scholarly journals A Tension/Pressure Integrated Resistive Sensor Comprising of a PDMS-LC-MWCNT Composite

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6078
Author(s):  
Miao Luo ◽  
Yumeng Zhang ◽  
Yuxiang Luo ◽  
Jiangang Lu
Keyword(s):  
Tensile Force ◽  
Applied Pressure ◽  
Gauge Factor ◽  
Integrated Sensor ◽  
Cross Sectional ◽  
Pdms Elastomer ◽  
Resistive Sensor ◽  
Multi Walled Carbon Nanotubes ◽  
Flexible Strain Sensor ◽  
Walled Carbon Nanotubes

A flexible strain sensor which integrates both pressure sensing and tension sensing functions is demonstrated with an active layer comprising of polydimethy-lsiloxane (PDMS) elastomer, liquid crystal (LC), and multi-walled carbon nanotubes (MWCNTs). The introduction of LC improves the agglomeration of MWCNTs in PDMS and decreases Young’s modulus of flexible resistive sensors. The tension/pressure integrated resistive sensor not only shows a broad tensile sensing range of 140% strain but also shows a good sensitivity of the gauge factor, 40, with tensile force. Besides, the tension/pressure integrated resistive sensor also shows good linearity and sensitivity under pressure. The resistance of the pressure sensor increases as the applied pressure increases because of the decrease in the cross-sectional area of the path. The sensor also shows good hydrophobic properties which may help it to work under complex environment. The tension/pressure integrated sensor shows great promising applications in electronic skins and wearable devices.

scholarly journals A cross-sectional study of changes in markers of immunological effects and lung health due to exposure to multi-walled carbon nanotubes

2017 ◽  
Vol 11 (3) ◽  
pp. 395-404 ◽  
Author(s):  
Jelle Vlaanderen ◽  
Anjoeka Pronk ◽  
Nathaniel Rothman ◽  
Allan Hildesheim ◽  
Debra Silverman ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional ◽  
Multi Walled Carbon Nanotubes ◽  
Immunological Effects ◽  
Lung Health ◽  
Walled Carbon Nanotubes

Electrical and piezoresistive properties of cement composites with carbon nanomaterials

2018 ◽  
Vol 52 (24) ◽  
pp. 3325-3340 ◽  
Author(s):  
Doo-Yeol Yoo ◽  
Ilhwan You ◽  
Hyunchul Youn ◽  
Seung-Jung Lee
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Carbon Nanomaterials ◽  
Peak Load ◽  
Compressive Load ◽  
Gauge Factor ◽  
Fractional Change ◽  
Graphite Nanofibers ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

This study investigates the effect of nanomaterials on the piezoresistive sensing capacity of cement-based composites. Three different nanomaterials—multi-walled carbon nanotubes, graphite nanofibers, and graphene oxide—were considered along with a plain mortar, and a cyclic compressive test was performed. Based on a preliminary test, the optimum flowability was determined to be 150 mm in terms of fiber dispersion. The electrical resistivity of the composites substantially decreased by incorporating 1 wt% multi-walled carbon nanotubes, but only slightly decreased by including 1 wt% graphite nanofibers and graphene oxide. This indicates that the use of multi-walled carbon nanotubes is most effective in improving the conductivity of the composites compared to the use of graphite nanofibers and graphene oxide. The fractional change in resistivity of the composites with nanomaterials exhibited similar behavior to that of the cyclic compressive load, but partial reversibility in fractional change in resistivity was obtained beyond 60% of the peak load. A linear relationship between the fractional change in resistivity and cyclic compression strain (up to 1500 με) was observed in the composites with multi-walled carbon nanotubes, and the gauge factor was found to be 166.6. It is concluded that cement-based composites with 1 wt% multi-walled carbon nanotubes can be used as piezoresistive sensors for monitoring the stress/strain generated in concrete structures.

scholarly journals Enhanced Detection Systems of Filling Rates Using Carbon Nanotube Cement Grout

Nanomaterials ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 10 ◽  
Author(s):  
Heeyoung Lee ◽  
Seonghoon Park ◽  
Sanggyu Park ◽  
Wonseok Chung
Keyword(s):  
Magnetic Field ◽  
Carbon Nanotubes ◽  
Field Tests ◽  
Cement Grout ◽  
Filling Rate ◽  
Cross Sectional ◽  
Detection Systems ◽  
Void Detection ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The addition of small amounts of carbon nanotubes (CNTs) to cement-based materials modifies their thermal and electrical characteristics. This study investigated the void detection and filling rates of cement grout with multi-walled carbon nanotubes (MWCNTs). MWCNT grouts of 40 mm × 40 mm × 160 mm were fabricated. Specimens were tested by thermal imaging, electrical resistance analyses, and magnetic field tests. The experimental parameters were the concentration of MWCNT and the grout filling rate. The filling rate was investigated by measuring resistance and magnetic field changes with respect to cross-sectional area, taking the voids into consideration. The results of the thermal image tests indicate that 1.0 wt % MWCNT cement grout is optimal for void detection.

