Meeting Abstract

8.7  Saturday, Jan. 4 08:48  Nanomechanical properties of insect wing layers SAMPLE, C.S.*; XU, A.; SWARTZ, S.M.; GIBSON, L.J.; Massachusetts Institute of Technology; Massachusetts Institute of Technology; Brown University; Massachusetts Institute of Technology csample@mit.edu

Insect wings often change shape dynamically during the wingbeat cycle, and these deformations can confer energetic and aerodynamic benefits during flight. Due to the lack of musculature within the wing itself, the changing form of the wing is determined primarily by its passive response to inertial and aerodynamic forces. This response is in part controlled by the wing’s mechanical properties, which vary across the membrane to produce regions of differing stiffness. Previous studies of wing mechanical properties have largely focused on surface or bulk measurements, but this ignores the layered nature of the wing. In our work, we investigated the mechanical properties of the wings of the house cricket (Acheta domesticus) with the aim of determining differences between the wing’s three layers: the dorsal and ventral epicuticle layers and the internal epidermal layer. The thickness of the three layers was measured using scanning electron microscopy. The Young’s modulus and hardness of the external epicuticle layers were measured via nanoindentation on the surface to shallow depths to avoid effects from the underlying layers. Nanoindentation was also performed at the center of cross-sectional samples of the wing to measure the mechanical properties of the epidermis. Measurements of both the surface and cross-section were repeated at several locations to investigate the variability of these properties. The results suggest that the epidermis is stiffer than the epicuticle, and the properties of both layers vary across the wing. Our findings lay the foundation for further investigation of the role played by this layered structure in wing deformation and insect flight.