Special: Unpaid Researchers.

Post-doc researcher: essential professional for an efficient research group

In the Covid-19 pandemic the world is now experiencing, the importance of science and technology has become more evident to many people, with examples ranging from diagnostic tests and vaccines to the electronic devices that allow us to do almost everything remotely.

However, few know in detail how scientific and technological knowledge is produced in universities, which are the main scientific knowledge “factories” in Brazil. For each advance reported in a scientific article or patent, or transformed into a product or process, there are months or years of reading, laboratory experiments, computer simulations, discussions, analysis, writing.

Furthermore, there is the administrative work necessary in all research, which includes, among other tasks, project preparations to compete for financing, the recruitment of human resources and the purchase of inputs and equipment – often involving bureaucratic imports.

Far from the image of a scientist working alone in the laboratory, the reality is that to accomplish all of this, each scientific project must have a team of collaborators. Ideally, these teams are made up of people with different degrees of qualification and experience: undergraduate and graduate students (human resources in training process), postdoctoral fellows (junior science professionals) and professors, devoted to teaching, research and mentoring students (group leaders).

In addition to working on their research projects, “post-docs” assist in the intermediation between the group leader and the students, and gain experience in research management, as they more actively participate in administrative activities. Unlike the professor, the post-doc has no obligation to teach, nor does he need to hold an administrative position at the university. “The postdoctoral student can dedicate his/her efforts entirely to research projects, ensuring efficiency,” says Osvaldo Novais de Oliveira Junior, professor at the São Carlos Institute of Physics at USP.

Everyone benefits in this structure. Scholarship students receive more attention in their training, the post-doc gains experience as scientist in the profession and the group becomes more productive. “In a group, the post-doc leverages research and allows for more complex work,” says Professor Mônica Cotta, leader of the Laboratory of Nano and Biosystems at UNICAMP.

Postdoctoral fellowships are shrinking

An apparently large number of trained PhDs are currently in an unsuccessful search for opportunities to exercise scientific activity in Brazil. This situation is related to the decrease in the number of scholarships offered by federal agencies that deal with research grants: CNPq and Capes. In fact, after reaching maximum values between 2014 and 2015, the number of postdoctoral fellowships has decreased significantly, as shown in these graphs.

Number of total scholarships (left) and by federal agency (right) for PhDs (postdoctoral scholarships, technological development, etc.) over the years. Scholarships for senior doctors or professors and scholarships for activities abroad were excluded. Data extracted from CAPES and CNPq.
Number of total scholarships (left) and by federal agency (right) for PhDs (postdoctoral scholarships, technological development, etc.) over the years. Scholarships for senior doctors or professors and scholarships for activities abroad were excluded. Data extracted from CAPES and CNPq.

Without remuneration, these highly trained and specialized professionals, whose training takes, on average, a decade, look for positions abroad, adding to the “brain drain” that occurs in times of little appreciation of science in the country. Or worse, they abandon science to ensure their financial survival.

Unlike other groups that are suffering from a decrease or lack of income during the pandemic, the group of unpaid PhDs is not visible in society, nor has it been addressed by any government aid program.

Faced with this scenario, B-MRS is gathering stories of PhDs who have not found opportunities to remain active in research, in order to sensitize society and the government to the difficulties these people and their families are going through and understand the negative impacts of this situation for the country. B-MRS also request the restoration of the number of postdoctoral scholarships, in addition to a policy aimed at valuing and encouraging the placement of PhDs in development and innovation activities in our society.

Tales: PhD in Chemistry, freelancer and volunteer researcher

Tales da Silva Daitx presenting his doctoral research during a conference in Hungria em 2019.
Tales da Silva Daitx presenting his doctoral research during a conference in Hungria em 2019.

To be a professor in some Brazilian university, performing research, teaching and mentoring. That is what Tales da Silva Daitx chose to do as a profession. He has liked science since he was a child, but it was at the university that he found the passion to discover new things and to transmit knowledge to others through research and teaching. Tales then went through the required path to properly train and be able to compete in a public or private teaching and research institution.

