| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Biological Materials Science
|
| Presentation Title |
Microstructure and Nanomechanical Properties of the Ironclad Beetle’s Exoskeleton |
| Author(s) |
Nayeon Lee, Vina Nguyen, Parker Berthelson, Robert D Moser, Raj Prabhu |
| On-Site Speaker (Planned) |
Nayeon Lee |
| Abstract Scope |
This study examined the structural design of natural composites within the exoskeleton of the Southwestern Ironclad Beetle known for its exceedingly hard cuticle. The Ironclad beetle’s exoskeleton is primarily composed of chitin fibers and protein, and organized into four layers; epicuticle, exocuticle, endocuticle, and epidermis. Structural and nanomechanical analyses revealed that each layer had distinctive function and was joined as functional gradient materials. The epicuticle was comprised of waxy and polygonal walls (~2 µm in diameter) functioning as a waterproof and anti-adhesive to inhibit microbial contamination. The exocuticle showed the highest Young’s modulus (~15 GPa) providing high strength properties. The endocuticle’s modulus was lesser (8~10 GPa). However, it gives resilience and toughness to the exoskeleton with fibrous stacking layers, knowns as Bouligand structures. Lastly, the modulus of the epidermis was 2~3 GPa to allow the attachment of muscle and soft tissue. These findings can be applied to design composite materials. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |