Zhou Jun, Gu Yudong, Fei Peng, Mai Wenjie, Gao Yifan, Yang Rusen, Bao Gang, Wang Zhong Lin
School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
Nano Lett. 2008 Sep;8(9):3035-40. doi: 10.1021/nl802367t. Epub 2008 Aug 16.
Strain sensors based on individual ZnO piezoelectric fine-wires (PFWs; nanowires, microwires) have been fabricated by a simple, reliable, and cost-effective technique. The electromechanical sensor device consists of a single electrically connected PFW that is placed on the outer surface of a flexible polystyrene (PS) substrate and bonded at its two ends. The entire device is fully packaged by a polydimethylsiloxane (PDMS) thin layer. The PFW has Schottky contacts at its two ends but with distinctly different barrier heights. The I- V characteristic is highly sensitive to strain mainly due to the change in Schottky barrier height (SBH), which scales linear with strain. The change in SBH is suggested owing to the strain induced band structure change and piezoelectric effect. The experimental data can be well-described by the thermionic emission-diffusion model. A gauge factor of as high as 1250 has been demonstrated, which is 25% higher than the best gauge factor demonstrated for carbon nanotubes. The strain sensor developed here has applications in strain and stress measurements in cell biology, biomedical sciences, MEMS devices, structure monitoring, and more.
基于单个氧化锌压电细线（PFW；纳米线、微线）的应变传感器已通过一种简单、可靠且经济高效的技术制造出来。机电传感器装置由一根电连接的单个PFW组成，该PFW放置在柔性聚苯乙烯（PS）基板的外表面并在其两端粘结。整个装置由聚二甲基硅氧烷（PDMS）薄层完全封装。PFW在其两端具有肖特基接触，但势垒高度明显不同。I-V特性对应变高度敏感，主要是由于肖特基势垒高度（SBH）的变化，该变化与应变成线性比例关系。SBH的变化被认为是由于应变诱导的能带结构变化和压电效应。实验数据可以通过热电子发射-扩散模型得到很好的描述。已证明高达1250的应变片系数，比碳纳米管所展示的最佳应变片系数高25%。这里开发的应变传感器可应用于细胞生物学、生物医学科学、微机电系统（MEMS）器件、结构监测等领域的应变和应力测量。
