Most materials exhibit positive Poisson's ratio (PR) values, but special structures can also present negative and, even rarer, zero (or close to zero) PR. Null PR structures have received much attention due to their unusual properties and potential applications in different fields, such as aeronautics and bioengineering. Herein, a new and simple near‐zero PR 2D topological model is presented based on a structural block composed of two smooth and rigid bars connected by a soft membrane or spring. It is not based on reentrant or honeycomb‐like configurations, which have been the basis of many null or quasinull PR models. The topological model is 3D printed, and the experimentally obtained PR is −0.003 ± 0.001 which is one of the closest to zero values ever reported. The possibility to extend this model to 3D systems with compression in any direction is discussed. The advantages and disadvantages of these models are also addressed.

中文翻译：

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新的零泊松比结构

大多数材料的泊松比（PR）值为正，但特殊结构也可能呈现负（甚至更罕见）为零（或接近零）的PR。空PR结构由于其不寻常的特性以及在航空和生物工程等不同领域中的潜在应用而备受关注。在此，基于一个结构块，提出了一种新的，简单的接近零的PR 2D拓扑模型，该结构块由通过软膜或弹簧连接的两个光滑且刚性的杆组成。它不是基于可重入或类似蜂窝的配置，而后者已成为许多null或准ull PR模型的基础。拓扑模型是3D打印的，实验获得的PR为-0.003±0.001，这是有史以来最接近于零的值之一。讨论了将该模型扩展到在任何方向都具有压缩功能的3D系统的可能性。这些模型的优缺点也得到解决。