Smart Clothing Applications Research Articles

Integration of PEDOT:PSS into Cotton Yarn as Ion‐Selective Sensors for Smart Clothing Applications

In recent years, textile sensors have played a crucial role in the development of smart clothing, which integrates electronic components and technology into garments. Furthermore, a variety of textile sensors in smart clothing have gained attention for their healthcare applications, including analyzing sweat, monitoring biomarkers, and sensing electrophysiology. The conductive polymer poly (3,4‐ethylene dioxythiophene): polystyrene sulfonate (PEDOT:PSS) has been explored for various applications, such as flexible and wearable electronics, neural interfaces, and bioelectronics devices. Herein, a sensitive and selective ion detection utilizing cotton yarn‐based textile sensors integrated with ion‐selective membranes (ISMs) is presented. First, a straightforward and reproducible approach for manufacturing textile sensors based on PEDOT:PSS is described. The relationship between the resistance change of these sensors and their performance, encompassing stability and flexibility is investigated. Following this, ISMs are integrated into the sensors to detect sodium (Na+) and potassium (K+) ions, separately. The sensors display a consistent linear response toward the detected ion in a concentration range from 1 to 50 mM. Moreover, the sensors exhibit notable selectivity against the undesired ion.

Influence of La3+ co-doping on the photoluminescence properties of YAG: Dy3+ electrospun light emitting nanofibers

Synthesizing Yttrium Aluminium Garnet (YAG) into nanoscale fibers significantly enhances its optical properties. These nanofibers exhibit excellent flexibility, lightweight nature, and high strength, making them highly suitable for smart clothing applications. Additionally, by doping rare earth ions into the YAG fibers, their luminescence properties can be further optimized, opening new possibilities for advanced smart clothing designs. In this paper, we present the successful fabrication of dysprosium (Dy) doped YAG nanofibers, lanthanum (La) doped YAG nanofibers, La co-doped Dy: YAG nanofibers with different concentration and investigate their photoluminescence properties. The photoluminescence excitation spectrum of the Dy3+-YAG nanofibers showed an intense peak centred at 350 nm due to absorption by Dy3+ ions and emits strong blue colour centred at 483 nm in emission spectrum, which is attributed to the 4F9/2 → 6H15/2 transition of Dy3+ions. The La3+-YAG nanofibers excited at 350 nm also showed an emission in blue region at 483 nm. Co-doping of La3+ ions in Dy3+-YAG nanofibers exhibited enhancement in the emission intensity significantly. In comparison with all as-synthesized nanofibers, specific concentration of Dy and La in YAG nanofibers would be the potential candidate for flexible light emitting devices.

Parasitic capacitance modeling and measurements of conductive yarns for e-textile devices

Conductive yarns have emerged as a viable alternative to metallic wires in e-Textile devices, such as antennas, inductors, interconnects, and more, which are integral components of smart clothing applications. But the parasitic capacitance induced by their micro-structure has not been fully understood. This capacitance greatly affects device performance in high-frequency applications. We propose a lump-sum and turn-to-turn model of an air-core helical inductor constructed from conductive yarns, and systematically analyze and quantify the parasitic elements of conductive yarns. Using three commercial conductive yarns as examples, we compare the frequency response of copper-based and yarn-based inductors with identical structures to extract the parasitic capacitance. Our measurements show that the unit-length parasitic capacitance of commercial conductive yarns ranges from 1 fF/cm to 3 fF/cm, depending on the yarn’s microstructure. These measurements offer significant quantitative estimation of conductive yarn parasitic elements and provide valuable design and characterization guidelines for e-Textile devices.

Smart Wearable Safety Jacket

Technology is now pervasive; it surrounds us and ingrains itself into our daily lives. By balancing usefulness and the joy that fashion brings, the Internet of Things (IoT) paradigm and its supporting smart wearables and IoT-based clothing have the potential to make a significant impact. In order to develop technologies that can predict wants and desires, smart garments seek a balance between fashion, engineering, interaction, user experience, cybersecurity, design, and science. These days, seamless and widespread integration of sensors into textiles as well as the creation of conductive yarn are made possible by the fast-moving convergence of textiles and electronics. Potential for processing biometric data such as heart rate, temperature, breathing, stress, movement, acceleration, or even fingerprints using smart fabrics that can interact with smartphones. hormone levels, suggests the dawn of a new shopping era. This article discusses the primary need for creating smart, Internet of Things-enabled clothing and illustrates the potential long-term effects of smart clothing on business models. The basic types and components of smart IoT wearables and clothes are described, their key needs are examined, and some of the most current smart clothing applications are evaluated. Additionally, a worldwide IoT architecture is offered. This article examines the history and current state of smart clothing in order to offer recommendations for the designers of a network that will connect clothing to other IoT devices in the future: Smart Clothing on the Internet.

