scholarly journals An Alternative Method to Develop Embroidery Textile Strain Sensors

Textiles ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 504-512
Author(s):  
Marc Martínez-Estrada ◽  
Ignacio Gil ◽  
Raúl Fernández-García
Keyword(s):  
Strain Sensors ◽  
Experimental Results ◽  
Healthcare Sector ◽  
Knee Angle ◽  
Pure Silver ◽  
Alternative Method ◽  
Textile Sensor ◽  
Commercial Applications ◽  
Conductive Yarn

In this paper, a method to develop embroidered textile strain resistive sensors is presented. The method is based on two overlapped zigzag conductive yarn patterns embroidered in an elastic textile. To demonstrate the functionality of the proposed configuration, a textile sensor embroidered with a conductor yarn composed of 99% pure silver-plated nylon yarn 140/17 dtex has been experimentally characterised for an elongation range from 0% to 65%. In order to show the sensor applicability, a second test with the sensor embroidered in a knee-pad has been done to evaluate the flexion knee angle from 180° to 300°. The experimental results show the usefulness of the proposed method to develop fabric strain sensors that can help to manufacture commercial applications on the healthcare sector.

scholarly journals A Knitted Sensing Glove for Human Hand Postures Pattern Recognition

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1364
Author(s):  
Seulah Lee ◽  
Yuna Choi ◽  
Minchang Sung ◽  
Jihyun Bae ◽  
Youngjin Choi
Keyword(s):  
Pattern Recognition ◽  
Confusion Matrix ◽  
Strain Sensors ◽  
Mixed Data ◽  
Human Hand ◽  
Flexible Sensors ◽  
Target Hand ◽  
The Cost ◽  
Grasp Posture ◽  
Conductive Yarn

In recent years, flexible sensors for data gloves have been developed that aim to achieve excellent wearability, but they are associated with difficulties due to the complicated manufacturing and embedding into the glove. This study proposes a knitted glove integrated with strain sensors for pattern recognition of hand postures. The proposed sensing glove is fabricated at all once by a knitting technique without sewing and bonding, which is composed of strain sensors knitted with conductive yarn and a glove body with non-conductive yarn. To verify the performance of the developed glove, electrical resistance variations were measured according to the flexed angle and speed. These data showed different values depending on the speed or angle of movements. We carried out experiments on hand postures pattern recognition for the practicability verification of the knitted sensing glove. For this purpose, 10 able-bodied subjects participated in the recognition experiments on 10 target hand postures. The average classification accuracy of 10 subjects reached 94.17% when their own data were used. The accuracy of up to 97.1% was achieved in the case of grasp posture among 10 target postures. When all mixed data from 10 subjects were utilized for pattern recognition, the average classification expressed by the confusion matrix arrived at 89.5%. Therefore, the comprehensive experimental results demonstrated the effectiveness of the knitted sensing gloves. In addition, it is expected to reduce the cost through a simple manufacturing process of the knitted sensing glove.

The effect of washing on the electrical performance of knitted textile strain sensors for quantifying joint motion

2021 ◽  
pp. 152808372110592
Author(s):  
Cristina Isaia ◽  
Simon McMaster ◽  
Donal McNally
Keyword(s):  
Elbow Flexion ◽  
Strain Sensors ◽  
Electrical Performance ◽  
Market Penetration ◽  
Maximum Extension ◽  
Maximum Flexion ◽  
Flexion Extension ◽  
Textile Sensor ◽  
Simulated Training

Successful market penetration of textile-based strain sensors requires long-term reliability which in turn relies on the washability of the sensor. First, this paper presents an evaluation of the effect of 5 washing cycles on the electrical performance of a knitted conductive transducer, over 1500 cycles of repetitive elongation. The promising behaviour of the textile sensor in this study showed that it might be possible to make a smart garment, capable of quantifying elbow flexion-extension motion, by integrating it into an elbow sleeve. Second, a prototype sleeve, incorporating a knitted sensor (the so-called smart sleeve), was tested in a simulated training/clinical setting by performing 50 flexion-extension cycles after 1, 5, 15, 25, 50 and 75 washes. In both studies, the electrical resistance of the sensor increased with the number of washes in a predictable manner and exhibited a repeatable, reliable and prompt response to elongation. In particular, the electrical pattern representing flexion-extension motion measured using the sleeve was clear and distinguishable up to the 75th wash. Moreover, resistance measurements within the same trial were repeatable at maximum flexion (≤2% variation) and at maximum extension (≤3% variation) and predictable with increasing washes (R2 = 0.992 at maximum flexion and R2 = 0.989 at maximum extension). The good washability of the smart sleeve, evidenced by its ability to detect, distinguish and measure parameters of flexion-extension motion up to 75 washes, makes it a suitable and sustainable choice for applications, such as strength conditioning or rehabilitation, where repetition count and speed are useful.

