A major challenge with current wearable electronics and e-textiles, including sensors, is power supply. As an alternative to batteries, energy can be harvested from various sources using garments or ...other textile products as a substrate. Four different energy-harvesting mechanisms relevant to smart textiles are described in this review. Photovoltaic energy harvesting technologies relevant to textile applications include the use of high efficiency flexible inorganic films, printable organic films, dye-sensitized solar cells, and photovoltaic fibers and filaments. In terms of piezoelectric systems, this article covers polymers, composites/nanocomposites, and piezoelectric nanogenerators. The latest developments for textile triboelectric energy harvesting comprise films/coatings, fibers/textiles, and triboelectric nanogenerators. Finally, thermoelectric energy harvesting applied to textiles can rely on inorganic and organic thermoelectric modules. The article ends with perspectives on the current challenges and possible strategies for further progress.
High‐performance fibers developed since the 1960s have a wide range of applications including firefighters' protective clothing. Firefighters' protective clothing made of inherently flame‐resistant ...high‐performance fibers offers excellent protection in the new condition. However, these fibers experience aging as any polymer material. The situation is amplified due to the severe conditions associated with the firefighters' activities. And the consequences of a loss in the performance of the protective clothing can be dramatic for the firefighter's safety. This article provides a comprehensively review of the aging behavior of high‐performance fibers used in firefighters' protective clothing. Residual performance data have been identified both for used firefighter garments as well as fabric specimens subjected to accelerated aging. Research shows that different aging conditions affect the different fibers to a different degree. The specific conditions in which the aging is applied also affects the outcome in terms of loss in performance. Techniques successfully used to quantify the effect of aging on the performance of fire‐resistant fabrics are also briefly mentioned. Finally, the knowledge gained from this analysis of the literature as well as research gaps and further areas of investigation are discussed in this neglected yet critical topic of firefighters' protective clothing aging.
SEM image of a high‐performance fiber showing structural damage after UV aging.
High‐performance fibers are known for their exceptional specific strength and resistance to various hazardous conditions, including fire. However, the long‐term performance of these fibers when ...exposed to convective heat has rarely been reported. This study investigated the accelerated thermal aging behavior of three high‐performance fabrics of different blends of inherently flame‐resistant high‐performance fibers: copolymer of aramids (Technora®)/polybenzoxazole (PBO); para‐aramid/meta‐aramid; and para‐aramid/polybenzimidazole (PBI). Fabric specimens were thermally aged for up to 1200 h at temperatures ranging from 90 to 320°C. While all three fabrics experienced losses in the breaking force, the Technora®/PBO fabric displayed the best strength retention, despite the complete disappearance of the Technora® fiber crystallinity after aging at 320°C for 1200 h. The para‐aramid/PBI blended fabric showed signs of competing aging processes at high temperatures. An increase in the fabrics' crystallinity and evidence of chain scission were observed after thermal aging. Additionally, degradation in the fabric's water‐repellent finish was observed. The findings of this study will contribute to the development of more durable and safer protective gear, particularly for high‐risk activities like firefighting.
Cracks in fibres after thermal aging.
A novel flexible thermal storage system based on organic phase change materials (PCMs) deposited on a non-woven polyester (PET) substrate is described in this article. Thermally regulating effects ...were created via encapsulation of polyethylene glycol (PEG) in carbon nanofibers (CNFs) to manufacture a shape-stable phase change material (SSPCM). Improvement in the thermal conductivity (TC) of the system was obtained by incorporating reduced graphite oxide nanoparticles (rGONP) into the CNFs. A new method was applied to load and secure the manufactured SSPCMs on the fibrous substrate so that an acceptable level of flexibility was preserved (change in bending length less than 30%). The sample performance was evaluated by measuring its thermal properties. The physical properties, wash fastness, abrasion resistance, morphology, and PCM leakage of the samples were also assessed. The results point to a good thermal storage ability of the samples with characteristic phase change temperature ranges of 30.1–31.4 °C and 19.2–24.3 °C for melting and freezing, respectively, and a latent heat of 8.9–22.9 J g
−1
for meting and 11.2–21.4 J g
−1
for freezing. The use of the CNF-rGONP for PEG enhanced the TC of the system by 454%, thus providing a rapid thermal response, and efficiently prevented the leakage of PEG. Finally, the loading and fixation method on the non-woven substrate allowed an acceptable level of durability with less than 4% of weight loss during washing and abrasion tests. This system provides a promising solution for rapid response, flexible thermal storage wearables.
