Materials Connect

#SciComm: How to structure an article on an unwieldy topic

The US National Academies (NAS) began a series of workshops last year to determine a roadmap for US science policy for the next 75 years. One of the workshops focused on US research universities. I sat in on the Workshop online, taking notes for a news article.

The next 75 years—this task is immense. I narrowed the topic to a materials science angle for the MRS Bulletin readership.

It’s still massive.

When thinking about who to interview from the materials research community, I realized the speakers at the workshop were predominantly over 60 (maybe some as young as 50). In determining the shaping of research universities and their policies, I thought it would be good to follow up with researchers at a wider spectrum of career stages.

Along with interviewing students and early-career researchers, I contacted older materials researchers who have served on science panels or have done other work related to the topics covered in the NAS workshop. In all, I interviewed 10 researchers, from undergrads to those who have retired.

As the NAS workshop took place during the 1^st wave of the COVID-19 pandemic, this global health emergency cast light on the direction research universities should take in the future, including further development of technology that would enable laboratory research from off-site.

In my notes from both the workshop and the interviews, I had information on:

• NAS workshop discussions
• effects of COVID-19 on university researchers
• diversity & inclusion of the future workforce
• diversity & inclusion of the population affected by research conducted at the US universities

I broke down the content by high-level topics:

• wake-up call based on the pandemic
• risks for materials research
• going forward

From the interviews, one statement kept overriding all the others. It’s the statement that most got my attention. In the structure of the article, I was unhappy that it would be buried deep inside.

Then I decided to take a risk. I realized if this statement held my attention the most, I should open the article with it, and see where it leads:

“I remember first hearing this term ‘digital divide’ in the mid-1990s. It was the concept of people from lower socioeconomic status not having access to computers and the Internet,” says Tabbetha Dobbins, the Interim Vice President for Research and Dean of the Graduate School at Rowan University in New Jersey, in an interview with MRS Bulletin. “It has always been talked about in a scope of, well, there will be jobs available to people who have these computer skills; and people who don't, won't be seeing those jobs.”

Dobbins recently participated in a webinar training K–12 teachers on diversity, equity, and inclusion where she learned that some students have trouble transitioning to online learning during the pandemic because their families cannot afford a computer and access to the Internet. They are, therefore, locked out of an education. “[The Internet] is at least a $70–$80 bill per month and some families simply can't sustain that,” she says. Looking toward US research universities of the 21st century, Dobbins says, “By taking our eye off of that ball 25 years ago and not fixing the problem, how far have we disadvantaged students into pursuing computational materials studies who come from low socioeconomic grounds?”

            –from The COVID-19 pandemic informs future directions of US research universities

What do you think? Does that thought capture your attention?

-Judy Meiksin

COVID-19 impact in education and R&D in Chile

Between the Andes to the east and the Pacific Ocean to the west is one of the longest and narrowest countries of the world - the Republic of Chile. Chile is most known for its Nobel laureates in literature, its world-class wines, its copper resources, and its educational system. Chile’s literacy rate is 96%, the highest in Latin America. According to the recently released Global Innovation Index 2020, Chile is the top innovative country from Latin America and the Caribbean, scoring 33.86/100 (for comparison, the USA scored 60.56/100). The index notes that Chile’s strengths lie in its institutions, educational level, competition factors, market scale, market capitalization, the applied tariff rate, and business sophistication. Chile’s research and development (R&D) budget (0.35% GDP) fluctuated substantially in recent years, and it is the lowest since 2011, with a stagnated 493 researchers in R&D per million people (for comparison: the USA has 4,412 researchers per million people). Such numbers continue declining, given the economic and social crisis from last year that culminated in the 2019-2020 Chilean protests and intensified with the COVID-19 global pandemic.

Dr. Ing. Alberto Monsalve González, a professor from the Metallurgical Engineering Department of the Universidad de Santiago de Chile, explains how the pandemic affected his work, Chilean education, and R&D. While his research projects on nanocomposites and metal alloys are mostly frozen, he focuses on writing articles and planning future work. Prof. Monsalve González commented that, with limited resources available, their government did some cuts in grants for post-graduate students, named ‘Becas Chile’. As future budget cuts were already announced, he is worried about the future of R&D. “Unfortunately, this will negatively impact the R&D in our country for the next [several] years,” he says. Prof. Monsalve González points out that materials science researchers could help prevent and minimize the effect of future pandemics. “There are not enough studies on antibacterial and antivirus effect of copper and its alloys. Another opportunity is the use of carbon compounds for effective filters for mechanical respirators and air-conditioning equipment,” he says.

