This paper presents a flexible 2.45-GHz wireless power harvesting wristband that generates a net dc output from a -24.3-dBm RF input. This is the lowest reported system sensitivity for systems ...comprising a rectenna and impedance-matching power management. A complete system has been implemented comprising: a fabric antenna, a rectifier on rigid substrate, a contactless electrical connection between rigid and flexible subsystems, and power electronics impedance matching. Various fabric and flexible materials are electrically characterized at 2.45 GHz using the two-line and the T-resonator methods. Selected materials are used to design an all-textile antenna, which demonstrates a radiation efficiency above 62% on a phantom irrespective of location, and a stable radiation pattern. The rectifier, designed on a rigid substrate, shows a best-in-class efficiency of 33.6% at -20 dBm. A reliable, efficient, and wideband contactless connection between the fabric antenna and the rectifier is created using broadside-coupled microstrip lines, with an insertion loss below 1 dB from 1.8 to over 10 GHz. A self-powered boost converter with a quiescent current of 150 nA matches the rectenna output with a matching efficiency above 95%. The maximum end-to-end efficiency is 28.7% at -7 dBm. The wristband harvester demonstrates net positive energy harvesting from -24.3 dBm, a 7.3-dB improvement on the state of the art.
This reprint focuses on the research of textile materials for conventional and protective clothing. More than ever, multidisciplinary research applied to the field of new textile materials and new ...techniques of processing and joining materials is needed. The main research topics of this Special Issue include research and development of new materials and the improvement of their properties, and the mechanical and thermal properties of yarns, materials and clothing. Simulations based on the physical and mechanical properties of fabrics for the purpose of prediction assessment of the appearance and behavior of clothing, as well as 3D virtual garment prototypes using 3D body models and involving 3D human-body scanning, are interesting and significant topics in the field of clothing engineering. The problem of microplastics that are produced during the manufacture or cleaning of synthetic textiles has also been investigated in this Special Issue.
PART 1. Functional Textiles: Photochromic Textiles Based upon Aqueous Blends of Oxygen-Deficient WO3-x and TiO2 Nanocrystals. 50/60 Hz Power Grid Noise as a Skin Contact Measure of Textile ECG ...Electrodes. Characterizing Steam Penetration through Thermal Protective Fabric Materials. Stretchable Textile Yarn Based on UHF RFID Helical Tag. Fibers and Textiles for Personal Protective Equipment. Textile-Based Sound Sensors (TSS). High-Performance and Functional Fiber Materials. Geotextiles—A Versatile Tool for Environmental Sensitive Applications in Geotechnical Engineering. Review of Fiber- or Yarn-Based Wearable Resistive Strain Sensors. Wearable Actuators: An Overview. Bacterial Secondary Metabolites as Biopigments for Textile Dyeing. PART 2: Process and Modelling. Loop Order Analysis of Weft-Knitted Textiles. New Geometrical Modelling for 2D Fabric and 2.5D Interlock Composites. Meso-Macro Simulations of the Forming of 3D Non-Crimp Woven Fabrics. Continuous Yarn Electrospinning. A Review on Tough Soft Composites at Different Length Scales. Textile Branch and Main Breakthroughs of the Czech Republic in the Field of Textile Machinery. Recent Efforts in Modeling and Simulation of Textiles. PART 3: Control. A Comparison of Two Different Light Booths for Measuring Color Difference of Metameric Pairs. Effect of Textile Characteristics on the AR-Glass Fabric Efficiency. Dielectric Properties of Textile Materials. PART 4: Consumers and Behavior. Development of a Consumer-Based Quality Scale for Artisan Textiles. Organic Cotton Clothing Purchase Behavior. A Review on Textile Recycling Practices and Challenges.