Protective textiles used for military applications must fulfill a variety of functional requirements, including durability, resistance to environmental conditions and ballistic threats, all while ...being comfortable and lightweight. In addition, these textiles must provide camouflage and concealment under various environmental conditions and, thus, a range of wavelengths on the electromagnetic spectrum. Similar requirements may exist for other applications, for instance hunting. With improvements in infrared sensing technology, the focus of protective textile research and development has shifted solely from providing visible camouflage to providing camouflage in the infrared (IR) region. Smart textiles, which can monitor and react to the textile wearer or environmental stimuli, have been applied to protective textiles to improve camouflage in the IR spectral range. This study presents a review of current smart textile technologies for visible and IR signature control of protective textiles, including coloration techniques, chromic materials, conductive polymers, and phase change materials. We propose novel fabrication technology combinations using various microfabrication techniques (e.g., three-dimensional (3D) printing; microfluidics; machine learning) to improve the visible and IR signature management of protective textiles and discuss possible challenges in terms of compatibility with the different textile performance requirements.
Worldwide demand for man-made cellulosic fibres (MMCF) are increasing as availability of cotton fibre declines due to climate change. Feedstock for MMCF include virgin wood, agricultural residues ...(e.g., straw), and pre- and post-consumer cellulosic materials high in alpha-cellulose content. Lyocell MMCF (L-MMCF) offer large advantages over other MMCF processes in terms of both environmental and social impacts: the solvent for cellulosic dissolution, n-methyl-morpholine-n-oxide, can be recycled, and the process utilizes non-toxic chemicals and low amounts of water. Hemp can be a preferential cellulosic feedstock for L-MMCF as hemp cultivation results in carbon dioxide sequestration, and it requires less water, fertilizers, pesticides, and herbicides than other L-MMCF feedstock crops. These factors contribute to hemp being an environmentally conscious crop. The increased legalization of industrial hemp cultivation, as well as recent lifts on cannabis restrictions worldwide, allows accessibility to local sources of cellulose for the L-MMCF process. In addition, hemp biomass can offer a much larger feedstock for L-MMCF production per annum than other cellulosic sources, such as eucalyptus trees and bamboo. This paper offers perspectives on the agricultural, manufacturing, and economic opportunities and challenges of utilizing hemp biomass for the manufacturing of L-MMCF.
Thermophysiological comfort is known to play a primary role in maintaining thermal balance, which corresponds to a person’s satisfaction with their immediate thermal environment. Among the existing ...test methods, sweating torsos are one of the best tools to provide a combined measurement of heat and moisture transfer using non-isothermal conditions. This study presents a preliminary numerical model of a single sector sweating torso to predict the thermophysiological comfort properties of fabric systems. The model has been developed using COMSOL Multiphysics, based on the ISO 18640-1 standard test method and a single layer fabric system used in sportswear. A good agreement was observed between the experimental and numeral results over different exposure phases simulated by the torso test (R2 = 0.72 to 0.99). The model enables a systematic investigation of the effect of fabric properties (thickness, porosity, thermal resistance, and evaporative resistance), environmental conditions (relative humidity, air and radiant temperature, and wind speed), and physiological parameters (sweating rate) to gain an enhanced understanding of the thermophysiological comfort properties of the fabric system.
Individuals with atypical breast shape/size often find it quite challenging to obtain a comfortable, supportive, and fitted bra off-the-shelf. They include people with very large breasts, who have ...significant breast asymmetry, and/or have undergone mastectomy or mammoplasty. This paper provides insights in their challenges and attempts to fill the gap in terms of critical review of the current state of knowledge around the topic of bras. Poor and ill fitted bras are associated with breast, chest and shoulder pain, embarrassment, and an overall reduction in quality of life among others. Building upon the advantages and limitations of solutions to improve the fit, support and comfort of bras found in the literature, this paper proposes strategies to solve these challenges. As the problem is multidisciplinary, a human-centered interdisciplinary approach is key to ensure that all aspects are considered at all stages of the process. A modular design allows selecting the fabric characteristics based on the requirements of each bra part. In terms of materials, stretch woven fabrics offer a large potential in the production of bras to enhance the support provided by areas such as the under band and back panels. Bespoke manufacturing takes into account the specificities of each individual. The road map proposed here will contribute to enhance the quality of life of individuals with atypical breast shape/size.
Thermophysiological comfort is a crucial aspect of human life, contributing to health and work performance. The current paper aims to enhance the understanding of current research, progress, and ...remaining challenges regarding clothing thermophysiological comfort from a textile science perspective. It provides a comprehensive review of several facets of clothing thermophysiological comfort, focusing on the history of thermophysiological comfort prediction models, heat and moisture transfer mechanisms in the skin–clothing–environment system, controlling factors of thermophysiological comfort, textile materials for superior thermophysiological comfort, and thermal comfort assessment techniques. The paper shows that previously developed thermophysiological comfort models were mainly based on the human thermoregulation process. However, the effect of the air gap size between the human skin and the cloth layer, i.e., the microclimate, on the heat and moisture transfer in the skin–clothing–environment system has been largely overlooked. In addition, thermophysiological comfort models of skin–clothing–environment systems generally only considered dry thermal resistance and evaporative resistance, yet many other fabric properties have effects on human thermophysiological comfort. Potential future directions are identified to fill some of the current gaps. A conceptual model of clothing comfort to contribute to a better understanding of thermophysiological comfort is also proposed.
PDF