A Subtlety of Sizing the Inset Gap Width of a Microstrip Antenna When Built on an Ultra-Thin Substrate in the S-Band

In this paper, Pyralux-a modern, ultra-thin, and acrylic-based laminate-was tested as a substrate of a microstrip antenna to examine the antenna characteristics when it is built on such a thin, flexible, and robust dielectric material, with the idea of eventually serving in wearable antennas in the context of smart-clothing applications. We particularly discuss the sensitivity of the design and fabrication of an inset-fed rectangular microstrip antenna (IRMA) in terms of its inset gap width when it is designed in the S-frequency band. The simulated and measured results showed a very small feasible range for the inset gap dimension with respect to the feed line width. Ultimately, an IRMA was successfully designed, fabricated, and tested with both SMA and U.FL connectors. The impedance bandwidth, in either case, was about 2%, the average value of directivity was 5.8 dB, and the realized efficiency was 2.67%, while the 3-dB beamwidths in the E-plane and the H-plane were 90° or wider.

Design and Analysis of UWB MIMO Antenna for Smart Fabric Communications

This paper presents a flexible multiple-input, multiple-output (MIMO) antenna with ultrawideband (UWB) performance for smart clothing applications. The MIMO antenna is comprised of four octagonal-shaped radiators with several slots loaded into them, and it offers a frequency range of 2.9–12 GHz. The unit cell has a size of 0.26λ0 × 0.164λ0 × 0.014λ0 and the MIMO antenna has a size of 0.48λ0 × 0.48λ0 × 0.014λ0, where λ0 corresponds to the lowest operating frequency. The radiation and diversity performances of the antenna are evaluated, and the obtained metrics are envelope correlation coefficient (ECC) <0.045, diversity gain (DG) >9.9 dB, total active reflection coefficient (TARC) <−14 dB, and channel capacity loss (CCL) <0.13 bits/s/Hz. The bending analysis of the MIMO antenna is performed. The specific absorption rate (SAR) of the MIMO antenna is also investigated, and the obtained values are 0.229 W/Kg (4 GHz), 0.253 W/Kg (7 GHz), and 0.463 W/Kg (10 GHz).

An All-Fabric Tactile-Sensing Keypad with Uni-Modal and Ultrafast Response/Recovery Time for Smart Clothing Applications.

Keypads constructed from fabric materials are the ideal input devices for smart clothing applications. However, multi-modal reaction problems have to be addressed before they can be of practical use on apparels, i.e., the fabric-based keypads need to distinguish between the legitimate actions by the fingertips and the illegitimate deformations and stresses caused by human movements. In this paper, we propose to use the humidity sensor functionalized from graphene oxide (GO)-coated polyester fibers to construct the e-textile keypads. As the moisture level in the proximity of human fingertips is much higher (over 70%) than other parts of the human body, humidity sensing has many advantages over other tactility mechanisms. Experiments have demonstrated that the GO-functionalized fabric keypad has a stable uni-modal tactility only to fingertip touches, and it is not sensitive to deformation, pressure, temperature variation, and other ambient interferences. With biasing and sensing circuits, the keypad exhibits a quick response and recovery time (around 0.1 s), comparable to mechanical keyboards. To demonstrate its application on smart clothing, the keypad was sewn on a sweater and embroidered conductive yarns were used to control an MP3 player in the pocket.