Prof. Monsalve González is worried about the students. He mentioned that since research laboratories at Universidad de Santiago de Chile are closed, students working on their theses will not finish on time. “This is a huge problem for our students because the actual crisis has delayed one year of many students' graduation,” he says. While other countries adopted a hybrid system of education, Chile preferred to keep it virtual mode only. Prof. Monsalve González worries about the quality of education through this modality. “Some universities have made a heroic effort to give teachers and students connectivity facilities to carry out online courses. The success of this kind of classes must be evaluated in the future,” he says. Prof. Monsalve González points out the constant evaluation of their educational system by adding: “Finally, it should be noted that the quality of university education in Chile [has been] under permanent review and study before this health crisis.”

When asked about his experiences with the new modalities of conferences, he confessed missing the one-to-one contact through in-person conferences and he has coped through the new modality. “Without a doubt, this aspect of our work has completely disappeared. Still, the online conferences, webinars, the free access to some publications, and the virtual contact by networks have helped to mitigate the lack of in-person contact with other researchers [around] the world,” he says.

-Mônica Jung de Andrade

COVID-19 impact in education and R&D in Argentina – presidential views

In the Pampas grass of the Americas, bordering five of the South American countries, is the Argentine Republic. While Argentina has three Nobel Prizes in the sciences and a successful nuclear program, its research and development (R&D) expenditure has been in decline for the last four years. As in most countries, the COVID-19 global pandemic reinforced these budget cuts and the R&D budget (0.54% GDP) is the lowest from the last 10 years.

Raúl Bolmaro and Orlando Auciello, both Argentinian citizens, working in R&D as full professors, and highly active in their professional associations in Argentina and the USA, respectively, explain further how the pandemic affected their work, and affected Argentinian R&D and its collaborations.

Prof. Raúl Bolmaro (Universidad Nacional de Rosario) and president of the Argentinian MRS (Asociación Argentina de Materiales).                                               Prof. Orlando Auciello (University of Texas at Dallas) and past president of the Materials Research Society (2013).

Prof. Bolmaro at the Universidad Nacional de Rosario, who is also the director of a research institute and president of the Asociación Argentina de Materiales (Argentinian MRS), has switched his activities strictly to a “home office” to draft scientific papers using past experimental results and ideas. He says that the accumulated knowledge on smart materials and characterization techniques have re-oriented his research group’s activities in support of bio-chemical and bio-technological developments, pursuing either detection, treatment, or relief techniques. Nevertheless, his activities also involve keeping the infrastructure of the institute ready for all areas. “Further continuing our regular research topics may seem somehow a waste of time; however, life must continue, considering that COVID-19 might be around for such a long time,” he says.

On the other hand, Prof. Auciello—who also holds a US citizenship and is on the faculty at the University of Texas-Dallas (UTDallas)—has been able to continue research on campus since January because his group is working on his patented technology of antiviral ultrananocrystalline diamond (UNCD) coating with pores ≤10 nm for application on protective masks to stop the transmission of the COVID-19 virus. “The COVID-19 virus, which has diameters in the range 60-140 nm, is not stopped efficiently by current masks with pores of 10-30 microns,” he says. His research group has continued its collaboration with colleagues in México, Argentina, Panama, and Brazil. Prof. Auciello says that the international collaborations facilitated the advancement of his research. “We have been doing clinical trials on UNCD-coated dental implants, in México, since 2018. The USA-México collaboration is enabling the introduction of the revolutionary UNCD-coated dental implants in México by 2021-2022. So, collaboration with scientists from Latin America has been and will continue to be extremely productive to insert new medical devices in the market,” he says.

As a past president of the Materials Research Society (MRS), Prof. Auciello, who has been a strong advocate for substantial changes in terms of diversity within MRS awards and is part of the diversity committee at UTDallas, says, “[Professional scientific] societies should have more minorities, from within and outside the USA, involved in committees and [positions that influence] Society direction.”

