Stainless Steel Yarns Research Articles

Woven Textile Pressure Switch

In this paper has shown that the three-dimensional hollow weaving technique enables to produce a textile pressure sensor in one continuous process. Based on the multilayer fabric principle, the hollow woven fabrics can be created by connecting adjacent layers of the fabrics according to certain rules. The appropriate fabric structure has been selected and the three-layer weaving technique was used to make the textile pressure switch. The fabric structure is selected to ensure that the top and bottom layers are kept at a distance from each other. The electrically conductive tracks were embedded in the hollow structure of the fabric in bottom and middle layers. Three conditions must be fulfilled in order to create the textile switch: a) the fabric in normal condition keeps the shape required, i.e. the conductive elements are physically separated from each other; b) when the fabric is pressed, conductive elements are in contact, i.e. the switch is now in an electrically on state; c) after the pressure has been removed the fabric returns to its original position, i.e. switch is in an electrically off state. The behavior of the electrically conductive yarn and conductive tracks were tested in various ways. The stainless steel yarn woven in particular way can be used to create woven conductive tracks. Example of application: the pressure sensitive woven rug, the whole area or part of which acts as the pressure sensor or simple switch. The pressure switch in the floor coverings can turn on alarm systems or indicator lamps in the floor or wall coverings for guidance systems in public buildings.

Mathematical Model Predicting the Heat and Power Dissipated in an Electro-Conductive Contact in a Hybrid Woven Fabric

Abstract Electro-conductive (EC) yarns can be woven into a hybrid fabric to enable electrical current to flow through the fabric from one component A to another component B. These hybrid fabrics form the bases of woven e-textiles. However, at the crossing point of an EC yarn in warp and in weft direction, there is a contact resistance and thus generation of heat may occur in this area. Both phenomena are inseparable: if the contact resistance in the EC contact increases, the generated heat will increase as well. Predicting this electrical and thermal behavior of EC contacts in hybrid woven fabrics with stainless steel yarns is possible with a mathematical model based on the behavior of a metal oxide varistor (MOV). This paper will discuss in detail how this can be achieved.

Highly Wearable, Breathable, and Washable Sensing Textile for Human Motion and Pulse Monitoring.

At present, pressure sensor textiles are of great significance in the area of wearable electronics, especially for making smart or intelligent textiles. However, the design of these textile-based devices with sensitive ability, simple fabrication, and low cost is still challenging. In this study, we developed a triboelectric sensing textile constructed with core-shell yarns. Nylon filament and polytetrafluoroethylene filament were selected as the positive and negative layers, respectively, in the woven structure while the built-in helical stainless steel yarn was serving as the inner electrode layer. The sensitivity of the sensing textile can reach up to 1.33 V·kPa-1 and 0.32 V·kPa-1 in the pressure range of 1.95-3.13 kPa and 3.20-4.61 kPa, respectively. This sensing textile presented good mechanical stability and sensing capability even after 4200 cycles of continuous operation or after 4 h continuous water washing. Benefiting from the favorable merits of being highly flexible, breathable, lightweight, and even dyeable, the fabricated device was capable of being placed on any desired body parts for quantifying the dynamic human motions. It can be effectively used to measure and monitor various human movements associated with different joints, such as the hand, elbow, knee, and underarm. Moreover, the sensing textile was able to capture real-time pulse signals and reflect the current health status for human beings. This study affords an innovative and promising track for multifunctional pressure sensor textiles with wide applications in smart textiles and personalized healthcare.

Knitted Cotton Fabric Strain Sensor by In-situ Polymerization of Pyrrole

The purpose of this research work was to develop a textile-based strain sensor. A conductive textile fabric was produced by the coating of knitted cotton fabric with in-situ polymerization of polypyrrole. The sensor consists of a conductive textile as an electrode, stainless steel yarn as interconnection, Arduino Nano as a controller, HC05 Bluetooth module, and a Lithium polymer battery as a power source. For the demonstration, the sensor was placed on the upper arm and bicep stretch was performed. It was observed that the contraction of the arm muscle causes a reduction in resistance of the electrode. Therefore, change in swelling was successfully detected from the increase and drop of resistance during contraction and relaxation of the muscle. This principle could be applied to determine the status of peripheral edema, where the increase in resistance in this work indicates edema is becoming severe.

