Face Mask Technologies

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Re: Face Mask Technologies

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Study highlights the importance of mask fit when double masking to protect against COVID-19

4/17/21


https://www.news-medical.net/news/20210 ... ID-19.aspx


A study published today in JAMA Internal Medicine shows that wearing two face coverings can nearly double the effectiveness of filtering out SARS-CoV-2-sized particles, preventing them from reaching the wearer's nose and mouth and causing COVID-19. The reason for the enhanced filtration isn't so much adding layers of cloth, but eliminating any gaps or poor-fitting areas of a mask.

" The medical procedure masks are designed to have very good filtration potential based on their material, but the way they fit our faces isn't perfect."

- Emily Sickbert-Bennett, PhD, Associate Professor of Infectious Diseases, UNC School of Medicine and Study's Lead Author

To test the fitted filtration efficiency (FFE) of a range of masks, UNC researchers worked with James Samet, PhD, and colleagues in the USEPA Human Studies Facility on the campus of UNC-Chapel Hill. There they filled a 10-foot by 10-foot stainless-steel exposure chamber with small salt particle aerosols, and had researchers don combinations of masks to test how effective they were at keeping particles out of their breathing space.

Each individual mask or layered mask combination was fitted with a metal sample port, which was attached to tubing in the exposure chamber that measured the concentration of particles entering the breathing space underneath the researcher's mask. A second tube measured the ambient concentration of particles in the chamber. By measuring particle concentration in the breathing space underneath the mask compared to that in the chamber, researchers determined the FFE.

"We also had the researchers in the chamber undergo a series of range-of-motion activities to simulate the typical motions a person may do throughout their day - bending at the waist, talking, and looking left, right, up and down," said Phillip Clapp, PhD, an inhalation toxicologist in the UNC School of Medicine who has been testing mask FFE with Sickbert-Bennett since the pandemic began.

According to their findings, the baseline fitted filtration efficiency (FFE) of a mask differs person to person, due to each person's unique face and mask fit. But generally, a procedure mask without altering the fit, is about 40-60% effective at keeping COVID-19-sized particles out. A cloth mask is about 40% effective.

Their recent findings on doubling of face masks, shows that when a cloth mask is placed over a surgical mask, the FFE improved by about 20%, and improved even more with a snug-fitting, sleeve-type mask, such as a gaiter. When layered over procedure masks, cloth masks improve fit by eliminating gaps and holding the procedure mask closer to the face, consistently covering the nose and mouth. When a procedure mask is worn over a cloth mask, FFE improved by 16%.

"We've found that wearing two loosely fitted masks will not give you the filtration benefit that one, snug-fitting procedure mask will," Sickbert-Bennett said. "And with the current data supporting how effective mask-wearing is at preventing the spread of COVID-19, the best kind of double-masking is when you and the person you are interacting with are each correctly wearing a very snug-fitting mask."

This study was partially funded by a grant from the Centers for Disease Control and Prevention (CDC), and expands upon research conducted by the agency earlier this year, which supported the CDC's recommendation of double-masking to the public. Sickbert-Bennett and Clapp have previously discussed this recommendation and their research on the importance of mask fit with news outlets in a recorded conversation, which can be seen here.

Source:

University of North Carolina Health Care
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Re: Face Mask Technologies

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Health Ranger posts new microscopy photos of covid swabs, covid masks and mysterious red and blue fibers

4/25/21


https://www.naturalnews.com/2021-04-25- ... ibers.html


What follows is a series of microscopy photos of covid swabs (a synthetic swab, then a cotton swab), a covid mask and some zoomed-in photos of mysterious red and blue fibers found in the masks.

The magnification range for these photos is 50X to 200X. Most were taken with white light, but several (as indicated) were taken with UV light.

The images shown here are 600 pixels wide. We have higher resolution images available to researchers and indy media journalists; contact us for those hi-res images.

More microscopy investigations are under way, and new images will be posted as they are finalized.

(Please refer to the original article for photos)
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Re: Face Mask Technologies

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Disposable face masks release potentially dangerous chemical pollutants

5/5/21


https://www.news-medical.net/news/20210 ... tants.aspx


Swansea University scientists have uncovered potentially dangerous chemical pollutants that are released from disposable face masks when submerged in water.

The research reveals high levels of pollutants, including lead, antimony, and copper, within the silicon-based and plastic fibres of common disposable face masks.

The work is supported by the Institute for Innovative Materials, Processing and Numerical Technologies (IMPACT) and the SPECIFIC Innovation & Knowledge Centre

Project lead Dr Sarper Sarp of Swansea University College of Engineering said:

"All of us need to keep wearing masks as they are essential in ending the pandemic. But we also urgently need more research and regulation on mask production, so we can reduce any risks to the environment and human health".

Outlined in a recent paper, the tests carried out by the research team used a variety of masks - from standard plain face masks to novelty and festive masks for children with many currently being sold in UK retail outlets.

