scholarly journals Fabrication and implementation of carbon nanotubes for piezoresistive-sensing applications: A review

Author(s):  
Anindya Nag ◽  
Subhas Chandra Mukhopadhyay
2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Waris Obitayo ◽  
Tao Liu

The use of carbon nanotubes for piezoresistive strain sensors has acquired significant attention due to its unique electromechanical properties. In this comprehensive review paper, we discussed some important aspects of carbon nanotubes for strain sensing at both the nanoscale and macroscale. Carbon nanotubes undergo changes in their band structures when subjected to mechanical deformations. This phenomenon makes them applicable for strain sensing applications. This paper signifies the type of carbon nanotubes best suitable for piezoresistive strain sensors. The electrical resistivities of carbon nanotube thin film increase linearly with strain, making it an ideal material for a piezoresistive strain sensor. Carbon nanotube composite films, which are usually fabricated by mixing small amounts of single-walled or multiwalled carbon nanotubes with selected polymers, have shown promising characteristics of piezoresistive strain sensors. Studies also show that carbon nanotubes display a stable and predictable voltage response as a function of temperature.


2015 ◽  
Vol 10 (1) ◽  
pp. 13-20
Author(s):  
Elisabete Galeazzo ◽  
Marcos C. Moraes ◽  
Henrique E. M. Peres ◽  
Michel O. S. Dantas ◽  
Victor G. C. Lobo ◽  
...  

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.


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.


2014 ◽  
Vol 807 ◽  
pp. 13-39
Author(s):  
Bavani Kasinathan ◽  
Ruzniza Mohd Zawawi

Carbon-based nanomaterials such as graphene, carbon nanotubes, carbon nanofibers and nanodiamonds have been fascinated considerable attention as promising materials for drug sensing. These materials have tremendous amount of attraction due to some extraordinary features such as excellent electrical and thermal conductivities as well as high mechanical strength. Hence, these nanomaterials have been used extensively in sensor technology in order to achieved desired sensitivities. To date, carbon based nanomaterials have been exploit in the development of various drug sensing due to their simple preparation methods, and cost effectiveness. The aim of this review is to focus upon carbon based nanomaterials predominantly on drugs sensing applications. This review has been written in summary form including properties, fabrication method, and analytical performances.Abbreviation:Au, Gold; CNFs, Carbon Nanofibers; CNTs, Carbon Nanotubes; CVD, Chemical Vapour Deposition; D-, Dextrorotatory enantiomer; D, Dimensional; DNase, deoxyribonuclease; ESD, Electrospinning deposition; GCE, Glassy Carbon Electrode; Gr, Graphene; GrO, Graphene Oxide; ILs, ionic liquids; L-, Levorotatory enantiomer; LOD, Limit of Detection; MTase, Methyltransferases; MW, Microwave; MWCNTs, Multi-walled Carbon nanotubes; NDs, Nanodiamonds; NPs, Nanoparticles; PECVD, Plasma Enhanced Chemical Vapour Deposition; RGO, Reduced Graphene Oxide; SPE, Screen-Printed Electrode; SPR, Surface Plasmon resonance; ssDNA, single-stranded DNA; SWCNTs, Single-walled Carbon nanotubes.


Author(s):  
Dumitru I. Caruntu ◽  
Cone S. Salinas Trevino

This paper deals with electrostatically actuated Carbon NanoTubes (CNT) cantilevers for bio-sensing applications. There are three kinds of forces acting on the CNT cantilever: electrostatic, elastostatic, and van der Waals. The van der Waals forces are significant for values of 50 nm or lower of the gap between the CNT and the ground plate. As both forces electrostatic and van der Waals are nonlinear, and the CNT electrostatic actuation is given by AC voltage, the CNT dynamics is nonlinear parametric. The method of multiple scales is used to investigate the system under soft excitations and/or weakly nonlinearities. The frequency-amplitude and frequency-phase behavior are found in the case of primary resonance. The CNT bio-sensor is to be used for mass detection applications.


2009 ◽  
Vol 1204 ◽  
Author(s):  
Paolo Bondavalli ◽  
Louis Gorintin ◽  
Pierre Legagneux ◽  
Didier Pribat ◽  
Laurent Caillier ◽  
...  

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.


2021 ◽  
Vol 11 (18) ◽  
pp. 8452
Author(s):  
Pedro de Almeida Carísio ◽  
Yasmim Gabriela dos Santos Mendonça ◽  
Carlos Fernando Teodósio Soares ◽  
Oscar Aurelio Mendoza Reales ◽  
Eduardo de Moraes Rego Fairbairn ◽  
...  

Due to their exceptional electrical properties, carbon nanotubes (CNTs) can be applied as conductive fillers to develop self-sensing cement-based matrices. In order to obtain an adequate self-sensing response, CNTs must be evenly dispersed through the cement matrix in a volume sufficient enough to create an electric percolation network. This is challenged by the difficulty of dispersing CNTs; therefore, there is a demand for an efficient dispersing agent that can be filled by superplasticiezers, which are products of known compatibility with cement and high availability. This research explores the use of four commercial superplasticizers available in Brazil, both naphthalene and ether polycarboxylate-based, as dispersing agents for CNTs in water. Ultrasonic energy was applied to aqueous solutions containing CNTs and superplasticizers. UV–Vis spectroscopy and ξ-potential measurements were used to investigate which superplasticizer was more effective to disperse the CNTs. Cement pastes were produced with the CNT dispersions and their electrical resistivity was measured. It was found that only superplasticizers without aliphatic groups in their structure were capable of dispersing CNTs in water. It was concluded that second-generation naphthalene-based superplasticizers were more efficient dispersing agents for CNTs than third-generation ether polycarboxylate-based ones for self-sensing applications.


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