Cost-Effective Yarn-Shaped Lithium-Ion Battery with High Wearability.

Because of flexibility, compactness, weavability, and ergonomic design, yarn-shaped lithium-ion batteries (LIBs) have enormous potential applications in wearable electronics. Still, the yarn-shaped LIB with the ability to meet commercialization requirements has never been reported, owing to the current challenge in complex material synthesis technologies, expensive raw material costs, poor safety performance, and nonstandard manufacturing equipment. Herein, we propose a yarn-shaped LIB that meets the aforementioned requirements. With a highly conductive and flexible stainless-steel yarn acting as the current collector, the electrode active materials and the gel electrolyte, which are commercially available at low cost, are uniformly coated onto the stainless-steel yarn by a simple and facile dipping-drying method. Even at different deformation conditions (i.e., bending or knotting), the specific capacity of the yarn-shaped LIB (7 cm long, <2 mm in diameter) assembled from graphite and lithium iron phosphate electrodes is maintained >85%. After charged treatment, it can successfully power up an electronic watch and an electronic thermo-hygrometer. Thanks to the simple preparation process, low cost of raw materials, and good safety performance, this work can promote the commercialization of wearable energy storage devices.

Analysis of Sensitivity, Linearity, Hysteresis, Responsiveness, and Fatigue of Textile Knit Stretch Sensors.

Wearable technology is widely used for collecting information about the human body and its movement by placing sensors on the body. This paper presents research into electronic textile strain sensors designed specifically for wearable applications which need to be lightweight, robust, and comfortable. In this paper, sixteen stretch sensors, each with different conductive stretch fabrics, are evaluated: EeonTex (Eeonyx Corporation), knitted silver-plated yarn, and knitted spun stainless steel yarn. The sensors’ performance is tested using a tensile tester while monitoring their resistance with a microcontroller. Each sensor was analyzed for its sensitivity, linearity, hysteresis, responsiveness, and fatigue through a series of dynamic and static tests. The findings show that for wearable applications a subset of the silver-plated yarn sensors had better ranked performance in terms of sensitivity, linearity, and steady state. EeonTex was found to be the most responsive, and the stainless steel yarn performed the worst, which may be due to the characteristics of the knit samples under test.

Continuous and scalable manufacture of amphibious energy yarns and textiles

Biomechanical energy harvesting textiles based on nanogenerators that convert mechanical energy into electricity have broad application prospects in next-generation wearable electronic devices. However, the difficult-to-weave structure, limited flexibility and stretchability, small device size and poor weatherability of conventional nanogenerator-based devices have largely hindered their real-world application. Here, we report a highly stretchable triboelectric yarn that involves unique structure design based on intrinsically elastic silicone rubber tubes and extrinsically elastic built-in stainless steel yarns. By using a modified melt-spinning method, we realize scalable-manufacture of the self-powered yarn. A hundred-meter-length triboelectric yarn is demonstrated, but not limited to this size. The triboelectric yarn shows a large working strain (200%) and promising output. Moreover, it has superior performance in liquid, therefore showing all-weather durability. We also show that the development of this energy yarn facilitates the manufacturing of large-area self-powered textiles and provide an attractive direction for the study of amphibious wearable technologies.

Development of textile-based transmission lines using conductive yarns and ultrasonic welding technology for e-textile applications

The development of the conductive transmission lines is crucial part for the creation of wearable electronic systems. The current focus of this study is to create signal transmission lines resistant to environmental effects. To do this, an ultrasonic welding technology has been used in order to analyze its suitability for e-textile transmission line manufacturing. Two groups of yarns, namely, stainless steel yarns and silver-plated yarns were used along with polyester fabrics. The used yarns were also varied according to their linear density and electrical conductivity. Based on the experimental results, while stainless steel yarns were merely affected in terms of conductivity change, silver-plated yarns found to be less suitable for ultrasonic welding technology. However, silver-plated yarns with higher linear density showed satisfactory results at moderate working conditions.