After graduating in Chemistry from the Federal University of Rio Grande do Sul (UFRGS), he entered the Chemistry graduate program at this university – a program of excellence and with the highest score in the evaluation of Capes (entity in charge of expansion and consolidation of graduate studies in Brazil). He spent six years there working on his master’s and doctorate, both focused on research in the field of intelligent materials.

In mid-March of this year, a few days after the World Health Organization (WHO) declared the Covid-19 pandemic, Tales defended his thesis, the final stage of every doctorate, at the Chemistry Institute of UFRGS. It was one of the last in-person defenses at the institute, together with his wife, who completed her doctorate at the same time. Since then, the couple, who live in Porto Alegre, are trying to earn an income to pay their bills and, at the same time, remain active and productive in research, two objectives that have not been possible to conciliate.

After his doctorate, Tales intended to move on to the next stage of his scientific career, a postdoctoral fellowship (popularly called “post-doc”). Thus, he contacted a research group from the Federal University of Santa Catarina (UFSC), where he could apply the knowledge acquired in graduate school in a project to develop smart nanoparticles for biodegradable packaging.

Thus, after defending his doctorate, already in the middle of a pandemic, Tales participated in two calls for proposals from CNPq, the main federal research funding agency, to try to obtain a post-doc grant, of around 4 thousand reais. Trained to carry out the project and with a competitive curriculum, with eleven scientific articles published in international journals and two patents (one filed and one already granted), Tales obtained a score close to the maximum in the first call. However, he was informed he would not be awarded a grant due to the resources available. The second notice, that would have the result in August, was suspended due to the pandemic.

Currently, while looking for other opportunities, Tales works as a voluntary postdoc (without a grant or any other type of remuneration) in the research group where he completed his doctorate. He participates in meetings, does bibliographic searches, and writes projects. However, he is unable to dedicate his efforts to these activities full time, since, to meet the couple’s basic financial needs, Tales became a freelancer. This 30-year-old professional, highly trained and specialized in an area of knowledge, is currently spending much of his time performing services, such as data entry in computer systems, which do not require such qualification.

“I think this situation in Brazil is a shame, the lack of opportunities for PhDs. In the past there was investment in science and technology, and it had good results. The country was well positioned in research around the world. But the investment did not continue, and that will bring it back to square one,” says Tales. “In addition, the pandemic has affected the research system. Public S&T policies should be revised,” he adds.

B-MRS Lives & Webinars: last month of the program.

sbpmat-Lives-logo_1500pxIn August, the last 2020 technical webinars of the B-MRS Lives & Webinars program were held. Five online lectures on scientific instrumentation and material characterization were given by professionals from instrumentation companies, from Brazil and abroad. Between 30 and 160 participants attended each of the lectures, held on B-MRS’s Zoom and Facebook.

The Lives & Webinars program is a B-MRS learning and training initiative during the period of social distancing due to the Covid-19 pandemic, carried out in partnership with instrumentation companies.

Watch the webinars held in August, whose recording was authorized by the speakers:

  • How Vacuum Innovation Drives Instrumentation (Agilent). See here.
  • Instrumented Indentation Techniques on Polymers (Nanovea e Altmann). See here.
  • Caracterização Elétrica de Materiais (Keysight). See here.
  • Not just for experts – PDF analysis in the home laboratory (Bruker). See here.
  • Soluções de vácuo para pesquisa em materiais (Edwards Vacuum). See here.

Featured paper: Kinetic model for more efficient organic solar cells.

Back cover of the J. Mater. Chem. C highlights the paper of the Brazilian team.
Back cover of the J. Mater. Chem. C highlights the paper of the Brazilian team.

Unlike other solar cells that have dominated the market for a long time, such as silicon cells, the organic ones are thin, light, flexible and semi-transparent. With these characteristics, they become very attractive for specific segments. In Brazil, for example, which has national production, some of the largest installed surfaces in the world can be seen in business buildings, as well as some installations in shopping centers, trucks and bus stops.

