Waste-Derived Sustainable Fluorescent Nanocarbon-Coated Breathable Functional Fabric for Antioxidant and Antimicrobial Applications

Hospital-acquired (nosocomial) infections account for the majority of adverse health effects during care delivery, placing an immense financial strain on healthcare systems around the world. For the first time, the present article provides evidence of a straightforward pollution-free technique to fabricate a heteroatom-doped carbon dot immobilized fluorescent biopolymer composite for the development of functional textiles with antioxidant and antimicrobial properties. A simple, facile, and eco-friendly approach was devised to prepare heteroatom-doped carbon dots from waste green tea and a biopolymer. The carbon dots showed an excitation-dependent emission behavior, and the XPS data unveiled that they are co-doped with nitrogen and sulfur. A facile physical compounding strategy was adopted to fabricate a carbon dot reinforced biopolymeric composite followed by immobilization onto the textile. The composite textiles revealed excellent antioxidant activity, determined by 1,1-diphenyl-2-picrylhydrazyl (>80%) and 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid assays (>90%). The results of the disc diffusion assay indicated that the composite textiles substantially inhibited the growth of both tested bacteria Escherichia coli and Bacillus subtilis with increasing coating cycles. The time-dependent antibacterial experiments revealed that the nanocomposite can inhibit significant bacterial growth within a few hours. The present study could open up the possibility for the commercialization of inexpensive smart textile substrates for the prevention of microbial contamination used for the medical and healthcare field.

ACTIVE-CONTRACTING VARIABLE-STIFFNESS FABRICS FOR SELF-FITTING WEARABLES

Self-fitting is the ability of a wearable, garment or body-mounted object to recover the exact shape and size of the human body. Self-fitting is highly desirable for wearable applications, ranging from medical and recreational health monitoring to wearable robotics and haptic feedback, because it enables complex devices to achieve accurate body proximity, which is often required for functionality. While garments designed with compliant fabrics can easily accomplish accurate fit for a range of body shapes and sizes, integrated actuators and sensors require fabric stiffness to prevent drift and deflection from the body surface. This paper merges smart materials and structures research with anthropometric analysis and functional apparel methodologies to present a novel, functionally gradient self-fitting garment designed to address the challenge of achieving accurate individual and population fit. This fully functional garment, constructed with contractile SMA knitted actuator fabrics, exhibits tunable %-actuation contractions between 4-50%, exerts minimal on-body pressure (≤1333 Pa or 10 mmHg), and can be designed to actuate fully self-powered with body heat. The primary challenge in the development of the proposed garment is to design a functionally gradient system that does not exert significant pressure on part of the leg and/or remain oversized in others. Our research presents a new methodology for the design of contractile SMA knitted actuator garments, describes the manufacture of such self-fitting garments, and concludes with an experimental analysis of the garment performance evaluated through three-dimensional marker tracking.

Durable, Highly Electrically Conductive Cotton Fabrics with Healable Superamphiphobicity

Electrically conductive fabrics with liquid repellency and corrosive resistance are strongly desirable for wearable displays, biomedical sensors, and so forth. In the present work, highly electrically conductive and healable superamphiphobic cotton fabrics are fabricated by a solution-dipping method that involves (NH₄)₂PdCl₄-catalyzed electroless deposition of Cu and the subsequent deposition of a mixture of fluorinated-decyl polyhedral oligomeric silsesquioxane (F-POSS) and 1 H,1 H,2 H,2 H-perfluorooctyltriethoxysilane (POTS) on cotton fabrics. Because of their superamphiphobicity, the resulting fabrics are self-cleaning and exhibit excellent resistance against corrosive acidic and basic solutions. The as-prepared fabrics have a sheet resistance of ∼0.33 Ω·sq^-1 and show excellent electromagnetic interference shielding and electrothermal heating ability. Because of the preserved F-POSS and POTS molecules, the fabrics can conveniently and repeatedly restore the loss of superamphiphobicity by applying a low voltage of 1.0 V or heating the fabrics at 135 °C to facilitate the migration of the preserved F-POSS and POTS to the surface of cotton fabrics. The integration of healable superamphiphobicity into the Cu-coated fabrics generates multiple functional cotton fabrics with excellent conductivity, electromagnetic interference shielding, self-cleaning ability, and significantly enhanced durability.