Strain Sensing Elastic Core-Spun Yarns Based on Long Silver Nanowires

Abstract Strain sensing is one of the important functions of intelligent fabric, which can transform the external stress (or strain) into visible electrical signals and monitor the characteristics of human physiology and motion. At present, the flexible strain sensor has low sensitivity, small strain range and unstable performance after repeated stretching. In this work, core-spun yarns with polyurethane (PU) filament as core and long silver nanowires (AgNWs) loaded cotton fiber as shell was fabricated by spinning technology. The results showed that when the loading of AgNWs was 10 wt%, the strain range of the PU/cotton@AgNWs core-spun yarn was 0-60%, the gauge factor of 12.6 was linear, and the strain sensing and mechanical properties were stable after repeated stretching. This strain sensing elastic core-spun yarns constructed by spinning technology could be used as one of the important materials for intelligent wearable devices.

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Direct Printing of a Flexible Strain Sensor for Distributed Monitoring of Deformation in Inflatable Structures

ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems ◽

10.1115/smasis2019-5713 ◽

2019 ◽

Author(s):

Mohammed Al-Rubaiai ◽

Ryohei Tsuruta ◽

Taewoo Nam ◽

Umesh Gandhi ◽

Xiaobo Tan

Keyword(s):

3D Printing ◽

Structural Changes ◽

Strain Sensor ◽

Strain Range ◽

Gauge Factor ◽

Distributed Monitoring ◽

Inflatable Structures ◽

Resistance Change ◽

Flexible Strain Sensor ◽

Conductive Paint

Abstract Inflatable structures provide significant volume and weight savings for future space and soft robotic applications. Structural health monitoring (SHM) of these structures is essential to ensuring safe operation, providing early warnings of damage, and measuring structural changes over time. In this paper, we propose the design of a single flexible strain sensor for distributed monitoring of an inflatable tube, in particular, the detection and localization of a kink should that occur. Several commercially available conductive materials, including 3D-printing filaments, conductive paint, and conductive fabrics are explored for their strain-sensing performance, where the resistance change under uniaxial tension is measured, and the corresponding gauge factor (GF) is characterized. Flexible strain sensors are then fabricated and integrated with an inflatable structure fabric using screen-printing or 3D-printing techniques, depending on the nature of the raw conductive material. Among the tested materials, the conductive paint shows the highest stability, with GF of 15 and working strain range of 2.28%. Finally, the geometry of the sensor is designed to enable distributed monitoring of an inflatable tube. In particular, for a given deformation magnitude, the sensor output shows a monotonic relationship with the location where the deformation is applied, thus enabling the monitoring of the entire tube with a single sensor.

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Synergistic Effect of Graphene/Silver Nanowire Hybrid Fillers on Highly Stretchable Strain Sensors Based on Spandex Composites

Nanomaterials ◽

10.3390/nano10102063 ◽

2020 ◽

Vol 10 (10) ◽

pp. 2063

Author(s):

Tan Thong Vo ◽

Hyeon-Jong Lee ◽

Sang-Yun Kim ◽

Ji Won Suk

Keyword(s):

Synergistic Effect ◽

High Performance ◽

Silver Nanowires ◽

Large Strain ◽

Strain Range ◽

Strain Sensors ◽

Silver Nanowire ◽

Gauge Factor ◽

Hybrid Fillers ◽

Conductive Nanomaterials

Embedding conductive nanomaterials into elastomeric polymer matrices is one of the most promising approaches for fabricating stretchable strain sensors capable of monitoring large mechanical movements or deformation through the detection of resistance changes. Here, hybrid fillers comprising graphene and silver nanowires (AgNWs) are incorporated into extremely stretchable spandex to fabricate strain sensors. Composites containing only graphene and those containing the graphene/AgNW hybrid fillers are systematically investigated by evaluating their electrical and mechanical properties. The synergistic effect between graphene and AgNWs enable the strain sensors based on the composites to experience a large strain range of up to 120%, and low hysteresis with a high gauge factor of 150.3 at a strain of 120%. These reliable strain sensors are utilized for monitoring human motions such as heartbeats and body movements. The findings of this study indicate the significant applicability of graphene/AgNW/spandex composites in future applications that demand high-performance stretchable strain sensors.

