Protection Level and Reusability of a Modified Full-Face Snorkel Mask as Alternative Personal Protective Equipment for Healthcare Workers during the COVID-19 Pandemic

Production of singlet oxygen from photosensitizer erythrosine for facile inactivation of coronavirus on mask

The global health crisis caused by the COVID-19 pandemic has led to a surge in demand and use of personal protective equipment (PPE) such as masks, putting great pressure on social production and the environment.It is urgent to find an efficient and non-destructive disinfection method for the safe reuse of PPE. This study proposes a PPE disinfection method that uses erythrosine, a U.S. Food and Drug Administration-approved food dye, as photosensitizer to produce singlet oxygen for virus inactivation, and indicates the completion of disinfection by its photobleaching color change.After spraying 100 μL of 10 μM erythrosine on the surface of the mask for 3 times and light exposure for 25 min, the titer of coronavirus decreased by more than 99.999%, and the color of erythrosine on the mask surface disappeared. In addition, the structure of the mask was intact and the filtration efficiency was maintained at > 95% after 10 cycles of erythrosine treatment.Therefore, this disinfection method can provide at least 10 cycles of reuse with the advantages of high safety and convenient, and the completion of disinfection can be indicated by its photobleaching, which is suitable for hospitals and daily life to reduce the consumption of PPE.

Polymer-Thread-Based Fully Textile Capacitive Sensor Embroidered on a Protective Face Mask for Humidity Detection

The COVID-19 pandemic has created a situation where wearing personal protective masks is a must for every human being and introduced them as a part of everyday life. This work demonstrates a new functionality embedded in single-use face masks through an embroidered humidity sensor. The design of the face mask humidity sensor is comprised of interdigitated electrodes made of polyamide-based conductive threads and common polyester threads which act as a dielectric sensing layer embroidered between them. Therefore, the embroidered sensor acts as a capacitor, the performance of which was studied in increasing humidity conditions in the frequency range from 1 Hz to 100 kHz. The moisture adsorbed by sensitive hygroscopic polyester threads altered their dielectric and permittivity properties which were detected by the change in capacitance values of the face mask sensors at different relative humidity (RH) levels. The calculated limit of detection (LOD) values for the two proposed sensors at different frequencies (1, 10, and 100 kHz) were found in the range from 11.46% RH-27.41% RH and 29.79% RH-38.65% RH. The tested sensors showed good repeatability and stability under different humidity conditions over a period of 80 min. By employing direct embroidery of silver-coated polyamide conductive threads and moisture-sensitive polyester threads onto the face mask, the present work exploits the application of polymer-based textile materials in developing novel stretchable sensing devices toward e-textile applications.

Filtration Performance Degradation of In-Use Masks by Vapors from Alcohol-Based Hand Sanitizers and the Mitigation Solutions

In the current COVID-19 pandemic, wearing masks and hand disinfection are widely adopted hygiene practices. Alcohol-based sanitizers are commonly used for hand disinfection, however, the alcohol vapors can dissipate the charges on electrostatic filters. In the present study, the effects of alcohol vapors from alcohol-based sanitizers during hand disinfection on the in-use masks are studied. The results show that the negative effects are not significant for nonelectrostatic cotton masks or N95 respirators with multiple charged layers, but noticeable for surgical masks. After five rounds of hand disinfection, the filtration efficiencies of the filtering materials of the surgical masks decrease by more than 8% for 400 and 500 nm particles and by 3.7 ± 1.8% for 1 µm particles, the effective filtration efficiency of the surgical masks worn by the volunteers (with leakage considered) decreases by about 5% for ambient aerosol. In another process to imitate intensive disinfection procedures by healthcare workers, a 30 min surface cleaning process using alcohol-based sanitizer is performed, and the effective efficiency of the N95 respirators worn by the volunteers decreases by nearly 9%. The simple practice of avoiding vapor during hand disinfection could mitigate the effects of alcohol vapor, which is demonstrated on two brands of surgical masks.

Protection, disinfection, and immunization for healthcare during the COVID-19 pandemic: Role of natural and synthetic macromolecules

The world is trying to improve public health while the outbreak of the COVID-19 is at its worst. So far, countless people have died from the COVID-19 disease and it is still a serious threat to human health. Synthetic and natural polymers are unavoidable materials in the healthcare sector. During the COVID-19 outbreak, diverse medical equipment and devices were designed and developed by using these macromolecules for the protection, disinfection, and immunization applications. Synthetic polymers such as polypropylene, polystyrene, poly(lactic acid), poly(ethylene terephthalate), and so forth have been successfully applied for the design and fabrication of diverse face masks, shields, anti-viral coatings, as well as diagnostic kits. Natural polymers having great features such as biodegradability and environmentally friendly are made from algae, plants, and animals. These polymers including sodium alginate, chitosan, cellulose, and gums have been shown a critical role in the fabrication of personal protective equipment, immunosensors, and anti-viral spray for control and fight against COVID-19. Besides, the problem of plastic waste can be solved by replacing them with natural polymers. This mini-review aims to show the application of polymer-based materials during the COVID-19 epidemic.

Overview of the User Experience for Snorkeling Mask Designs during the COVID-19 Pandemic

During the first wave of the COVID-19 pandemic, industries and academic institutes have collaborated to resolve the worldwide medical supply shortage issues. Innovative designs of 3D-printed items were proposed and developed by the maker community as a temporary solution to address the lack of personal protective equipment. An overview of global ongoing and past initiatives during the COVID-19 pandemic along with their challenges on retrofitting full-face snorkeling masks for healthcare applications such as splash-proof face shields, respirator masks and non-invasive ventilation systems are reported in this contribution. This study reviews these global initiatives and challenges. From our analysis, the present situation highlights the need to build solid networks between healthcare institutes and the different rapid prototyping initiatives. A clear feedback system needs to be implemented to facilitate effective collaboration between engineering (maker) and healthcare teams, to optimize the available human resources, and to achieve adequate product developments responding to the needs of healthcare workers.