Machine for the Hydrostatic Extrusion–Drawing of Wire

1972 ◽  
Vol 186 (1) ◽  
pp. 499-507
Author(s):  
H. Ll. D. Pugh ◽  
P. T. Wilkinson ◽  
M. H. Hodge
Keyword(s):  
Copper Wire ◽  
Research Work ◽  
Hydrostatic Extrusion ◽  
Experimental Results ◽  
Experimental Investigations ◽  
Small Scale ◽  
New Process ◽  
And Performance ◽  
Commercial Applications ◽  
Fine Copper

Research work on hydrostatic extrusion at N.E.L. (National Engineering Laboratory) has led to the development of a new process for producing wire. A detailed account is given of machines specially designed to exploit this process of hydrostatic extrusion–drawing mainly on the production of fine copper wire. A small-scale machine was built to confirm the design and for experimental investigations. The success of this preliminary work has led to the construction of a large prototype production machine for commercial applications. The operation and performance of both machines is described and some experimental results given.

scholarly journals Impact of Conductive Yarns on Embroidery Textile Moisture Sensor

2019 ◽  
Author(s):  
Marc Martinez-Estrada ◽  
Raul Fernandez-Garcia ◽  
Ignacio Gil
Keyword(s):  
Relative Humidity ◽  
Performance Comparison ◽  
Experimental Results ◽  
Climatic Chamber ◽  
Moisture Measurement ◽  
Moisture Sensor ◽  
Sensor Sensitivity ◽  
Conductive Yarns ◽  
Lcr Meter ◽  
Conductive Yarn

In this work, two embroidered textile moisture sensors are characterized with three different conductive yarns. The sensors are based on a capacitive interdigitated structure embroidered on a cotton substrate with an embroidered conductor yarn. The performance comparison of 3 different type of conductive yarns has been addressed. In order to evaluate the sensor sensitivity, the impedance of the sensor has been measured by means of a LCR meter from 20 Hz to 20 kHz on a climatic chamber with a sweep of the relative humidity from 30% to 65% at 20 ºC. The experimental results show a clear and controllable dependence of the sensor impedance with the relative humidity and the used conductor yarns. This dependence points out the optimum conductive yarn to be used to develop wearable applications for moisture measurement.

scholarly journals Wearable Lumbar-Motion Monitoring Device with Stretchable Strain Sensors

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Hiroyuki Nakamoto ◽  
Tokiya Yamaji ◽  
Akio Yamamoto ◽  
Hideo Ootaka ◽  
Yusuke Bessho ◽  
...  
Keyword(s):  
Risk Factors ◽  
Low Back Pain ◽  
Back Pain ◽  
Strain Sensors ◽  
Experimental Results ◽  
Monitoring Device ◽  
Low Back ◽  
Motion Measurement ◽  
Periodic Cycles ◽  
Lumbar Motion

Low-back pain is a common affliction. Epidemiological analyses have reported that periodic cycles of lumbar flexion and rotation are major risk factors for low-back pain. To prevent low-back pain, a lumbar-motion monitoring device could help diagnosticians assess patients’ risk for low-back pain. This study proposes such a device that uses lightweight stretchable strain sensors. Six of these strain sensors form a parallel-sensor mechanism that measures rotation angles of lumbar motion in three axes. The parallel-sensor mechanism calculates rotation angles from the lengths of the strain sensors iteratively. Experimental results reveal that the prototype device is effective for lumbar-motion measurement and significantly improves in terms of wearability over comparable devices.

Core Conductive Yarn Based Integral Knitted ESD Garments Part I. Metallic Core Conductive Yarns Investigation

2013 ◽  
Vol 772 ◽  
pp. 467-473 ◽  
Author(s):  
Codrin Donciu
Keyword(s):  
Electrostatic Discharge ◽  
Experimental Results ◽  
Current Paper ◽  
Metallic Core ◽  
Different Types ◽  
Conductive Yarns ◽  
Conductive Yarn

A research regarding the integral knitted structures for electrostatic discharge (ESD) protective garments with core conductive fibres is currently undergoing. The results of the research will be published in three papers. The current paper presents a study on the knitted structures made with metallic core conductive fibres. A number of 15 samples made with different types of fibres were manufactured and tested for their ESD characteristics. From the experimental results, conclusions were drawn about ESD performances of tested samples.

Comparison of Polynomial Cam Profiles and Input Shaping for Driving Flexible Systems

2012 ◽  
Vol 134 (12) ◽  
Author(s):  
Brice Pridgen ◽  
William Singhose
Keyword(s):  
Rise Time ◽  
Laplace Transforms ◽  
Experimental Results ◽  
Input Shaping ◽  
Flexible Systems ◽  
Residual Vibration ◽  
Alternative Method ◽  
Cam Follower ◽  
Low Pass ◽  
Polynomial Profiles

Polynomial profiles can be used as reference commands to limit induced vibration in flexible systems. Due to their ease of design and low-pass filtering effects, polynomial profiles are often found in cam-follower systems. Polynomial profiles have also been used as smooth reference commands for automated machines. However, despite extensive work to develop and improve such profiles, inherent tradeoffs still exist between induced vibration, rise time, and ease of design. Input shaping is an alternative method for generating motion commands that reduce residual vibration. This paper compares polynomial profiles to input-shaped commands for the application of reducing vibration in flexible systems. Analyses using Laplace transforms reveal that input shapers suppress vibration at regularly spaced frequencies. However, polynomial profiles do not share this property. Simulations and experimental results show that input shaping improves rise time and reduces residual vibration in comparison to polynomial profiles.