Textile yarn thermocouples for use in fabrics

Thermocouples are mainly used for accurate temperature measurements, but they can also be used for the generation of electric energy at low voltage and low power. If inserted into wearable garments, these thermocouples can be used to supply the electric energy required by portable electronic devices. The heat from the human body gives rise to a temperature gradient which can be converted into electric power. In this article, we study the possibility to create a thermocouple and thermopile from pure conductive textile yarns. Among the materials tested, nickel-coated carbon fiber in combination with stainless steel yarn, polypyrrole-coated carbon fiber, or carbon fiber has good potential to be a textile-based thermocouple. We also successfully made a 10-pair carbon fiber–nickel-coated carbon fiber junction thermopile from a single nickel-coated carbon fiber yarn by removing the nickel selectively through etching process.

The electric energy stored in PEDOT:PSS capacitors integrated on textile substrate

PurposeThe purpose of this paper is to develop a capacitor fully integrated into a wearable textile fabric for the application on smart clothing.Design/methodology/approachA small capacitor with stainless steel yarns as the electrodes and poly-(3,4–ethylenedioxythiophene): polystryrene sulphonate (PEDOT:PSS) as the dielectric material has been made, integrated into a textile fabric. The electric performance of the capacitor was analyzed and compared with other kinds of electric capacitors.FindingsThe fabricated small, PEDOT:PSS capacitor could finally power a calculator for 37 s with the energy stored in it.Originality/valueThis finding is of an important significance for a further development on the capacitor with a better performance.

Novel high-performance asymmetric supercapacitors based on nickel-cobalt composite and PPy for flexible and wearable energy storage

Wearable fiber-shaped supercapacitor (SC) is a kind of one-dimensional flexible devices that can be directly knitted or sewn into various kinds of textile soft-substrate for wearable energy storage. Herein, acid-pretreated stainless steel yarn (SSY) has been developed to support electrodeposition of active materials of nickel/cobalt composite and polypyrrole (PPy) as the positive and negative electrodes, respectively. The asymmetric all-solid-state supercapacitors (AASs) showed both high electrochemical properties and excellent mechanical flexibility under various degrees of deformation. The highest volumetric capacitance reached 14.69 F cm−3 at the current density of 25 mA cm−3, and the maximum energy density was 3.83 mWh·cm−3 (0.032 mWh·cm−2) at a power density of 18.75 mW cm−3 (0.284 mW cm−2). The AASs were highly flexible and durable for directly being sewn into textile fabrics, and exhibited a good electrochemical stability under 6000 charging/discharging cycles. This work uses the common materials and facile methods to fabricate the flexible and wearable AASs with enhanced electrochemical properties, showing a decent way in developing flexible SC devices.

Yarn-form electrodes with high capacitance and cycling stability based on hierarchical nanostructured nickel-cobalt mixed oxides for weavable fiber-shaped supercapacitors

Integration of microelectronic devices into traditional clothing for smart wearable electronic textiles attracts increasing attentions in recent years, which will boost the economy in the next few decades. The flexible and weavable micropower units are the key component for smart wearable electronic textiles. Herein, the soft and conductive stainless steel yarn is chosen to serve as both substrate and collector, satisfying the requirements of high flexibility and good electrical conductivity. As expected, the as-obtained yarn-form electrodes based on nickel-cobalt oxide with ultrathin two-dimensional nanosheet hierarchical arrays and grown binder-freely on the conductive stainless steel yarn substrate exhibit a higher specific capacitance (90.82 mF cm−1 or 289.24 mF cm-2 at the current of 0.33 mA cm−1) and a better cyclic stability (92.4% retention of specific capacitance after 3000 cycles at the current of 1.67 mA cm−1), compared to those based on nickel-cobalt oxide with nanowires in this work. Through the further assembly of the as-prepared yarn-form electrodes into the parallel arrangement, the symmetric all-solid-state fiber-shaped supercapacitor with a high energy density (3.9 μWh·cm−1 or 12.42 μWh·cm−2) and good flexibility and weaveability is fabricated, which has great potential to serve as weavable power unit for smart wearable electronic devices.

An Experimental Study for the Production of Electromagnetic Shielding Clothing

In the modern society, human beings are often exposed to electromagnetic radiation (EMR). Despite its bad effects on the human body, few apparel scholars paid attention to developing “EMR-proof” clothing. Therefore, the purpose of this paper is to conduct experiments for the development of EMR-proof clothing. We conducted experiments to investigate the effectiveness of two EMR shielding (EMRS) fabrics – stainless steel yarn (SSY) blended fabrics and silver yarn (SY) blended fabrics – when these fabrics partially covered the clothing. In our experiments, we covered the front side of a baseball jacket and the head with the two EMRS fabrics and generated EMRs through a cell phone to measure the EMRS effects of the two fabrics by using an EMR meter. The major findings of our experiments indicated that SSY blended fabric and the SY blended fabric were effective in protecting EMR when they partially covered clothing.