In order to overcome the shortcoming that a fabric defect detection method can only fit into a certain type of fabric, this paper presents a novel method by integrating the idea of the integral image ...into the Elo-rating algorithm (IIER), which can detect the defects of various types of fabric speedily. Firstly, the golden sub-blocks are extracted from defect-free images. The whole images are divided into many sub-blocks, and the integral images of these sub-blocks are obtained. Next, the R sub-blocks are randomly selected from these integral sub-blocks, and each block is assigned an initial Elo point. Afterwards, the R sub-blocks are matched against all sub-blocks and the Elo points are updated after each competition. Finally, regions with bright defects accumulate high Elo points and regions with dark defects accumulate low Elo points. Thus, the threshold value image can be obtained by thresholding the final Elo points, in which white, gray and black regions correspond to bright, dark-defect and defect-free regions, respectively. The performance of the proposed method is evaluated on databases of three categories of fabric, namely raw fabric, yarn-dyed fabric and patterned fabric. The experimental results show that the IIER is a universal algorithm, which has high detection rate for different types of fabrics; in particular, the average correct detection rate can reach 100% for dot-patterned fabric. In addition, the detection time can be significantly reduced comparing with the Elo-rating algorithm (ER). Particularly for star-patterned fabric, the average detection time per image is 24.18 seconds less than the ER.
•Ballistic performance of para-aramid and UHMWPE based laminates has been studied.•Soft armours made from para-aramid woven fabrics show high back face signature.•Soft armours made from UHMWPE ...laminates demonstrate the least back face signature and highest bullet deformation.•Use of spacer fabric as backing material shows promising results.
This study presents the ballistic protection performance and failure modes of soft armour panels (SAPs) made from different structures, including woven fabrics and unidirectional (UD) laminates. SAPs made from para-aramid woven fabrics and UD laminates, and ultra-high molecular weight polyethylene (UHMWPE) UD laminates were developed and subjected to ballistic impact against 9 mm lead core bullets at an average velocity of 430 m s−1. Ballistic performance of SAPs was evaluated in terms of back face signature (BFS), perforation ratio (PR) and expansion of bullet. UD laminate-based SAPs outperformed their counterparts based on para-aramid woven fabric. While among the UD laminates, UHMWPE variants surpassed their para-aramid counterparts. Microscopic images and scanning electron micrographs showed extensive thermal degradation and melting in first few layers of SAP made from UHMWPE UD laminates, whereas para-aramid panels failed mainly due to fibre rupture, fibrillation along with debonding and delamination in their UD variants. Therefore, an ideal SAP design should incorporate a heat resistant material in the front layers followed by high-modulus ballistic materials in subsequent layers. Use of spacer fabric as backing material can partially replace high-cost ballistic materials without compromising ballistic performance.
Identifying novel natural fibers/fabrics with proper properties as reinforcement material is a new challenge in the field of bio-composites. Hence, the aim of this paper is to study the possibility ...of using a natural fabric extracted from Manicaria saccifera palm as a novel reinforcement in composites. This fabric was extensively characterized by chemical composition analysis, infrared spectroscopy (FTIR) analysis, morphological studies (SEM), thermo-gravimetric analysis (TGA) and physical /mechanical properties studies. From SEM analysis it was identified globular protrusions spread uniformly over the fiber which could help the mechanical interlock with the resin. As well, Manicaria fabric showed good thermal stability, low density, low moisture content and good tensile properties. Further, their properties are comparable to most natural cellulose fabrics and some synthetic fabrics, such as fiber glass fabrics. Manciaria saccifera fabric showed to be a suitable candidate as natural reinforcement material for the development of bio- composite.
Wearable electronic textiles are used in sensors, energy-harvesting devices, healthcare monitoring, human–machine interfaces, and soft robotics to acquire real-time big data for machine learning and ...artificial intelligence. Wearability is essential while collecting data from a human, who should be able to wear the device with sufficient comfort. In this study, reduced graphene oxide (rGO) and silver nanowires (AgNWs) were supersonically sprayed onto a fabric to ensure good adhesiveness, resulting in a washable, stretchable, and wearable fabric without affecting the performance of the designed features. This rGO/AgNW-decorated fabric can be used to monitor external stimuli such as strain and temperature. In addition, it is used as a heater and as a supercapacitor and features an antibacterial hydrophobic surface that minimizes potential infection from external airborne viruses or virus-containing droplets. Herein, the wearability, stretchability, washability, mechanical durability, temperature-sensing capability, heating ability, wettability, and antibacterial features of this metallized fabric are explored. This multifunctionality is achieved in a single fabric coated with rGO/AgNWs via supersonic spraying.