When asked about the impact of the pandemic on the educational system in Argentina, Prof. Bolmaro pours his frustration about the 200 days of frozen activities followed by classes on virtual mode and its difficulty to deliver experimental courses that shape many of the skills needed for technical knowledge. “The complete learning-teaching interaction has been damaged profoundly, despite the efforts made by professors and students to imagine new ways for transferring back and forth information and knowledge,” he says. Like its neighboring countries, undergraduate education at all Argentinian public universities is tuition-free. However, Prof. Bolmaro worries about the students from less economically favored families during this pandemic.

“The economic burden of getting your own electronic devices falls on your own shoulders, already weakened by successive social and economic crises,” he says. With sadness, he adds, “What has been for many years a motive for pride (tuition-free education) has become the main source for despair among the students who cannot sometimes even go back to their home cities or countries.”

He is very concerned about the declining situation of R&D in Argentina as well. “We must take in account that Argentina has been economically declining for the last 30 years and with a stagnated per capita national income for more than a decade,” he says. Prof. Bolmaro goes further explaining the decline of both infrastructure and salaries in the Argentinian R&D. R&D recovery in a post-pandemic situation is alarming, as he points out. “The main problem will come from the needs of renovation and spare parts for fixing an already aging large science equipment and facilities. Salaries have been cut to a third in terms of dollars in the last year, which makes the research activity less attractive to new generations,” he says.

When asked about how they have been coping with the exchange of knowledge through virtual conferences versus in-person conferences, Prof. Bolmaro and Prof. Auciello both agreed that the only drawback is not being able to interact personally with more scientists, but they both have observed the several advantages of the virtual conferences, such as the more efficient use of time and resources. Prof. Auciello has been able to deliver talks to Dubai, Europe, and Asia, by either sending the talk in a video format and being present to answer questions, or presenting it live. He seems satisfied with his virtual experiences: “Given my age, I need to apply the science-based knowledge and look for keeping my health,” he says.

Prof. Bolmaro, who has also been able to deliver talks and online classes to various countries, adds: “Because of being somehow in the end of the world, as sometimes the south cone and Patagonia are called, our journeys to attend conferences and workshops are reduced to no more than one every year in average, if we are talking about northern hemisphere events.” He believes the post-pandemic situation will have its own challenges for organizing international conferences: “We hope for having better funding when the activities reopen, but we keep thinking about the long journeys that we will have to endure and survive in the expected interregnum of better COVID safety in the north and poor coverage in the south. Organizing international conferences will become such a challenge, with a transition perhaps dominated by hybrid-conducted ones.”

-Mônica Jung de Andrade

COVID-19 R&D Impact in Uruguay

In South America, Uruguay is showing an inverse trend seen in its neighboring countries. Whilst only 0.48% of GDP is invested in R&D, scientists are being the protagonists in this. Uruguay is dealing well with the pandemic, and their coronavirus cases are far fewer than its neighbors, thus the only Latin American country in the EU’s Covid-19 “safe list.” Ivana Aguiar and María Eugenia Pérez, who are professors at Universidad de la República and deeply engaged volunteers within the Materials Research Society (MRS) since 2011, explain how the COVID-19 pandemic has further impacted education and R&D in Uruguay.

Unlike most of the countries during this pandemic and the big economy deficit of Uruguay, most of the budget dedicated to research is not under the budget cut policies—at least for this year. The government reflected on the scientists’ role to contain the pandemic situation and the research community has been key to developing tests for the pandemic.

Prof. Aguiar and Prof. Pérez work with semiconductor nanomaterials for radiation detection, photocatalysis for water remediation, and medical applications. When asked how the COVID-19 pandemic affected their lab activities, they were unanimous that even though they are now slowly going back to normal, some of their planned lab activities had been postponed. Both are taking advantage of many virtual conferences to share their research, and they were pleased to see an increasing offer of webinars from MRS. Prof. Aguiar, who has organized the MRS virtual event “Sustainability in my Community” during the 2016 MRS Spring Meeting, was happy to learn about the latest news of a virtual mode for the next MRS meeting.

Besides reading and writing articles, for them it has been a period focused on teaching in a completely virtual-mode classroom, which demanded a lot of time to adapt for both students and educators. Even though COVID-19 cases in Uruguay are low, Universidad de la República plans to continue virtual-mode classes for the next semester as well. Commenting further about the positive impact of virtual modality, which was already a trend, Prof. Pérez says, “It actually helped to connect more often with people I would not be in contact with so often, and I believe that commerce, meetings, etc. will be kept virtual to a high degree [in the post-pandemic situation].” With her little daughter at home while she works, it has been more challenging for Prof. Aguiar, “It is difficult to concentrate in long-time activities while working from home.”

