Bio-Inspired Materials With Tunable Mechanical Properties

Despite the small set of building blocks used for their assembly, naturally occurring materials such as proteins show remarkably diversity in their mechanical properties ranging from something resembling rubber – low stiffness, high resilience and extensibility – to silk – high stiffness and strength. Inspired by such versatility, we report the computational characterization and experimental fabrication of nanocomposites with tunable mechanical properties via “secondary structures” patterning. By performing FEM calculations, we show how the large variation in mechanical properties is enabled by the folding and unfolding of such secondary structures. Parametric studies reveal how specific features in the designed pattern can be used to tune the material’s mechanical properties as well as to avoid the propagation of undesired cracks across the structure. Our results open the possibilities for manufacture of flexible materials with targeted strength and extensibility.

Research supported by the National Science Foundation, Emerging Frontiers in Research and Innovation Award # EFRI-1240264 and also the Division of Materials Research Award # DMR 1120923.