无需外力，神奇超材料可自行收放

Core Insights - Researchers at Leiden University have developed a remarkable metamaterial that can autonomously contract and expand without external force, resembling a "breathing" mechanism, opening new avenues for smart reconfigurable materials and micro-robotics [1][2] Group 1: Metamaterial Characteristics - The metamaterial is the first of its kind to exhibit such dynamic behavior at the microscopic level, challenging traditional perceptions of matter where movement is typically attributed to the material itself [1] - The structure is composed of tiny silica spheres assembled into meticulously designed building blocks, with each unit being one-tenth the width of a human hair, arranged in a rhombic pattern [1] - The precise control of particle connections ensures mechanical stability while allowing for free rotation, culminating in a complex architecture known as "cage lattice" [1] Group 2: Mechanism of Movement - Under optical microscopy, these microstructures display the ability to spontaneously contract and expand, driven by thermal energy that facilitates elegant folding and unfolding [2] - The movement is coordinated; when one set of quadrilaterals rotates clockwise, adjacent sets respond by rotating counterclockwise, creating a harmonious rhythm of contraction and expansion [2] - The introduction of magnetic particles allows for control over this microscopic "dance," with magnetic fields enabling precise regulation of the structure's contraction and expansion [2] Group 3: Future Applications - A theoretical framework has been established to describe the interaction between thermal motion and the metamaterial, with experimental results aligning closely with theoretical predictions [3] - This self-breathing metamaterial is expected to lay the groundwork for applications in artificial muscles, adaptive optical devices, and micro-robots that can autonomously respond to environmental changes [3]