A study on the tubular composite with tunable compression mechanical behavior inspired by wood cell

Plant Fibers as Composite Reinforcements for Biomedical Applications

Plant fibers possess high strength, high fracture toughness and elasticity, and have proven useful because of their diversity, versatility, renewability, and sustainability. For biomedical applications, these natural fibers have been used as reinforcement for biocomposites to infer these hybrid biomaterials mechanical characteristics, such as stiffness, strength, and durability. The reinforced hybrid composites have been tested in structural and semi-structural biodevices for potential applications in orthopedics, prosthesis, tissue engineering, and wound dressings. This review introduces plant fibers, their properties and factors impacting them, in addition to their applications. Then, it discusses different methodologies used to prepare hybrid composites based on these widespread, renewable fibers and the unique properties that the obtained biomaterials possess. It also examines several examples of hybrid composites and their biomedical applications. Finally, the findings are summed up and some thoughts for future developments are provided. Overall, the focus of the present review lies in analyzing the design, requirements, and performance, and future developments of hybrid composites based on plant fibers.

Additively manufactured biomorphic cellular structures inspired by wood microstructure

Biological cellular materials are an important area of research in Additive manufacturing due to their intricate lightweight designs and forms with high energy absorption characteristics under compressive loading. In this study, we utilize the capability of Additive Manufacturing (AM) technology, experimental testing, and Finite Element Analysis (FEA) to design and investigate the mechanical behavior and energy absorption capabilities of novel Biomorphic Cellular Structures (BCS) inspired by the microstructure of cedar, oak, and palm wood. A comparative study of the elastic properties of the biomorphic cellular structures is carried out. The deformation and failure modes of the different cells were studied, and their performance was also discussed. Nonlinear finite element numerical simulation conducted has shown high accuracy in the prediction of deformation of the samples manufactured using additive manufacturing. The results show that cedar-bcs provides the best mechanical performance compared to the other two biomorphic cellular structures which could be as a result of its more vertical cell wall orientation, nevertheless, the palm-bcs showed a step-wise deformation and improved collapse stress. The obtained results suggest that the unique opportunities offered by the proposed experimental method, in combination with computational models, could serve to provide novel important information for the rational design of additively manufactured porous biomorphic materials.

Optimization design of lightweight structure inspired by glass sponges (Porifera, Hexacinellida) and its mechanical properties

The glass sponge is a porous lightweight structure in the deep sea. It has high toughness, high strength, and high stability. In this work, a super-depth-of-field microscope was employed to observe the microstructure of the glass sponge. Based on its morphological characteristics, two novel bio-inspired lightweight structures were proposed, and the finite-element analyses (FEA) of the structures were carried out under compression, torsion, and bending loads, respectively. The structure samples were fabricated using stereolithography 3D-printing technology, and the dimension sizes of the samples were equal to those of the corresponding FEA models. Mechanical tests were performed on an electronic universal testing machine, and the results were used to demonstrate the reliability of the FEA. Additionally, lightweight numbers (LWN) were proposed to evaluate the lightweight efficiency, and a honeycomb structure was selected as the reference structure. The results indicate that the lightweight numbers of the novel bio-inspired structures are higher than those of the honeycomb structure, respectively. Finally, the proposed structures were optimized by the response surface, BP (Back Propagation) and GA-BP (Genetic Algorithm optimized Back Propagation) method. The results show that the GA-BP model after training has a high accuracy. These results can provide significant guidance for the design of tube-shaped, thin-walled structures in the engineering.