Bio-inspired Impact-resistant and Energy-absorbing Materials: A review

In critical engineering sectors such as aerospace, automotive crashworthiness, infrastructure protection, and personal protective equipment (PPE), developing lightweight materials that combine high load-bearing capacity with superior energy absorption efficiency remains a core challenge in structural safety design. Traditional impact-resistant materials often suffer from the trade-off between strength and toughness. Recently, bio-inspired impact-resistant and energy-absorbing materials, evolved over millions of years in nature, have offered a new pathway to overcome this bottleneck. This paper systematically reviews the latest progress in bio-inspired energy-absorbing structures, focusing on their design philosophies, deformation mechanisms, and performance optimization strategies. First, alternating soft-hard laminated and helicoidal structures are analyzed, revealing their mechanisms for inducing crack deflection and energy dissipation through multiscale interfaces. Second, cellular and topologically porous structures are discussed, highlighting their excellent performance in rapid stress wave attenuation and stable crushing energy absorption. Finally, multiscale gradient and hierarchical structures are introduced, illustrating the contribution of gradient distribution to improving buckling resistance and specific energy absorption (SEA). By reviewing these typical biological prototypes and their engineering applications, this paper notes that bio-inspired structures are driving a paradigm shift in protection from "strength-dominated" to "structure-dominated" design. Future prospects for the intelligent and sustainable application of biomimetic materials in extreme environments are also discussed, aiming to provide theoretical support and design guidelines for next-generation high-efficiency, lightweight, and high-performance impact protection systems.