Closed-Loop Recycling of Wearable Electronic Textiles.

Wearable electronic textiles (e-textiles) are transforming personalized healthcare through innovative applications. However, integrating electronics into textiles for e-textile manufacturing exacerbates the rapidly growing issues of electronic waste (e-waste) and textile recycling due to the complicated recycling and disposal processes needed for mixed materials, including textile fibers, electronic materials, and components. Here, first closed-loop recycling for wearable e-textiles is reported by incorporating the thermal-pyrolysis of graphene-based e-textiles to convert them into graphene-like electrically conductive recycled powders. A scalable pad-dry coating technique is then used to reproduce graphene-based wearable e-textiles and demonstrate their potential healthcare applications as wearable electrodes for capturing electrocardiogram (ECG) signals and temperature sensors. Additionally, recycled graphene-based textile supercapacitor highlights their potential as sustainable energy storage devices, maintaining notable durability and retaining ≈94% capacitance after 1000 cycles with an areal capacitance of 4.92 mF cm⁻2. Such sustainable closed-loop recycling of e-textiles showcases the potential for their repurposing into multifunctional applications, promoting a circular approach that potentially prevents negative environmental impact and reduces landfill disposal.

High-Performance Stretchable Strain Sensors Based on Auxetic Fabrics for Human Motion Detection.

Wearable strain sensors play a pivotal role in real-time human motion detection and health monitoring. Traditional fabric-based strain sensors, typically with a positive Poisson's ratio, face challenges in maintaining sensitivity and comfort during human motion due to conflicting resistance changes in different strain directions. In this work, high-performance stretchable strain sensors are developed based on graphene-modified auxetic fabrics (GMAF) for human motion detection in smart wearable devices. The proposed GMAF sensors, with a negative Poisson's ratio achieved through commercially available warp-knitting technology, exhibit an 8-fold improvement in sensitivity compared to conventional plain fabric sensors. The unique auxetic fabric structure enhances sensitivity by synchronizing resistance changes in both wale and course directions. The GMAF sensors demonstrate excellent washability, showing only slight degradation in auxeticity and an acceptable increase in resistance after 10 standard wash cycles. The GMAF sensors maintain stability under different strain levels and various motion frequencies, emphasizing their dynamic performance. The sensors exhibit superior conformability to joint movements, which effectively monitor a full range of motions, including joint bending, sports activities, and subtle actions like coughing and swallowing. The research underscores a promising approach to achieve industrial-scale production of wearable sensors with improved performance and comfort through fabric structure design.

Efficacy of auxetic lattice structured shoe sole in advancing footwear comfort-From the perspective of plantar pressure and contact area.

Introduction: Designing footwear for comfort is vital for preventing foot injuries and promoting foot health. This study explores the impact of auxetic structured shoe soles on plantar biomechanics and comfort, motivated by the integration of 3D printing in footwear production and the superior mechanical properties of auxetic designs. The shoe sole designs proposed in this study are based on a three-dimensional re-entrant auxetic lattice structure, orthogonally composed of re-entrant hexagonal honeycombs with internal angles less than 90 degrees. Materials fabricated using this lattice structure exhibit the characteristic of a negative Poisson's ratio, displaying lateral expansion under tension and densification under compression. Methods: The study conducted a comparative experiment among three different lattice structured (auxetic 60°, auxetic 75° and non-auxetic 90°) thermoplastic polyurethane (TPU) shoe soles and conventional polyurethane (PU) shoe sole through pedobarographic measurements and comfort rating under walking and running conditions. The study obtained peak plantar pressures (PPPs) and contact area across seven plantar regions of each shoe sole and analyzed the correlation between these biomechanical parameters and subjective comfort. Results: Compared to non-auxetic shoe soles, auxetic structured shoe soles reduced PPPs across various foot regions and increased contact area. The Auxetic 60°, which had the highest comfort ratings, significantly lowered peak pressures and increased contact area compared to PU shoe sole. Correlation analysis showed that peak pressures in specific foot regions (hallux, second metatarsal head, and hindfoot when walking; second metatarsal head, third to fifth metatarsal head, midfoot, and hindfoot when running) were related to comfort. Furthermore, the contact area in all foot regions was significantly associated with comfort, regardless of the motion states. Conclusion: The pressure-relief performance and conformability of the auxetic lattice structure in the shoe sole contribute to enhancing footwear comfort. The insights provided guide designers in developing footwear focused on foot health and comfort using auxetic structures.

Application of Superabsorbent Spacer Fabrics as Exuding Wound Dressing.

Exuding wound care requires a dressing to quickly absorb exudates and properly manage moisture during the healing process. In this study, the superabsorbent spacer fabrics were designed and fabricated for application in exuding wound dressings. The fabric structure consists of three layers, including two outer hydrophobic layers made of polyester/spandex yarns and one superabsorbent middle layer made of superabsorbent yarns. In order to confirm the performance of these superabsorbent spacer fabrics, their dressing properties were tested and compared with two commercial foam dressings. The results showed that all the superabsorbent spacer fabrics had much faster wetting speeds (less than 2 s) than the foam dressings (6.04 s for Foam A and 63.69 s for Foam B). The absorbency of the superabsorbent spacer fabrics was at least twice higher than that of the foam dressings. The air permeability of the superabsorbent spacer fabrics (higher than 15 mL/s/cm² at 100 Pa) was much higher than that of the foam dressings which had a too low permeability to be measured by the testing device. In addition, the water vapor permeability, thermal insulation, and conformability of superabsorbent spacer fabrics were comparable to foam dressings. The study indicates that the superabsorbent spacer fabrics are suitable for exuding wound dressing applications.

A novel silver-containing absorbent wound dressing based on spacer fabric.

An ideal absorbent dressing requires high absorbency, moisture retention and antimicrobial properties. In this study, the application of silver-containing spacer fabric as an antimicrobial wound dressing was investigated. The silver distribution on the spacer fabric was different from that of layer-by-layered fabric. The middle layer of the spacer fabric contained much higher amounts of silver, while the layer-by-layered fabric had lower silver contents in its middle layers than its surface layers. The silver-containing spacer fabric could keep a better moist environment for the wound than commercial foam dressing. For the silver-containing spacer fabric, 100% reductions in viability were observed for both the Gram-positive Staphylococcus aureus and the Gram-negative Klebsiella pneumoniae after only 1 h. The spacer fabric could keep most of the silver in its middle layer and kill bacteria in the middle layer rather than at the wound contact surface. This way to absorb wound exudates and kill bacteria within the dressing reduces the silver concentration on the wound bed, and therefore this could be an efficient way to lower the potential of silver entering the human body, and prevent silver toxicity and accelerate wound healing.