Bamboo: A Mechanically Optimum Design in Nature

This chapter reviews the latest research on the mechanics and morphology of bamboo. Bamboo is one of the fastest-growing plants, even under unmanaged conditions; thus, it has the potential to become a renewable natural resource. The rapid maturation of bamboo is due to its hollow structure, which requires less photosynthetic material to grow and makes its culm lightweight (which, in turn, suppresses the risk of collapse by self-weight). More noteworthy is the mechanical optimality in naturally designed bamboo culms, as can be deduced from the delicate harmony and balance between the circular crossbeam (diaphragm) at a node and the reinforcing fiber (vascular bundle sheath) inside the culm. Surprisingly, the spatial arrangement of the two attributes is finely tuned to optimally improve the mechanical performance of bamboo culm, as confirmed by state-of-the-art research. A better understanding of the optimal design for enhancing the mechanical function of bamboo culm will lead to a nature-derived optimal design of functional materials with excellent mechanical properties.