scholarly journals Highly Sensitive E-Textile Strain Sensors Enhanced by Geometrical Treatment for Human Monitoring

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2383 ◽  
Author(s):  
Chi Cuong Vu ◽  
Jooyong Kim
Keyword(s):  
Form Factors ◽  
Human Movement ◽  
Fast Response ◽  
Strain Sensors ◽  
Electronic Textiles ◽  
Smart Textiles ◽  
Electronic Manufacturing ◽  
Starting Point ◽  
Textile Sensors ◽  
Manufacturing Techniques

Electronic textiles, also known as smart textiles or smart fabrics, are one of the best form factors that enable electronics to be embedded in them, presenting physical flexibility and sizes that cannot be achieved with other existing electronic manufacturing techniques. As part of smart textiles, e-sensors for human movement monitoring have attracted tremendous interest from researchers in recent years. Although there have been outstanding developments, smart e-textile sensors still present significant challenges in sensitivity, accuracy, durability, and manufacturing efficiency. This study proposes a two-step approach (from structure layers and shape) to actively enhance the performance of e-textile strain sensors and improve manufacturing ability for the industry. Indeed, the fabricated strain sensors based on the silver paste/single-walled carbon nanotube (SWCNT) layers and buffer cutting lines have fast response time, low hysteresis, and are six times more sensitive than SWCNT sensors alone. The e-textile sensors are integrated on a glove for monitoring the angle of finger motions. Interestingly, by attaching the sensor to the skin of the neck, the pharynx motions when speaking, coughing, and swallowing exhibited obvious and consistent signals. This research highlights the effect of the shapes and structures of e-textile strain sensors in the operation of a wearable e-textile system. This work also is intended as a starting point that will shape the standardization of strain fabric sensors in different applications.

scholarly journals A Novel Textile Stitch-Based Strain Sensor for Wearable End Users

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1469 ◽  
Author(s):  
Orathai Tangsirinaruenart ◽  
George Stylios
Keyword(s):  
Mechanical Properties ◽  
Electrical Resistance ◽  
Body Movement ◽  
Strain Sensor ◽  
Strain Sensors ◽  
Gauge Factor ◽  
Heart Monitoring ◽  
Textile Sensors ◽  
Good Repeatability ◽  
The Ideal

This research presents an investigation of novel textile-based strain sensors and evaluates their performance. The electrical resistance and mechanical properties of seven different textile sensors were measured. The sensors are made up of a conductive thread, composed of silver plated nylon 117/17 2-ply, 33 tex and 234/34 4-ply, 92 tex and formed in different stitch structures (304, 406, 506, 605), and sewn directly onto a knit fabric substrate (4.44 tex/2 ply, with 2.22, 4.44 and 7.78 tex spandex and 7.78 tex/2 ply, with 2.22 and 4.44 tex spandex). Analysis of the effects of elongation with respect to resistance indicated the ideal configuration for electrical properties, especially electrical sensitivity and repeatability. The optimum linear working range of the sensor with minimal hysteresis was found, and the sensor’s gauge factor indicated that the sensitivity of the sensor varied significantly with repeating cycles. The electrical resistance of the various stitch structures changed significantly, while the amount of drift remained negligible. Stitch 304 2-ply was found to be the most suitable for strain movement. This sensor has a wide working range, well past 50%, and linearity (R2 is 0.984), low hysteresis (6.25% ΔR), good gauge factor (1.61), and baseline resistance (125 Ω), as well as good repeatability (drift in R2 is −0.0073). The stitch-based sensor developed in this research is expected to find applications in garments as wearables for physiological wellbeing monitoring such as body movement, heart monitoring, and limb articulation measurement.

scholarly journals SMART FABRICS-WEARABLE TECHNOLOGY

2020 ◽  
Vol 4 (10) ◽  
pp. 78-98
Author(s):  
Yinka-Banjo Chika ◽  
Salau Abiola Adekunle
Keyword(s):  
Power Management ◽  
Electronic Devices ◽  
Wearable Technology ◽  
Electronic Systems ◽  
Electronic Manufacturing ◽  
Smart Fabrics ◽  
Wearable Systems ◽  
Recent Developments ◽  
Embedded Electronics ◽  
Manufacturing Techniques

