Visualizing Complex Anatomical Structure in Bamboo Nodes Based on X-ray Microtomography

In recent years,bamboo has been widely used in a broad range of applications,a thorough understanding of the structural characteristics of bamboo nodes is essential for better processing and manufacturing of biomimetic materials.This study investigated the complex anatomical structure for the nodes of two bamboo species,Indocalamus latifolius(Keng)McClure and Shibataea chinensis Nakai,using a high-resolution X-ray microtomography(μCT).The results show that the vascular bundle system in the nodal region of I.latifolius and S.chinensis is a net-like structure composed of horizontal and axial vascular bundles.Furthermore,the fiber sheath surrounding metaxylem vessels tended to be shorter in the tangential direction.This structure of bamboo nodes facilitates the tangential and axial transport of moisture and nutrients.The anatomical structure of I.latifolius and S.chinensis nodes has obvious differences,especially in the arrangement of vascular bundles.Vascular bundle frequency was significantly higher in S.chinensis nodes than in I.latifolius nodes.These findings indicate thatμCT is a nondestructive three-dimensional imaging method that can used to examine the anatomical structure of bamboo nodes.

Study of the Climbing Behavior of the Flagella of Calamus Simplicifolius Based on Micro-CT and Nanoindentation

Rattan is a typical tropical climbing plant that uses flagella to climb supports to grow.A comprehensive understanding of the anatomic structure and micromechanics of rattan flagella might inspire more research on biomimetic climbing materials.Here,the structure and micromechanical properties of flagella in calamus simplicifolius were examined by Micro-Computed Tomography(Micro-CT)and nanoindentation techniques,respectively.The results showed that the rachis of the flagella mainly comprised vascular bundles surrounded by basic tissues,which had a gradient density decreasing from outsides to insides.The prickles are derived from the epidermis or the epidermis and cortical tissue of the flagellum,which do not possess vascular tissue.The entire tip of the prickle was composed almost of fibrous cells.The indentation modulus of elasticity of the prickle was 17.03 GPa,which was 17.93%higher in comparison with the rachis.The hardness of the prickle was 539.27 MPa and was slightly higher than that of the rachis.The results indicated that the discrepancy of micromechanical strengths in different parts of flagella reflects on their unique roles in the process of climbing.