scholarly journals Conductivity-Dependent Strain Response of Carbon Nanotube Treated Bacterial Nanocellulose

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
S. Farjana ◽  
F. Toomadj ◽  
P. Lundgren ◽  
A. Sanz-Velasco ◽  
O. Naboka ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Bacterial Cellulose ◽  
Tensile Force ◽  
Gauge Factor ◽  
Multiwalled Carbon ◽  
Electrically Conductive ◽  
Dispersion Process ◽  
Dependent Strain ◽  
Double Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

This paper reports the strain sensitivity of flexible, electrically conductive, and nanostructured cellulose which was prepared by modification of bacterial cellulose with double-walled carbon nanotubes (DWCNTs) and multiwalled carbon nanotubes (MWCNTs). The electrical conductivity depends on the modifying agent and its dispersion process. The conductivity of the samples obtained from bacterial cellulose (BNC) pellicles modified with DWCNT was in the range from 0.034 S·cm−1to 0.39 S·cm−1, and for BNC pellicles modified with MWCNTs it was from 0.12 S·cm−1to 1.6 S·cm−1. The strain-induced electromechanical response, resistance versus strain, was monitored during the application of tensile force in order to study the sensitivity of the modified nanocellulose. A maximum gauge factor of 252 was found from the highest conductive sample treated by MWCNT. It has been observed that the sensitivity of the sample depends on the conductivity of the modified cellulose.

Enhanced Electromechanical Properties of Carbon Nanotube/Polyurethan Composite by KMnO4 Oxidation

2014 ◽  
Vol 605 ◽  
pp. 235-238
Author(s):  
Roman Bořuta ◽  
Petr Slobodian ◽  
Robert Olejnik ◽  
Michal Machovsky ◽  
Pavel Riha
Keyword(s):  
Electrical Resistance ◽  
Gauge Factor ◽  
Strain Sensing ◽  
Sensing Element ◽  
Electromechanical Properties ◽  
Deformation Strain ◽  
High Deformation ◽  
Polyurethane Composite ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The effect of oxidation of multi-walled carbon nanotubes by KMnO4on the electrical resistance of a nanotube network/polyurethane composite subjected to bending has been studied. In this respect, the main achievement is a multiple increase of gauge factor for the evaluating electromechanical properties of the composite after nanotube oxidation with KMnO4. It indicates favorable properties of the composite for its use as a high-deformation strain-sensing element.

scholarly journals Flexible Strain-Sensitive Silicone-CNT Sensor for Human Motion Detection

2022 ◽  
Vol 9 (1) ◽  
pp. 36
Author(s):  
Natalia A. Demidenko ◽  
Artem V. Kuksin ◽  
Victoria V. Molodykh ◽  
Evgeny S. Pyankov ◽  
Levan P. Ichkitidze ◽  
...  
Keyword(s):  
Laser Radiation ◽  
Human Motion ◽  
Gauge Factor ◽  
Human Hand ◽  
Human Motion Detection ◽  
Multi Walled Carbon Nanotubes ◽  
Sensor Signals ◽  
Sensitive Sensor ◽  
Sensitive Characteristics ◽  
Walled Carbon Nanotubes

This article describes the manufacturing technology of biocompatible flexible strain-sensitive sensor based on Ecoflex silicone and multi-walled carbon nanotubes (MWCNT). The sensor demonstrates resistive behavior. Structural, electrical, and mechanical characteristics are compared. It is shown that laser radiation significantly reduces the resistance of the material. Through laser radiation, electrically conductive networks of MWCNT are formed in a silicone matrix. The developed sensor demonstrates highly sensitive characteristics: gauge factor at 100% elongation −4.9, gauge factor at 90° bending −0.9%/deg, stretchability up to 725%, tensile strength 0.7 MPa, modulus of elasticity at 100% 46 kPa, and the temperature coefficient of resistance in the range of 30–40 °С is −2 × 10−3. There is a linear sensor response (with 1 ms response time) with a low hysteresis of ≤3%. An electronic unit for reading and processing sensor signals based on the ATXMEGA8E5-AU microcontroller has been developed. The unit was set to operate the sensor in the range of electrical resistance 5–150 kOhm. The Bluetooth module made it possible to transfer the received data to a personal computer. Currently, in the field of wearable technologies and health monitoring, a vital need is the development of flexible sensors attached to the human body to track various indicators. By integrating the sensor with the joints of the human hand, effective movement sensing has been demonstrated.