The rise in single-use masks, and the associated waste, due to the COVID-19 pandemic has been documented as a new cause of pollution. The study aimed to explore this direct link - with investigations to identify the level of toxic substances present.

The findings reveal significant levels of pollutants in all the masks tested - with micro/nano particles and heavy metals released into the water during all tests. Researchers conclude this will have a substantial environmental impact and, in addition, raise the question of the potential damage to public health - warning that repeated exposure could be hazardous as the substances found have known links to cell death, genotoxicity and cancer formation.

To combat this, the team advise further research and subsequent regulations be put in place in the manufacturing and testing process.

Project lead Dr Sarper Sarp explained:

" The production of disposable plastic face masks (DPFs) in China alone has reached approximately 200 million a day, in a global effort to tackle the spread of the new SARS-CoV-2 virus. However, improper and unregulated disposal of these DPFs is a plastic pollution problem we are already facing and will only continue to intensify."

"There is a concerning amount of evidence that suggests that DPFs waste can potentially have a substantial environmental impact by releasing pollutants simply by exposing them to water. Many of the toxic pollutants found in our research have bio-accumulative properties when released into the environment and our findings show that DPFs could be one of the main sources of these environmental contaminants during and after the Covid-19 pandemic.

It is, therefore, imperative that stricter regulations need to be enforced during manufacturing and disposal/recycling of DPFs to minimise the environmental impact.'

"There is also a need to understand the impact of such particle leaching on public health. One of the main concerns with these particles is that they were easily detached from face masks and leached into the water with no agitation, which suggests that these particles are mechanically unstable and readily available to be detached.

Therefore, a full investigation is necessary to determine the quantities and potential impacts of these particles leaching into the environment, and the levels being inhaled by users during normal breathing. This is a significant concern, especially for health care professionals, key workers, and children who are required to wear masks for large proportions of the working or school day."

Source:

Swansea University
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Re: Face Mask Technologies

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Single-use face masks are a ticking time bomb of global pollution, experts warn

5/7/21


https://science.news/2021-05-07-face-ma ... perts.html


Single-use face masks are a ticking plastic bomb for the environment, according to a commentary published in Frontiers of Environmental Science and Engineering. Zhiyong Ren, a professor of civil and environmental engineering from Princeton University, and Elvis Xu, an environmental scientist from the University of Southern Denmark, authored the commentary.

Based on recent studies, the authors estimated that some 129 billion single-use face masks are used per month worldwide. This figure corresponds to three million masks used per minute. Most of these masks are made from plastic microfibers, typically ranging in size from five millimeters (mm) to microscopic lengths.

There have been increasing reports as well of the inappropriate disposal of soiled face masks. The authors said it is urgent to recognize single-use face masks as a potential environmental threat to prevent them from becoming the next big plastic problem.

Face masks could be worse than plastic bottles

More than 300 million tons of plastic were being produced worldwide per year before the pandemic. However, recent estimates show that face masks are now being produced worldwide at an unprecedented rate, with China leading the way.

In fact, China, now the world’s largest face mask producer, increased its face mask production by a factor of 10 last March to meet the surge in demand. That put the production of single-use face masks on a similar scale as plastic bottles. (Related: Plastic BAN List highlights the 9 top sources of plastic pollution.)

But unlike plastic bottles, single-use masks can neither be reused nor recycled. In fact, 25 percent of all bottles produced are recycled thanks to official guidance from local and national governments. On the other hand, there is no official guidance for the recycling of masks. So it’s not surprising that most soiled masks end up polluting both terrestrial and aquatic environments.

Moreover, the masks’ materials make them more likely to persist and accumulate in the environment. A single-use mask typically has three layers: a polyester outer layer, a polypropylene or polystyrene middle layer and an inner layer made of an absorbent material like cotton.

Polypropylene is notorious for being one of the most problematic plastics. It is typically used to produce various plastic products, such as plastic containers, reusable water bottles, plastic furniture, medical components, luggage and even car parts.

As a ubiquitous material, polypropylene is also typically found accumulating in the environment. According to Xu and Ren, masks are able to resist degradation even when subjected to heat and solar radiation in nature because of polypropylene’s recalcitrant properties.

They also explained that masks can generate large numbers of microscopic polypropylene particles as they become weathered in the environment. These particles can break down further into nanoplastics.

Products like plastic bottles and plastic bags would take centuries to break down into micro- and nanoplastics. But since single-use face masks are already made from micro-sized plastic fibers, they may release those fibers into the environment more readily, explained Xu and Ren.

The authors also pointed out that nanomasks could further compound this problem. Nanomasks are new-generation masks that use nano-sized plastic fibers to protect the wearer from inhaling pathogens. But as is the case with the standard single-use masks, these nanomasks may be another source of plastic pollution.

However, Xu and Ren said they do not know how masks contribute to the large number of plastic particles detected in the environment because no data on mask degradation in nature exists.

That said, it’s safe to assume that, like other plastic waste, masks accumulate in nature. They may even release harmful chemicals and pathogenic microorganisms that threaten plants, animals and humans.

