Figure 1. Hierarchical structure of bamboo.

The vascular bundles in the parenchyma matrix are surrounded by supporting fibers which are known to be the source of remarkable mechanical properties of bamboo. Bamboo fibers have a hierarchical structure in which cellulose microfibrils reinforce the intertwined hemicellulose-lignin matrix. Linear chains of glucose with orderly hydrogen bonds form the crystalline regions of microfibrils while irregular hydrogen bonds create the amorphous regions. The cross section of these microfibrils is either rectangular or hexagonal.