A shapeable, ultra-stretchable rubber strain sensor based on carbon nanotubes and Ag flakes via melt-mixing process

2021 ◽  
Vol 9 (16) ◽  
pp. 3502-3508
Author(s):  
Qiang Zhang ◽  
Shirui Pan ◽  
Chao Ji ◽  
Jianqiao Song ◽  
Rui Zhang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Strain Sensor ◽  
Strain Sensors ◽  
Mixing Process ◽  
Melt Mixing ◽  
Detection Range

Promoting the detection range, durability, and shapeable manufacturing of flexible strain sensors is essential to broaden their applications.

scholarly journals A Fully Inkjet-Printed Strain Sensor Based on Carbon Nanotubes

Coatings ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 792 ◽  
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.

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

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Wei Qiu ◽  
Shi-Lei Li ◽  
Wei-lin Deng ◽  
Di Gao ◽  
Yi-Lan Kang
Keyword(s):  
Carbon Nanotubes ◽  
Raman Spectroscopy ◽  
Carbon Nanotube ◽  
Plane Strain ◽  
Standard Procedure ◽  
Strain Sensor ◽  
Mathematic Model ◽  
Strain Sensors ◽  
Polarization Control ◽  
Strain Components

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.

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

Nanoscale ◽  
2018 ◽  
Vol 10 (28) ◽  
pp. 13599-13606 ◽  
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%).

scholarly journals Stretchable Strain Sensor with Controllable Negative Resistance Sensitivity Coefficient Based on Patterned Carbon Nanotubes/Silicone Rubber Composites

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 716
Author(s):  
Rong Dong ◽  
Jianbing Xie
Keyword(s):  
Carbon Nanotubes ◽  
Silica Gel ◽  
Strain Sensor ◽  
Sensitivity Coefficient ◽  
Negative Resistance ◽  
Human Motion ◽  
Strain Sensors ◽  
Application Range ◽  
Human Motion Monitoring ◽  
Soft Elastomer

In this paper, stretchable strain sensors with a controllable negative resistance sensitivity coefficient are firstly proposed. In order to realize the sensor with a negative resistance sensitivity coefficient, a stretchable stress sensor with sandwich structure is designed in this paper. Carbon nanotubes are added between two layers of silica gel. When the sensor is stretched, carbon nanotubes will be squeezed at the same time, so the sensor will show a resistance sensitivity coefficient that the resistance becomes smaller after stretching. First, nanomaterials are coated on soft elastomer, then a layer of silica gel is wrapped on the outside of the nanomaterials. In this way, similar to sandwich biscuits, a stretchable strain sensor with controllable negative resistance sensitivity coefficient has been obtained. Because the carbon nanotubes are wrapped between two layers of silica gel, when the silica gel is stretched, the carbon nanotubes will be squeezed longitudinally, which increases their density and resistance. Thus, a stretchable strain sensor with negative resistance sensitivity coefficient can be realized, and the resistivity can be controlled and adjusted from 12.7 Ω·m to 403.2 Ω·m. The sensor can be used for various tensile testing such as human motion monitoring, which can effectively expand the application range of conventional tensile strain sensor.

Effects of Carbon Nanotubes on Processing Stability of Polyoxymethylene in Melt−Mixing Process

2007 ◽  
Vol 111 (37) ◽  
pp. 13945-13950 ◽  
Author(s):  
You Zeng ◽  
Zhe Ying ◽  
Jinhong Du ◽  
Hui-Ming Cheng
Keyword(s):  
Carbon Nanotubes ◽  
Mixing Process ◽  
Melt Mixing ◽  
Processing Stability

scholarly journals Strain Sensors: A Highly Sensitive and Reliable Strain Sensor Using a Hierarchical 3D and Ordered Network of Carbon Nanotubes (Small 25/2015)

Small ◽  
2015 ◽  
Vol 11 (25) ◽  
pp. 2958-2958
Author(s):  
Jeongeun Seo ◽  
Tae Jae Lee ◽  
Chaehyun Lim ◽  
Subeom Lee ◽  
Chen Rui ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Strain Sensor ◽  
Strain Sensors ◽  
Highly Sensitive

scholarly journals Multipoint-Detection Strain Sensor with a Single Electrode Using Optical Ultrasound Generated by Carbon Nanotubes

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3877
Author(s):  
Won Young Choi ◽  
Hyeong Geun Jo ◽  
Soo Won Kwon ◽  
Young Hun Kim ◽  
Joo Young Pyun ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Polyvinylidene Fluoride ◽  
Strain Sensor ◽  
Human Motion ◽  
Strain Sensors ◽  
Acoustic Energy ◽  
Multiple Electrodes ◽  
S Curve ◽  
Pulse Echo ◽  
Pulse Echo Method

