The highly flexible and extensible wing skin of bats enables various wing shapes and flight modes, which distinguishes it from all other natural flyers making bats an ideal model for micro-aerial vehicles. We propose that an understanding of the relationship between the structure, properties and function of the wing tissue is essential to replicate and utilize the bat’s natural capabilities. In this work, we present the first biaxial mechanical characterization of bat wing skin, identify key mechanisms in its deformation, and employ these concepts to fabricate biomimetic skins. Ten Glossophaga soricina bat specimens were available for experiment obtained from Prof. Swartz or Brown University. Of the 20 excised wing skin samples, 11 were used for establishing testing protocols, 3 tore during preparation, and 6 were tested for the characterization presented in this work. The tissue was shown to be nonlinear, heterogeneous, anisotropic, and viscoelastic. The wrinkled tissue structure and substantial anisotropy promote great spanwise deployment and deformation increasing wing area and aspect ratio enabling greater lift generation. Comparison of the material structural organization with strain field responses demonstrated that the underlying fiber architecture corresponds to observed local strain variations and that the tissue represents a departure from traditional fiber reinforced materials since the mesoscopic elastin fiber architecture appears to be the soft component while the matrix provides the stiffening role. Fabricated skins capture the inherent mismatch in natural configurations of the spanwise elastin fibers and the matrix and exhibit the characteristic wrinkle pattern observed in the in vivo bat wing skin. Future work will include static mechanical testing of the synthetic skins as well as aerodynamic testing to investigate the link between tissue structure, properties and functional flight capabilities.
- Aerospace Division
Biaxial Mechanical Characterization of Bat Wing Skin and Development of Biomimetic Constructs
- Views Icon Views
- Share Icon Share
- Search Site
Skulborstad, AJ, & Goulbourne, NC. "Biaxial Mechanical Characterization of Bat Wing Skin and Development of Biomimetic Constructs." Proceedings of the ASME 2013 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. Volume 1: Development and Characterization of Multifunctional Materials; Modeling, Simulation and Control of Adaptive Systems; Integrated System Design and Implementation. Snowbird, Utah, USA. September 16–18, 2013. V001T01A017. ASME. https://doi.org/10.1115/SMASIS2013-3190
Download citation file: