Nanoscale structural and mechanical characterization of the cell wall of bamboo fibers

Bamboo is a natural biological composite with superior mechanical strength and toughness. What is the secret recipe that Mother Nature uses to fabricate bamboo? Here we report discovery of cobble-like polygonal cellulose nanograins with a diameter of 21–198 nm in the cell wall of bamboo fibers. These nanograins are basic building blocks that are used to construct individual bamboo fibers. Nanoscale mechanical tests were carried out on individual fiber cell walls by nanoindentation. The nanograin-structured bamboo fibers are not brittle in nature but somewhat ductile. The bamboo fiber reinforcing mechanisms are discussed with reference to the hierarchical structure and mechanical properties of individual bamboo components.