With the development of wearable devices, strain sensors have attracted large interest for the detection of human motion, movement, and breathing. Various strain sensors consisting of stretchable conductive materials have been investigated based on resistance and capacitance differences according to the strain. However, this method requires multiple electrodes for multipoint detection. We propose a strain sensor capable of multipoint detection with a single electrode, based on the ultrasound pulse–echo method. It consists of several transmitters of carbon nanotubes (CNTs) and a single polyvinylidene fluoride receiver. The strain sensor was fabricated using CNTs embedded in stretchable polydimethylsiloxane. The received data are characterized by the different times of transmission from the CNTs of each point depending on the strain, i.e., the sensor can detect the positions of the CNTs. This study demonstrates the application of the multipoint strain sensor with a single electrode for measurements up to a strain of 30% (interval of 1%). We considered the optical and acoustic energy losses in the sensor design. In addition, to evaluate the utility of the sensor, finger bending with three-point CNTs and flexible phantom bending with six-point CNTs for the identification of an S-curve having mixed expansion and compression components were carried out.

Highly Stretchable Resistive Strain Sensors Using Multiple Viscous Conductive Materials

2020 ◽  
Author(s):  
Hongyang Shi ◽  
Xinda Qi ◽  
Yunqi Cao ◽  
Nelson Sepúlveda ◽  
Chuan Wang ◽  
...  
Keyword(s):  
Large Strain ◽  
Strain Sensor ◽  
Strain Sensors ◽  
Fabrication Process ◽  
Gauge Factor ◽  
Wearable Electronics ◽  
Detection Range ◽  
Conductive Materials ◽  
Highly Stretchable ◽  
Good Repeatability

Abstract This paper proposes a highly stretchable strain sensor using viscous conductive materials as resistive element and introduces a simple and economic fabrication process by encapsulating the conductive materials between two layers of silicone rubbers Ecoflex 00-30. The fabrication process of the strain sensor is presented, and the properties of the viscous conductive materials are studied. Characterization shows that the sensor with conductive gels, toothpastes, carbon paint, and carbon grease can sustain a maximum tensile strain of 200% and retain good repeatability, with a strain gauge factor of 2.0, 1.75, 3.0, and 7.5, respectively. Furthermore, strain sensors with graphite and carbon nanotubes mixed with conductive gels are fabricated to explore how to improve the gauge factor. With a focus on the most promising material, conductive carbon grease, cyclic stretching tests are conducted and show good repeatability at 100% strain for 100 cycles. Lastly, it is demonstrated that the stretchable strain sensor made of carbon grease is capable of measuring finger bending. With its easy and low-cost fabrication process, large strain detection range and good gauge factor, the conductive materials-based strain sensors are promising for future biomedical, wearable electronics and rehabilitation applications.

Electrical impedance analysis of carbon nanotube/epoxy nanocomposite-based piezoresistive strain sensors under uniaxial cyclic static tensile loading

2019 ◽  
Vol 54 (6) ◽  
pp. 845-855 ◽  
Author(s):  
Abdulkadir Sanli ◽  
Olfa Kanoun
Keyword(s):  
Carbon Nanotubes ◽  
Electrochemical Impedance ◽  
Strain Sensor ◽  
Tensile Load ◽  
High Sensitivity ◽  
Impedance Spectrum ◽  
Element Model ◽  
Strain Sensors ◽  
Load Impedance ◽  
Static Tensile

Carbon nanotubes-based nanocomposites have gained a great amount of attraction and play a key role in the realization of strain sensors owing to their remarkable physical properties. In this study, the piezoresistivity of multi-walled carbon nanotubes (MWCNTs)/epoxy-based nanocomposite-based strain sensor under static tensile load is examined using electrochemical impedance spectroscopy. Morphological examinations show that MWCNTs are randomly and homogeneously distributed in the epoxy polymer matrix. A simplified resistance constant phase element model is proposed and validated by impedance spectrum to fit the impedance spectra and the equivalent circuit parameters are extracted under uniaxial static load. Impedance results suggest that depending on the frequency regions, the sensor exhibits different responses under loading. Moreover, the proposed sensor gives high sensitivity, linearity and low hysteresis under cyclic quasi-static loading and unloading that makes the sensor a promising candidate for practical strain sensor applications.

Sign in / Sign up

Export Citation Format

Share Document