• Journal of Fashion Business
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• v.21 no.2
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• pp.78-90
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• 2017

In this study, brassiere prototype was developed for attaching the measuring module of ECG measurement and body movement while sleeping. For ECG measurement, textile electrodes was made of stretch fabric containing polyurethane in consideration of elasticity of brassiere band. It was used as a conductive yarn by silver coating on the warp. The textile electrodes was woven with twisted twill to increase the density of conductive yarns. The pressure of the brassiere band was enough to sensing stably the ECG, and the elastic band of the brassiere was designed to be wider than 3cm to install the textile electrodes inside, so that textile electrodes was close fitting to the skin at a constant pressure without lifting. The textile electrodes coated with silicon on rear was attached to brassiere elastic band, and the module was installed with a snap connector to textile electrodes of brassiere band. The module was suitable to monitering ECG measurement of a typical R peak, pulse rate and body movement while sleeping without interfering.

• Science of Emotion and Sensibility
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• v.11 no.3
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• pp.419-426
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• 2008

In order to develop "textile electrode - sensing clothing" which is a sort of smart clothing to measure electric activities of heart, we propose possible ways to develop textile electrode and design of sensing clothing, ultimately aiming to develop "ECG sensing clothing for lifestyle monitoring". Conventional sensors for measuring typical electric activities of heart keep certain distance between measuring electrodes to measure signals for electric activities of heart, but these sensors often cause inappropriate factors (e.g. motional artifacts, inconvenience of use, etc) for monitoring natural cardiac activities in our daily life. In addition, most of textile electrodes have made it difficult to collect data due to high impedance and unstable contact between skin and electrodes. To overcome these questions, we minimized distance between electrodes and skin to maximize convenience of use. And in order to complement contact between skin electrodes, we modified textile electrode's form and developed ways to design clothing. As a result, we could find out clinical significance by investigating possible associations of clinical electrocardiogram (ECG) with variation of distance between electrodes, and could also demonstrate clinically significant associations between textile electrode developed herein and clothing.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.5
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• pp.367-372
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• 2013

In this paper, micro dried bio-potential electrodes are demonstrated for sEMG (surface ElectroMyoGraphic) signal measurement using conductive epoxy on the textile fabric. Micro dried bio-potential electrodes on the textile fabric substrate have several advantages over the conventional wet/dry electrodes such as good feeling of wearing, possibility of extended-wearing due to the good ventilation. Also these electrodes on the textile fabric can easily apply to the curved skin surface. These electrodes are fabricated by the screen-printing process with the size of $1mm{\times}10mm$ and the resultant resistance of these electrodes have the average value of $0.4{\Omega}$. The conventional silver chloride electrode shows the average value of $0.3{\Omega}$. However, the electrode on the textile fabric are able to measure the sEMG signal without feeling of difference and this electrode shows the lower resistance of $1.03{\Omega}$ than conventional silver chloride electrode with $2.8{\Omega}$ in the condition of the very sharp curve surface (the radius of curvature is 40 mm).

• Journal of Biomedical Engineering Research
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• v.44 no.1
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• pp.80-84
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• 2023

Electrodes are one of the types of biosensors capable of measuring bio signals, such as electrocardiogram (ECG) and electromyogram (EMG) signals. These electrodes are used in various fields and offer the advantage of being able to measure ECG signals without the need for skin attachment, compared to Ag/AgCl electrodes. The purpose of this study was to evaluate the efficacy of conductive textile electrodes in collecting ECG signals in a bed-like environment. Three adult participants were involved, and a total of 30 minutes of ECG signals were collected for each participant. The collected ECG signals were analyzed to determine the heart rate, normLF and a comparison was made between the conductive textile electrodes and Ag/AgCl electrodes. As a result, the change in heart rate and normLF could be observed, and in particular, the difference between the two electrodes decreased. This study confirmed that conductive textile electrodes can effectively collect ECG signals in a bed-like environment. It is hoped that this research will lead to the development of a system that can detect various sleep-related diseases through the use of these electrodes.

