Deciphering structural biological materials: Viewing from the mechanics perspective and their prospects

Structural biological materials are multiphase composite materials in nature. Their mechanical properties are extraordinary despite their weak constituents. This review aims to decipher how these remarkable properties are achieved from the perspective of mechanics. The following three key codes can contribute to this: material properties derived from building blocks, geometrical information related to the size effects and dimensional characteristics, and their combination embedded in architectures. First, the prominent role of building blocks in structural biological materials and their mechanical characteristics are elucidated. Second, the importance of geometrical features extracted from structural biological materials in connecting the building blocks and architectures in biological systems is highlighted. The abovementioned principles and concepts underlying diverse architectures are demonstrated to interpret the structural-mechanical characteristics of hierarchical biological materials. This work seeks to enrich the understanding of structural biological materials from a mechanics perspective and trigger breakthroughs in the development of advanced bio-inspired materials.