High-breathable, antimicrobial and water-repellent face mask for breath monitoring

Innovative biosensing smart masks: unveiling the future of respiratory monitoring

Real-time monitoring of respiratory health is increasingly critical, particularly in addressing global health challenges such as Corona Virus Disease 2019 (COVID-19). Smart masks equipped with biosensing mechanisms revolutionize respiratory health monitoring by enabling real-time detection of respiratory parameters and biomarkers. In recent years, significant advancements have been achieved in the development of smart masks based on different sensor types with high sensitivity and accuracy, flexible functionality, and portability, providing new approaches for remote and real-time monitoring of respiratory parameters and biomarkers. In this review, we aim to provide a comprehensive overview of the current state of development and future potential of biosensing smart masks in various domains. This review outlines a systematic categorization of smart masks according to diverse sensing principles, classifying them into six categories: electrochemical sensors, optical sensors, piezoelectric sensors, and others. This review discusses the basic sensing principles and mechanisms of smart masks and describes the existing research developments of their different biosensors. Additionally, it explores the innovative applications of smart masks in health monitoring, protective functions, and expanding application scenarios. This review also identifies the current challenges faced by smart masks, including issues with sensor accuracy, environmental interference, and the need for better integration of multifunctional features. Proposed solutions to these challenges are discussed, along with the anticipated role of smart masks in early disease detection, personalized medicine, and environmental protection.

Zein-based nanostructured coatings: A green approach to enhance virucidal efficacy of protective face masks

Face masks represent a valuable tool to prevent the spreading of airborne viruses; however, they show poor comfort and scarce antiviral efficacy. Zein-based coatings are herein exploited to enhance antiviral performance. Zein functionalization is done through acidifying agents (lactic acid, LA). Coatings are characterized in terms of morphological, mechanical, breathability, and cytotoxicity analyses. The antiviral efficacy is tested in vitro against four viruses (Human Coronavirus OC43, Herpes Simplex Virus type 1, Human Adenovirus type 5, and MPox Virus) according to a biological assay on cell cultures. Zein/Zein LA antiviral activity seems to be linked to its positive surface charge that enables to form electrostatic interactions with negatively charged-viruses, resulting in the highest activity (reduction >2 Log) on Human Coronavirus OC43 and Herpes Simplex Virus type 1, with efficacy comparable or higher than that of copper/copper oxide-based- coatings. No significant activity is observed against Human Adenovirus type 5 and MPox Virus, due to their high resistance to inactivating treatments. Zein-based systems are not cytotoxic and their water vapor permeability is reduced of 26 % compared to that of not-coated systems. These promising results offer interesting insights into design of antiviral and sustainable coatings for personal protective equipment.

Development of Technology for Providing Antimicrobial Properties to Medical Disposable Masks

Wearing masks to protect against communicable diseases is an effective tool used in many countries affected by the COVID-19 pandemic. The antibacterial activity, antibacterial efficiency, microbial purity, and breathability properties of medical disposable masks are very important. Ag is most commonly applied to antimicrobial textiles. In this work, three antimicrobial additives were used. Four compositions of the binders with antimicrobial additives were prepared and applied to one-layer non-woven PP material. The influence of the binder antimicrobial polymer coating on the breathability and antibacterial activity of the non-woven PP material was evaluated. The results show that the composition of the polyacrylic acid binder had the least effect on their breathability and samples with the silver chloride formulation showed the best antimicrobial response. Based on the microbiological and air permeability results of the samples of the one-layer non-woven material with coating, the samples of two layers and three layers of the medical mask model were prepared. Microbiological studies have shown that a three-layered medical mask model with silver chloride composition in the middle layer, on both sides of the model, has antibacterial efficiency against three pathogens (E. Coli, K. Pneumoniae, and S. Aureus). The performance of this medical mask model has been found to meet the requirements for type I medical masks according to the EN 14863 standard. Studies have shown that the microbial purity of the mask model is CFU/g < 3.

Functionalized Face Masks as Smart Wearable Sensors for Multiple Sensing

Wearable sensors provide continuous physiological information and measure deviations from healthy baselines, resulting in the potential to personalize health management and diagnosis of diseases. With the emergence of the COVID-19 pandemic, functionalized face masks as smart wearable sensors for multimodal and/or multiplexed measurement of physical parameters and biochemical markers have become the general population for physiological health management and environmental pollution monitoring. This Review examines recent advances in applications of smart face masks based on implantation of digital technologies and electronics and focuses on respiratory monitoring applications with the advantages of autonomous flow driving, enrichment enhancement, real-time monitoring, diversified sensing, and easily accessible. In particular, the detailed introduction of diverse respiratory signals including physical, inhalational, and exhalant signals and corresponding associations of health management and environmental pollution is presented. In the end, we also provide a personal perspective on future research directions and the remaining challenges in the commercialization of smart functionalized face masks for multiple sensing.

