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.

天然材料通常表现出不规则和非周期性的结构，赋予它们引人注目的功能，例如身体保护、伪装和机械应力调节。在这些功能中，机械应力调节对于稳态调节和组织重塑至关重要。在这里，我们通过生成计算框架揭示了应力调节功能与仿生建筑材料的不规则性之间的关系。该框架优化了一组有限的基本构建块的空间分布，并使用这些块来组装具有异质、无序微观结构的不规则材料。尽管是不规则和非周期性的，但组装的材料显示出空间变化的特性，可以精确地将应力分布调节到各种控制区域和负载情况下的目标值，呼应了天然材料强大的应力调节能力。生成的不规则建筑材料的性能通过 3D 打印物理样本进行实验验证 - 观察到与目标应力分布非常一致。由于其能够重定向负载，同时保持适当的应力以刺激骨骼修复，我们展示了应力可编程建筑材料作为骨科股骨修复支撑的潜在应用。