Despite this grim outlook, Xu and Ren said there are several things that citizens, officials and scientists can do to minimize the impact of face masks on the environment. These include:

Set up mask-only trash bins for collection and disposal
Replace disposable masks with reusable ones
Develop biodegradable face masks
Consider standardization, guidelines and strict implementation of waste management for mask wastes
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Re: Face Mask Technologies

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Scientists assess the filtration efficacy of 227 models of face masks sold in Brazil

6/3/21


https://www.news-medical.net/news/20210 ... razil.aspx


The novel coronavirus is transmitted mainly via inhalation of saliva droplets or respiratory secretions suspended in air, so that face covering and social distancing are the most effective ways to prevent COVID-19 until enough vaccines are available for all.

In Brazil, fabric masks are among the most widely used because they are cheap, reusable and available in several colors or designs. However, this type of face covering's capacity to filter aerosol particles of a size equivalent to the novel coronavirus can vary between 15% and 70%, according to a study conducted in Brazil by the University of São Paulo (USP).

The study was supported by FAPESP, and the principal investigator was Paulo Artaxo, a professor in the university's Physics Institute (IF-USP). It was part of an initiative called (respire! to assure access to safe masks for the university community. The results are reported in an article in the journal Aerosol Science and Technology.

" We appraised the filtration efficacy of 227 models sold by drugstores and other common types of store in Brazil to see how much genuine protection they afford the general public."

- Paulo Artaxo, Professor, Physics Institute (IF-USP), Agência FAPESP

The scientists conducted a test using a device that contained a sodium chloride solution and emitted aerosol particles of 100 nanometers. SARS-CoV-2 is about 120 nanometers in diameter. A burst of aerosols was triggered, and particle concentration was measured before and after the mask.

As expected, surgical masks were most effective in the test, as were the FFP2 or N95 models certified for professional use, filtering 90%-98% of the particles. Next came masks made of non-woven fabric (TNT) or polypropylene and sold in many kinds of store, with an efficiency of 80%-90%, followed by those made of ordinary cotton, spandex or microfiber, which filtered 40% on average (15%-70%).

Several factors were critical in enhancing or reducing the degree of protection. "Generally speaking, masks with a central seam protect less because the sewing machine makes holes that increase the passage of air. A tightly fitting top edge improves filtration significantly.

Some masks made of fabric include fibers of nickel, copper or other metals that inactivate the virus and hence protect the wearer more effectively.

There are even electrically charged models that retain more particles. In all cases, however, efficacy drops when the mask is washed because of wear and tear," said Fernando Morais, first author of the article. Morais is a PhD candidate at IF-USP and a researcher at the Nuclear and Energy Research Institute (IPEN), an agency of the São Paulo State Government.

Breathability

According to Artaxo, dual-layer cotton masks filtered considerably better than single-layer models, but efficacy was hardly altered by a third layer, which reduced breathability.

"The study innovated in several ways. One was its evaluation of breathability or resistance to air passage," Artaxo said. "TNT and cotton masks were best in this regard. The FFP2 and N95 models were not as comfortable, but paper masks were the worst. This is important because if a person can't bear wearing a mask even for five minutes, it's useless."

The authors of the article note that although mask efficacy varies, all types help reduce transmission of the virus, and mask-wearing in conjunction with social distancing is fundamental to control the pandemic.

They advocate mass production of FFP2/N95 masks for distribution free of charge to the general public. This "should be considered in future pandemics", according to Vanderley John, penultimate author and coordinator of (respire!, which is organized by USP's Innovation Agency.

"Transmission of the virus is demonstrably airborne and wearing a mask all the time is one of the best prevention strategies, as well as leaving doors and windows open to ventilate rooms as much as possible," Artaxo said.

Source:

Fundação de Amparo à Pesquisa do Estado de São Paulo

Journal reference:

Morais, F. G., et al. (2021) Filtration efficiency of a large set of COVID-19 face masks commonly used in Brazil. Aerosol Science and Technology. doi.org/10.1080/02786826.2021.1915466.
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Re: Face Mask Technologies

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Nanotech antimicrobial masks filter 99.9% of bacteria, viruses, and haze particles

6/9/21

https://phys.org/news/2021-06-nanotech- ... teria.html


Materials scientists from Nanyang Technological University, Singapore (NTU Singapore) have developed a reusable "nanotech mask" that can filter out 99.9 percent of bacteria, viruses and particulate matter (PM), as well as kill bacteria.

Its novel antimicrobial coating kills bacteria within 45 seconds and is effective for at least 144 hours (six days).

Its filtration efficiency surpasses those of N95 masks (95 percent filtration of PM0.3) and can be washed and reused over 10 times.

In mid-May, Singapore tightened its COVID-19 measures as the country was facing an increase in the number of infections, and the population was advised to use face masks with high filtration capability to help curb the spread of the coronavirus.

The made-in-NTU mask comprises two key components: an antimicrobial coating made from copper nanoparticles developed and patented by Professor Lam Yeng Ming, coated on a fabric mask invented by Associate Professor Liu Zheng, which has a unique dielectric property that attracts all nanoparticles and germs.

