Fan Xuanqing, Pan Zijian, Zhu Yunfan, Li Min, Ma Yunpeng, Li Yuhang
Tianmushan Laboratory, Yuhang District, Hangzhou 311115, China.
Hangzhou International Innovation Institute, Beihang University, Hangzhou 311115, China.
Micromachines (Basel). 2024 Dec 13;15(12):1493. doi: 10.3390/mi15121493.
The continuous expansion of wireless communication application scenarios demands the active tuning of electromagnetic (EM) metamaterials, which is essential for their flexible adaptation to complex EM environments. However, EM reconfigurable systems based on intricate designs and smart materials often exhibit limited flexibility and incur high manufacturing costs. Inspired by mechanical metastructures capable of switching between multistable configurations under repeated deformation, we propose a planar kirigami frequency selective surface (FSS) that enables mechanical control of its resonant frequency. This FSS is composed of periodically arranged copper square-ring resonators embedded in a kirigami-structured ecoflex substrate. Through simple tensile deformation, the shapes and positions of the square-ring resonators on the kirigami substrate are altered, resulting in changes to the coupling between capacitance and inductance, thereby achieving active tuning. Combining EM finite element simulations and transmittance measurements, we demonstrate that biaxial mechanical stretching allows for continuous adjustment of the FSS resonant frequency and -10 dB bandwidth. Additionally, the FSS exhibits excellent polarization and incident angle stability. Structural parameterization of the square-ring kirigami FSS was conducted to elucidate the deformation-electromagnetic coupling mechanism underlying the active tuning. These insights provide a foundation for guiding the application of square-ring kirigami FSS in various practical engineering domains.
无线通信应用场景的不断扩展要求对电磁超材料进行主动调谐，这对于它们灵活适应复杂电磁环境至关重要。然而，基于复杂设计和智能材料的电磁可重构系统往往灵活性有限且制造成本高昂。受能够在反复变形下在多稳态配置之间切换的机械超结构的启发，我们提出了一种平面折纸频率选择表面（FSS），它能够对其谐振频率进行机械控制。这种FSS由周期性排列的铜方环谐振器组成，这些谐振器嵌入在折纸结构的生态柔性基板中。通过简单的拉伸变形，折纸基板上的方环谐振器的形状和位置发生改变，导致电容和电感之间的耦合发生变化，从而实现主动调谐。结合电磁有限元模拟和透射率测量，我们证明双轴机械拉伸能够连续调节FSS谐振频率和-10 dB带宽。此外，该FSS表现出优异的极化和入射角稳定性。对方环折纸FSS进行了结构参数化，以阐明主动调谐背后的变形-电磁耦合机制。这些见解为指导方环折纸FSS在各种实际工程领域的应用奠定了基础。
