Abstract:
Nowadays, the increasing electromagnetic waves generated by wearable devices are becoming an emerging issue for human health, so stretchable electromagnetic interference (EMI) shielding materials are highly demanded. Elephant trunks are capable of grabbing fragile vegetation and tearing trees thanks not only to their muscles but also to their folded skins. Inspired by the wrinkled skin of the elephant trunks, herein, we propose a winkled conductive film based on single-walled carbon nanotubes (SWCNTs) for multifunctional EMI applications. The conductive film has a sandwich structure, which was prepared by coating SWCNTs on both sides of the stretched elastic latex cylindrical substrate. The shrinking-induced winkled conductive network could withstand up to 200% tensile strain. Typically, when the stretching direction is parallel to the polarization direction of the electric field, the total EMI shielding effectiveness could surprisingly increase from 38.4 to 52.7 dB at 200% tensile strain. It is mainly contributed by the increased connection of the SWCNTs. In addition, the film also has good Joule heating performance at several voltages, capable of releasing pains in injured joints. This unique property makes it possible for strain-adjustable multifunctional EMI shielding and wearable thermotherapy applications.
摘要:
如今,可穿戴设备产生的不断增加的电磁波正在成为人类健康的新兴问题,因此,对可拉伸的电磁干扰(EMI)屏蔽材料的要求很高。大象树干能够抓住脆弱的植被和撕裂树木,这不仅归功于它们的肌肉,也归功于它们折叠的皮肤。灵感来自大象树干的皱纹皮肤,在这里,我们提出了一种基于单壁碳纳米管(SWCNT)的闪烁导电膜,用于多功能EMI应用。导电膜具有夹层结构,通过在拉伸的弹性乳胶圆柱形基材的两侧涂覆SWCNTs来制备。收缩引起的扭曲导电网络可以承受高达200%的拉伸应变。通常,当拉伸方向平行于电场的极化方向时,在200%的拉伸应变下,总的EMI屏蔽效率可以令人惊讶地从38.4增加到52.7dB。这主要是由SWCNT的连接增加造成的。此外,该薄膜在多个电压下也具有良好的焦耳加热性能,能够释放受伤关节的疼痛。这种独特的特性使得应变可调的多功能EMI屏蔽和可穿戴的热疗应用成为可能。