Liu Chang, Cai Jun, Dang Pengzhan, Li Xinghao, Zhang Deyuan
School of Mechanical Engineering and Automation, Beihang University, Beijing, China 100191.
Beijing Machine and Equipment Institute, Beijing, China 100854.
ACS Appl Mater Interfaces. 2020 Mar 11;12(10):12101-12108. doi: 10.1021/acsami.0c00034. Epub 2020 Feb 27.
With the rapid development of flexible electronic facilities, conventional electromagnetic interference (EMI) shielding materials cannot meet the increasing demands of flexible deformation and stable EMI shielding performance. To solve this problem, in this research, stretchable conductive microcoils made from biotemplates were confined in an orderly manner in the microgrooves of a honeycomb mold and then were sintered to form stable and conductive honeycomb networks, followed by immersion in silicone rubber to fabricate deformable EMI shielding materials. The morphologies and structures of the samples were analyzed in detail, and the conductive performance, mechanical deformation capacity, and electromagnetic (EM) characteristics of the as-prepared materials under different deformation situations were studied. The results showed that the honeycomb-structured EMI shielding materials could maintain a stable electrical conductivity and EMI shielding property under repeated stretching from 0 to 50%. Notably, the EMI shielding effectiveness of samples with 0.4 mm thicknesses increase from 23.3-26.2 to 34.3-35.7 dB in the X-band (7.8-12.4 GHz) when the tested sample is stretched to 50%, which is higher than most values of stretchable EMI shielding materials ever reported. This electrical filler particle and body structure simultaneously deforming strategy will open new routes toward the development of deformable EMI shielding materials and broaden the EM range in applications such as flexible EM protection skins, wearable EM devices, and flexible displays.
随着柔性电子设备的快速发展，传统的电磁干扰（EMI）屏蔽材料无法满足日益增长的柔性变形和稳定EMI屏蔽性能的需求。为了解决这一问题，在本研究中，由生物模板制成的可拉伸导电微线圈被有序地限制在蜂窝模具的微槽中，然后进行烧结以形成稳定的导电蜂窝网络，随后浸入硅橡胶中以制备可变形的EMI屏蔽材料。详细分析了样品的形态和结构，并研究了所制备材料在不同变形情况下的导电性能、机械变形能力和电磁（EM）特性。结果表明，蜂窝结构的EMI屏蔽材料在从0到50%的反复拉伸下能够保持稳定的电导率和EMI屏蔽性能。值得注意的是，当测试样品拉伸到50%时，厚度为0.4mm的样品在X波段（7.8-12.4GHz）的EMI屏蔽效能从23.3-26.2dB提高到34.3-35.7dB，高于以往报道的大多数可拉伸EMI屏蔽材料的值。这种电填充颗粒和主体结构同时变形的策略将为可变形EMI屏蔽材料的开发开辟新途径，并拓宽在柔性电磁防护皮肤、可穿戴电磁设备和柔性显示器等应用中的电磁范围。
