Scholarlink

<p>Developing flexible electromagnetic interference (EMI) shielding materials with both high shielding effectiveness (SE) and low secondary reflection has become a key challenge in alleviating the contradiction between electronic integration and electromagnetic compatibility. In this study, we constructed a subwavelength periodic array (SPA) of square pyramid structures in interlayer region of an “absorption-shielding” double-layer multi-walled carbon nanotube/waterborne polyurethane (MWCNT/WPU) EMI shielding composite film. The SPA of square pyramid structures is positioned between the upper layer of dielectric loss and the lower layer of high conductivity, inducing intra-element localized destructive interference (IEL-DI) and interelement coupling-induced destructive interference (IECI-DI). This structure further promotes the “absorption-reflection-reabsorption” shielding mechanism, endowing the composite film with excellent EMI shielding performance and high absorption characteristics.&#xa0;When the array distance is 0.6&#xa0;mm and the total thickness is 3&#xa0;mm, the double-layer composite achieves an EMI SE of 29.5&#xa0;dB and an absorptivity (A) of 0.90 at 18&#xa0;GHz, which is 0.14 higher than that of the planar double-layer structure. Through electromagnetic simulation, the power loss density, power flow, electric field, and magnetic field distributions within the material were systematically analyzed, revealing the shielding mechanism of element localized field enhancement effects on electromagnetic waves (EMWs) from a multi-physics perspective. This study reveals the constitutive relationship between the interlayer SPA of square pyramid structures and electromagnetic properties and provides a new idea for the design of low-reflection EMI shielding composites.</p> Graphical abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Subwavelength periodic arrays and synergistic double-layer structural design of MWCNT/WPU composite for high-absorption EMI shielding

  • 期刊论文

  • 发表日期：

    2026年4月6日

查看全文
  • Tong Liu,
  • Qi Ni,
  • Jiaxiao Sun,
  • Kezhi Qi,
  • Lu Xu,
  • Qingqing Ni

摘要

Developing flexible electromagnetic interference (EMI) shielding materials with both high shielding effectiveness (SE) and low secondary reflection has become a key challenge in alleviating the contradiction between electronic integration and electromagnetic compatibility. In this study, we constructed a subwavelength periodic array (SPA) of square pyramid structures in interlayer region of an “absorption-shielding” double-layer multi-walled carbon nanotube/waterborne polyurethane (MWCNT/WPU) EMI shielding composite film. The SPA of square pyramid structures is positioned between the upper layer of dielectric loss and the lower layer of high conductivity, inducing intra-element localized destructive interference (IEL-DI) and interelement coupling-induced destructive interference (IECI-DI). This structure further promotes the “absorption-reflection-reabsorption” shielding mechanism, endowing the composite film with excellent EMI shielding performance and high absorption characteristics. When the array distance is 0.6 mm and the total thickness is 3 mm, the double-layer composite achieves an EMI SE of 29.5 dB and an absorptivity (A) of 0.90 at 18 GHz, which is 0.14 higher than that of the planar double-layer structure. Through electromagnetic simulation, the power loss density, power flow, electric field, and magnetic field distributions within the material were systematically analyzed, revealing the shielding mechanism of element localized field enhancement effects on electromagnetic waves (EMWs) from a multi-physics perspective. This study reveals the constitutive relationship between the interlayer SPA of square pyramid structures and electromagnetic properties and provides a new idea for the design of low-reflection EMI shielding composites.

Graphical abstract