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Fabrication of Carbon Nanotube/Low Density Polyethylene Composites for Strain Sensing

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.495.33 ◽

2011 ◽

Vol 495 ◽

pp. 33-36

Author(s):

Radwa R. Abdel Chafy ◽

Mustafa H. Arafa ◽

Amal M. K. Esawi

Keyword(s):

Electrical Resistance ◽

Composite Films ◽

Load Condition ◽

Strain Range ◽

Low Density Polyethylene ◽

Gauge Factor ◽

Low Density ◽

Strain Sensing ◽

Percolation Behavior ◽

Measured Resistance

Carbon Nanotubes (CNTs) have shown remarkable electrical, piezoresistive properties as well as other physical properties. The aim of this study is to investigate the potential of CNT-polymer composites in strain sensing using low density polyethylene (LDPE) polymer. Different CNT loadings were used (0, 1, 2, 3.5, 5, 6.5 and 8 weight %). CNT/LDPE composite films of 1mm thickness were fabricated using compression molding. The electrical resistance at no load condition was measured and the percolation behavior was obtained. The percolation threshold was found to be in the range of (2-5) wt%, where a decrease in resistivity by 5 orders of magnitude was observed. The sensitivity (gauge factor – GF) of the films was evaluated by correlating the strain applied with the simultaneously measured resistance. For a strain range of up to 320 µε, a gauge factor of 200 was achieved at a CNT loading of 5 wt%.

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Graphene as a Piezoresistive Material in Strain Sensing Applications

Micromachines ◽

10.3390/mi13010119 ◽

2022 ◽

Vol 13 (1) ◽

pp. 119

Author(s):

Farid Sayar Irani ◽

Ali Hosseinpour Shafaghi ◽

Melih Can Tasdelen ◽

Tugce Delipinar ◽

Ceyda Elcin Kaya ◽

...

Keyword(s):

Mechanical Strain ◽

Evolutionary Process ◽

Strain Range ◽

Device Fabrication ◽

Strain Sensors ◽

Gauge Factor ◽

Strain Sensing ◽

Characterization Methods ◽

Accuracy Measurement ◽

Sensing Applications

High accuracy measurement of mechanical strain is critical and broadly practiced in several application areas including structural health monitoring, industrial process control, manufacturing, avionics and the automotive industry, to name a few. Strain sensors, otherwise known as strain gauges, are fueled by various nanomaterials, among which graphene has attracted great interest in recent years, due to its unique electro-mechanical characteristics. Graphene shows not only exceptional physical properties but also has remarkable mechanical properties, such as piezoresistivity, which makes it a perfect candidate for strain sensing applications. In the present review, we provide an in-depth overview of the latest studies focusing on graphene and its strain sensing mechanism along with various applications. We start by providing a description of the fundamental properties, synthesis techniques and characterization methods of graphene, and then build forward to the discussion of numerous types of graphene-based strain sensors with side-by-side tabular comparison in terms of figures-of-merit, including strain range and sensitivity, otherwise referred to as the gauge factor. We demonstrate the material synthesis, device fabrication and integration challenges for researchers to achieve both wide strain range and high sensitivity in graphene-based strain sensors. Last of all, several applications of graphene-based strain sensors for different purposes are described. All in all, the evolutionary process of graphene-based strain sensors in recent years, as well as the upcoming challenges and future directions for emerging studies are highlighted.

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Graphene/PVA buckypaper for strain sensing application

Scientific Reports ◽

10.1038/s41598-020-77139-2 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Ahsan Mehmood ◽

N. M. Mubarak ◽

Mohammad Khalid ◽

Priyanka Jagadish ◽

Rashmi Walvekar ◽

...

Keyword(s):

