Summary

This project investigates the bionanoscience and material properties of the peacock mantis shrimp’s dactyl club, a biological hammer capable of delivering strikes over 1000 N at 14–23 m/s without fracturing. The club’s exceptional impact resistance and toughness arise from its hierarchical Bouligand structure—a helicoidal arrangement of chitin-protein nanofibrils reinforced with amorphous calcium carbonate and calcium phosphate.

Using Scanning Electron Microscopy (SEM) and Field Emission SEM (FESEM), we examined the microstructure of the dactyl club’s three main regions (impact, periodic, and striated). These imaging techniques revealed the helicoidal and sinusoidal fiber orientations responsible for the club’s ability to dissipate energy and prevent crack propagation. Dynamic Finite Element Analysis (DFEA) further demonstrated that the structure distributes stress effectively during high-speed impacts, preventing catastrophic failure.

The biomineralization process of the club, observable via X-ray Fluorescence (XRF), shows how calcium and brominated organic components are deposited during molting to regenerate and strengthen the club.

Inspired by this natural design, engineers and scientists are exploring biomimetic applications. In materials science, the Bouligand chitin structure guides the development of lightweight, impact-resistant composites through methods like lamination and colloidal directed assembly, enabling innovations in automotive, aerospace, and renewable energy technologies.

In biomedical engineering, the dactyl club’s principles have inspired the fabrication of artificial menisci and tissue scaffolds that mimic its toughness and flexibility. The shrimp’s key biopolymer, chitin, and its derivative chitosan are also applied in drug delivery, cancer treatment, wound healing, and prosthetics due to their biocompatibility and biodegradability.

While challenges such as limited solubility, processing complexity, and variable biocompatibility remain, chitin-based research represents a promising frontier for sustainable, high-performance materials. The mantis shrimp dactyl club thus exemplifies how nanostructural hierarchy and biomineralization can inspire next-generation impact-resistant and biomedical materials.

3D Model of Chitin Bouligand Structure

I modeled the 3D structure in Autodesk Fusion 360 knowing each layer would have to be rotated by 5° until reaching a full 180° rotation to form the overall helical structure. This model however does not go until the full 180°. This was one of my first times using CAD software, and I 3D printed the final product to showcase in our class presentation.

Research Paper

https://docs.google.com/document/d/1dtj8rx0X3O28ok2uFB1Z_YLbIlk4ZOYeXXwRpObdMIA/edit?usp=sharing

Presentation

https://docs.google.com/presentation/d/1Hi3vn1aw8fjv3YEq2B8gzCVZ3PCbxT37GWUbafSeCF0/edit?usp=sharing

Bouligand Inspired Chitin Toughness Design