Smart fabrics, generally regarded as smart Textiles are fabrics that have embedded electronics and interconnections woven into them, resulting in physical flexibility that is not achievable with other known electronic manufacturing techniques. Interconnections and components are intrinsic to the fabric therefore are not visible and less susceptible of getting tangled by surrounding objects. Smart fabrics can also more easily adapt to quick changes in the sensing and computational requirements of any specific application, this feature being useful for power management and context awareness. For electronic systems to be part of our day-to-day outfits such electronic devices need to conform to requirements as regards wear-ability, this is the vision of wearable technology. Wearable systems are characterized by their capability to automatically identify the activity and the behavioral status of their wearer as well as of the situation around them, and to use this information to adjust the systems' configuration and functionality. This write-up focused on recent developments in the field of Smart Fabrics and pays particular attention to the materials and their manufacturing techniques.

An efficient PEDOT-coated textile for wearable thermoelectric generators and strain sensors

2019 ◽  
Vol 7 (12) ◽  
pp. 3496-3502 ◽  
Author(s):  
Yanhua Jia ◽  
Lanlan Shen ◽  
Jing Liu ◽  
Weiqiang Zhou ◽  
Yukou Du ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Strain Sensors ◽  
Thermoelectric Generators ◽  
Electronic Textiles ◽  
Water Durability

Highly flexible PEDOT-based electronic textiles were successfully fabricated for wearable thermoelectric generators and strain sensors with high sensitivity and superior water durability.

scholarly journals Single-Layer Pressure Textile Sensors with Woven Conductive Yarn Circuit

2020 ◽  
Vol 10 (8) ◽  
pp. 2877 ◽  
Author(s):  
Gaeul Kim ◽  
Chi Cuong Vu ◽  
Jooyong Kim
Keyword(s):  
Pressure Sensor ◽  
Pressure Sensors ◽  
Single Layer ◽  
Fast Response ◽  
Resistance Change ◽  
Load Pressure ◽  
Pressure Sensitive ◽  
High Durability ◽  
Textile Sensors ◽  
Conductive Fibers

Today, e-textiles have become a fundamental trend in wearable devices. Fabric pressure sensors, as a part of e-textiles, have also received much interest from many researchers all over the world. However, most of the pressure sensors are made of electronic fibers and composed of many layers, including an intermediate layer for sensing the pressure. This paper proposes the model of a single layer pressure sensor with electrodes and conductive fibers intertwined. The plan dimensions of the fabricated sensors are 14 x 14 mm, and the thickness is 0.4 mm. The whole area of the sensor is the pressure-sensitive point. As expected, results demonstrate an electrical resistance change from 283 Ω at the unload pressure to 158 Ω at the load pressure. Besides, sensors have a fast response time (50 ms) and small hysteresis (5.5%). The hysteresis will increase according to the pressure and loading distance, but the change of sensor loading distance is very small. Moreover, the single-layer pressure sensors also show high durability under many working cycles (20,000 cycles) or washing times (50 times). The single-layer pressure sensor is very thin and more flexible than the multi-layer pressure sensor. The structure of this sensor is also expected to bring great benefits to wearable technology in the future.

Manufacturing techniques and property evaluations of conductive elastic knits

2018 ◽  
Vol 49 (4) ◽  
pp. 503-533
Author(s):  
Ching-Wen Lou ◽  
Chih-Hung He ◽  
Jia-Horng Lin
Keyword(s):  
Electric Circuit ◽  
Positive Influence ◽  
Electronic Textiles ◽  
Electric Circuits ◽  
Twisted Yarn ◽  
Conductive Yarns ◽  
Wearable Electronic ◽  
Metallic Wires ◽  
Manufacturing Techniques ◽  
Maximum Increment

