Humidity Sensitivity of Multi-Walled Carbon Nanotube Networks Deposited by Dielectrophoresis
1
The state Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments, Tsinghua University, Beijing 100084, P.R. China
2
Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota, MN 55455, USA
*
Author to whom correspondence should be addressed.
Sensors 2009, 9(3), 1714-1721; https://doi.org/10.3390/s90301714
Received: 22 January 2009
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Revised: 10 March 2009
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Accepted: 10 March 2009
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Published: 11 March 2009
(This article belongs to the Special Issue Selected Papers from the 1st International Conference of the Chinese Society of Micro/Nano Technology)
This paper presents an investigation on the humidity sensitivity of deposited multi-walled carbon nanotube (MWCNT) networks using ac dielectrophoresis (DEP) between interdigitated electrodes (IDEs). MWCNTs dispersed in ethanol were trapped and enriched between IDEs on a Si/SiO2 substrate under a positive DEP force. After the DEP process, the ethanol was evaporated and the MWCNT network on a substrate with IDEs was put into a furnace for repeated thermal annealing. It was found that the resistance stability of the network was effectively improved through thermal annealing. The humidity sensitivity was obtained by measuring the resistance of the MWCNT network with different relative humidity at room temperature. The experimental results show the resistance increases linearly with increasing the relative humidity from 25% to 95% RH with a sensitivity of 0.5%/%RH. The MWCNT networks have a reversible humidity sensing capacity with response time and recovery time of about 3 s and 25 s, respectively. The resistance is dependent on temperature with a negative coefficient of about -0.33%/K in a temperature range from 293 K to 393 K.
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MDPI and ACS Style
Liu, L.; Ye, X.; Wu, K.; Han, R.; Zhou, Z.; Cui, T. Humidity Sensitivity of Multi-Walled Carbon Nanotube Networks Deposited by Dielectrophoresis. Sensors 2009, 9, 1714-1721. https://doi.org/10.3390/s90301714
AMA Style
Liu L, Ye X, Wu K, Han R, Zhou Z, Cui T. Humidity Sensitivity of Multi-Walled Carbon Nanotube Networks Deposited by Dielectrophoresis. Sensors. 2009; 9(3):1714-1721. https://doi.org/10.3390/s90301714
Chicago/Turabian StyleLiu, Litao, Xiongying Ye, Kang Wu, Rui Han, Zhaoying Zhou, and Tianhong Cui. 2009. "Humidity Sensitivity of Multi-Walled Carbon Nanotube Networks Deposited by Dielectrophoresis" Sensors 9, no. 3: 1714-1721. https://doi.org/10.3390/s90301714
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