Although the organic version of solar cells also offer advantages in large-scale production (simpler industrial processes with lower carbon footprint, such as the roll-to-roll), conquering big markets largely depends on an ongoing efficiency improvement to convert sunlight into electricity. To overcome this challenge, it is essential to develop materials with suitable properties and to combine different materials within the device.

A scientific team from the Brazilian Federal University of Paraná (UFPR) studied in detail, using experimental and theoretical tools, the charge generation mechanism in organic solar cells – a complex process that is not yet fully understood. In practice, the results of this work help choosing which materials should be used and how they should be synthesized, so that their properties enhance the efficiency in converting light into electricity. The research paper was reported in the Journal of Materials Chemistry C (impact factor 7.059), where it was highlighted on the back cover.

Unraveling the exciton dissociation 

In the sandwich of layers that forms solar cells, the active layer (responsible for absorbing light and generating electric charges) is composed of semiconductor materials that, for organic devices, are polymers or other carbon-based molecules. When excited by light, these materials do not generate free electric charges, as is the case with inorganic semiconductors. They generate excitons, which are electron–hole pairs connected by forces of attraction between the negative charge of the first and the positive charge of the second.

In order to generate free charges, which form the electric current, it is necessary to break this connection, in a phenomenon called exciton dissociation. One way to achieve this is to create, in the active layer, an interface between an electron donating material and an electron acceptor. “Depending on the combination of these two materials, exciton dissociation processes can occur at a very low time scale, resulting in a more efficient charge generation,” explains Leandro Benatto, corresponding author of the paper. “However, this process is still not well understood,” he adds.

In their work, Leandro and the other authors focused specifically on trying to understand the exciton dissociation and the generation of free charges at the interface between the donor and acceptor material. The team carried out photoluminescence experiments, which are generally used to measure the efficiency in generating free charges in systems of this type, and developed a mathematical model that simulates the process. The experimental and theoretical results were very similar, proving the model’s accuracy. “We developed a model that simulates the kinetics of the process, including the several stages of exciton dissociation and considering the main characteristics of the interface,” he says. “Based on the kinetic model, it was possible to reproduce the experimental results in a comprehensible manner and more clearly observe the main factors that influence the efficiency of the free charge generation process in donor/acceptor interfaces,” he adds.

Fullerenes vs. Non Fullerenes

The study that produced the article was coordinated by two professors from the Physics Department of UFPR, Marlus Koehler and Lucimara Stolz Roman, who have a longstanding partnership in the theoretical and experimental study of organic solar cells. “The theoretical part began to be developed in 2019, at the end of my PhD in Physics at UFPR under the guidance of Professor Marlus, and continued in my postdoctoral work at the Nanostructured Devices Laboratory (DINE) under the coordination of Professor Lucimara,” says Leandro. Also participating in the research were Maiara de Jesus Bassi, PhD student in Physics in the group of Professor Lucimara, and Luana Cristina Wouk, PhD in Physics who was also under the supervision of Professor Lucimara Roman, and currently working at CSEM Brazil, a private applied research center, which helped contextualize the problem in the large-scale development scenario.

The initial idea of the work was to understand the difference between two types of electron acceptor molecules: those derived from fullerene (a carbon allotrope), which have excellent performance in the collection and transport of electrons but have a limited spectrum of light absorption, and compounds not derived from fullerenes, which in recent years have optimized the collection and transport properties. “This is a very interesting topic since, recently, the efficiency of organic solar cells based on non-fullerenes surpassed the efficiency of those based on fullerenes, although, a few years ago, it could not be imagined that fullerenes would be surpassed,” reports Leandro. “Currently, laboratory produced organic solar cells based on non-fullerenes have reached 18% efficiency,” he adds.

This research received funding from Brazilian agencies Capes, CNPq and FAPEMIG, INCT–Nanocarbono and COPEL (Companhia Paranaense de Energia).

The authors of the paper, from the left: Leandro Benatto, Maiara de Jesus Bassi, Luana Cristina Wouk, Lucimara Stolz Roman and Marlus Koehler.
The authors of the paper, from the left: Leandro Benatto, Maiara de Jesus Bassi, Luana Cristina Wouk, Lucimara Stolz Roman and Marlus Koehler.

