Department of Civil and Environmental Engineering, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA.
Department of Advanced Manufacturing and Robotics, Peking University, Beijing, 100871, China.
Nat Commun. 2024 May 21;15(1):4072. doi: 10.1038/s41467-024-47831-2.
Natural materials typically exhibit irregular and non-periodic architectures, endowing them with compelling functionalities such as body protection, camouflage, and mechanical stress modulation. Among these functionalities, mechanical stress modulation is crucial for homeostasis regulation and tissue remodeling. Here, we uncover the relationship between stress modulation functionality and the irregularity of bio-inspired architected materials by a generative computational framework. This framework optimizes the spatial distribution of a limited set of basic building blocks and uses these blocks to assemble irregular materials with heterogeneous, disordered microstructures. Despite being irregular and non-periodic, the assembled materials display spatially varying properties that precisely modulate stress distribution towards target values in various control regions and load cases, echoing the robust stress modulation capability of natural materials. The performance of the generated irregular architected materials is experimentally validated with 3D printed physical samples - a good agreement with target stress distribution is observed. Owing to its capability to redirect loads while keeping a proper amount of stress to stimulate bone repair, we demonstrate the potential application of the stress-programmable architected materials as support in orthopedic femur restoration.
天然材料通常具有不规则和非周期性的结构，赋予它们令人信服的功能，如身体保护、伪装和机械应力调节。在这些功能中，机械应力调节对于体内平衡调节和组织重塑至关重要。在这里，我们通过一个生成式计算框架揭示了生物启发结构材料的应力调节功能与不规则性之间的关系。该框架优化了有限数量基本构建块的空间分布，并使用这些块组装具有异质、无序微观结构的不规则材料。尽管这些材料是不规则和非周期性的，但组装后的材料具有空间变化的特性，可以精确地将应力分布调节到各个控制区域和载荷情况下的目标值，这与天然材料强大的应力调节能力相呼应。通过 3D 打印物理样本对生成的不规则结构材料进行了实验验证——观察到与目标应力分布的良好一致性。由于其能够在保持适当的应力以刺激骨修复的同时重新分配负载的能力，我们展示了作为骨科股骨修复支撑物的可编程应力结构材料的潜在应用。