Sputtering-Deposited Ultra-Thin Ag-Cu Films on Non-Woven Fabrics for Face Masks with Antimicrobial Function and Breath NOx Response

The multifunctional development in the field of face masks and the growing demand for scalable manufacturing have become increasingly prominent. In this study, we utilized high-vacuum magnetron sputtering technology to deposit a 5 nm ultra-thin Ag-Cu film on non-woven fabric and fabricated ultra-thin Ag-Cu film face masks. The antibacterial rates against Escherichia coli and Staphylococcus aureus were 99.996% and 99.978%, respectively, while the antiviral activity against influenza A virus H1N1 was 99.02%. Furthermore, the mask's ability to monitor respiratory system diseases was achieved through color change (from brownish-yellow to grey-white). The low cost and scalability potential of ultra-thin silver-copper film masks offer new possibilities for practical applications of multifunctional masks.

Fabrication of Poly(Lactic Acid)@TiO2 Electrospun Membrane Decorated with Metal-Organic Frameworks for Efficient Air Filtration and Bacteriostasis

The development of high-performance filtration materials is essential for the effective removal of airborne particles, and metal-organic frameworks (MOFs) anchored to organic polymer matrices are considered to be one of the most promising porous adsorbents for air pollutants. Nowadays, most air filters are generally based on synthetic fiber polymers derived from petroleum residues and have limited functionality, so the use of MOFs in combination with nanofiber air filters has received a lot of attention. Here, a conjugated electrostatic spinning method is demonstrated for the one-step preparation of poly(lactic acid) (PLA) nanofibrous membranes with a bimodal diameter distribution and the anchoring of Zeolitic Imidazolate Framework-8 (ZIF-8) by the introduction of TiO2 and in situ generation to construct favorable multiscale fibers and rough structures. The prepared PLA/TZ maintained a good PM2.5 capture efficiency of 99.97%, a filtration efficiency of 96.43% for PM0.3, and a pressure drop of 96.0 Pa, with the highest quality factor being 0.08449 Pa-1. Additionally, ZIF-8 was uniformly generated on the surface of PLA and TiO2 nanofibers, obtaining a roughened structure and a larger specific surface area. An enhanced filtration retention effect and electrostatic interactions, as well as active free radicals, can be generated for the deep inactivation of bacteria. Compared with the unmodified membrane, PLA/TZ prepared antibacterial characteristics induced by photocatalysis and Zn2+ release, with excellent bactericidal effects against S. aureus and E. coli. Overall, this work may provide a promising approach for the development of efficient biomass-based filtration materials with antimicrobial properties.

Highly Antibacterial and Self-Healing Janus Fabric for Effective Body Moisture/Thermal Management and Durable Waterproof

Despite the development of many functional fabrics, they are unable to meet practical needs due to their monolithic functions and low durability. Therefore, a multifunctional waterborne polyurethane nanodroplet containing disulfide bonds (WSPU) was synthesized using a simple and environmentally friendly approach. The functional WSPU nanodroplet coating endowed fabrics with a variety of properties, including exceptional hydrophobicity, antibacterial properties, self-healing at room temperature, directional transport, etc. The functionalized fabric demonstrated durable mechanical and chemical stabilities due to the combined effects of disulfide bond reconstruction and hydrophobic chain migration. It exhibited the ability to regain its hydrophobic properties at room temperature after 50 friction cycles were performed without requiring external stimulation. Furthermore, the fabric maintained a water contact angle above 140°, even after being subjected to washing, boiling, and immersion in acid and alkali solutions. In addition, as a result of the fabric's Janus-like wettability, it performed various functions in accordance with varying weather conditions, in terms of wearing comfort and breathability. In hot weather or during exercise, the Janus fabric with the hydrophilic side facing outward enhances the process of sweat-directed perspiration, resulting in a notable cooling effect. On rainy days, the Janus fabric, when positioned with the hydrophobic side facing outward, exhibited excellent waterproof performance. This study presents an opportunity to explore the development of multifunctional fabrics through the combined effects of several functions.