[Paper: Kinetic model for photoluminescence quenching by selective excitation of D/A blends: implications for charge separation in fullerene and non-fullerene organic solar cells. L. Benatto, M. de Jesus Bassi, L. C. Wouk de Menezes, L. S. Roman and  M. Koehler. J. Mater. Chem. C, 2020,8, 8755-8769].

B-MRS member joined the advisory boards of two RSC journals.

Prof Ana Flávia Nogueira
Prof Ana Flávia Nogueira

Professor Ana Flávia Nogueira (UNICAMP), B-MRS member, joined this year the advisory boards of two renowned journals in the field of Materials, both from the Royal Society of Chemistry (RSC). These are the  Journal of Materials Chemistry A (impact factor = 11.301), where the Brazilian scientist is the only representative from Latin America, and Journal of Materials Chemistry C (impact factor = 7.059), where Professor Ana Flávia and Professor Carlos Graeff, also a B-MRS member, are the only scientists from Latin American institutions.

B-MRS Newsletter. Year 7, issue 7.

 

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Newsletter of the
Brazilian Materials
Research Society

Year 7, issue 7. August 7, 2020.

From Ideia to Innovation

Doctors and nurses wearing masks are icons of the current Covid-19 pandemic. Going back to the history of respiratory protection masks, one can find advances, made in different places on the planet, in materials, technologies, concepts and methods that enabled the development of current, efficient and certified masks. Get to know a bit of this history, here.

mascaras news

Featured Paper

Scientific work carried out at IQSC-USP generated a low cost and easy to manufacture nanostructured material, based on non-precious metals inserted in carbon layers, which demonstrated high performance as a catalyst for electrochemical reactions used in the generation of renewable energies. The work was recently reported in the Journal of Materials Chemistry A. Know more.

artigo news

B-MRS Lives & Webinars

– The XIX B-MRS Meeting + IUMRS ICEM Organizing Committee and the B-MRS Board of Directors invite the entire community to participate in a brief ONLINE meeting in the late afternoon of August 30, 2020, when the event opening, which was postponed due to the pandemic, was scheduled to take place in Foz do Iguaçu. Know more.

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– Eight technical webinars were held throughout July (second month of the Lives & Webinars program). Learn more and access the recordings of the already held webinars, here.

– Access the schedule for August, choose the webinars you are interested in and register (free), here.

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B-MRS News

– FNDCT. B-MRS endorsed the manifesto for the total release of FNDCT resources. Know more.

Capes. B-MRS endorsed manifesto against the centralizing management mode of the current presidency of Capes. Know more.

CNPq. B-MRS endorsed letter to the president of CNPq, pointing out problems and possible solutions in the implementation of the 25/2020 master’s and doctoral scholarships. Know more.

Webseries. Webseries episodes about Brazilian science related to materials research have an exclusive premiere for B-MRS channels. Know more.

– Science and democracy. B-MRS participated in the “Virada pela Democracia” (Turning-point for Democracy), held on July 4 and 5, with a video statement on the relationship between science and democracy, which was included in a panel organized by SBPC. Watch the video of Professor Ivan Bechtold, scientific director of B-MRS, recorded for this occasion, here.

News from B-MRS Members

Professor Luciana Reyes Pires Kassab (Faculty of Technology of São Paulo/CEETEPS), B-MRS member, was distinguished with the category of Senior Member of OSA (The Optical Society). Know more.

Opportunities

– Postdoctoral fellowship at UFRGS (Brazil) in surface chemistry for the development of technology for SARS-Cov-2 detection tests. Know more.

Events and ONLINE events

Webinars on research and teaching techniques and tools in the materials field. June – August, 2020. ONLINE. Organization: B-MRS. Site.

IV Simpósio de Fotobiofísica – UV e Vírus. 21 de agosto de 2020. ONLINE. Organização: Departamento de Física da USP. Folder para download.

