Tensile properties of individual multicellular Bacillus subtilis fibers

论文摘要

Microfibers formed by Bacillus subtilis（B. subtilis） have attracted interest because of their potential for use as biodegradable fibers. In this work, an efficient method based on the micro-liquid bridge method（LBM） is proposed to investigate the mechanical properties and the deformation evolution in individual fibers. For the first time, tensile testing of fibers of this type containing several cells is conducted in a scanning electron microscope（SEM） chamber and the in situ deformation evolution of the fibers and the septa is observed. Experimental results show that these fibers are almost broken at the positions of the septa at low humidity, but also show that their fracture morphologies are different. At high humidity, local necking deformation occurs at the septum position. To explore the deformation mechanism of an individual bacterial fiber with a diameter of several hundred nanometers under different humidity conditions, we use the finite element method（FEM） to analyze the tensile deformation behavior of these fibers when their septa are at various separation levels. The numerical results indicate that weak interactions among the septa lead to the dispersion of both the fibrous tensile strength and the modulus. These results may be helpful in understanding the deformation mechanism, thus leading to further improvements in the mechanical performance of these fibers.

论文目录

• 1 Background
• 2 Experiments and results
• 3 Finite element simulations of stretched B.subtilis fiber
•   3.1 Cell division of B.subtilis and formation of a sep-tum
•   3.2 Finite element models of fibers at varying separa-tion levels
•   3.3 Material properties
•   3.4 Numerical results
• 4 Discussion
• 5 Conclusions
• Appendix The details of finite element model
•   A1 Elastic model at low humidity
•   A2 Viscoelastic model at high humidity

文章来源

类型: 期刊论文

作者: Xuan Ye,Tao Wang,Zhuo Zhuang,XiDe Li

来源: Science China(Physics,Mechanics & Astronomy) 2019年09期

年度: 2019

分类: 基础科学,工程科技Ⅰ辑

专业: 有机化工

单位: Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University,Center for Nano and Micro Mechanics, Tsinghua University

基金: supported by the National Natural Science Foundation of China(Grant Nos.11872035,11472151,11632010,and 11227202)

分类号: TQ341

页码: 74-82

总页数: 9

文件大小: 917K

下载量: 12