• Fashion & Textile Research Journal
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• v.21 no.6
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• pp.697-707
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• 2019

This review paper deals with materials, classification, and a current article investigation on smart textile sensors for wearable vital signs monitoring (WVSM). Smart textile sensors can lose electrical conductivity during vital signs monitoring when applying them to clothing. Because they should have to endure severe conditions (bending, folding, and distortion) when wearing. Imparting electrical conductivity for application is a critical consideration when manufacturing smart textile sensors. Smart textile sensors fabricate by utilizing electro-conductive materials such as metals, allotrope of carbon, and intrinsically conductive polymers (ICPs). It classifies as performance level, fabric structure, intrinsic/extrinsic modification, and sensing mechanism. The classification of smart textile sensors by sensing mechanism includes pressure/force sensors, strain sensors, electrodes, optical sensors, biosensors, and temperature/humidity sensors. In the previous study, pressure/force sensors perform well despite the small capacitance changes of 1-2 pF. Strain sensors work reliably at 1 ㏀/cm or lower. Electrodes require an electrical resistance of less than 10 Ω/cm. Optical sensors using plastic optical fibers (POF) coupled with light sources need light in-coupling efficiency values that are over 40%. Biosensors can quantify by wicking rate and/or colorimetry as the reactivity between the bioreceptor and transducer. Temperature/humidity sensors require actuating triggers that show the flap opening of shape memory polymer or with a color-changing time of thermochromic pigment lower than 17 seconds.

• Journal of the Korean Society of Clothing and Textiles
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• v.44 no.3
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• pp.427-440
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• 2020

This study developed a vest prototype capable of monitoring body temperature using textile electrodes to prevent the sudden death of babies as well as to determine the quality of developed products by evaluating usability with commercial products. Based on the results of the 7th Size Korea Project, a basic pattern for a vest prototype was drafted by applying the average size of two-year-old Korean babies. Two prototypes were the detachable (VEST I) and integrated textile electrodes vest type (VEST II), which followed the same design. The materials were 100% cotton single jersey (SJ) and double jersey (DJ). Six experts evaluated the usability of the developed vests (VEST I & VEST II) and commercial product (VEST M). The single-layer woven textile electrode appeared to have a slightly higher conductivity than the double-layer one. There was no statistical difference in the body temperature sensing function between VEST I and VEST II. Finally, the superiority of the VEST I was verified through a comparison with commercial products (VEST M). The usability test suggested that a wearable smart clothing system of the integrated conductive textile could be further commercialized for bio-monitor applications in Ubiquitous-health care.

• Science of Emotion and Sensibility
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• v.26 no.4
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• pp.41-50
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• 2023

This study aims to develop electromyography (EMG) textile electrodes and assess their performance and signal stability by examining variations in layer count and fabric types. We fabricated the electrodes through layering and pressing techniques, focusing on configurations with different layer counts (Layer-0, Layer-1, and Layer-2). Our findings indicate that layer presence significantly influences muscle activation measurements, with enhanced performance correlated with increased layer numbers. Subsequently, we created electrodes from five distinct fabrics (neoprene, spandex cushion, 100% polyester, nylon spandex, and cotton canvas), each maintaining a Layer-2 structure. In performance tests, nylon spandex fabric, particularly heavier variants, outperformed others, while the spandex cushion electrodes showed superior stability in muscle activation signal acquisition. This research elucidates the connection between electrode performance and factors like layer number and electrode-skin contact area. It suggests a novel approach to electrode design, focusing on layer properties and targeted pressure application on specific sensor areas, rather than uniformly increasing sleeve pressure.