Textiles can have valuable functions in terms of measurement, detection and communication when they are incorporated into functional electronic devices. However, the additional electric circuits limit the flexibility and extensibility, making the wearers uncomfortable and the manufacturing difficult. Therefore, in this study, conductive elastic knits are made of metallic yarns and expected to be used as wearable electronic textiles. In order to retain the flexibility of knits, a crochet machine with jacquard equipment is used to create knit patterns as electric circuits. Regardless of whether it is single-twisted yarn, double-twisted yarn, single-wrapped yarn, or double-wrapped yarn, the metallic wires can be completely covered in polyester filaments. Variations in twist numbers of conductive yarns or knit patterns are beneficial to the tensile strength with a maximum increment of 14%, and changing twist numbers of conductive yarns or knit patterns have a positive influence on the air permeability with a maximum increment of 24%. According to the results of the electric circuit stability test, using double-covered yarns ensures the knits a stabilized electric circuit regardless of the knit pattern.

scholarly journals Stretchable Strain Sensors for Human Movement Monitoring

2020 ◽  
Author(s):  
Abhishek Singh Dahiya ◽  
Thierry Gil ◽  
Nadine Azemard ◽  
Jerome Thireau ◽  
Alain Lacampagne ◽  
...  
Keyword(s):  
Human Movement ◽  
Strain Sensors ◽  
Movement Monitoring

All-fabric interconnection and one-stop production process for electronic textile sensors

2016 ◽  
Vol 87 (12) ◽  
pp. 1445-1456 ◽  
Author(s):  
Jung-Sim Roh
Keyword(s):  
Production Process ◽  
Production Method ◽  
Base Layer ◽  
Electronic Textiles ◽  
Conductive Materials ◽  
Textile Sensors ◽  
One Stop ◽  
External Forces ◽  
Electronic Textile ◽  
Electronic Technologies

This study developed and tested the development of an all-fabric interconnection and one-stop production process for electronic textiles that are combined with electronic technologies on textiles. Primarily, this is a one-stop production method for electronic textiles consisting of multilayer structured fabrics for implementation of electronic functions in which (1) precise circuit patterns are formed, (2) conductive materials or conductive circuits on each fabric layer are electrically connected, and (3) individual fabric layers are fixed to the base layer through embroidery, while fabric layers are layered one by one using a commercial computer numeric control embroidery machine. Since the multilayer fabric structured electronic textiles constructed have different layers of conductive materials connected electrically, quickly durably, and reliably through embroidery, (1) the electrically connected parts are not likely to be broken by external forces, (2) all parts to be connected to external devices are formed on one piece of fabric so that the work to connect the textiles to an external device is simple, and (3) workability and productivity are improved so that manufacturing costs can be reduced and the textiles can be mass produced. Therefore, this one-stop method using commercial machinery has great potential as a highly useful technology that can be implemented on an industrial scale.

scholarly journals QUARK MODEL ESTIMATES OF THE STRUCTURE OF THE MESON-N-N*(1/2-) TRANSITION VERTICES

2007 ◽  
Vol 16 (01) ◽  
pp. 81-95
Author(s):  
M. DILLIG ◽  
S. S. ROCHA ◽  
G. F. MARRANGHELLO ◽  
E. F. LÜTZ ◽  
C. A. Z. VASCONCELLOS
Keyword(s):  
Form Factors ◽  
Baryon Resonance ◽  
Explicit Representation ◽  
Coupling Constants ◽  
Meson Exchange ◽  
Diquark Model ◽  
Actual Problem ◽  
Exchange Processes ◽  
Starting Point ◽  
Pseudo Scalar

We address an actual problem of baryon-resonance dominated meson-exchange processes in the low GeV regime, i.e. the phase and the structure of meson-NN* transition vertices. Our starting point is a quark-diquark model for the baryons (obeying approximate covariance; the mesons are kept as elementary objects), together with the relative phases for the NN vertices, as determined from low energy NN scattering. From the explicit representation of the N and N* baryons, we exemplify the derivation of phases, coupling constants and form factors of the NN* (J = 1/2-) transition vertices for pseudo-scalar, scalar and vector mesons.

scholarly journals Studies of technology in prehistoric archaeology

2011 ◽  
pp. 465-480
Author(s):  
Selena Vitezovic
Keyword(s):  
Material Culture ◽  
Complex Analysis ◽  
Raw Materials ◽  
Raw Material ◽  
Social Foundations ◽  
Starting Point ◽  
Material Choice ◽  
Manufacturing Techniques ◽  
High Level ◽  
Organization Of Production