Prof Lam, who is also the Chair of NTU's School of Materials Science and Engineering, said their mask prototype combines the two most desired properties needed to fight COVID-19, into a single filter.

"In experiments, our copper nanoparticle coating has an extremely fast and sustained antibacterial activity, with a killing efficiency of up to 99.9 percent when it meets multi-drug resistant bacteria. This coating will help to reduce the spread of bacteria as it kills microbes in droplets trapped by the mask fibers, which provide excellent filtration efficiency. This should give users a double layer of protection compared to conventional surgical masks," explained Prof Lam.

Experiments on the antibacterial effectiveness of the mask were conducted in collaboration with scientists from the National University of Singapore (NUS). They simulated real-life conditions by introducing multi-drug resistant bacteria in droplet form onfabric surfaces and observed that almost all the bacteria were dead by 45 seconds.

The reason for the effectiveness of the antimicrobial coating was two-fold: the first is the extremely small size of the nanoparticles, which are about 1,000 times smaller than the width of a human hair. Collectively, millions of nanoparticles provide a huge surface area for the viruses and bacteria to contact, compared to bigger particles.

The second is the high level of oxidative damage caused by the copper oxide material. Copper oxide induces the generation of reactive oxygen species, resulting in DNA damage of important cell structures in the bacteria, such as the cell membrane, severely damaging it and causing the bacteria to die.

To make it easy to apply, the antimicrobial nanoparticle solution is designed to be spray-coated on all soft and hard surfaces.

Various peer-reviewed studies have shown that copper oxide is effective in killing viruses, such as the recent study published in ACS Applied Materials & Interfaces by The University of Hong Kong and Virginia Tech, where door handles were coated with a layer of copper oxide material.

The NTU team tested their nanoparticle coating in harsh conditions for120 washing cycles(inthe presence of soap or its active componentsat 45 degC) and found that there was almost no copper loss—posing very little risk of toxicity to humans.

The nanoparticles are also bonded to the fibers within the mask, so there is no contact with human skin when the mask is worn.

Superior trapping capabilities of the mask

Killing viruses and bacteria would only work if the mask is able to trap and stop them from passing through. This is where Assoc Prof Liu's breakthrough came in handy.

Last year, his team developed a way to integrate dielectric materials to plastic fibers during the manufacturing process of an unwoven fabric filter made from Polypropylene (PP), commonly used in disposable surgical masks used by hospitals. This was done in collaboration with Prof Guan Li from the Renmin University of China.

The dielectric materials have excellent electrostatic capabilities, which can attract and bind to particles possessing a negative or positive charge, similar to how magnets attract metal particles.

Made from fibers with a diameter of 200 to 300 nanometres, the mask has a higher surface area that lowers the breathing resistance—making it easy for its wearer to breathe as compared to conventional N95 respirators, which are denser.

In tests, the next-generation dielectric composite fabric had 50 percent higher filtration efficiency than pure PP masks, which are commonly rated at 95 percent BFE (Bacterial Filtration Efficiency).

Assoc Prof Liu said: "With our new composite filter, we can achieve up to 99.9 percent BFE, trapping almost all microbes and particulate matter from smoke or haze. Its filtration efficiency surpasses a N95 mask but allows the wearer to breathe much easier.

"More importantly, it can be mass-produced easily using the current production process. It is also washable for more than 10 times before losing filtration efficiency, making it more sustainable than current one-use disposable masks."

In experiments, the mask was able to attract and trap a broad range of particulate matter: from PM10 (average particle size of 10 microns) to PM0.3 (0.3 microns—about 0.3 percent the diameter of a human hair) with a filtration efficiency of 99.9 percent.

The antimicrobial coating has a patent filed through NTU's enterprise and innovation company, NTUitive, and Prof Lam's team is already working with a local company to coat it on their products.

Assoc Prof Liu's dielectric composite fabric material is now used by an overseas manufacturer to make N95 masks that are as easy to breathe as disposable surgical masks and are available commercially.

The team is now looking to work with local industry partners who are keen to license and scale up the production of their 2-in-1 mask and are currently preparing scientific papers for submission in scientific journals.

NTU scientists have been working on developing solutions in the global fight against COVID-19.

These include innovations such as autonomous disinfection robots, COVID-19 rapid test kits and a breathalyzer device, a smart mask, antimicrobial coatings, as well as fundamental research on the coronavirus to find new drug targets for treatment and vaccine development.

Healthcare is one of humanity's grand challenges that NTU seeks to address under theNTU 2025 strategic plan.

More information: Mohsen Hosseini et al, Cupric Oxide Coating That Rapidly Reduces Infection by SARS-CoV-2 via Solids, ACS Applied Materials & Interfaces (2021). DOI: 10.1021/acsami.0c19465
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Re: Face Mask Technologies

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Developing a face mask that can detect COVID-19

7/6/21


https://www.news-medical.net/news/20210 ... ID-19.aspx

A face mask has been developed that can detect COVID-19. News-Medical spoke to the researchers behind this idea to find out more about how it works.