XLI Congresso Brasileiro de Aplicações de Vácuo na Indústria e na Ciência. Foz do Iguaçu, PR (Brasil). 5 a 7 de outubro de 2020. Site.

5th International Conference of Surfaces, Coatings and NanoStructured Materials – Americas (NANOSMAT-Americas). Foz do Iguaçu, PR (Brazil). October 7 – 10, 2020. Site.

7th Meeting on Self Assembly Structures in Solution and at Interfaces. Bento Gonçalves, RS (Brazil). November 4 – 6, 2020. Site.

Pan American Ceramics Congress and Ferroelectrics Meeting of Americas (PACC-FMAs 2020). Panama (Panama). November 15 – 19, 2020. Site.

4th Workshop on Coated Tools & Multifunctional Thin Films. Campinas, SP (Brazil). November 16 – 19, 2020. Site.

International Conference on Defects in Insulating Materials (ICDIM 2020). November 23 – 27, 2020. ONLINE. Organization: UFS. Site.

XIX B-MRS Meeting + IUMRS ICEM (International Conference on Electronic Materials). Foz do Iguaçu, PR (Brasil). August 29 – September 2, 2021. Site.

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XIX B-MRS Meeting + IUMRS ICEM
(Foz do Iguaçu, Brazil,
August 29 – September 2, 2021)

Call for symposium proposals is open! Know more.

New date of the event: August 29 – September 2, 2021.

Same venue: Rafain Convention Center – Foz do Iguaçu.

Symposium proposal submission: May 4 – November 2, 2020.

Abstract submission: February 1 – April 11, 2021.

Plenary sessions: 7 plenary lectures and 1 memorial lecture confirmed.

Event website: www.sbpmat.org.br/19encontro/

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You can suggest news, opportunities, events or reading tips in the materials field to be covered by B-MRS Newsletter. Write to comunicacao@sbpmat.org.br.
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Online event for the B-MRS community.

When: August 30, 2020 (Sunday) at 6 pm.

Where: On B-MRS Zoom and Facebook (https://www.facebook.com/SBPMat/).

Language: Portuguese.

The afternoon of August 30, 2020 was reserved on the agenda of many members of our community for the opening of the XIX B-MRS Meeting, which would take place at the Hotel Rafain in Foz do Iguaçu. Due to the Covid-19 pandemic, the event was moved to next year (from August 29 to September 2, 2021). In this context, the event’s organizing committee and B-MRS’s board invite the community to meet on that day and time – when we would open the annual event of the Society – to participate in a brief online meeting. The organizing committee of the XIX B-MRS Meeting will address the transfer of the event, the new agenda and the call for symposia, which is already open. The B-MRS board will speak about the society’s activities during the pandemic and about the University Chapters program. To close this brief virtual meeting of the community, the former president of B-MRS Professor Osvaldo Novais de Oliveira Junior (IFSC-USP) will offer a brief lecture on the prospects for science in the post-pandemic scenario.

IMPORTANT! To participate in the Zoom room, with limited spaces, it is necessary to register here.

B-MRS Lives & Webinars: second month of the program.

The month of July included eight technical webinars from the B-MRS Lives & Webinars program, delivered by professionals from instrumentation companies. Between 100 and 200 participants attended each of the lectures, held on Zoom and on B-MRS’s Facebook. Four more webinars will take place during the month of August.

The Lives & Webinars program is a B-MRS initiative for learning and training during the period of social distancing due to the Covid-19 pandemic, carried out in partnership with instrumentation companies.

The program includes a variety of subjects, from fundamentals and applications of techniques widely used by the Materials research community, to the presentation of state-of-the-art instruments and digital tools for teaching in the field of Materials.

