video: A video of a sample during measurement. The left part exhibits a bottom view onto the plate in between the left- and right-handed part of the samples. The right part is a side view onto the same sample. Upon pushing onto the sample, one can see a rotation around the pushing axis on the left and a compression along the pushing axis on the right-hand. For illustration, the in plane displacement vectors are depicted in blue and red. This material relates to a paper that appeared in the 24 November 2017 issue of Science, published by AAAS. The paper, by T. Frenzel at Karlsruhe Institute of Technology in Karlsruhe, Germany, and colleagues was titled, "Three-dimensional mechanical metamaterials with a twist." view more
Credit: T. Frenzel <i>et al., Science</i> (2017)
一项新的研究介绍了一种超材料设计，该材料能因应直线纯粹的推动而变成向右或向左的扭转。Corentin Coulais在相关的《视角》中说，这一手性反应有悖于普通固体力学的观点，因为在普通固体力学中根本不存在这一材料属性；该《视角》讨论了这项工作的历史和其对未来的意义。在超材料中完成这一吊诡的力学行为令这一领域向被改造成以独特方式变形人造材料的广泛、合理的设计又迈进了一步。人造材料的研发为在其它情况下无法实现的材料属性开辟了门径；略举几例，这些属性有：极端的强度、重复使用性、减震能力、可编程性及复原能力；这些属性在太空使命、光学器件和射流技术中都有用途。操纵超材料的挑战之一是实现一种出乎经典标准预期之外的力学反应；例如，让一种固体在被压缩时不缩反涨。在这里，通过分层计算机模拟、3-D激光微缩印刷（可进行大规模制造）和复杂的微机械实验技术，Tobias Frenzel和同事能对受压时会扭曲的3-D超材料进行优化、制造和表征。在光的受到直线力时可进行手性样运动属性的启发下，Frenzel等人有效地在固体中将一种直线运动（推力）转变成旋转力（扭曲）。Coulais补充说，正如类似的先前在骨骼中报告的尺寸效应，这些超材料也可被用于假肢，并能为生物性固体如何发挥功能提供宝贵的线索。
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Journal
Science