Strain Sensor of Carbon Nanotubes in Microscale: From Model to Metrology

A strain sensor composed of carbon nanotubes with Raman spectroscopy can achieve measurement of the three in-plane strain components in microscale. Based on previous work on the mathematic model of carbon nanotube strain sensors, this paper presents a detailed study on the optimization, diversification, and standardization of a CNT strain sensor from the viewpoint of metrology. A new miniaccessory for polarization control is designed, and two different preparing methods for CNT films as sensing media are introduced to provide diversified choices for applications. Then, the standard procedure of creating CNT strain sensors is proposed. Application experiments confirmed the effectiveness of the above improvement, which is helpful in developing this method for convenient metrology.

Download Full-text

On finding of high piezoresistive response of carbon nanotube films without surfactants for in-plane strain detection

Journal of Intelligent Material Systems and Structures ◽

10.1177/1045389x11426179 ◽

2011 ◽

Vol 22 (18) ◽

pp. 2155-2159 ◽

Cited By ~ 7

Author(s):

Y. Miao ◽

L. Chen ◽

Y. Lin ◽

R. Sammynaiken ◽

W. J. Zhang

Keyword(s):

Carbon Nanotubes ◽

Carbon Nanotube ◽

Plane Strain ◽

Composite Films ◽

Strain Sensors ◽

Gauge Factor ◽

Experimental Discovery ◽

Strain Detection ◽

Nanotube Films

The use of carbon nanotubes (CNTs) for construction of sensors is promising. This is due to some unique characteristics of CNTs. In recent years, strain sensors built from CNT composite films have been developed; however, their low piezoresistive sensitivity (gauge factor (GF)) in in-plane strain detection is a concern compared with other strain sensors. This article reports an experimental discovery of the superior piezoresistive response of a CNT film that is free of surfactants, known as the pure CNT film. The mechanism for the high GF with the pure CNT film strain sensors is also discussed.

Download Full-text

Ultra-stretchable and highly sensitive strain sensor based on gradient structure carbon nanotubes

Nanoscale ◽

10.1039/c8nr02528b ◽

2018 ◽

Vol 10 (28) ◽

pp. 13599-13606 ◽

Cited By ~ 31

Author(s):

Binghao Liang ◽

Zhiqiang Lin ◽

Wenjun Chen ◽

Zhongfu He ◽

Jing Zhong ◽

...

Keyword(s):

Carbon Nanotubes ◽

Carbon Nanotube ◽

Strain Sensor ◽

High Sensitivity ◽

Strain Sensors ◽

Sensitive Strain ◽

Gauge Factor ◽

Gradient Structure ◽

Highly Sensitive ◽

Highly Stretchable

A highly stretchable and sensitive strain sensor based on a gradient carbon nanotube was developed. The strain sensors show an unprecedented combination of both high sensitivity (gauge factor = 13.5) and ultra-stretchability (>550%).

Download Full-text

Polarization Configuration and Control Method of Micro-Raman Spectros Copy for in-Plane Strainmeasurement by Using Carbon Nanotube Sensor

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.787.675 ◽

2013 ◽

Vol 787 ◽

pp. 675-680

Author(s):

Zhong Bao Wang ◽

Dong Hui Fu ◽

Wei Qiu

Keyword(s):

Carbon Nanotube ◽

Plane Strain ◽

Strain Measurement ◽

Control Method ◽

Strain Sensor ◽

Analytical Relationship ◽

Strain Components ◽

Polarized Raman ◽

And Control ◽

Relationship Of

This paper introduceda study for the methodology of carbon nanotube (CNT) sensor applicable for the strain measurement in microscale. By using the Raman strain sensitive and polarization selectivity of the carbon nanotubes, the analytical relationship of carbon nanotube strain sensor for each polarization Raman configuration are deduced and compared. The work regarded that the dual coordination polarization-controlled configuration is most suitable for the in-plane strain measurement. Then, a new method for this configuration is presented. Experiments proved that the proposed method can effectively realize the measurement of in-plane strain components by using polarized Raman.