Please could you introduce yourself and tell us what inspired your research into coronavirus disease 2019 (COVID-19)?


Peter Nguyen is a Research Scientist at the Wyss Institute at Harvard University and Luis Soenksen (interviewer), is a Research Scientist and Venture Builder at the MIT Jameel Clinic for AI & Healthcare.

Our laboratory at MIT/Harvard (https://www.collinslab.mit.edu/) is currently focused on ways to bring advanced biological circuits, a field known as ‘synthetic biology,’ out of the laboratory and into everyday technology. This led us to focus on biosensor-containing wearables.

Current commercially available wearables (e.g., FitBit or Apple Watch) detect physiological signals electronically. However, they cannot detect exposure to a pathogen or a toxin. That is something that currently requires an entire laboratory to process samples.

Our sensors can now bring that same testing power to wearables to detect and identify pathogens (any bacteria or virus) as well as toxins. In essence, our technology miniaturizes an entire laboratory onto a wearable garment. When the pandemic hit, we immediately pivoted our work to developing a wearable that could detect COVID-19 in an unobtrusive, inexpensive, and quick way.

Nearly 4 million people have died so far from the COVID-19 outbreak. Why is it important for researchers and organizations to come together and work collaboratively to help advance our detection and prevention methods?


Collaboration within the research community by sharing data, ideas, and constructive feedback is essential to making sure we have a diversity of approaches and technologies at our disposal. We all build off of each other in a wonderful way, the amazing vaccine technology that arose from this pandemic is an example of that.

Our detection/monitoring technology needs to catch up. We have benefited greatly from thoughtful discussions with researchers in disparate fields and clinicians, too. It’s especially important for a multidisciplinary project such as this.

What are biosensors and how are they able to detect pathogens and toxins?


Biosensors use engineered genetic circuits to create sensors and detectors for a desired molecular target through biology, in contrast to electronic/mechanical/optical sensors. We think biosensors are uniquely suited for pathogen and toxin detection, as they are most able to directly interface with these molecular components.

Our physiological responses to these threats are fundamentally biological in nature. By reengineering the interactions between biological molecules, highly sensitive sensors can be created. Biosensors will enable the next generation of artificially engineered wearables that have sensing capabilities similar to that of our own skin or immune system.

You have been working on this wearable freeze-dried cell-free (wFDCF) technology for over three years and first used it with paper. What problems did you encounter when attempting to recreate this biosensor so that it is wearable and how did you overcome them?

Our work for the COVID-19 face mask is definitely built upon our previous Ebola and Zika paper-based diagnostics. Those tests demonstrated the freeze-dried technology but still required a trained user to prepare a sample, apply it to the paper, and instruments to process it. For our current work, we wanted to focus on having the technology be autonomously operating, with automatic sample collection, integrated sample preparation, and minimal user intervention.

For the face mask, all the user has to do to activate the sensor to begin the analysis is press a button. These various obstacles were not trivial, taking us several years to engineer. A big problem we encountered was evaporation, as the FDCF reactions need water to work. So much of the engineering in the wearables was designing the sensors to minimize evaporation while maintaining flexibility and continuity with the environment, by using specially designed hydrophobic elastomeric sensor chambers.

Also, the face mask sensors used a more complex multi-reaction design, requiring time delays to ensure that each freeze-dried reaction occurred in a stepwise manner and was yet able to run autonomously. Each step and component had to be arduously optimized so that the entire system executed robustly. There was a lot of material optimization as well, to ensure that we had the right flow of water and compatibility with the various reagents.

Please can you describe how you carried out your latest research into developing this wearable biosensor? How does this biosensor work?

The COVID-19 sensor here also contains freeze-dried biological sensors (based on CRISPR enzymes). Attached to the sensor is a sample collection pad that collects the user’s breath aerosols. When the user has worn the mask for an appropriate amount of time (a minimum of 15-30 minutes), they press a button that pierces a water-filled blister pouch, which immediately wicks water through the sample collection pad, pushing along any viral particles into the sensor for analysis. The sensor contains three freeze-dried reactions, each separated by a dissolvable time delay.

First, an optimized detergent mixture disrupts any viral membranes. The second reaction is a coupled reverse transcriptase – recombinase polymerase amplification (RT-RPA) isothermal reaction, which converts the viral RNA to DNA and amplifies an area of it (the gene coding for the spike protein). The third and last reaction is the CRISPR (Cas12a) sensor, which detects the amplified DNA. There is a probe molecule that gets cleaved (cut) by the Cas12a if it is activated.

At the very end, once the sensor has been executed, the reaction flows to a lateral flow strip (similar to a pregnancy test) where the result is presented simply as a visible pattern of bands that varies by virtue of whether the probe has been cleaved or not.

Your face mask can detect the presence of SARS-CoV-2 with the same accuracy as standard PCR tests. What other advantages does this face mask have over other methods used to diagnose COVID-19 such as PCR tests?