Design of Novel Wearable, Stretchable, and Waterproof Cable-Type Supercapacitors Based on High-Performance Nickel Cobalt Sulfide-Coated Etching-Annealed Yarn Electrodes.

Rapid advances in functional electronics bring tremendous demands on innovation toward effective designs of device structures. Yarn supercapacitors (SCs) show advantages of flexibility, knittability, and small size, and can be integrated into various electronic devices with low cost and high efficiency for energy storage. In this work, functionalized stainless steel yarns are developed to support active materials of positive and negative electrodes, which not only enhance capacitance of both electrodes but can also be designed into stretchable configurations. The as-made asymmetric yarn SCs show a high energy density of 0.0487 mWh cm-2 (10.19 mWh cm-3 ) at a power density of 0.553 mW cm-2 (129.1 mW cm-3 ) and a specific capacitance of 127.2 mF cm-2 under an operating voltage window of 1.7 V. The fabricated SC is then made into a stretchable configuration by a prestraining-then-releasing approach using polydimethylsiloxane (PDMS) tube, and its electrochemical performance can be well maintained when stretching up to a high strain of 100%. Moreover, the stretchable cable-type SCs are stably workable under water-immersed condition. The method opens up new ways for fabricating flexible, stretchable, and waterproof devices.

Ionic shot noise in an electrochemical capacitor system made of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) film and silver-coated polybenzoxazole-stainless steel electrodes on textile fabrics

Unusual noisy discharge profiles were observed from some of our textile-based energy storage devices having asymmetrical electrodes consisting of pure stainless steel and silver-coated polybenzoxazole yarns. Our hypothesis was that it was due to the ionic shot noise behavior that occurred in electrochemical devices and is a well-known phenomenon in electronic devices. The poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) polymer coverage on the cell surface, which functioned as a solid electrolyte in this system, was believed to play an important role. To confirm this assumption, devices made with different drop-coating strategies to obtain thin and thick layers of PEDOT:PSS polymer on the cell surface were prepared. The noisy discharge profiles were observed from devices with thin polymer layers, while those with thick layers exhibited normal discharge profiles. The morphology of cell surfaces was characterized by a stereo microscope. Cross-section analysis of a device with a thick layer was employed to further characterize its film formation and elemental properties using Scanning Electron Microscopy-Electron Dispersive Spectroscopy. Formation of multilayers of PEDOT:PSS polymer on the cell surface allowed a continuous interaction between electrode metals and PEDOT:PSS ions at the interface area. The noisy component was caused by the movement of silver ions hopping from one trap to the next. A qualitative model of the autocorrelation function executed to the data with noisy behavior further confirmed the ionic shot noise phenomenon.

Shielding of electromagnetic radiation by multilayer textile sets

This paper presents the continuation of research on shielding efficiency (SE) of electromagnetic radiation (EMR) by woven fabric made of cotton (warps and wefts) and a hybrid yarn (wefts). This hybrid yarn was made of stainless steel yarn by Bekinox wrapped with an enamelled copper wire from Synflex Elektro GmbH, Germany. The pitch of copper coil on a hybrid yarn equals 3 mm. The wefts were introduced into the fabric in the following order: 1 hybrid yarn, 1 cotton yarn, 1 hybrid yarn, 1 cotton yarn, etc. The construction of this specific fabric was proven to be the most efficient in terms of the hybrid weft construction and the fabric construction to shield EMR among other previously tested fabrics with different weft configuration. The current study proposes to verify the effect of the number of layers of the fabrics and their mutual configuration on the final SE of the multilayered set. Some of the most interesting findings of this study are that increasing the number of layers placed on top of one another with an offset angle of 0° to more than two does not provide a higher SE; however, using three such layers provides an SE of 56 dB, which is over two times higher than that provided by a single layer. Increasing the number of layers of fabric aligned at an angle of 45° provides a higher SE only for a frequency of 30 MHz.