Battery-Less Sensing of Body Movements Through Differential Backscattered RFID Signals

RFID tags not only can be used as identification devices, with antenna sensing techniques, they can also be used as low-cost and battery-less sensors. However, RFID antenna sensing relies on the impedance and/or gain modulation of the tag’s antenna, and extracts the sensing information through the RSSI variation of the backscattered signals. The sensing information is prone to the interferences and noises in the reader-tag communication channel, as well as the distance variations if the sensors are in constant motion. In this paper, we propose a sensor structure that is constructed from adjacently placed double tags to address these issues. The EM properties of the antennas of the double tags behave differently (or even oppositely) under the same sensing variation; therefore, the differential backscattered signals of the dual-tag sensor can eliminate the common-mode interferences while preserving the sensing information. We have constructed one curvature sensor and one deformation sensor with embroidered antennas (using conductive yarns) and all-fabric materials, and sewn the sensors on apparels to demonstrate their use in smart clothing applications. The experiments show that even when the human body is in constant motion, the curvature sensor sewn on the knee area can effectively monitor human’s body gesture, while the deformation sensor sewn on the chest area can precisely detect the respiration activities.

신축성 전도 섬유의 소프트 구동기 적용 및 성능 분석

In this study, soft actuators comprising conductive fibers, flexible polymers, and shape memory alloys, which can be used as textile products, are introduced. Conductive fibers play an important role because they can be used as sensors in wearable devices. The conductive fiber introduced in this study is a form that can be combined with a polymer, and it comprises a form wrapped around a flexible polymer. When an electric current is applied to the shape memory alloy embedded in the polymer, macroscopic deformation occurs due to phase transformation from the Martensite to the Austenite phase. Conductive fibers used in soft actuators are affected by resistive heat generated by the shape memory alloy and bending deformation of the actuator. Accordingly, changes in the conduction properties of conductive fibers were observed due to bending deformation and temperature changes. We also fabricated soft actuators with different types of polymers and observed the differences. The soft actuator presented in this study is a one-piece combination of a conductor and an actuator using a textile-type conductor, and it is likely to be used in smart clothing applications.

Dual function composite fibers of cellulose with activated carbon aerogel and carbide derived carbon

AbstractPolymers of natural origin, especially cellulose, have risen to the focus of smart materials, and also energy storage materials' research as sustainable matrix alternatives. In this work, novel composites of cellulose with activated carbon aerogel (ACA) and carbide‐derived carbon (CDC) are demonstrated. The composites were formulated as fibers from regenerated cellulose (Cell). The electromechanical response as linear actuation in stress and strain of the fibers was studied in an organic electrolyte at low applied potentials in range of 0.55 to −0.8 V. Cyclic voltammetry and square wave potential steps were performed revealing for both composite fibers expansion at positive charging. The Cell‐ACA fibers showed a stronger response compared with Cell‐CDC, largely due to the particle structure, reflected in higher electronic conductivity. The chronopotentiometric measurements showed that Cell‐ACA also had the higher specific capacitance of the two of 47.5 F g−1. The dual‐function of Cell‐ACA and Cell‐CDC of electromechanical activity and energy storage capability can have potential in smart clothing applications.

Printed Graphene, Nanotubes and Silver Electrodes Comparison for Textile and Structural Electronics Applications.

Due to the appearance of smart textiles and wearable electronics, the need for electro-conductive textiles and electro-conductive paths on textiles has become clear. In this article the results of a test of developed textile electro-conductive paths obtained by applying the method of screen printing pastes containing silver nanoparticles and carbon (graphene, nanotubes, graphite) are presented. Conducted research included analysis of the adhesion test, as well as evaluation of the surface resistance before and after the washing and bending cycles. Obtained results indicated that the samples with the content of carbon nanotubes 3% by weight in PMMA on substrate made of aramid fibers (surface mass of 260 g/m2) were characterized by the best adhesion and the best resistance to washing and bending cycles. Such electro-conductive paths have potential to be used in smart clothing applications.

