Modular chiral origami metamaterials
['Zhao, Tuo', 'Chen, Minjie', 'Paulino, Glaucio H.']; Nature; 2025-04-01
『Abstract』Metamaterials with multimodal deformation mechanisms resemble machines , especially when endowed with autonomous functionality. A representative architected assembly, with tunable chirality, converts linear motion into rotation . These chiral metamaterials with a machine-like dual modality have potential use in areas such as wave manipulation , optical activity related to circular polarization and chiral active fluids . However, the dual motions are essentially coupled and cannot be independently controlled. Moreover, they are restricted to small deformation, that is, strain ≤2%, which limits their applications. Here we establish modular chiral metamaterials, consisting of auxetic planar tessellations and origami-inspired columnar arrays, with decoupled actuation. Under single-degree-of-freedom actuation, the assembly twists between 0° and 90°, contracts in-plane up to 25% and shrinks out-of-plane more than 50%. Using experiments and simulations, we show that the deformation of the assembly involves in-plane twist and contraction dominated by the rotating-square tessellations and out-of-plane shrinkage dominated by the tubular Kresling origami arrays. Moreover, we demonstrate two distinct actuation conditions: twist with free translation and linear displacement with free rotation. Our metamaterial is built on a highly modular assembly, which enables reprogrammable instability, local chirality control, tunable loading capacity and scalability. Our concept provides routes towards multimodal, multistable and reprogrammable machines, with applications in robotic transformers, thermoregulation, mechanical memories in hysteresis loops, non-commutative state transition and plug-and-play functional assemblies for energy absorption and information encryption.
『摘要』
具有多模态变形机制的超材料类似于机器,尤其是在被赋予自主功能时更是如此。一种具有可调手性的代表性结构组件能将直线运动转化为旋转运动。这些具有机器般双模态特性的手性超材料在波操控、与圆极化相关的光学活性和手性活性流体等领域具有潜在用途。然而,这两种运动本质上是耦合的,无法独立控制。此外,它们仅限于小变形,即应变≤2%,这限制了其应用范围。在此,我们构建了模块化手性超材料,由负泊松比平面镶嵌结构和折纸启发的柱状阵列组成,二者具有解耦驱动功能。在单自由度驱动下,该组件能在0°至90°之间扭转,平面内收缩可达25%,平面外收缩超过50%。通过实验和模拟,我们发现该组件的变形包括由旋转方形镶嵌结构主导的平面内扭转和收缩,以及由管状Kresling折纸阵列主导的平面外收缩。此外,我们还展示了两种不同的驱动条件:自由平移时的扭转和自由旋转时的线性位移。我们的超材料建立在高度模块化的组件基础上,可实现可重新编程的不稳定性、局部手性控制、可调负载能力和可扩展性。我们的概念为开发多模态、多稳态和可重新编程的机器提供了途径,可应用于变形机器人、温度调节、滞回环中的机械记忆、非交换状态转换以及用于能量吸收和信息加密的即插即用功能组件等领域。
『总结』
本研究开发了模块化手性超材料,通过解耦驱动实现了多种变形模式,并展示了其在多领域应用的潜力,如变形机器人、温控和加密组件等。
『闲叙』