Lessons from nature: 3D printed bio-inspired porous structures for impact energy absorption – A review

As a result of their mechanical characteristics, biological structures often provide inspiration for the development of high-performance mechanical structures. Nevertheless, traditional production processes are often incapable of precisely reproducing the intricate and exquisite nature of biological systems. Modern additive manufacturing techniques provide a pathway to the creation of materials with complex patterns that are inspired by biological processes. In this paper, we identify the different types of biomimetic porous structures seen in nature, many of which are composite structures, and categorise them. We also identify the natural species with porous structures and illustrate their functions. In addition, this review paper presents how these porous structures have been mimicked for engineering applications. Figures are shown to demonstrate the scale (meso, micro, and nano) at which the porous structures are emulated. As biological porous structures have been successfully mimicked into synthetic materials using additive manufacturing (AM), we classify the types of 3D printing with respect to impact loading applications and describe the various types of additive manufacturing processes used to manufacture biomimetic porous structures. This review paper will be of interest to academics looking to design innovative lightweight porous composite structures and use emerging technologies to investigate their energy absorption properties, which have a wide range of engineering applications.