Shi Qiwu, Tian Ke, Zhu Hongfu, Li Zi-Run, Zhu Li-Guo, Deng Hua, Huang Wanxia, Fu Qiang
College of Materials Science and Engineering , Sichuan University , Chengdu 610065 , Sichuan , China.
Department of Materials Science and Engineering , University of California , Berkeley , California 94720 , United States.
ACS Appl Mater Interfaces. 2020 Feb 26;12(8):9790-9796. doi: 10.1021/acsami.9b21890. Epub 2020 Feb 17.
Dynamic tuning of terahertz (THz) wave has a great potential application as smart THz devices, such as switches, modulators, sensors, and so on. However, the realization of flexible THz modulation with high efficiency is rarely observed, which is nearly absent from the booming development and demands on flexible electronics. Here, we report a flexible THz modulation based on conductive polymer composites composed of thermoplastic polyurethane (TPU) and conductive particles (Ni). By designing the additive content of Ni particles, such a flexible layer exhibits resistivity change of 6-7 orders under tensile strain due to the formation of an electron-transport channel provided by the in situ evolution of the Ni network. It could be used to dynamically control the THz transmission with a giant modulation depth of around 96%, at a high strain operation (up to around 58.5%). Moreover, these characteristics are demonstrated to be available for highly tension sensitive THz spectroscopy and imaging. This work opens up a connection between flexible polymer-based composites and THz dynamic devices. It proposes an unprecedented flexible THz modulation with giant tuning efficiency and provides a scheme for contactless and passive tension sensors.
太赫兹（THz）波的动态调谐作为智能太赫兹器件，如开关、调制器、传感器等，具有巨大的潜在应用价值。然而，很少观察到高效的柔性太赫兹调制的实现，在蓬勃发展的柔性电子学及其需求中，这几乎是缺失的。在此，我们报道了一种基于由热塑性聚氨酯（TPU）和导电颗粒（Ni）组成的导电聚合物复合材料的柔性太赫兹调制。通过设计Ni颗粒的添加量，这样一个柔性层在拉伸应变下由于Ni网络原位演化提供的电子传输通道的形成而呈现出6 - 7个数量级的电阻率变化。它可用于在高应变操作（高达约58.5%）下以约96%的巨大调制深度动态控制太赫兹传输。此外，这些特性被证明可用于对张力高度敏感的太赫兹光谱学和成像。这项工作开辟了基于柔性聚合物的复合材料与太赫兹动态器件之间的联系。它提出了一种前所未有的具有巨大调谐效率的柔性太赫兹调制，并为非接触式和无源张力传感器提供了一种方案。