Programming, information and registration (free): https://www.sbpmat.org.br/en/lives-webinars/

Watch the webinars held in June and July whose recordings were authorized by the speakers:

  • “Micro-XRF aplicado a Ciências dos Materiais” (Essencis e Bruker). Veja aqui.
  • “Microscopias FTIR, Raman e Eletrônica de Transmissão para Análise de Materiais” (Thermo Fisher). Veja aqui.
  • “Técnicas de magnetometria para a pesquisa em nanopartículas magnéticas” (Quantum Design). Veja aqui.
  • “3D optical profilometry for material science applications” (Sensofar e Analítica). Veja aqui.
  • “Crossbeam laser – Enabling New Microscopy Workflows Through Gentle Large-Volume Material Removal” (Zeiss). Veja aqui.
  • “Caracterização de poros e partículas e determinação da densidade de materiais cerâmicos” (Anton Paar). Veja aqui.
  • “Aprendizagem ativa unindo metodologia de seleção de materiais e simulação em tempo real” (Ansys e ESSS). Veja aqui.
  • “Imageamento químico e estrutural 2D/3D de alta resolução: Raman, FLIM e espectroscopia óptica aplicados a ciências dos materiais e da vida” (Horiba). Veja aqui.
  • “Espalhamento dinâmico de luz – caracterização de nanopartículas” (Instrutécnica). Veja aqui.
  • “Caracterização eletroquímica de dispositivos fotovoltaicos” (Metrohm). Veja os slides aqui.
  • “Caracterização do material da sua camada: espessura, composição química e propriedades mecânicas como dureza, elasticidade, plasticidade e adesão” (Fischer). Veja aqui.

From Idea to Innovation: From gauze cloths to nonwoven respirators.

Since the official declaration of the Covid-19 pandemic on March 11, there has been much controversy about the use of masks, especially in the first months. However, one aspect has never been questioned: the masks that offer greater protection to the user should be worn by frontline workers of the fight against Covid-19, these men and women who perform essential work in the pandemic and are in daily contact with high concentrations of the Sars-Cov-2 virus in hospitals and cemeteries. Images of doctors, nurses and cemetery workers wearing masks and other PPE (personal protective equipment) have become icons of the pandemic currently affecting the world.

In fact, the masks best suited to protect these professionals are given the technical name of “respirators” (yes, the same term used for devices that help ICU patients to breathe and which have also been protagonists in this pandemic), seeing that their main objective is to filter the air breathed by the user, preventing a large part of the airborne particles (including viral particles) from entering the airways through the nose and mouth.

The respirators recommended for these professionals in the Covid-19 epidemic (certified as N95, KN95, PFF2 or DS2, depending on the country of certification) have high capacity to prevent the passage of particles. But that is not enough. In addition to being good at filtering, respirators need to ensure a minimum of comfort and good airflow so as not to suffocate the user throughout the workday. They also need to be firmly fastened to the head. Finally, they must ensure effective sealing around the mouth and nose to minimize the entry of unfiltered air into the airways of the worker using them. This set of features distinguishes respirators from other types of masks, including surgical masks.

On the left, a surgical mask. On the right, a respirator. (3M video scene print) https://youtu.be/JR2uLfEVD2w).
On the left, a surgical mask. On the right, a respirator. (print of 3M video scene https://youtu.be/JR2uLfEVD2w).

To bring together these characteristics, N95 respirators include a series of developments and advances linked mainly to the materials used and the product design, as well as methods to prove their effectiveness.

Early days: the antiplague mask

The idea of filtering the air to protect people from pathogens that enter the body through the respiratory tract is not new, but it is also not that old. People wearing rigid masks or handkerchiefs to protect themselves from diseases were depicted in Renaissance paintings. However, this protection was associated with several beliefs with no scientific basis, and not with the idea that microorganisms can cause disease, a concept whose discovery dates back to the second half of the 19th century in Europe.

At the end of the 19th century, another step was taken in Europe with the scientific finding that droplets leaving the airways carry bacteria. Consequently, we have the first examples of surgeons using pieces of gauze tied to the head by strings to cover the mouth and nose during surgeries, in order to not contaminate patients.

In 1910, while the use of surgical masks was slowly spreading across Europe, the masks moved on from the operating rooms. More precisely, it was during the so-called “Manchurian plague” – an epidemic that occurred in northern China – that the first clear example of the use of masks is found with the aim of protecting the user, especially doctors, from an infectious disease. In this epidemic, a pathogen (probably a bacterium) caused pneumonia, which, according to the records of the time was lethal in almost all cases. The plague decimated some 60,000 people in less than a year.