Testing Machine ◽

Strain Range ◽

Industrial Applications ◽

Human Motion ◽

Gauge Factor ◽

Strain Sensing ◽

Tensile Testing Machine ◽

Sensor Applications ◽

Human Motion Detection ◽

Sensing Applications

AbstractStrain sensors in the form of buckypaper (BP) infiltrated with various polymers are considered a viable option for strain sensor applications such as structural health monitoring and human motion detection. Graphene has outstanding properties in terms of strength, heat and current conduction, optics, and many more. However, graphene in the form of BP has not been considered earlier for strain sensing applications. In this work, graphene-based BP infiltrated with polyvinyl alcohol (PVA) was synthesized by vacuum filtration technique and polymer intercalation. First, Graphene oxide (GO) was prepared via treatment with sulphuric acid and nitric acid. Whereas, to obtain high-quality BP, GO was sonicated in ethanol for 20 min with sonication intensity of 60%. FTIR studies confirmed the oxygenated groups on the surface of GO while the dispersion characteristics were validated using zeta potential analysis. The nanocomposite was synthesized by varying BP and PVA concentrations. Mechanical and electrical properties were measured using a computerized tensile testing machine, two probe method, and hall effect, respectively. The electrical conducting properties of the nanocomposites decreased with increasing PVA content; likewise, electron mobility also decreased while electrical resistance increased. The optimization study reports the highest mechanical properties such as tensile strength, Young’s Modulus, and elongation at break of 200.55 MPa, 6.59 GPa, and 6.79%, respectively. Finally, electrochemical testing in a strain range of ε ~ 4% also testifies superior strain sensing properties of 60 wt% graphene BP/PVA with a demonstration of repeatability, accuracy, and preciseness for five loading and unloading cycles with a gauge factor of 1.33. Thus, results prove the usefulness of the nanocomposite for commercial and industrial applications.

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Study on properties of elastic core-spun yarns containing a mix of spandex and PET/PTT bi-component filament as core

Textile Research Journal ◽

10.1177/0040517517693982 ◽

2017 ◽

Vol 88 (9) ◽

pp. 1065-1076 ◽

Cited By ~ 14

Author(s):

Tao Hua ◽

Ngo S Wong ◽

Wai M Tang

Keyword(s):

Draw Ratio ◽

Linear Density ◽

Test Results ◽

Ring Spinning ◽

Elastic Core ◽

Spun Yarn ◽

Yarn Properties ◽

Spun Yarns ◽

Core Components ◽

Yarn Hairiness

This paper presents a development of elastic core-spun yarn containing a mix of spandex and polyethylene terephthalate/polytrimethylene terephthalate (PET/PTT) bi-component filament as core to obtain better yarn properties, especially for elastic property. Eight types of core-spun yarns, consisting of different core components with various values of linear density and covered with cotton fibers, were produced using a modified ring-spinning machine with a core spinning attachment. The influences of core components, linear density, and draw ratio of spandex on yarn structure and properties were investigated. The experimental results demonstrate that core-spun yarns containing a mix of spandex and PET/PTT bi-component filament have much lower yarn stress decay as well as lower hairiness and CVm value of evenness compared to the yarns using only spandex. For the yarns containing a mix of spandex and PET/PTT bi-component filament, the yarns containing 70 denier spandex have higher elongation and stress decay compared to the yarns containing 40 denier spandex. The test results show that the elongation of yarns containing a mix of spandex and PET/PTT bi-component filament increases with the increase of the draw ratio of spandex. The stress decay of yarns containing a mix of 70 denier spandex and PET/PTT filament shows a similar trend to the elongation. Moreover, the yarn samples containing a mix of spandex and PET/PTT filament as core exhibit good yarn evenness, with very few thick places and neps, as well as low yarn hairiness.

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Embedded 3D Printing of Highly Flexible Nanocomposites With Piezoresistive Sensing Capabilities

Volume 4: Advances in Aerospace Technology ◽

10.1115/imece2020-23173 ◽

2020 ◽

Author(s):

Blake Herren ◽

Mrinal C. Saha ◽

M. Cengiz Altan ◽

Yingtao Liu

Keyword(s):

3D Printing ◽

Human Skin ◽

Strain Sensor ◽

Strain Range ◽

High Sensitivity ◽

Curing Temperature ◽

Gauge Factor ◽

Strain Sensing ◽

Sensing Applications ◽

Human Joints

Abstract In recent years, highly flexible nanocomposite sensors have been developed for the detection of a variety of human body movements. To precisely detect the bending motions of human joints, the sensors must be able to conform well with the human skin and produce signals that effectively describe the amount of deformation applied to the material during bending. In this paper, a carbon nanotube-based piezoresistive strain sensor is developed via the direct ink writing based embedded 3D printing method. The optimum weight concentration range of carbon nanotubes in the nanocomposite inks, appropriate for embedded 3D printing, is identified. Samples with complex 2D and 3D geometries are printed to demonstrate the manufacturing capabilities of the embedded printing process. The sensitivity of the piezoresistive strain sensor is optimized by determining the ideal nanofiller concentration, curing temperature, and nozzle size to produce the highest gauge factor in a wide strain range. The piezoresistive and mechanical properties of the optimized sensors are fully characterized to verify the suitability for skin-attachable strain sensing applications. The developed sensors have a wide sensing range, high sensitivity, and minimal strain rate dependence. In addition, their low elasticity and high biocompatibility allow them to be comfortably bonded on the human skin.