Technology studies have always been the most important focus of archaeology, as a science which analyzes human past through the study of material culture. To say that something is technological in archaeology, means to put the concept of technology in the centre of theoretical studies, and to study not only the form of the object, but also the entire sequence of technological factors, from raw material choice, mode of use, up to the reasons for abandonment. The concept of technology in anthropology and archaeology is based on the original meaning of the word ????? in ancient Greek, meaning the skill, i. e., to study how something is being done. Such a concept of technology as a skill or mode of doing something was for the first time outlined by the French anthropologist Marcel Mauss, whose starting point was that every technological statement was at the same time social or cultural statement and that technological choices have social foundations. Pierre Lemonnier further developed the anthropology of technology, focusing on the question of technological choices, as well as numerous other anthropologists. In archaeology, the most important contribution to the study of technology was the work of Andr? Leroi-Gourhan, who created the concept of cha?ne op?ratoire, as an analytical tool for studying the mode of creating, using and discarding an artefact, starting with raw material acquisition, mode of manufacture, final form, use (including caching, breaking and repairing) up to the final discarding. It is not only about reconstructing the algorithmic sequence of operations in creating one object, but it is a complex analysis of operational chain within one society which includes the analysis of technological choices. The analyses of technologies today include a variety of different approaches, most of them with emphasis on the cultural and social aspects of technology. The analysis of bone industry in the Early and Middle Neolithic in central Balkans (Starcevo culture), which included not only final objects, but also manufacture debris and semi-finished products, revealed a well developed industry, with a high level of technological knowledge on the properties of raw materials, skillful manufacture, well organized production, as well as possibility of a certain degree of specialization on the micro and macro level (within one settlement and within a group of settlements). Both raw material choices and manufacturing techniques, as well as the final forms, demonstrated a high standardization level. Also certain symbolic value was attributed to some raw materials, and there is a possibility that skill itself was valued. Further analyses of multiple technologies will help in reconstructing the organization of production, social and economic aspects in Neolithic societies, as well as the role of technology in everyday and ritual life.

scholarly journals Liquid Metal-Based Devices: Material Properties, Fabrication and Functionalities

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3400
Author(s):  
Jian Dong ◽  
Yuanyuan Zhu ◽  
Zhifu Liu ◽  
Meng Wang
Keyword(s):  
Liquid Metal ◽  
Material Properties ◽  
Flow Characteristics ◽  
Strain Sensors ◽  
Electrical Stability ◽  
Nonlinear Materials ◽  
Capillary Method ◽  
Communication Device ◽  
Fluid Properties ◽  
Manufacturing Techniques

This paper reviews the material properties, fabrication and functionalities of liquid metal-based devices. In modern wireless communication technology, adaptability and versatility have become attractive features of any communication device. Compared with traditional conductors such as copper, the flow characteristics and lack of elastic limit of conductive fluids make them ideal alternatives for applications such as flexible circuits, soft electronic devices, wearable stretch sensors, and reconfigurable antennas. These fluid properties also allow for innovative manufacturing techniques such as 3-D printing, injecting or spraying conductive fluids on rigid/flexible substrates. Compared with traditional high-frequency switching methods, liquid metal (LM) can easily use micropumps or an electrochemically controlled capillary method to achieve reconfigurability of the device. The movement of LM over a large physical dimension enhances the reconfigurable state of the antenna, without depending on nonlinear materials or mechanisms. When LM is applied to wearable devices and sensors such as electronic skins (e-skins) and strain sensors, it consistently exhibits mechanical fatigue resistance and can maintain good electrical stability under a certain degree of stretching. When LM is used in microwave devices and paired with elastic linings such as polydimethylsiloxane (PDMS), the shape and size of the devices can be changed according to actual needs to meet the requirements of flexibility and a multistate frequency band. In this work, we discuss the material properties, fabrication and functionalities of LM.

Sign in / Sign up

Export Citation Format

Share Document