It was initially believed that the disease was transmitted by rat fleas, but that idea fell when Dr. Wu Lien-teh was hired by the Chinese government to deal with the epidemic. After performing an autopsy, Wu obtained the necessary evidence to claim that the pathogen was transmitted through the air. Based on this observation, and based on the surgical mask concept he had seen in Europe, he developed a cotton filter mask wrapped in gauze that covered mouth and nose and several layers of cloth wrapped around the head and tied around the neck in order to guarantee that the mask was fastened and sealed the face. Wu called his invention an “antiplague mask” and tried to disseminate its use among those who cared for the sick, and, as far as possible, also among patients and the general population.

Images of the “Manchurian Plague”. On the left, the antiplague mask. On the right, bodies of victims of the disease next to a person on the combat team, wearing the mask.
Images of the “Manchurian plague”. On the left, the antiplague mask. On the right, bodies of victims of the disease next to a person on the combat team, wearing the mask.

Other mask models appeared at this time in Manchuria, including a hood with eye holes, but Wu’s model seems to have been the one accepted. Apparently, the antiplague mask, with its several layers preventing the passage of droplets and its relatively high filtering capacity, reasonably protected the user from the pathogen. However, some people doubted its effectiveness and also the transmission of the disease through the air. Such was the case with a prominent French doctor who came to Manchuria to work on the epidemic. He denied using the mask, fell ill and died within a few days, according to Wu in his autobiography.

A few years later, in 1918, the use of masks spread throughout the world with the rapid spread of the deadly flu pandemic unjustly called the “Spanish flu”, which was caused by the H1N1 influenza virus and killed 50 to 100 million people in about two years. During this period, the masks, made of gauze and other cotton fabrics, became part of not only the uniforms of doctors and nurses, but also the uniforms of city policemen as well as the soldiers who were still fighting in the trenches at the end of the First World War. These masks were produced more professionally and extensively, with teams of Red Cross nurses cutting and sewing fabrics. In some cities, part of the population adopted this protective accessory, usually made at home. In other cities, its use was mandatory.

Images of the “Spanish flu” in the United States. Nurse taking care of a patient and wearing an improvised cloth mask, and Red Cross workers producing masks for soldiers.
Images of the “Spanish flu” in the United States. Nurse taking care of a patient and wearing an improvised cloth mask, and Red Cross workers producing masks for soldiers.

Meanwhile, in the early decades of the twentieth century, doctors were trying to determine which type of mask would be most efficient to protect the user from respiratory droplets carrying microorganisms, and some new models and patents emerged, but without major innovations. These masks were usually made of several layers of cotton gauze. Sometimes they included an additional layer of waterproof material and, in the most advanced models, a metal frame. All these masks were washed or sterilized and reused.

Respiratory protection for industrial workers

At the same time, researchers, companies and governments in countries like the United States were working on the development and regulation of respiratory protection for other workers: those in mining and construction, who were highly exposed to inhaling particles dangerous to their health. This problem was not new. Records from Ancient Rome, in the 1st century AD, show the use of animal skins to cover part of the face in order to filter out the presence of airborne toxic powders. However, in the 1930s, a tragedy forced the need to urgently implement this type of protection. Hundreds of workers died from lung problems caused by inhaling silica dust during the construction of a tunnel in the state of West Virginia, in the United States.

In the late 1950s, in the United States, a woman in her forties propelled the history of the development of respirators. Sara Finkelstein, with a degree in Design, but interested in multidisciplinary approaches, founded the Sara Little Design Consultancy, whose name alluded to her short stature (and her good humor). One of her first works was for 3M, in the company’s wrapping and fabrics division, where a new material for decorative tapes was being tested, the “nonwoven fabric”.

