Fabrication of Carbon Nanotube Gas Sensor Using Step-Wise Dielectrophoretic Deposition Onto Interdigitated Pyrolyzed Carbon Electrodes

2021 ◽  
Author(s):  
Taajza Singleton ◽  
Lawrence Kulinsky
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Gas Sensor ◽  
Carbon Electrodes ◽  
Proof Of Concept ◽  
Nitrogen Gas ◽  
Electrical Field ◽  
The Creation ◽  
Field Lines

Abstract Carbon nanotubes (CNTs) have been implemented in the creation of many micro- and nano-devices due to their physical properties such as large volume-to-surface area as well as their high thermal and electrical conductivity. The paper describes a novel dielectrophoretic step-wise deposition of CNTs (that alternates deposition of CNTs and drying steps) between the interdigitated fingers of carbon electrodes. Multiphysics simulation illustrates the physics of CNT alignment along the electrical field lines that forms a basis for dielectrophoretic deposition of CNTs. This fabrication methodology resulted in the creation of a proof-of-concept nitrogen gas sensor.

Carbon Nanotube Gas Sensor Fabricated on Anodic Aluminum Oxide

2007 ◽  
Vol 124-126 ◽  
pp. 1309-1312
Author(s):  
Nguyen Duc Hoa ◽  
Nguyen Van Quy ◽  
Gyu Seok Choi ◽  
You Suk Cho ◽  
Se Young Jeong ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Gas Sensor ◽  
Chemical Vapor ◽  
Fast Response ◽  
Device Fabrication ◽  
Alumina Oxide ◽  
Response And Recovery ◽  
New Type ◽  
P Type

A new type of gas sensor was realized by directly depositing carbon nanotube on nano channels of the anodic alumina oxide (AAO) fabricated on p-type silicon substrate. The carbon nanotubes were synthesized by thermal chemical vapor deposition at a very high temperature of 1200 oC to improve the crystallinity. The device fabrication process was also developed. The contact of carbon nanotubes and p-type Si substrate showed a Schottky behavior, and the Schottky barrier height increased with exposure to gases while the overall conductivity decreased. The sensors showed fast response and recovery to ammonia gas upon the filling (400 mTorr) and evacuation.

scholarly journals Segregated network polymer/carbon nanotubes composites

2004 ◽  
Vol 2 (2) ◽  
pp. 363-370 ◽  
Author(s):  
A. Mierczynska ◽  
J. Friedrich ◽  
H. Maneck ◽  
G. Boiteux ◽  
J. Jeszka
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Percolation Threshold ◽  
Network Formation ◽  
Processing Parameters ◽  
Low Grade ◽  
Single Walled Carbon ◽  
Conductive Composites ◽  
Grade Material

AbstractIn this work we present the preparation of conductive polyethylene/carbon nanotube composites based on the segregated network concept. Attention has been focused on the effect of decreasing the amount of filler necessary to achieve low resistivity. Using high- and low-grade single-walled carbon nanotube materials we obtained conductive composites with a low percolation threshold of 0.5 wt.% for high-grade nanotubes, about 1 wt% for commercial nanotubes and 1.5 wt% for low-grade material. The higher percolation threshold for low-grade material is related to low effectiveness of other carbon fractions in the network formation. The electrical conductivity was measured as a function of the single-walled carbon nanotubes content in the polymer matrix and as a function of temperature. It was also found that processing parameters significantly influenced the electrical conductivity of the composites. Raman spectroscopy was applied to study single wall nanotubes in the conductive composites.

Silicon Nitride – Carbon Nanotube Composites

2007 ◽  
Vol 554 ◽  
pp. 123-128 ◽  
Author(s):  
Csaba Balázsi ◽  
Zsolt Czigány ◽  
Ferenc Wéber ◽  
Zoltán Kónya ◽  
Zófia Vértesy ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Silicon Nitride ◽  
Hot Isostatic Pressing ◽  
High Pressure Processing ◽  
Gas Pressure ◽  
Multiwall Carbon Nanotube ◽  
Nitrogen Gas ◽  
Transmission Electron ◽  
Nanotube Composites

Multiwall carbon nanotube reinforced silicon nitride composites have been prepared by hot isostatic pressing. A manufacturing process has been worked out to avoid the damage of nanotubes during sintering. This method provides their preservation even in severe circumstances at temperature 1700°C and gas pressure 20 MPa. As shown by scanning and transmission electron microscopy after low and high pressure processing, carbon nanotubes have good adherence to the silicon nitride grains. Moreover, carbon nanotubes have been found to be located not only at grain surfaces, but in several cases they are well integrated with the silicon nitride grains. Composites with higher strengths can be obtained by increasing the nitrogen gas pressure.

Preparation and characterization of polyvinyl alcohol/carbon nanotube (PVA/CNT) conductive nanofibers

2012 ◽  
Vol 32 (6-7) ◽  
pp. 407-413 ◽  
Author(s):  
Ozcan Koysuren
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Polyvinyl Alcohol ◽  
Specific Capacitance ◽  
Electrode Surface ◽  
Electrospinning Process ◽  
Morphology Analysis ◽  
Highly Porous

Abstract The aim of this study was to prepare polyvinyl alcohol/carbon nanotube (PVA/CNT) conductive nanofibers by the electrospinning process. Prior to composite preparation, carbon nanotubes are dispersed homogeneously in N-methyl-2-pyrrolidone (NMP) and mixed with a PVA solution. A series of PVA/CNT films and nanofibers with various CNT compositions are prepared. Electrical conductivity and specific capacitance of spin-coated PVA/CNT films and electrospun PVA/CNT fibers increase with an increase in CNT content. Electrospun PVA/CNT nanofibers with a larger electrode surface result in a higher specific capacitance when compared with spin-coated PVA/CNT films. According to the morphology analysis, homogeneous and highly porous PVA/CNT mats containing 50–300 nm diameter nanofibers are obtained by the electrospinning process.

Solution-Based Fabrication of Carbon Nanotube Gas Sensor by Using Dielectrophoresis and Spin-Column Chromatography

2013 ◽  
Vol 699 ◽  
pp. 915-920
Author(s):  
Hideaki Watanabe ◽  
Hiroki Komure ◽  
Michihiko Nakano ◽  
Junya Suehiro
Keyword(s):  
Carbon Nanotubes ◽  
Electronic Structure ◽  
Carbon Nanotube ◽  
Gas Sensor ◽  
Column Chromatography ◽  
Gas Sensors ◽  
Single Walled Carbon Nanotubes ◽  
Sensor Response ◽  
Spin Column ◽  
Walled Carbon Nanotubes

Single-walled carbon nanotubes (SWCNTs) gas sensor has attracted a great deal of attention because of their remarkable properties. The sensor response is attribute to the semiconducting CNT whose electronic properties depend on its chirality. The authors have previously found that the sensor response increased by using separated semiconducting SWCNTs from a mixture with metallic one. Since the electronic structure (metallic or semiconducting) of CNTs is governed by their chirality, a chirality-selective fabrication of CNT gas sensor is essential to improve their performance. In this study, we proposed chirality-based separation of semiconducting SWCNTs by using spin-column chromatography. Pristine CNT suspension was separated into three fractions that had different chiralities of semiconducting SWCNTs. Separated semiconducting CNTs of each fraction were used for fabrication of three CNT gas sensors by dielectrophoresis. Comparison of these sensor responses to NO2 revealed that sensor response depended on the chirality.

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