Flexible Ecoflex®/Graphene Nanoplatelet Foams for Highly Sensitive Low-Pressure Sensors

The high demand for multifunctional devices for smart clothing applications, human motion detection, soft robotics, and artificial electronic skins has encouraged researchers to develop new high-performance flexible sensors. In this work, we fabricated and tested new 3D squeezable Ecoflex® open cell foams loaded with different concentrations of graphene nanoplatelets (GNPs) in order to obtain lightweight, soft, and cost-effective piezoresistive sensors with high sensitivity in a low-pressure regime. We analyzed the morphology of the produced materials and characterized both the mechanical and piezoresistive response of samples through quasi-static cyclic compression tests. Results indicated that sensors infiltrated with 1 mg of ethanol/GNP solution with a GNP concentration of 3 mg/mL were more sensitive and stable compared to those infiltrated with the same amount of ethanol/GNP solution but with a lower GNP concentration. The electromechanical response of the sensors showed a negative piezoresistive behavior up to ~10 kPa and an opposite trend for the 10–40 kPa range. The sensors were particularly sensitive at very low deformations, thus obtaining a maximum sensitivity of 0.28 kPa−1 for pressures lower than 10 kPa.

Multimodal Electrophysiological Signal Measurement using a New Flexible and Conductive Polymer Fiber-electrode.

A new multi-material polymer fiber electrode has been developed for smart clothing applications. The conductive fiber is optimized for bipotential measurements such as surface electromyogram (sEMG) and electrocardiogram (ECG). The main benefit of this fiber is its flexibility and being a dry and non-obtrusive electrode. It can be directly integrated into a garment to make a smart textile for real time biopoten-tial monitoring. A customized wireless electronic system has been developed to acquire electrophysiological signal from the fiber. The receiver base station is connected to a PC host running Matlab. The multi-material polymer fiber electrode recording setting were first optimized in length and inter-electrode distance by recording different sEMG signals. The typical sEMG signal to noise ratio ranges from 19.1 dB to 33.9 dB depending on the geometry. These value are comparable with those obtained with Ag/AgCl electrodes and dry electrode-base commercial system such as Delsys Trigno. The frequency domain analysis obtained from the power spectral density reveals that the new flexible fiber-electrode enables high sEMG signals recording quality while being suitable for integration in smart clothing fabric. A muscle fatigue analysis and ECG recording are also presented in this study. The multi-material polymer fiber electrodes demonstrate a viable solution for sEMG and ECG data acquisition.

Towards The Internet of Smart Clothing: A Review on IoT Wearables and Garments for Creating Intelligent Connected E-Textiles

Technology has become ubiquitous, it is all around us and is becoming part of us. Togetherwith the rise of the Internet of Things (IoT) paradigm and enabling technologies (e.g., Augmented Reality (AR), Cyber-Physical Systems, Artificial Intelligence (AI), blockchain or edge computing), smart wearables and IoT-based garments can potentially have a lot of influence by harmonizing functionality and the delight created by fashion. Thus, smart clothes look for a balance among fashion, engineering, interaction, user experience, cybersecurity, design and science to reinvent technologies that can anticipate needs and desires. Nowadays, the rapid convergence of textile and electronics is enabling the seamless and massive integration of sensors into textiles and the development of conductive yarn. The potential of smart fabrics, which can communicate with smartphones to process biometric information such as heart rate, temperature, breathing, stress, movement, acceleration, or even hormone levels, promises a new era for retail. This article reviews the main requirements for developing smart IoT-enabled garments and shows smart clothing potential impact on business models in the medium-term. Specifically, a global IoT architecture is proposed, the main types and components of smart IoT wearables and garments are presented, their main requirements are analyzed and some of the most recent smart clothing applications are studied. In this way, this article reviews the past and present of smart garments in order to provide guidelines for the future developers of a network where garments will be connected like other IoT objects: the Internet of Smart Clothing.

Designs of Textile Antenna Arrays for Smart Clothing Applications

Abstract In this work, three designs of textile antennas, namely, a rectangular microstrip patch antenna, annular slot antenna, and planar inverted-F antenna (PIFA), operating in the 2.45 GHz WLAN band were developed for smart clothing applications. Conductive textile, a copper-plated polyester fabric, was used for fabricating antenna radiators and grounds. An insulating neoprene fabric with a thickness of 4 mm and a permittivity of 1.5 was used for preparing the substrates. The textile patch antenna achieved a maximum gain of 5.96 dBi and a bandwidth of 4.6%. The annual slot antenna showed a moderate gain and bandwidth of 2.9 dBi and 13.1%, respectively. The PIFA achieved the widest bandwidth of 31% but the smallest gain of 1.2 dBi. Furthermore, the performance deterioration of the proposed antennas under various bending conditions was analyzed to evaluate their suitability for wearable applications. Moreover, two 2 × 2 patch and slot antenna arrays were assembled to increase gain and bandwidth. The measured results proved that the developed antenna designs provide superior performance.

