Controlled fabrication of carbon nanotube NO2 gas sensor using dielectrophoretic impedance measurement
Controlled fabrication of carbon nanotube NO2 gas sensor using dielectrophoretic impedance measurement
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DOI：
10.1016/j.snb.2004.09.048
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发表时间：
2005-07
影响因子：
8.4
通讯作者：
J. Suehiro;Guangbin Zhou;Hiroshi Imakiire;W. Ding;M. Hara
中科院分区：
文献类型：
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作者：
J. Suehiro;Guangbin Zhou;Hiroshi Imakiire;W. Ding;M. Hara
作者先前已经展示了一种使用介电泳的碳纳米管（CNT）气体传感器的电动制造方法。该技术的一个优点是，可以通过监测传感器的电阻抗（介电泳阻抗测量，DEPIM）在真实的时间基础上量化捕获的纳米管的量。在本研究中，我们将DEPIM技术扩展到碳纳米管气体传感器的可控组装。这实现了具有相同电特性（例如初始电导）的CNT气体传感器的生产。研究了不同初始电导值下传感器对ppm级二氧化氮气体的响应。结果发现，相对电导变化的CNT气体传感器NO2暴露后增加几乎成比例的初始电导为一个恒定的NO2浓度。这使得能够通过归一化来定义CNT传感器的固有灵敏度。发现单壁CNT气体传感器比多壁CNT传感器具有更高的归一化灵敏度。
The authors have previously demonstrated an electrokinetic fabrication method of a carbon nanotube (CNT) gas sensor using dielectrophoresis. One advantage of the technique was that one could quantify the amount of trapped nanotubes on a real time basis by monitoring electrical impedance of the sensor (dielectrophoretic impedance measurement, DEPIM). In the present study, we extended the DEPIM technique to controllable assembly of the carbon nanotube gas sensor. This realized a production of CNT gas sensors with identical electrical properties such as initial conductance. The gas sensor response to ppm-level nitrogen dioxide (NO2) gas was investigated with various values of the initial conductance. It was found that relative conductance change of the CNT gas sensor after NO2exposure increased almost proportionally with the initial conductance for a constant NO2concentration. This enabled to define intrinsic sensitivity of CNT sensors by normalization. It was found that a single-wall CNT gas sensor had higher normalized sensitivity than a multi-wall CNT sensor.