A Flexible and Knittable Fiber Supercapacitor for Wearable Energy Storage with High Energy Density and Mechanical Robustness

A flexible and knittable symmetric all-solid-state fiber supercapacitor (ASSFS) was fabricated by using two polypyrrole (PPy) microcone arrays coated stainless steel yarns (SSY) as fiber electrodes and current collectors. The microcone arrays and interconnected network structure of PPy could increase transport path for ions/electrons and enlarge the real contact area between PPy and electrolyte, leading to superior specific capacitance. In addition, the fiber electrode has a high tensile strength of ∼1200 MPa and elongation at break is 12.5%. The outstanding mechanical performance of the fiber electrode is attributed to the high mechanical properties of the SSY and the protection of PPy coating. The resultant ASSFS exhibits maximum specific capacitance of 42.7 F/cm3, energy density of 3.8 mWh/cm3 and power density of 388 mW/cm3 (normalized to the whole device). The specific capacitance maintains 100% at different bending angles and 93.5% of its initial value after 1000 bending cycles. As a demonstration, a fabric and a bracelet knitted with five ASSFSs connected in series can light a LED.

Electrochemical Impedance Analysis of a PEDOT:PSS-Based Textile Energy Storage Device.

A textile-based energy storage device with electroactive PEDOT:PSS (poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate)) polymer functioning as a solid-state polyelectrolyte has been developed. The device was fabricated on textile fabric with two plies of stainless-steel electroconductive yarn as the electrodes. In this study, cyclic voltammetry and electrochemical impedance analysis were used to investigate ionic and electronic activities in the bulk of PEDOT:PSS and at its interfaces with stainless steel yarn electrodes. The complex behavior of ionic and electronic origins was observed in the interfacial region between the conductive polymer and the electrodes. The migration and diffusion of the ions involved were confirmed by the presence of the Warburg element with a phase shift of 45° (n = 0.5). Two different equivalent circuit models were found by simulating the model with the experimental results: (QR)(QR)(QR) for uncharged and (QR)(QR)(Q(RW)) for charged samples. The analyses also showed that the further the distance between electrodes, the lower the capacitance of the cell. The distribution of polymer on the cell surface also played important role to change the capacitance of the device. The results of this work may lead to a better understanding of the mechanism and how to improve the performance of the device.

Study of the Contact Resistance of Interlaced Stainless Steel Yarns Embedded in Hybrid Woven Fabrics

Abstract The contact resistance of two interlacing electro-conductive yarns embedded in a hybrid woven fabric will constitute a problem for electro-conductive textiles under certain circumstances. A high contact resistance can induce hotspots, while a variable contact resistance may cause malfunctioning of the components that are interconnected by the electro-conductive yarns. Moreover, the contact robustness should be preserved over time and various treatments such as washing or abrading should not alter the functioning of the electro-conductive textiles. The electrical resistance developed in the contact point of two interlacing electro-conductive yarns is the result of various factors. The influence of diameter of the electro-conductive stainless steel yarns, the weave pattern, the weft density, and the abrasion on the contact resistance was investigated. Hybrid polyester fabrics were produced according to the design of experiments (DoE) and statistical models were found that describe the variation of the contact resistance with the selected input parameters. It was concluded that the diameter of the stainless steel warp and weft yarns has a statistically significant influence on the contact resistance regardless of the weave. Weft density had a significant influence on the contact resistance but only in case of the twill fabrics. Abrasion led to an increase in contact resistance regardless of the weave pattern and the type of stainless steel yarn that was used. Finally, a combination of parameters that leads to plain and twill fabrics with low contact resistance and robust contacts is recommended.

Comparative study of the weft-knitted strain sensors

In this study, weft-knitted strain-sensing structures are described, along with the materials and manufacturing techniques required to produce the fabrics on a computerised flat-bed knitting machine. Knitted sensing fabrics with conductive yarns, i.e. silver-plated nylon yarn and polyester-blended stainless steel yarn have been created with different design possibilities. A laboratory test set-up was built to characterise the knitted sensors and the resulting equivalent resistance under the different level of strains. The most successful samples have been realised through a series of single conductive courses within the interlock base fabric structure using silver-plated nylon in terms of responsivity, repeatability and lower electrical signal drift. Deficiencies associated with strain-sensing structures realised through the intermeshing of conductive yarns have also been addressed.