A novel textile antenna using composite multifilament conductive threads for smart clothing applications

ABSTRACTThis letter proposes a wearable antenna fabricated by multifilament threads. The radiator is conductive threads filled with a copper wire, directly sewn onto a piece of cloth. Its advantages include better impedance matching, enhanced radiation efficiency, and additional value to smart clothing because the radiator is shaped into a logotype. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1232–1236, 2016

Wearable Electronics of Silver-Nanowire/Poly(dimethylsiloxane) Nanocomposite for Smart Clothing.

Wearable electronics used in smart clothing for healthcare monitoring or personalized identification is a new and fast-growing research topic. The challenge is that the electronics has to be simultaneously highly stretchable, mechanically robust and water-washable, which is unreachable for traditional electronics or previously reported stretchable electronics. Herein we report the wearable electronics of sliver nanowire (Ag-NW)/poly(dimethylsiloxane) (PDMS) nanocomposite which can meet the above multiple requirements. The electronics of Ag-NW/PDMS nanocomposite films is successfully fabricated by an original pre-straining and post-embedding (PSPE) process. The composite film shows a very high conductivity of 1.52 × 104 S cm−1 and an excellent electrical stability with a small resistance fluctuation under a large stretching strain. Meanwhile, it shows a robust adhesion between the Ag-NWs and the PDMS substrate and can be directly machine-washed. These advantages make it a competitive candidate as wearable electronics for smart clothing applications.

Highly Stretchable 2D Fabrics for Wearable Triboelectric Nanogenerator under Harsh Environments.

Highly stretchable 2D fabrics are prepared by weaving fibers for a fabric-structured triboelectric nanogenerator (FTENG). The fibers mainly consist of Al wires and polydimethylsiloxane (PDMS) tubes with a high-aspect-ratio nanotextured surface with vertically aligned nanowires. The fabrics were produced by interlacing the fibers, which was bonded to a waterproof fabric for all-weather use for fabric-structured triboelectric nanogenerator (FTENG). It showed a stable high-output voltage and current of 40 V and 210 μA, corresponding to an instantaneous power output of 4 mW. The FTENG also exhibits high robustness behavior even after 25% stretching, enough for use in smart clothing applications and other wearable electronics. For wearable applications, the nanogenerator was successfully demonstrated in applications of footstep-driven large-scale power mats during walking and power clothing attached to the elbow.

All-fabric intelligent temperature regulation system for smart clothing applications

The state-of-the-art in the field of smart interactive textiles is to develop a pure textile with smart electronics (all-fabric electronics). This article reports the production and testing of a temperature sensing and heating textile which consistently maintains a certain targeted temperature in order to provide optimal thermal comfort in everyday wear regardless of the internal microclimate and external climate conditions as well as the voltage level of the battery. The design and fabrication method of the robust, reliable, flexible, light, highly breathable, and simply constructed smart textile with dual functionality of temperature sensing and heating was explored with a metal composite embroidery yarn. The feasibility of the temperature regulating system based on the power on-off switching method referencing real-time temperature measured from the correlation between resistance and temperature of the heating metal composite embroidery yarn textile was shown. A uniform temperature distribution, a quick adjustment to a newly set temperature, and effective maintaining of a set temperature were identified. Many potential customized designs for smart garments will be possible in a wide range of fabric size, heating area, and different temperature requirement.

The future design direction of Smart Clothing development

Literature indicates that Smart Clothing applications, the next generation of clothing and electronic products, have been struggling to enter the mass market because the consumers' latent needs have not been recognised. Moreover, the design direction of Smart Clothes remains unclear and unfocused. Nevertheless, a clear design direction is necessary for all product development.Therefore, this research aims to identify the design directions of the emerging Smart Clothes industry by conducting a questionnaire survey and focus groups with its major design contributors. The results reveal that the current strategy of embedding a wide range of electronic functions in a garment is not suitable. This is primarily because it does not match the users' requirements, purchasing criteria and lifestyle. The results highlight the respondents' preference for personal healthcare and sportswear applications that suit their lifestyle, are aesthetically attractive, and provide a practical function.