Bionic Beetle Nickel-Titanium Medical Skeleton with Excellent Deformation Recovery Ability and Mechanical Properties

Abstract

Nickel-titanium alloy exhibits potential for bone repair due to its high strength and deformation recovery properties. However, its elevated elastic modulus may result in 'stress shielding' concerns. Taking inspiration from beetles' elytra and cuticle structures, we utilized LPBF technology to develop two types of bionic bones: single bionic bones and composite bionic bones (Z4, D4, F4). The experimental results demonstrate that the composite bionic bone, consisting of a single bionic bone, exhibits a strengthening effect that surpasses theoretical expectations. By conducting finite element simulations and compression experiments, the mechanical properties and deformation characteristics of the composite bionic skeleton are compared with those of the traditional skeleton, confirming the viability of the bionic approach. Additionally, we investigated the impact of different geometric cross-sections on the mechanical properties and deformation patterns of bionic bones with similar porosity levels. Our findings indicate that F-shaped bones display the most stable deformation patterns compared to other bionic bones. Among these, the bionic skeleton F6 with a hexagonal cross-section demonstrates superior mechanical properties within the F-shaped skeleton category. Its elastic modulus ranges from 0.83 to 1.8 GPa, effectively reducing Young's modulus and mitigating the 'stress shielding' effect. Moreover, the material exhibits a strength varying from 81 to 236 MPa, meeting the necessary standards for medical implants. Even under a 15% compression deformation, the shape memory recovery rate achieves an impressive 98.33%, showcasing its exceptional deformation recovery capabilities. This study provides valuable insights for the application of additively manufactured porous nickel-titanium structures in the field of bone implants.

Keywords: additive manufacturing, Porous Nickel-titanium Alloy, Bone Implants, Biomimetic Design