Technique of Javascript Code Obfuscation Based on Control Flow Tansformations

2014 ◽  
Vol 519-520 ◽  
pp. 391-394
Author(s):  
Zhi Yue Wang ◽  
Wei Min Wu
Keyword(s):  
Rapid Development ◽  
Source Code ◽  
Control Flow ◽  
Experimental Results ◽  
Web Development ◽  
Code Obfuscation ◽  
Scripting Language ◽  
Commercial Applications

With the rapid development of scripting language, javascript has been widely used in the application and web development industry.One of the main disadvantages of javascript for developers of commercial applications is the ease by which customers and competitors can study, analyze, and reuse the source code . Therefore, this paper proposes a technique of javascript code obfuscation based on control flow tansformations. The experimental results prove that,its effective protect javascript source code.

Development of Modeling Techniques for Damping Applications of Nano Structured Composites With High Aspect Ratio Fillers

2010 ◽  
Author(s):  
Joshua A. Varischetti ◽  
Jae-Soon Jang ◽  
Jonghwan Suhr
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Structural Integrity ◽  
Low Frequency ◽  
Experimental Results ◽  
Experimental Investigations ◽  
Frequency Range ◽  
Analysis Techniques ◽  
Nano Scale ◽  
Commercial Applications

Recent advances in the production and wide scale availability of nano scale constituents, coupled with ongoing fundamental research utilizing them as fillers in host matrices for a variety of specific engineering inquiries has led to a notable interest in the use of nano scale fillers for specific commercial applications, specifically in the aerospace industry. Damping is of particular importance in modern composites, having high stiffness and low density, damping becomes a large issue, both for structural integrity as well as noise attenuation. The largest obstacle which must first be overcome in order to incorporate the nano scale constituents in commercial applications is the development of design useful modeling and analysis techniques which allow for calculated design decisions based on constituent properties. Currently, there is a large gap in performance of nano structured composites, where in the current analysis techniques tend to overstate the performance achieved relative to experimental results. This discrepancy has been attributed to a number of factors ranging from non-perfect geometry, to issues at the interface between matrix and filler, however there has not yet been a detailed investigation to the ability to accurately predict composite viscoelastic performance based on constituent properties. On of the most common approaches to modeling high aspect ratio nano fillers, carbon nano tubes and carbon nano fibers, is to assume a perfect cylindrical geometry, even though it is well understood that these fillers can have a significant curvature or waviness to them. This investigation combines modeling work looking at the effect of the waviness and the resulting reinforcement provided, in terms of viscoelastic response, which is then compared to experimental results. Damping is characterized with respect to operating temperatures and frequency range, of specific interest is the low frequency range, which is traditionally more difficult to damp. Experimental investigations utilize dynamic mechanical analysis (DMA) to characterize viscoelastic performance, which is then compared to modeling data where it has been found that trends can be accurately predicted.

scholarly journals Impact of Manufacturing Variability and Washing on Embroidery Textile Sensors

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3824 ◽  
Author(s):  
Marc Martinez-Estrada ◽  
Bahareh Moradi ◽  
Raúl Fernández-Garcia ◽  
Ignacio Gil
Keyword(s):  
Relative Humidity ◽  
Time Use ◽  
User Needs ◽  
Pure Silver ◽  
Process Variability ◽  
Moisture Sensor ◽  
Sensor Performance ◽  
Washing Process ◽  
Textile Sensors ◽  
Textile Sensor

In this work, an embroidered textile moisture sensor is presented. The sensor is based on a capacitive interdigitated structure embroidered on a cotton substrate with an embroidery conductor yarn composed of 99% pure silver plated nylon yarn 140/17 dtex. In order to evaluate the sensor sensitivity, the impedance of the sensor has been measured by means of a impedance meter (LCR) from 20 Hz to 20 kHz in a climatic chamber with a sweep of the relative humidity from 25% to 65% at 20 °C. The experimental results show a clear and controllable dependence of the sensor impedance with the relative humidity. Moreover, the reproducibility of the sensor performance subject to the manufacturing process variability and washing process is also evaluated. The results show that the manufacturing variability introduces a moisture measurement error up to 4%. The washing process impact on the sensor behavior after applying the first washing cycle implies a sensitivity reduction higher than 14%. Despite these effects, the textile sensor keeps its functionality and can be reused in standard conditions. Therefore, these properties point out the usefulness of the proposed sensor to develop wearable applications within the health and fitness scope including when the user needs to have a life cycle longer than one-time use.

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