scholarly journals Studying of a sensitive material based on Ecoflex and CNTs for flexible strain sensors

2021 ◽  
Vol 2086 (1) ◽  
pp. 012010
Author(s):  
N A Demidenko ◽  
A V Kuksin ◽  
E S Davydova ◽  
V A Zaborova ◽  
L P Ichkitidze ◽  
...  
Keyword(s):  
Strain Sensors ◽  
Gauge Factor ◽  
Functional Material ◽  
Sensitive Material ◽  
Electrically Conductive ◽  
Flexible Sensors ◽  
Laser Structuring ◽  
Multi Walled Carbon Nanotubes ◽  
High Elongation ◽  
Walled Carbon Nanotubes

Abstract Nowadays there is a great need for the development of flexible strain sensors that can register human body’s movements. In the field of wearable and smart electronics such sensors are actively being developed. Resistive-type flexible sensors are the easiest to manufacture. Their mechanism of sensitivity to deformations is based on a change in electrical resistance during deformations. In this work, we have developed the functional material for strain sensor with high tensile properties, strength and electrical conductivity. This material based on a matrix of silicone elastomer and a multi-walled carbon nanotubes (MCNTs) filler. The material showed a high elongation of 950 % with a tensile strength of 1.437 MPa. The manufacturing process included laser structuring of MCNTs to form an electrically conductive network. The linear gauge factor was 3.4, and the angular gauge factor was 0.26.

Cross-Sectional Deformation in Multi-Walled Carbon Nanotubes under Hydrostatic Pressure

2016 ◽  
Vol 258 ◽  
pp. 65-68
Author(s):  
Motohiro Sato ◽  
Yu Yachi ◽  
Ikuyo Koike ◽  
Hiroyuki Shima ◽  
Yoshitaka Umeno
Keyword(s):  
Carbon Nanotubes ◽  
Deformation Mode ◽  
Md Simulations ◽  
Continuum Approximation ◽  
Cross Sectional ◽  
Multi Walled Carbon Nanotubes ◽  
Elastic Approximation ◽  
Walled Carbon Nanotubes ◽  
Critical Buckling Pressure ◽  
Deformation Modes

This contribution provides simulated results of cross-sectional deformations observed in carbon nanotubes under high pressure. Molecular dynamics (MD) simulations were performed to explore radial buckling characteristics of multi-walled carbon nanotubes, and confirmed a variety of large-amplitude deformation modes. The energetically stable deformation mode turned out to be strongly dependent on the diameter of the innermost tube and the number of concentric walls. Critical buckling pressure obtained by MD simulations was compared with that estimated from a continuum elastic approximation, by which the validity of the continuum approximation was assessed.

scholarly journals Flexible Piezoresistive Sensor with the Microarray Structure Based on Self-Assembly of Multi-Walled Carbon Nanotubes

Sensors ◽  
2019 ◽  
Vol 19 (22) ◽  
pp. 4985 ◽  
Author(s):  
Peng Zhang ◽  
Yucheng Chen ◽  
Yuxia Li ◽  
Yun Zhao ◽  
Wei Wang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Pressure Sensor ◽  
Self Assembly ◽  
Tensile Force ◽  
Pressure Sensors ◽  
Layer By Layer ◽  
Piezoresistive Sensor ◽  
Multi Walled Carbon Nanotubes ◽  
Flexible Pressure Sensor ◽  
Walled Carbon Nanotubes

High-performance flexible pressure sensors have great application prospects in numerous fields, including the robot skin, intelligent prosthetic hands and wearable devices. In the present study, a novel type of flexible piezoresistive sensor is presented. The proposed sensor has remarkable superiorities, including high sensitivity, high repeatability, a simple manufacturing procedure and low initial cost. In this sensor, multi-walled carbon nanotubes were assembled onto a polydimethylsiloxane film with a pyramidal microarray structure through a layer-by-layer self-assembly system. It was found that when the applied external pressure deformed the pyramid microarray structure on the surface of the polydimethylsiloxane film, the resistance of the sensor varied linearly as the pressure changed. Tests that were performed on sensor samples with different self-assembled layers showed that the pressure sensitivity of the sensor could reach − 2.65     kPa − 1 , which ensured the high dynamic response ability and the high stability of the sensor. Moreover, it was proven that the sensor could be applied as a strain sensor under the tensile force to reflect the stretching extent or the bending object. Finally, a flexible pressure sensor was installed on five fingers and the back of the middle finger of a glove. The obtained results from grabbing different weights and different shapes of objects showed that the flexible pressure sensor not only reflected the change in the finger tactility during the grasping process, but also reflected the bending degree of fingers, which had a significant practical prospect.

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