Download Full-text

Ultra-stretchable, sensitive and durable strain sensors based on polydopamine encapsulated carbon nanotubes/elastic bands

Journal of Materials Chemistry C ◽

10.1039/c8tc02702a ◽

2018 ◽

Vol 6 (30) ◽

pp. 8160-8170 ◽

Cited By ~ 47

Author(s):

Yalong Wang ◽

Yanyan Jia ◽

Yujie Zhou ◽

Yan Wang ◽

Guoqiang Zheng ◽

...

Keyword(s):

Carbon Nanotubes ◽

Carbon Nanotube ◽

High Strain ◽

Strain Sensor ◽

Strain Range ◽

Strain Sensors ◽

Elastic Band ◽

Elastic Bands ◽

Flexible Strain Sensor

A polydopamine (PDA)/carbon nanotube (CNT)/elastic band (EB) flexible strain sensor has desirable integration of an ultra-high strain range (920% strain), large sensitivity and superior durability (10 000 cycles).

Download Full-text

A Review: Carbon Nanotube-Based Piezoresistive Strain Sensors

Journal of Sensors ◽

10.1155/2012/652438 ◽

2012 ◽

Vol 2012 ◽

pp. 1-15 ◽

Cited By ~ 152

Author(s):

Waris Obitayo ◽

Tao Liu

Keyword(s):

Carbon Nanotubes ◽

Carbon Nanotube ◽

Composite Films ◽

Strain Sensors ◽

Voltage Response ◽

Strain Sensing ◽

Multiwalled Carbon ◽

Sensing Applications ◽

Mechanical Deformations ◽

Electrical Resistivities

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.

Download Full-text

The Generation of a Carbon Nanotube- Cyclodextrin Complex

MRS Proceedings ◽

10.1557/proc-703-v13.8 ◽

2001 ◽

Vol 703 ◽

Author(s):

G.F. Farrell ◽

G. Chambers ◽

A.B Dalton ◽

E. Cummins ◽

M. McNamara ◽

...

Keyword(s):

Carbon Nanotubes ◽

Aqueous Solution ◽

Raman Spectroscopy ◽

Carbon Nanotube ◽

Intermolecular Interaction ◽

Intermolecular Interactions ◽

Small Diameter ◽

Cyclodextrin Complex ◽

Yellow Solution ◽

Single Wall Nanotubes

ABSTRACTIn this study the intermolecular interactions of small diameter (∼0.7nm) carbon nanotubes and γ-cyclodextrin were examined. Four samples of γ cyclodextrin and HiPco carbon nanotubes were prepared. The first, by grinding the tubes and the cyclodextrin (1:30 ratio) together in a dry mixture, the second was prepared in a similar fashion but was ground in the presence of water (1ml). Finally an aqueous solution of γ-cyclodextrin (0.3M) and HiPco carbon nanotubes (5mg) was prepared by refluxing for ∼100 hours, forming a pale yellow solution from which a number of crystals were produced, both the solution and the recrystallised material were analysed. The samples were analysed using UV-Vis-NIR and Raman spectroscopy. The results presented are the first spectroscopic evidence of an intermolecular interaction between γ-cyclodextrin and single wall nanotubes.

Download Full-text

A Fully Inkjet-Printed Strain Sensor Based on Carbon Nanotubes

Coatings ◽

10.3390/coatings10080792 ◽

2020 ◽

Vol 10 (8) ◽

pp. 792 ◽

Cited By ~ 1

Author(s):

Hsuan-Ling Kao ◽

Cheng-Lin Cho ◽

Li-Chun Chang ◽

Chun-Bing Chen ◽

Wen-Hung Chung ◽

...

