ABSTRACT
A proof of concept is demonstrated concerning self-charging fabrics for air filtration purposes based on common household fibers. Triboelectrically dissimilar fibers, such as wool and polyester, were interwoven into a single-layer fabric, so that local charges can be developed and partially retained at the junctions of the insulating fibers as a result of their constant frictional contact. Voluminous fibers that are typically used for knitting were chosen here, leveraging their broad availability and ease of use, so that they can be handwoven into a leak-free fabric, preventing unfiltered air to pass through directly. When tested for PM2.5 and PM10 removal, this hybrid fabric outperforms a single-material fabric made similarly from household cotton yarns. And its pressure drop and filtration efficiency were found to be in between those of a common surgical mask and a KN95 mask.
ABSTRACT
Summary Transmission of infectious respiratory diseases starts with pathogen-laden respiratory droplets released from a source, the removal of which should help to prevent or slow down the overall spread of the pathogens. Here, we demonstrate that a surface-agnostic, non-destructive, polymer-based coating can significantly enhance the capture of aerosols and droplets. The water-based formulation contains only cosmetic ingredients and yields uniform and conformal coatings on a broad range of indoor environmental surfaces, regardless of the material composition, wettability, and texture. The coating remains transparent and haze free even after extensive droplet deposition. Additives can be incorporated to bring additional functions, such as coloration and sanitization. The strategy enhances the function of transparent protective barriers and can repurpose large areas of barely touched indoor environmental surfaces for droplet removal, eliminating these infectious sources from the chain of transmission.
ABSTRACT
Transmission of infectious respiratory diseases starts from pathogen-laden respiratory droplets released during coughing, sneezing, or speaking. Here we report an on-mask chemical modulation strategy, whereby droplets escaping a masking layer are chemically contaminated with antipathogen molecules (e.g., mineral acids or copper salts) preloaded on polyaniline-coated fabrics. A colorimetric method based on the color change of polyaniline and a fluorometric method utilizing fluorescence quenching microscopy are developed for visualizing the degree of modification of the escaped droplets by H+ and Cu2+, respectively. It is found that even fabrics with low fiber-packing densities (e.g., 19%) can readily modify 49% of the escaped droplets by number, which accounts for about 82% by volume. The chemical modulation strategy could offer additional public health benefits to the use of face covering to make the sources less infectious, helping to strengthen the response to the current pandemic or future outbreaks of infectious respiratory diseases.
ABSTRACT
The COVID-19 pandemic is one of those global challenges that transcends territorial, political, ideological, religious, cultural, and certainly academic boundaries. Public health and healthcare workers are at the frontline, working to contain and to mitigate the spread of this disease. Although intervening biological and immunological responses against viral infection may seem far from the physical sciences and engineering that typically work with inanimate objects, there actually is much that can-and should-be done to help in this global crisis. In this Perspective, we convert the basics of infectious respiratory diseases and viruses into physical sciences and engineering intuitions, and through this exercise, we present examples of questions, hypotheses, and research needs identified based on clinicians' experiences. We hope researchers in the physical sciences and engineering will proactively study these challenges, develop new hypotheses, define new research areas, and work with biological researchers, healthcare, and public health professionals to create user-centered solutions and to inform the general public, so that we can better address the many challenges associated with the transmission and spread of infectious respiratory diseases.