• Textile Coloration and Finishing
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• v.35 no.2
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• pp.121-127
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• 2023

In this study, a comprehensive investigation was conducted on the morphological and property changes of laser-induced nanocarbon (LINC) as a function of laser process parameters. LINC was formed on the surfaces of polyimide films with different backbone structures under various process conditions, including laser power, scan speed, and resolution. Three different forms of LINC electrodes (i.e., continuous 3D porous graphene, wooly nanocarbon fibers, line cut) were formed depending on the laser power and scan speed. Furthermore, heteroatom doping induced from the chemical structure of the polyimide during laser patterning was found to be effective in modifying the electrical properties of LINC electrodes. The LINC surfaces exhibited different microstructures depending on the laser beam resolution under constant laser power and scan speed, allowing for controllable surface wettability. The correlation between the chemical structure of the polymer substrate, laser process parameters, and carbonized surface properties in this study is expected to be utilized as fundamental understanding for the manufacturing of next-generation carbon-based electronic devices.

• Science of Emotion and Sensibility
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• v.21 no.4
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• pp.63-76
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• 2018

The purpose of this study was to investigate the effect of contact type textile electrode structure on heart activity signal acquisition for smart healthcare. In this study, we devised six contact type textile electrodes whose electrode size and configuration were manipulated for measuring heart activity signals using computerized embroidery. We detected heart activity signals using a modified lead II and by attaching each textile electrode to the chest band in four healthy male subjects in a standing static posture. We measured the signals four times repeatedly for all types of electrodes. The heart activity signals were sampled at 1 kHz using a BIOPAC ECG100, and the detected original signals were filtered through a band-pass filter. To compare the performance of heart activity signal acquisition among the different structures of the textile electrodes, we conducted a qualitative analysis using signal waveform and size as parameters. In addition, we performed a quantitative analysis by calculating signal power ratio (SPR) of the heart activity signals obtained through each electrode. We analyzed differences in the performance of heart activity signal acquisition of the six electrodes by performing difference and post-hoc tests using nonparametric statistic methods on the calculated SPR. The results showed a significant difference both in terms of qualitative and quantitative aspects of heart activity signals among the tested contact type textile electrodes. Regarding the configurations of the contact type textile electrodes, the three-dimensionally inflated electrode (3DIE) was found to obtain better quality signals than the flat electrode. However, regarding the electrode size, no significant difference was found in performance of heart signal acquisition for the three electrode sizes. These results suggest that the configuration method (flat/3DIE), which is one of the two requirements of a contact type textile electrode structure for heart activity signal acquisition, has a critical effect on the performance of heart activity signal acquisition for wearable healthcare. Based on the results of this study, we plan to develop a smart clothing technology that can monitor high-quality heart activity without time and space constraints by implementing a clothing platform integrated with the textile electrode and developing a performance improvement plan.

• Science of Emotion and Sensibility
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• v.24 no.2
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• pp.49-56
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• 2021

In this study, we investigated the necessary mechanical properties of conductive multifilament yarns for fabricating the electrodes of biosignal measurement pressure and stretch textile sensors using embroidery. When electrodes and circuits for smart wearable products are produced through the embroidery process using conductive multifilament yarns, unnecessary material loss is minimized, and complex electrode shapes or circuit designs can be produced without additional processes using a computer embroidering machine. However, because ordinary missionary threads cannot overcome the stress in the embroidery process and yarn cutting occurs, herein, we analyzed the S-S curve, thickness, and twist structure, which are three types of silver-coated multifilament yarns, and measured the stress in the thread of the embroidery simultaneously. Thus, the required mechanical properties of the yarns in the embroidery process were analyzed. In the actual sample production, cutting occurred in silver-coated multifilament rather than silver-coated polyamide/polyester, which showed the lowest S-S curve. In the embroidery process, the twist was unwound through repetitive vertical movement. Further, we fabricated a piezoresistive pressure/tension sensor to measure gauge factor, which is an index for measuring biological signals. We confirmed that the sensor can be applied to the fabrication of embroidery electrodes, which is an important process in the mass production of smart wearable products.