Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechatronic System, School of Mechanical Engineering, Tianjin University of Technology, Tianjin, 300384, China.
Beijing Key Laboratory on Nonlinear Vibrations and Strength of Mechanical Structures, Beijing University of Technology, Beijing, 100124, China.
Sci Rep. 2019 Mar 25;9(1):5051. doi: 10.1038/s41598-019-41487-5.
Many biomaterials utilize chiral growth to imitate biological functions. A prominent example can be found in growing cucumbers, which use tendrils as winding support for both fixation and climbing. A number of tendril-mimicking materials and artificial plant-like mechanical machines have been developed to imitate tendril deformation. However, tendrils tend to not only show spiral or parallel shapes, but also a combination of both configurations. It remains unclear whether these morphologies are regular and how they form mechanically. Here, the morphology of climbing tendrils as a complex nonlinear phenomenon is investigated via experimental and theoretical approaches. The results of the experiments clarify the relationship between tendril morphologies and actual tendril growth as well as relevant stress characteristics during the climbing of a support by the tendril, and their mechanical properties. On this basis, the three-dimensional configuration problem of a cylinder-constrained rod has been utilized to describe the phenomenon of a tendril climbing support. The phenomena of spiral and parallel configuration combinations in tendrils could be effectively explained by studying similar homoclinic and heteroclinic orbits. Applying these results accurately guides the development of mimicking material.
许多生物材料利用手性生长来模拟生物功能。一个突出的例子可以在黄瓜的生长中找到，黄瓜的卷须作为固定和攀爬的缠绕支撑。已经开发出许多模仿卷须的材料和人工植物状机械机器来模仿卷须变形。然而，卷须不仅表现出螺旋或平行的形状，而且还表现出这两种形状的组合。目前尚不清楚这些形态是否规则，以及它们是如何机械形成的。在这里，通过实验和理论方法研究了攀援卷须作为复杂非线性现象的形态。实验结果阐明了卷须形态与实际卷须生长以及卷须攀援支撑过程中的相关应力特性之间的关系，以及它们的力学特性。在此基础上，利用圆柱约束杆的三维构型问题来描述卷须攀援支撑的现象。通过研究类似的同宿和异宿轨道，可以有效地解释卷须中螺旋和平行构型组合的现象。准确应用这些结果可以准确指导仿生材料的开发。
