Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA.
ACS Nano. 2011 Feb 22;5(2):1556-63. doi: 10.1021/nn103183d. Epub 2011 Feb 2.
A simple yet effective method for assembly of highly aligned nanowires (NWs) on stretchable substrates is reported. In this method, NWs were first transferred to a strained stretchable substrate. After the strain was released, the NWs aligned in the transverse direction and the area coverage of the NWs on the substrate increased. This method can be applied to any NWs deposited on a stretchable film and can be repeated multiple times to increase the alignment and density of the NWs. For silver (Ag) and silicon (Si) NWs on poly(dimethylsiloxane) (PDMS) substrates, the probability of NW alignment increased from 29% to 90% for Ag NWs, and from 25% to 88% for Si NWs after two assembly steps; the density increased by 60% and 75% for the Ag and Si NWs, respectively. The large-strain elasticity of the substrate and the static friction between the NWs and the substrate play key roles in this assembly method. We find that a model that takes into account the volume incompressibility of PDMS reliably predicts the degree of NW alignment and NW density. The utility of this assembly method was demonstrated by fabricating a strain sensor array composed of aligned Si NWs on a PDMS substrate, with a device yield of 95%.
一种简单而有效的方法，用于在可拉伸基底上组装高度对齐的纳米线（NWs）。在该方法中，首先将 NWs 转移到应变的可拉伸基底上。释放应变后，NWs 在横向方向上对齐，并且 NW 在基底上的覆盖面积增加。该方法可以应用于沉积在可拉伸膜上的任何 NW，并且可以重复多次以增加 NW 的对齐度和密度。对于聚二甲基硅氧烷（PDMS）基底上的银（Ag）和硅（Si）NW，在两个组装步骤之后，Ag NW 的 NW 对齐概率从 29％增加到 90％，Si NW 的 NW 对齐概率从 25％增加到 88％；Ag 和 Si NW 的密度分别增加了 60％和 75％。基底的大应变弹性和 NW 与基底之间的静摩擦力在这种组装方法中起关键作用。我们发现，考虑到 PDMS 的体积不可压缩性的模型可以可靠地预测 NW 的对齐度和 NW 的密度。通过在 PDMS 基底上制造由对齐的 Si NW 组成的应变传感器阵列，展示了这种组装方法的实用性，器件产率为 95％。