It’s very convenient – if you are already wearing a mask, why not have a test while you are wearing one?
It’s noninvasive, detecting the virus from the user’s breath. The longer the breath capture, the more sample available for the analysis.
It is inexpensive - currently, our prototype COVID-19 diagnostic sensor costs in total approximately $5 USD, not including the cost of the mask itself. At this cost, we think it would be competitive as a disposable all-in-one mask and test. We anticipate that with a mass-manufactured product, this price point should drop.
It hits the sweet spot of sensitivity and speed – unlike an antigen test, this is a nucleic acid amplification test (NAAT), which directly detects the genome of the virus. Unlike a typical PCR test, this face mask test can give results within 90 minutes without needing to send anything to a lab.
No instrumentation and minimal user operation – The sensor is fully integrated into the material, and all the user needs to do to activate it is press a button. There are no instruments or power needed.
It runs at room temperature – This is something that sounds trivial, but it actually quite hard to achieve. All of the reactions are able to work at room temperature, which was what enabled us to dispense with laboratory instruments (for example, heating required by PCR).

What other applications could this face mask potentially be applied to?


One immediate application could be detecting and monitoring the spread of COVID-19 variants. If masks were mailed to a population and the results reported on an app, we might be able to get an extremely detailed map of the spread of a variant, enabling quick policy decisions.

If there was a particularly bad influenza season, these masks could potentially be used to distinguish between the flu and the common cold, enabling rapid administration of antivirals.

There is research showing that other diseases and even cancer can be detected through exhaled volatile organic compounds (VOCs). If we could develop biosensors to detect these VOCs, it could greatly expand the range of what is detectable beyond respiratory pathogens.

Do you believe that this wearable biosensor will help us to further detect coronavirus cases early enabling us to stop the spread of the virus?


One shortcoming in our global preparedness laid bare during this pandemic was the lack of rapid and sensitive testing, which greatly lagged behind the surging infections. Our mask technology could allow us to greatly increase the testing frequency to where it needs to be, enabling potentially daily testing by having a diagnostic that is easy to use for the general population without the need of a laboratory (as the test is completely self-contained and only requires the press of a button).

We believe that by reducing the barrier to diagnostic testing so that it can be performed anywhere by anyone and yet still provide robust results, we could drastically increase the density and frequency of testing. That would be a key piece of the puzzle that is needed to stop this current pandemic in its tracks and contain any future disease outbreaks before it becomes a pandemic.

What are the next steps in your research?

Given the low cost, the convenience, the shelf stability, and the high performance of the face mask diagnostics, we think manufacturers will be excited to work with us to develop a commercial version from our prototype.

We are actively looking for commercial partners to engage in design for mass manufacturing of the face mask. This process could be quite accelerated with the right partners and government support. We are also looking into developing versions of the face mask sensor that can differentiate between the COVID-19 variants.

Where can readers find more information?

https://www.nature.com/articles/s41587-021-00950-3
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Re: Face Mask Technologies

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Homemade face masks work; effectiveness varies depending on how they are made

9/14/21


https://phys.org/news/2021-09-homemade- ... aries.html


Since the spread of virus causing COVID-19 continues, experts recommended wearing homemade facemasks when surgical or N95 masks are not available to prevent the spread of the pandemic. While such makeshift masks are more economical and accessible in low-capita countries, the effectiveness of cloth masks has not been studied in depth.

In Physics of Fluids, researchers from the Indian Institute of Science studied the fate of a large-sized surrogate cough droplets at different velocities, corresponding from mild to severe, while using various locally procured fabrics as masks.

"Our results show cotton, towel-based fabrics were most effective among the considered fabrics and must be stitched together as multiple layers for making homemade facemasks," said author Saptarshi Basu. "A three or more-layered homemade mask is recommended, since it can suppress aerosolization significantly."

The researchers analyzed the effect of washing on mask effectiveness, and results showed a negligible influence of washing on mask efficacy for up to 70 wash cycles.

Using a piezoelectric-based droplet dispenser, the researchers created surrogate cough droplets that impacted a single layer of different fabric samples at different velocities. The fabrics used in the research included single layers of summer stole, handkerchief, cotton towel, and surgical masks.

The specific cotton-fabric materials were selected based on their daily usage and the propensity of people to cover their face using these cloth materials. The researchers used high-speed imaging to quantify the threshold for penetration and amount of droplet penetration at different velocities.

The researchers looked at how fabric properties, like pore size and porosity, influences droplet penetration through the mask.

The results are relevant for many groups including policy makers investigating how to counter aerosol generation through secondary atomization of cough droplets as they penetrate the mask fabric. For mask fabricators and the general population, it is helpful to know that N95 and surgical masks are most effective, but when those aren't available, some specific cotton materials or homemade fabrics are suitable for effective makeshift face masks.