Keyword(s):

Carbon Nanotubes ◽

Surface Morphology ◽

Silver Film ◽

Strain Sensor ◽

Strain Sensors ◽

Gauge Factor ◽

Lower Sensitivity ◽

High Reproducibility ◽

Silver Films ◽

Microcrack Detection

A fully inkjet-printed strain sensor based on carbon nanotubes (CNTs) was fabricated in this study for microstrain and microcrack detection. Carbon nanotubes and silver films were used as the sensing layer and conductive layer, respectively. Inkjet-printed CNTs easily undergo agglomeration due to van der Waals forces between CNTs, resulting in uneven films. The uniformity of CNT film affects the electrical and mechanical properties. Multi-pass printing and pattern rotation provided precise quantities of sensing materials, enabling the realization of uniform CNT films and stable resistance. Three strain sensors printed eight-layer CNT film by unidirectional printing, rotated by 180° and 90° were compared. The low density on one side of eight-layer CNT film by unidirectional printing results in more disconnection and poor connectivity with the silver film, thereby, significantly increasing the resistance. For 180° rotation eight-layer strain sensors, lower sensitivity and smaller measured range were found because strain was applied to the uneven CNT film resulting in non-uniform strain distribution. Lower resistance and better strain sensitivity was obtained for eight-layer strain sensor with 90° rotation because of uniform film. Given the uniform surface morphology and saturated sheet resistance of the 20-layer CNT film, the strain performance of the 20-layer CNT strain sensor was also examined. Excluding the permanent destruction of the first strain, 0.76% and 1.05% responses were obtained for the 8- and 20-layer strain sensors under strain between 0% and 3128 µε, respectively, which demonstrates the high reproducibility and recoverability of the sensor. The gauge factor (GF) of 20-layer strain sensor was found to be 2.77 under strain from 71 to 3128 µε, which is higher than eight-layer strain sensor (GF = 1.93) due to the uniform surface morphology and stable resistance. The strain sensors exhibited a highly linear and reversible behavior under strain of 71 to 3128 µε, so that the microstrain level could be clearly distinguished. The technology of the fully inkjet-printed CNT-based microstrain sensor provides high reproducibility, stability, and rapid hardness detection.

Download Full-text

Highly stretchable multi-walled carbon nanotube/thermoplastic polyurethane composite fibers for ultrasensitive, wearable strain sensors

Nanoscale ◽

10.1039/c9nr01005j ◽

2019 ◽

Vol 11 (13) ◽

pp. 5884-5890 ◽

Cited By ~ 42

Author(s):

Zuoli He ◽

Gengheng Zhou ◽

Joon-Hyung Byun ◽

Sang-Kwan Lee ◽

Moon-Kwang Um ◽

...

Keyword(s):

Carbon Nanotube ◽

Thermoplastic Polyurethane ◽

Strain Sensor ◽

Strain Sensors ◽

Wet Spinning ◽

Polyurethane Composite ◽

Multi Walled Carbon Nanotube ◽

Highly Sensitive ◽

Spinning Process ◽

Highly Stretchable

In this manuscript, we report a novel highly sensitive wearable strain sensor based on a highly stretchable multi-walled carbon nanotube (MWCNT)/Thermoplastic Polyurethane (TPU) fiber obtained via a wet spinning process.

Download Full-text

Entangled Network of Carbon Nanotubes Embedded in Polyurethane and its Use for Body Kinematics and Joint Flexion Sensing

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.543.39 ◽

2013 ◽

Vol 543 ◽

pp. 39-42 ◽

Cited By ~ 1

Author(s):

Petr Slobodian ◽

Pavel Riha ◽

Petr Saha

Keyword(s):

Carbon Nanotubes ◽

Carbon Nanotube ◽

Athletic Training ◽

Knee Flexion ◽

Strain Sensor ◽

Sensing Element ◽

Electrically Conductive ◽

Human Knee ◽

Cyclic Movement ◽

Joint Flexion

Monitoring body kinematics and joint flexion has fundamental relevance in orthopedics and rehabilitation. The used sensing element is prepared from a highly-deformable polymer composite composed of a network of entangled electrically-conductive carbon nanotubes embedded in elastic polyurethane. The composite is prepared by an innovative procedure in which the non-woven polyurethane filtering membrane and the carbon nanotube cake are integrated by compression molding. As an example of the composite use as a strain sensor, human knee flexion and its cyclic movement is monitored, that may be applicable in athletic training as well as in orthopedics and rehabilitation.

Download Full-text