This study aims to examine the antimicrobial properties and washing resistance of cotton fabrics coated with propolis-doped hydrogel. More specifically, we compared the hygienic properties of AgNO
3
...(a common antimicrobial agent in textile materials), and the antimicrobial properties of propolis for the first time. We used PVA and NaCMC for hydrogel production because they are biocompatible and non-toxic. Later, we looked at how effective the propolis or AgNO
3
-doped hydrogel-coated cotton fabrics are against gram-positive and gram-negative bacteria and
Candida albicans
fungus, and compared their findings. Our results demonstrated that propolis could be a natural antibacterial alternative to AgNO
3
. The more active substance content there was, the more antibacterial and washing resistant it became. We used SEM images of the hydrogel coating and SEM–EDX images to how much silver the silver-doped layers contained. ATR–FTIR results also supported flavonoids and phenol in the structure of propolis itself. The changes in the basic comfort properties of the products were at acceptable levels.
Graphical abstract
Recently, many methods based on low-rank representation have been proposed for fabric defect detection. Most of them relax the low-rank decomposition problem to a nuclear norm minimization (NNM) ...problem to pursue the convexity of the objective function. When solving the standard NNM problem, matrix singular values have to be treated equally. This, however, would be impractical in the scenario of fabric defect detection as the matrix singular values have clear physical meanings, and thus, they should be treated differently. In this article, we propose a weighted double-low-rank decomposition method (WDLRD) to treat the matrix singular values differently by assigning different weights. Thus, the most important/distinguishing characteristics of a fabric image can be preserved. Another difference between WDLRD and the other existing low-rank-based methods is that WDLRD considers a defective fabric image being decomposed to two low-rank matrices, i.e., low-rank defect-free matrix and low-rank defect matrix, as the defect-free and defective regions are usually composed of homogeneous objects that have a high correlation. Besides, WDLRD is more robust for defect detection in various situations by adding a noise term to avoid noise or other interference on the fabric surface. In addition, a defect prior is incorporated into the objective function of WDLRD to guide locating the defective regions. The proposed optimization problem can be easily solved by an iterative algorithm based on augmented Lagrange multipliers. Experimental results on TILDA, periodically patterned fabric, and Textile & Apparel Artificial Intelligence databases show that the proposed WDLRD obtains better performance than state-of-the-art methods in locating the defective regions on fabric images. Note to Practitioners -This article is motivated by the problem that the performance of fabric defect detection in the textile industry is poor. It is necessary to develop an effective method to improve the defect detection accuracy and reduce overall manufacturing cost. Existing automatic defect detection approaches usually contain two stages: first, capture fabric images from the weaving machine and then use a defect detection algorithm in a host computer to conduct a real-time inspection and give an alarm if defects occur. This article focuses on locating defects for given defective images after the procedure of binary classification (which determines an image as defective or defect free). The article proposes an objective function to mathematically interpret the optimization problem between fabric images and predictive defects. The optimal solution can be obtained by employing the alternating direction method of multipliers (ADMMs). The proposed method is described as a new defect detection algorithm. Extensive experiments were conducted to evaluate the algorithm, and the experimental results indicate that the proposed method is superior to many existing fabric defect detection methods. Preliminary experiments suggest that this method is feasible but has not yet been really used in production. In future research, we will collect more fabric images from the textile industry and develop large-scale databases for verifying the proposed method for real-life applications.
Porous acoustic materials are among the most frequently employed acoustic materials. This paper evaluates the acoustic performance of porous materials concerning the addition of how the fabric layout ...and addition of an air gap influence sound absorption coefficient at low and medium frequencies. The acoustic measurements were performed on multilayers of woven fabrics formed from different weave structures and nonwoven fabrics using an impedance tube. The result indicates that due to the different geometrical structures of woven fabric and the layout designs of multilayer fabrics, significant improvements were observed in sound absorption performance at the frequency range from 160 Hz to 3150 Hz. The air gap with a multilayer of porous material enhanced low to medium-frequency sound absorption. Furthermore, the physical fabric properties analysis of porosity using X-ray tomography indicates that the surface of a single layer of plain fabric structures is more porous than that of sateen, rib, and twill woven fabrics. The correlation between the air permeability and sound absorption coefficient (α) results indicates an inverse relationship for multilayer porous fabrics.
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