The findings also could be applicable in applications ranging from agriculture to medical practices, where placing a wire mesh or perhaps an engineered cellulose mesh of variable porosity can reduce the momentum of incoming spray from a nozzle, thereby ensuring optimal spread of nutrients or pesticides to crops or better disinfection in hospital

The article, "Efficacy of homemade face masks against human coughs: Insights on penetration, atomization and aerosolization of cough droplets," is authored by Bal Krishan, Dipendra Gupta, Gautham Vadlamudi, Shubham Sharma, Dipshikha Chakravortty, and Saptarshi Basu. The article will appear in Physics of Fluids on Sept. 14, 2021.

More information: "Efficacy of homemade face masks against human coughs: Insights on penetration, atomization and aerosolization of cough droplets," Physics of Fluids (2021). aip.scitation.org/doi/full/10.1063/5.0061007
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Re: Face Mask Technologies

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New coating technology uses 'nanoworms' to kill COVID-19

9/15/2
1

https://phys.org/news/2021-09-coating-t ... ovid-.html


An antiviral surface coating technology sprayed on face masks could provide an extra layer of protection against COVID-19 and the flu.

The coating developed at The University of Queensland has already proven effective in killing the virus that causes COVID-19, and shows promise as a barrier against transmission on surfaces and face masks.

UQ's Australian Institute for Bioengineering and Nanotechnology researcher Professor Michael Monteiro said the water-based coating deployed worm-like structures that attack the virus.

"When surgical masks were sprayed with these 'nanoworms," it resulted in complete inactivation of the Alpha variant of SARS-CoV-2 and influenza A," Professor Monteiro said.

The coating was developed with Boeing as a joint research project, and was tested at the Peter Doherty Institute for Infection and Immunity at The University of Melbourne.

"These polymer 'nanoworms' rupture the membrane of virus droplets transmitted through coughing, sneezing or saliva and damage their RNA," Professor Monteiro said.

"The chemistry involved is versatile, so the coating can be readily redesigned to target emerging viruses and aid in controlling future pandemics."

Professor Monteiro said face masks would continue to be an important part of helping prevent or reduce community transmission of COVID-19.

"Antiviral coatings applied on mask surfaces could reduce infection and provide long-lasting control measures to eliminate both surface and aerosolised transmission," he said.

"We know that COVID-19 remains infectious for many hours or days on some surfaces, and provides a direct route to infection.

"Therefore, there is greater emphasis on eliminating both surface and airborne transmission to complement vaccination of the population to stop the current pandemic."

The coating is environmentally friendly, water-based and its synthesis aligns with manufacturing techniques used in the paint and coatings industry.

The research is published in ACS Nano.

More information: Valentin A. Bobrin et al, Water-Borne Nanocoating for Rapid Inactivation of SARS-CoV-2 and Other Viruses, ACS Nano (2021). DOI: 10.1021/acsnano.1c05075
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Re: Face Mask Technologies

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Creating a face mask that adapts to your environment

10/11/21

https://www.news-medical.net/news/20211 ... nment.aspx


In this interview, News-Medical speaks to Professor Seung Hwan Ko about his latest research in which he developed a face mask that can adapt to your changing conditions and environment.

People are becoming accustomed to wearing face masks daily due to the ongoing COVID-19 pandemic. What inspired your research into face masks and how they can be adapted for better use?


Most of the face masks invented so far have not paid attention to the dynamic change of the users’ condition and environment. Instead, most face masks have just focused on increasing the filtering efficiency. However, even though the mask itself has a very high filtration efficiency, it does not mean it is user-friendly (usually, a high-efficiency filter means the mask is hard to breathe and uncomfortable).

At certain conditions, other components are more important than filtration efficiency. For example, last year, I read news articles saying that several students died during a physical education class while wearing a mask. This may imply that one single type of filter mask cannot react properly to the dynamically changing condition of the user and the user should therefore carry various types of face mask and change them depending on their physical demand or environment change.

We tried to invent an AI-driven face mask that detects the user’s condition (predict the short-term respiration rate change with the aid of AI) or detects the environmental air quality change and automatically changes the pore size, changing the trade-off between the comfortability and filtering efficiency.

The main purpose of face masks is to filter out harmful pollutants. How do face masks do this?


Most of the off-the-shelf face masks adopt fabric air filters in which very thin (about 10 – 100 times thinner than a human hair) fibers entangle each other to form a loosely packed sponge-like porous structure. As an airstream goes through the complex, intertwined network of tiny air tunnels, the small airborne particles, which we call pollutants, collide with the fibers and adhere to them. This is how the face masks do the filtration.

Our invention also shares the same working mechanism in terms of the filtration of the pollutants, yet differs greatly in that it allows for dynamic tuning of how the mechanism actually works.

Can you describe how face masks are often designed and developed?


Until two years ago, it is true that there was not much interest in face masks because masks were just a sanitary product that was located on the outskirts of our ordinary lives. However, the global COVID-19 pandemic changed the situation.

Through the last year and even today, countless reports on developing new, advanced forms of face masks are being made, while the majority of those still rely on conventional, passive air filtration technology. To the best of our knowledge, our invention is the first-ever reported development of a ‘dynamically tunable face mask’.

