Electrical behavior of devices composed by dielectrophoretically deposited carbon nanotubes for gas sensing applications

Intensive research has been focused on investigating new sensing materials, such as carbon nanotubes (CNT) because of their promising characteristics. However, there are challenges related to their application in commercial devices such as sensitivity, compatibility, and complexity of miniaturization, among others. We report the study of the electrical behavior of devices composed by multi-walled carbon nanotubes (MWCNT) deposited between aluminum electrodes on glass substrates by means of dielectrophoresis (DEP), which is a simple and cost-effective method. The devices were fabricated by varying the DEP process time. Remarkable changes in their electric resistance were noticed depending on the MWCNT quantities deposited. Other electrical properties of devices such as high sensitivity, fast response time and stability are also characterized in humid environment. A humidity sensing mechanism is proposed on the basis of charge transfer between adsorbed water molecules and the MWNTC surface or between water and the glass surface.

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Carbon Nanotubes for Gas Sensing Applications

Carbon Nanomaterials for Gas Adsorption ◽

10.1201/b13722-10 ◽

2012 ◽

pp. 333-468 ◽

Cited By ~ 1

Author(s):

Michele Penza

Keyword(s):

Carbon Nanotubes ◽

Gas Sensing ◽

Sensing Applications

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Carbon Materials for Gas and Bio-Sensing Applications Beyond Graphene

Materials Research Foundations - Toxic Gas Sensors and Biosensors ◽

10.21741/9781644901175-2 ◽

2021 ◽

pp. 39-68

Keyword(s):

Carbon Nanotubes ◽

Active Site ◽

Material Science ◽

Gas Sensing ◽

Functionalized Nanoparticles ◽

Sensing Applications ◽

Electrochemical Biosensing ◽

New Ideas ◽

Enzymatic Biosensors ◽

Enhanced Stability

The development of technology in the area of material science and nanotechnology is a worldwide concern to researchers for generating a substance by synthesizing nanoparticles with required properties. Carbonaceous materials have gained numerous interests because of their direct electron or charge transfer capacity between active site reception and functionalized nanoparticles without involvement of a mediator. However, among all existing materials, carbon nanotubes have been proven to elite beyond graphene. Carbon nanotubes (CNTs) possess extraordinary electrochemical biosensing and gas sensing due to their specific properties. This encourages researchers to gain new ideas about construction and development of immunosensors, genosensors, enzymatic biosensors and specific gas sensors based on above nanoparticles. Qualification of working electrode via incorporation of two or more of these nanoparticles gives enhanced stability, better sensitivity and functionality to the sensor. This chapter reviews basic information about sensors, their types, functionalization, fabrication mechanisms and applications for future prospective.

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CNTFET Gas Sensors Using SWCNT Mats: Method for Low-cost Fabrication, Solution to Improve Selectivity, Experimental Results using Interfering Agents

MRS Proceedings ◽

10.1557/proc-1204-k07-04 ◽

2009 ◽

Vol 1204 ◽

Cited By ~ 1

Author(s):

Paolo Bondavalli ◽

Louis Gorintin ◽

Pierre Legagneux ◽

Didier Pribat ◽

Laurent Caillier ◽

...

Keyword(s):

Carbon Nanotubes ◽

Gas Sensors ◽

Field Effect ◽

Gas Sensing ◽

Field Effect Transistors ◽

Low Cost ◽

Experimental Results ◽

Flexible Substrates ◽

Metal Electrodes ◽

Sensing Applications

AbstractThe first paper showing the great potentiality of Carbon Nanotubes Field Effect transistors (CNTFETs) for gas sensing applications was published in 2000 [1]. It has been demonstrated that the performances of this kind of sensors are extremely interesting: a sensitivity of around 100ppt (e.g. for NO2 [2]) has been achieved in 2003 and several techniques to improve selectivity have been tested with very promising results [2]. The main issues that have not allowed, up to now, these devices to strike more largely the market of sensors, have been the lack of an industrial method to obtain low-cost devices, a demonstration of their selectivity in relevant environments and finally a deeper study on the effect of humidity and the possible solutions to reduce it. This contribution deals with CNTFETs based sensors fabricated using air-brush technique deposition on large surfaces. Compared to our last contribution [3], we have optimized the air-brush technique in order to obtain high performances transistors (Log(Ion)/Log(Ioff) ∼ 5/6) with highly reproducible characteristics : this is a key point for the industrial exploitation. We have developed a machine which allows us the dynamic deposition on heated substrates of the SWCNT solutions, improving dramatically the uniformity of the SWCNT mats. We have performed tests using different solvents that could be adapted as a function of the substrates (e.g. flexible substrates). Moreover these transistors have been achieved using different metal electrodes (patented approach [4]) in order to improve selectivity. Results of tests using NO2, NH3 with concentrations between ∼ 1ppm and 10ppm will be shown during the meeting.

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