Mechanical metamaterials represent a class of deformable systems, which exhibit macroscopic deformations, mechanical, and/or thermal properties. These emerge due to the structure of their subunits rather than their materials composition and typically exhibit anomalous (normally negative) macroscopic structural, mechanical, or thermal property/properties caused by a change in shape/size of the system. Herein, a class of honeycombs is discussed, which push to the extreme the classical definition of “mechanical metamaterials,” exhibiting temperature‐tunable Poisson's ratio properties. More specifically, centrosymmetric honeycombs with T‐shaped joints constructed from different materials are shown to exhibit temperature‐dependent Poisson's ratio values, which can be either positive or negative (auxetic) depending on the external stimulus the system is subjected to. The sign and magnitudes of the Poisson's ratio values are explained in terms of particular geometries that these composite honeycomb systems attain at different temperature conditions. In particular, auxeticity is attributed to the transformation of the T‐shaped units to re‐entrant units. Practical aspects on how these properties may be achieved are discussed, including the possibility that the changes in shape, and hence Poisson's ratios, are induced via different extents of dryness on opposite surfaces of ligaments made from absorbent materials.

中文翻译：

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具有可调泊松比的智能蜂窝“机械超材料”

机械超材料代表了一类可变形的系统，它们表现出宏观的变形，机械和/或热性能。这些是由于其亚基的结构而不是其材料组成而出现的，并且通常表现出由系统形状/尺寸的变化引起的异常（通常为负）的宏观结构，机械或热学性质/性质。本文讨论了一类蜂窝，将“机械超材料”的经典定义推到了极致，表现出可调节温度的泊松比特性。更具体地说，具有由不同材料制成的T形接缝的中心对称蜂窝体显示出取决于温度的泊松比值，根据系统所受到的外部刺激，它可以是正的或负的（促发性的）。泊松比值的符号和大小是根据这些复合蜂窝系统在不同温度条件下获得的特定几何形状来解释的。特别是，膨胀性归因于T形单位向折返单位的转化。讨论了如何实现这些特性的实际方面，包括引起形状变化和泊松比变化的可能性 膨胀性归因于T形单位向折返单位的转化。讨论了如何实现这些特性的实际方面，包括引起形状变化和泊松比变化的可能性 膨胀性归因于T形单位向折返单位的转化。讨论了如何实现这些特性的实际方面，包括引起形状变化和泊松比变化的可能性在由吸收性材料制成的韧带的相对表面上通过不同程度的干燥。