When asked about what they expect the post-pandemic R&D situation in Uruguay will look like, they both said that science visibility during this pandemic will positively impact R&D budget prospects. Prof. Pérez says, “In terms of science policy, we showed that science is a critical aspect of a country’s development. This was the case for Uruguay, in which very little of the GDP was destined to research. Scientists should make themselves heard about the importance of scientific research and promoting science careers in the country.”

- Monica Jung de Andrade

COVID-19 R&D Impact in Brazil

In a country where 1.26% of GDP is invested in R&D (47% of it is from the private sector), Brazilians have been with a shortage on research funding for a while, preventing its further growth. Since the recession in the economy in 2015-2016, Brazilian researchers have been struggling to obtain funds for their research. Osvaldo N. Oliveira Jr., who is a professor at the University of São Paulo and past president of the Brazilian MRS (Sociedade Brasileira de Pesquisa em Materiais, SBPMat), explains how the COVID-19 pandemic has further impacted research in Brazil.

Whilst as a supervisor and group leader, Prof. Oliveira Jr. works from home through virtual meetings with his students and collaborators, as well as taking part in webinars (either attending in the audience or delivering lectures). “These activities do not replace attending conferences in person, but they minimize the possible isolation one may feel,” he says. However, at his laboratory, he says that only a few students are working now, and a number of experiments had to be postponed. Prof. Oliveira Jr., who is a world-renowned expert in ultrathin film sensors, adds, “In the other area I have been working on, related to artificial intelligence, research has been continued and even strengthened.”

He believes the following three major topics/areas will see further investments in R&D with the COVID-19 pandemic:

• new fast, accurate and low-cost diagnostic methodologies based on immunosensors and genosensors for infection outbreaks;
• new materials with antimicrobial properties for prevention and novel therapeutic strategies;
• integration of machine learning and other artificial intelligence methods into materials applications, such as data analysis for diagnosis and to search for new molecules and materials for therapy.

Together with collaborators from different fields, Prof. Oliveira Jr.’s research group is working on topics from items 1) and 2) above. Prof. Oliveira Jr. says, “We are investing heavily on new strategies for data analysis, with the hope of integrating data from text, clinical exams, and images into a single system for diagnosis.”

When asked about the funding impact on R&D in Brazil with the COVID-19 pandemic, Prof. Oliveira Jr. feels disheartened. He mentioned that the extra funds to address the pandemic is insufficient to compensate the other cuts that caused a shortage of scholarships for graduate students and post-docs.

He says, “Today, many scientists with PhDs have to live with savings they may have made or with help from their families. With all the visibility that science has had in the media, I am hopeful that the government agencies and companies will realize that investing in research is the only way forward for the security of the country.”

- Monica Jung de Andrade

The importance of feedback for information sharing: insights from a comedy club and materials science

My favorite comedy club in Manchester, UK, has – like so many other organizations operating during the Covid-19 pandemic – converted to working online. Normally a comedy club would have a stage, a microphone and a live audience but the online format means that the audience is silent and faceless. One of the most common responses of the comedians is that it’s really difficult to perform when you don’t know how your performance is being received: just how funny are you? This experience made me think about how scientific information is passed on from one person to another.

When you’re new to public speaking, giving a lecture to a big room full of people can feel a bit like hurling information into a void, an experience that sounds quite similar to those of the comedians in the online comedy club. However, even though many universities have also switched to giving lectures online, the lecturers have an advantage over the comedians: they can get feedback from the students, either through surveys or through marking assignments.

In a normal face-to-face lecture I find it very helpful to split the lecture up into small sections and ask the students to do a short assignment in between, usually in small groups. The assignments often involve using some specific software and it’s very helpful for me to be able to walk around the room, check progress and offer help. Trying to do the same thing over video-conference seems very daunting! The software, known as TRIM, calculates how an ion with a given energy will interact with a material and produces some visual representations of ion tracks that are great for aiding understanding. I’m so used to simply pointing at the screen in a situation where both the lecturer and students can use gesture and facial expressions to infer meaning that I know I’m going to need to think hard about how to adapt the lecture this fall.

