ACS Appl Mater Interfaces. 2019 Aug 7;11(31):28033-28042. doi: 10.1021/acsami.9b07671. Epub 2019 Jul 30.
The rapid progress in electronic applications for movable devices requires the conductive matrix to be not only flexible but also stretchable. A simple microstrip patch antenna was fabricated based on silver ink polysiloxane composite with a stretchable polysiloxane substrate at a resonance frequency of 2.50 GHz. It is designed at a postpercolation threshold of 35, 45, and 60 vol % conductive filler loading so as to allow a consistent conductivity at an ample range of cyclic stretching. With the presence of coupling agent and additives, the patch antenna displayed an extremely good adhesion between the ink and the substrate, which prevents any local rupture during stretching. Variable range hopping model verified that conductivity occurs through hopping and tunneling mechanisms, giving transient optimum conductivity in the range of 10-70 S/cm at 10-20% strain amplitude range. The fabricated prototype of microstrip patch antenna displayed a decreasing resonant frequency with strain. Of note, the radiation loss and the bandwidth values are proportionally related to the conductivities during stretching. These results verified the proposed mechanisms of construction and destruction of conductivity occurring during the percolation threshold process. The fabricated antenna proved the feasibility for use as a stretchable device at an ultrahigh-frequency band.
电子移动设备应用的快速发展要求导电矩阵不仅具有柔韧性，而且还具有可拉伸性。本文基于银油墨聚硅氧烷复合材料和具有可拉伸聚硅氧烷基底，制作了一个简单的微带贴片天线，其共振频率为 2.50GHz。该天线设计的导电填料填充率在 35%、45%和 60%的逾渗阈值，以在充足的循环拉伸范围内保持一致的导电性。由于偶联剂和添加剂的存在，贴片天线显示出油墨与基底之间极好的附着力，防止在拉伸过程中出现局部破裂。变程跳跃模型验证了电导率通过跳跃和隧道机制发生，在 10-20%应变幅度范围内，电导率在 10-70S/cm 的范围内出现瞬态最佳电导率。微带贴片天线的制作原型显示出随着应变的增加共振频率逐渐降低。值得注意的是，辐射损耗和带宽值与拉伸过程中的电导率成比例相关。这些结果验证了在逾渗阈值过程中发生的电导率的构建和破坏的提出机制。所制作的天线证明了在超高频带作为可拉伸器件使用的可行性。