Many people find face masks uncomfortable, particularly when exercising. Why is this?

When people wear a mask, they find the masks uncomfortable, especially when exercising, because the body needs more oxygen and breathing rate increases. However, a mask usually induces the pressure drop (or pressure difference) due to the presence of the filter.

The pressure drop (or pressure difference) increases more for the higher efficiency filter. The higher pressure drop (or pressure difference) makes it hard for the user to breathe and consumes more energy (thus makes the user uncomfortable).

Can you describe how you carried out your latest research into designing a face mask that adapts to changing conditions?

Our team is a cooperative coalescence of experts from various fields of engineering, ranging from material science, mechanical, electrical engineering, and even machine intelligence. That’s how we’ve been able to develop an operable AI-driven face mask starting from scratch.

Our team started by conceiving an archetype idea that was a little bit vague to see the first time. However, the well-trained engineering minds from various facets made it possible to materialize the idea into a tangible, convincing entity. In that sense, we would say, there has been collaborative multidisciplinary engineering behind the successful execution of our work.

How did you develop your dynamic respirator? How does this air filter work in different conditions?

One of the striking features of our dynamic respirator is that it can automatically transform its filtration characteristics to fit the given circumstance. This means the system is designed to be capable of ‘sensing’ the environment associated with its operation.

Thus, we endowed the sensing ability to the system by incorporating sensors. A PM (particulate matter) sensor is used to measure how much of the ambient air is polluted and the barometers are used for sensing the wearer’s respiratory pattern reflecting the physical condition. The information gathered from the sensors is then used to make comprehensive ‘situational awareness’ of the AI algorithm which then generates the dynamic adjustment of filtration characteristics to the different scenarios.

What benefits will this face mask have for people compared to other face masks available?


The traditional mask usually has the basic concept that users need to adapt themselves to the mask (this means that users need to bear the uncomfortable situation). However, we tried to invent a new concept in which the mask adapts itself to the user’s condition and external environment.

I think our AI-driven mask is the first demonstration to consider the dynamic change of user’s demand and environmental conditions, and it changes the current focus in masks from filters to people (users) for the first time.

What role did artificial intelligence (AI) play in your research?

What we’ve been trying to build through this work was an automated respirator that can seamlessly adapt to an individual wearer, necessitating a highly personalized operational algorithm; the respirator and algorithm running will, in a figurative sense, recognize ‘characteristic’ transitions of respiratory patterns of a specific user.

However, the characteristic of how the transition occurs, for example, differs among individuals. This makes developing a universal algorithm that can be released to the public extremely challenging. In this context, we choose to develop an AI algorithm that learns the respiratory characteristics of individual wearers to enable ‘universal personalization’, which is not possible with ordinary, inflexible algorithms.

Do you believe that if adaptable face masks were readily available more people would wear them regularly, potentially reducing the spread of COVID-19?

The major motivation for the AI-driven mask came from my personal experience. When I go to the gym or go out jogging, I feel a strong urge to take off the mask during exercise. I could also see many people putting the mask away while using the running machine. During the COVID-19 situation, many places (indoor or outdoor) have a strict restriction policy for wearing a mask.

The major reason why they don’t wear the mask is simply that they can be very uncomfortable breathing while wearing it. AI-driven masks automatically adjust the trade-off between the filtering efficiency and comfortability to satisfy the users’ dynamic condition and enviornment change. The adaptable face masks are expected to help more people wear masks regularly and potentially reduce the spread of COVID-19.

What further research needs to be carried out before these personalized facemasks can be readily available?

Miniaturization of the mask and to shed light on the use of the face mask in the market. Technological advancements often tend to hide the technology itself from our sight. Light enough, small enough, and therefore oblivious technologies, can offer pure utility on their own without distracting the user. This philosophy is leading our team to discover further various engineering options to minimize the entire system and improve the user experience.

What are the next steps in your research?

Together with the miniaturization, we are trying to discover various elastic materials to endow next-level functionality to the stretchable air filter, one key part of our system. For example, we may make an air filter that can generate even a small amount of electricity as a result of the mechanical modulation of the air filter.

Or, we may focus on self-healable materials to enhance the long-term usability and mechanical stability of the stretchable air filter. Most of all, we are expecting active cooperation with medical experts from every corner of the globe to transfer our technology to the industry.
Where can readers find more information?

More detailed information on the AI-driven smart face mask can be found in the recent publication


“Dynamic Pore Modulation of Stretchable Air Filter for Machined Learned Adaptive Respiratory Protection”, ACS Nano, in press, 2021. [doi/10.1021/acsnano.1c06204]

A further related study from our group on the transparent and reusable filter can be found in our previous publication “High Efficiency, Transparent, Reusable and Active PM2.5 Filters by Hierarchical Ag Nanowire Percolation Network”, Nano Letters, 17, 4339-4346, 2017. [doi/10.1021/acs.nanolett.7b01404]
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