Bamboo is a natural composite material with a high strength-to-weight ratio traditionally used in various consumer products as well as in building and modern advanced and sustainable manufacturing technology. While its macroscopic mechanical properties are well known, nanoscale studies of the mechanical properties of the hierarchical structure of bamboo at the level of individual cells and cell walls are lacking. Here we use different AFM-based methods to analyse the mechanical properties of individual bamboo fibres that are the foundation of the hierarchical structure at the nanoscale. The elastic modulus of the fiber in the outer region varies from 7.5 to 8.9 GPa, while that of the inner fiber ranges between 4.1 and 6.1 GPa. The results demonstrate that the fibre stiffness varies in nanoscale regions between fibre interior and the fibre wall and strongly depends on the position of the individual bamboo fibre within the culm. Outer fibres with high cellulose fibril density and low lignin level show low adhesion interaction force (13.5%) in the interface between cellulose and lignin/hemicellulose matrix, hence, resulting in low plastic deformation energy release during mechanical deformation. The implications of the interrelation of plasticity, lignin level, and adhesion force are discussed for the application of bamboo as a high-performance, renewable, and sustainable material.

竹子是一种具有高强度重量比的天然复合材料，传统上用于各种消费品以及建筑和现代先进可持续制造技术。虽然其宏观机械性能众所周知，但缺乏对竹子分层结构在单个细胞和细胞壁水平上的机械性能的纳米级研究。在这里，我们使用不同的基于 AFM 的方法来分析单个竹纤维的机械性能，这是纳米级分层结构的基础。外部区域纤维的弹性模量在7.5至8.9GPa之间变化，而内部纤维的弹性模量在4.1至6.1GPa之间变化。结果表明，纤维刚度在纤维内部和纤维壁之间的纳米级区域中变化，并且很大程度上取决于竹秆内单个竹纤维的位置。具有高纤维素原纤维密度和低木质素水平的外层纤维在纤维素和木质素/半纤维素基质之间的界面中表现出低粘附相互作用力（13.5%），因此导致机械变形期间塑性变形能量释放低。讨论了可塑性、木质素水平和粘附力之间的相互关系对于竹子作为高性能、可再生和可持续材料的应用的影响。