and nervous systems. Because skin can make up the majority of the wing surface, understanding the mechanical nature of skin in flying animals is critically important to understanding both how animals fly, and the evolutionary origins and diversification of animal flight. One way in which bats differ from all other flying animals and from the flying vehicles that humans build is that their wings deform and stretch tremendously during flight. This research project will focus on the unique structure and function of bat skin, and how it contributes to the flight capacity of bats. This project proposes to understand how the skin of the wing helps to control the dynamic changes in 3D wing shape that are integral to bat flight performance. To achieve this goal, this collaborative project will integrate biology and engineering research to gain an in-depth understanding of the nature of bat wing skin, a remarkable and complex biological material. First, high-speed videography of natural flight in bats will be used to document how wing skin stretches and deforms during normal wing movements. Second, a comparative analysis of the diversity of structure of connective tissues and muscles underlying wing skin will be undertaken in a group of 87 of the more than 1200 living bat species, selected to represent bat diversity and evolutionary relationships. Third, unique mechanical tests of wing skin will be made by applying forces in a manner that mimics, for the first time, what skin experiences during flight. Using a special technique that employs polarized light, it will be possible to quantify microscopic deformations over entire skin samples for the first time. This new method will make it possible to gain fundamental insights into wing skin as a material and into wings as airfoils. Finally, data from all of these studies will be incorporated into engineering models of structure-property relationships for bat skin. These models will not only provide deeper insights into the mechanics of the skin, but will also make predictions about skin function and dynamics that go beyond what can be observed under laboratory test conditions.Engineering sciences increasingly look to the biological world for design ideas and studies of bat wing architecture and materials can uncover a menu of distinctive traits that can inspire novel aerospace materials, airfoil designs, and other cutting-edge technologies. In addition, theory and modeling tools developed here for highly deforming wing skin will be applicable to tissue mechanics in a variety of biological and biomedical applications. Public fascination with bats and the beauty of bat form and motion provide natural starting points for communication; the principal investigators and their students will conduct outreach at local public schools and museums, create web-based content for many audiences, and participate in film and television programming.The investigators will make special efforts to identify, recruit, and retain undergraduate and graduate students from underrepresented groups, and to involve them as team members at every level. A biology component will be added to the NSF-GEMS (Girls in Engineering, Math & Science) program in Kingston, Jamaica, which will incorporate animal flight and natural history of Jamaica. This enhancement will broaden the range of science in the program, offer outreach training to graduate students, and give girls hands-on experience of science in their own environment.