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Fabrication and Performance Evaluation of Highly Sensitive Flexible Strain Sensors with Aligned Silver Nanowires

Micromachines ◽

10.3390/mi11020156 ◽

2020 ◽

Vol 11 (2) ◽

pp. 156 ◽

Cited By ~ 2

Author(s):

Jae Hyuk Choi ◽

Myung Gyu Shin ◽

Young Jung ◽

Dong Hwan Kim ◽

Jong Soo Ko

Keyword(s):

Silver Nanowires ◽

Low Cost ◽

Strain Sensor ◽

Strain Range ◽

Longitudinal Direction ◽

Dip Coating ◽

Strain Sensors ◽

Gauge Factor ◽

Lateral Direction ◽

And Performance

In this study, we fabricated strain sensors by aligning silver nanowires and transferring them with polydimethylsiloxane (PDMS) and compared the performances of the fabricated strain sensors along the alignment direction. Two types of flexible strain sensors embedded with the aligned silver nanowires were fabricated: one in the longitudinal direction, which is the same as the alignment direction, and the other in the lateral direction, which is perpendicular to the alignment direction. We then evaluated their properties. The proposed longitudinally aligned strain sensor showed the maximum sensitivity (gauge factor (GF) = 89.99) under 25% tensile conditions, which is 7.08 times higher than the sensitivity (GF = 12.71) shown by the laterally aligned strain sensor under 25% tensile conditions. This finding confirmed that the alignment direction of silver nanowires influences the sensitivity of flexible strain sensors. Furthermore, this study demonstrates that the laterally aligned strain sensor (ε > 60%) can be used in wearable devices because it satisfies the required strain range (ε > 50%). Since the strain sensors were fabricated using the temperature-controlled dip coating process, they can be produced at low cost in large quantities, and thus they have advantages for commercialization. These characteristics will be applicable to various flexible devices as well as to flexible strain sensors.

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Analysis of Spun Yarn Failure. Part II: The Translation of Strength from Fiber Bundle to Different Spun Yarns

Textile Research Journal ◽

10.1177/0040517505053957 ◽

2005 ◽

Vol 75 (10) ◽

pp. 741-744 ◽

Cited By ~ 9

Author(s):

Anindya Ghosh ◽

S. M. Ishtiaque ◽

R. S. Rengasamy

Keyword(s):

Fiber Bundle ◽

Spun Yarn ◽

Spun Yarns

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Robust Conductive Hydrogels with Ultrafast Self-Recovery and Nearly Zero Response Hysteresis for Epidermal Sensors

Nanomaterials ◽

10.3390/nano11071854 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1854

Author(s):

Xiuru Xu ◽

Chubin He ◽

Feng Luo ◽

Hao Wang ◽

Zhengchun Peng

Keyword(s):

Guar Gum ◽

Strain Range ◽

Sio2 Nanoparticles ◽

Fast Response ◽

Gauge Factor ◽

Practical Applications ◽

Hydroxypropyl Guar ◽

Stable Chemical ◽

Conductive Hydrogel ◽

Conductive Hydrogels

Robust conductive hydrogels are in great demand for the practical applications of smart soft robots, epidermal electronics, and human–machine interactions. We successfully prepared nanoparticles enhanced polyacrylamide/hydroxypropyl guar gum/acryloyl-grafted chitosan quaternary ammonium salt/calcium ions/SiO2 nanoparticles (PHC/Ca2+/SiO2 NPs) conductive hydrogels. Owing to the stable chemical and physical hybrid crosslinking networks and reversible non-covalent interactions, the PHC/Ca2+/SiO2 NPs conductive hydrogel showed good conductivity (~3.39 S/m), excellent toughness (6.71 MJ/m3), high stretchability (2256%), fast self-recovery (80% within 10 s, and 100% within 30 s), and good fatigue resistance. The maximum gauge factor as high as 66.99 was obtained, with a wide detectable strain range (from 0.25% to 500% strain), the fast response (25.00 ms) and recovery time (86.12 ms), excellent negligible response hysteresis, and good response stability. The applications of monitoring the human’s body movements were demonstrated, such as wrist bending and pulse tracking.

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