This group of materials is defined and understood through its opposite, the group of fabrics. While fabrics are obtained by weaving or knitting, non-woven fabrics are manufactured using other processes to connect the fibers together. One of the most common processes is meltblowing, in which a molten polymer is blown through a mold with very small orifices by a strong air blast, causing the random deposition of polymeric fibers and thus forming the nonwoven fabric. Another difference: fabrics are ordered structures of threads, usually arranged at right angles; nonwovens, on the other hand, are tangles of crude fibers. With a very porous structure, formed by very small pores and fibers intertwined in a disordered way, nonwoven fabrics are great filtering materials: they let gases pass, while solids are trapped in the fiber maze.

But back to Sara Little: aware of the impact materials innovation can generate not only in a company, but also in the lives of consumers of the final products, she made a presentation to 3M directors proposing the many possibilities for the application of nonwoven materials, recommending the development of a business area dedicated to these materials. At that time, the nonwoven industry was very new in the United States, as well as in Europe; it is estimated that the production of these materials on a pilot scale started in the 1930s.

Apparently, Sara Little designed, for 3M, some products using nonwoven fabric, starting with a bra cup. The idea and design of the first 3M respirator, with its semicircular shape resembling a bra, the clip to seal the mask over the nose and the elastics to fasten it to the head is mainly attributed to her. It is said that Sara’s intention was to create protection for hospital workers, whose routine she had known personally after many years of accompanying sick family members. However, at that moment there was no consensus regarding the health professionals’ need to use respirators, except for the use of masks during surgical procedures, which were mainly aimed at protecting patients from the doctors’ respiratory secretions and protecting doctors from blood and other patient fluids.

At 3M, the first respirator was launched in the early 1960s, with no official certification but with proof of its efficiency in filtering powders, which is so necessary to protect workers exposed to inhaling harmful particles in mining, construction and car painting activities, among others. In 1972, 3M was the first company to introduce a certified respirator to the market.

Respirators for doctors and nurses

Regarding the filtration of microorganisms, at that time there was no clear evidence, but some records show that these respirators, manufactured on an industrial scale, were sold to doctors and nurses who wanted to protect themselves. With the introduction of nonwoven materials replacing fabrics, disposable masks began to enter hospitals, a well received novelty at the time as it reduced costs related to washing and sterilization personnel and, at the same time, brought more sanitary security.

For about twenty years, with no major news of diseases transmitted by respiratory droplets or airborne, N95 respirators have spread and were recognized as respiratory protection equipment in the industry. However, in the 1990s, the use of this personal protective equipment increased in hospitals given the outbreaks of antibiotic-resistant tuberculosis that had infected many health professionals.

In the same decade, new technologies absorbed by the industry allowed to further improve the performance of respirators, especially with regard to the retention of smaller particles, such as viruses. With these processes, which have some patents, it was possible to generate an electrostatic charge in the fibers of the nonwoven material, which attracted the particles – somewhat similar to what happens when pieces of paper stick to a balloon that has been rubbed against a wool coat. Thanks to this strategy, the capacity of respirators to retain particles has increased without having to add new layers of filtering material, thus preserving the good air intake that respirators must provide.

One of the researchers involved in patents on processes for electrostatic charge of nonwoven materials has gained a lot of visibility recently. This is Peter Tsai, who made his contributions while professor at The University of Tennessee, in the United States. Tsai returned to scientific activity in March of this year shortly after retiring. As a specialist in the manufacturing and treatment processes of the nonwoven materials used in masks, Tsai has been working to help establish safe sterilization mechanisms for N95 respirators, given the scarcity of this product generated by the Covid-19 pandemic.

With all these advances in materials, technologies, concepts and methods, respirators have entered the 21st century ready to help healthcare workers reduce the risk of infection from viral diseases that are transmitted through droplets and respiratory secretions, and even through the air. And they really helped. N95 respirators were recommended for health personnel in the 2002 and 2003 SARS epidemic, in the Mers outbreaks that have been occurring since 2012, in the 2009 swine flu pandemic and, currently, in the Covid-19 pandemic.

Health professionals and cemetery workers in Brazil working in the Covid-19 pandemic.
Health professionals and cemetery workers in Brazil in the Covid-19 pandemic.

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