The TRIM software is part of the Stopping and Range of ions in Matter (SRIM) package and provides a wealth of information about an energetic ion interacting with a target material. It’s a very visual way of getting to grips with radiation damage which makes it great for a demonstration in a lecture.

Gestures and facial expressions are some ways of gaining feedback, and this is incredibly important for checking scientific understanding. Imagine having a conversation with someone where you’re explaining something that is new to the other person. You’d probably start with the simplest thing and you’d get a response from the other person. You’d then start gradually building up the complexity and information would pass back and forth, each interaction adding a layer to the sphere of knowledge until you both arrive at the same level of understanding. Along the way the other person will ask questions, seeking clarification and letting you know that they are interested in what you have to say. This shared understanding becomes an organic thing; it grows depending on how you both interact with each other.

The model for communication, developed by Shannon and Weaver (The Mathematical Theory of Communication, University of Illinois Press, 1949), explains that the two people involved in communication must interact if the message is to be understood.

The same organic method of knowledge sharing happens with the written word too. In writing this blog, each author gets feedback from the other bloggers which points out sections that were difficult to understand. The feedback is incorporated into the final published version. This also happens in the peer review process when a manuscript is submitted to a journal.

Giving a lecture, or a stand-up comedy show, to a faceless audience that may be distracted by the cat can be a somewhat surreal experience. Feedback is an essential component of communication; without it, we are just shouting into a void: an exercise that is tiring and, ultimately, pointless. So perhaps now is the time to adapt and do something new to get that same feedback and make sure our science is still heard and understood. One useful adaptation I have noticed when using video communication is that, since I can see my own facial expressions and gestures, I can get an idea of how the others might be receiving my non-verbal communication and I can then modify it on-the-fly to create a more meaningful experience.

Emojis have long been used for communicating feelings online and can also be incorporated into video-communication. In a lecture, they could be used to check that the audience understands what is being said, or maybe to alert the lecturer to something isn’t quite right. In this way, a virtual experience can be even more enriching than a face-to-face one.

Moving a lecture, or indeed any performance or type of communication, to a purely virtual world also means that it can be recorded. This makes it easy to review our own lectures and find ways to make improvements, or to select parts of the lecture to create a mini-series.

Some of these features may work very well for small audiences but how good could they be for a class of a hundred people or more? Would we need to consider one approach for a small audience, and a different approach for a much larger one? Experience, gathered and shared by the entire online community over time, will guide us. In the future, perhaps we can imagine a world where virtual reality makes it feel like you’re attending a real-live lecture where the speaker can move through the audience and interact with individuals.

COVID-19: From my home office to yours – we’re in it together!

Like many folks around the world, MRS staff - since March 16^th - has been working from home in order to stem the spread of the 2019 novel coronavirus.

From our home offices, we’ve been covering materials-related COVID-19 news such as a podcast episode on the development of a microneedle array that is key to a skin patch that delivers a vaccine, and a webinar on how materials research can counter the pandemic.

Researchers on COVID-19 are working at breakneck speed that it’s actually difficult to keep up with all the news! We’ve captured some of the more relevant news articles and linked these on the MRS COVID-19 Information and Resources page. This is where we also keep updates regarding the MRS Meetings for 2020.

Stay safe! Stay well!

-Judy Meiksin

How can materials science contribute to fighting against the new coronavirus?

Virus outbreaks are nothing new in history, such as the 1918 flu pandemic and the more recent Zika (2015–2016) and Ebola (2014-2016) outbreaks. But the new coronavirus, covid-19, is dominating the news today since the World Health Organization (WHO) has declared covid-19 a pandemic.

While biologists and medical researchers are working on a treatment, other scientific areas can also contribute to stopping covid-19 and caring for patients. For example, the need for medical equipment has urged engineers to use 3D printing to fabricate reanimation machines, valves, and respiratory aids, demonstrating the potential and benefits of such a technology. Materials science can play a crucial role too.

Characterizing the virus and its modes of action

Developing adequate means for treating viral infection requires prior knowledge of the microbe structure and mode of action. The entry and infection of a cell by a virus is a multi-step process; the first step is the attachment of the virus to receptors at the surface of a cell. What is at the surface of the virus therefore plays a key role in the process. It is known that coronaviruses are round shells of proteins that protect the genetic material, RNA, within. On those shells are exposed spike proteins (S) that contain the receptor-binding site to the cell.¹

Recently, the structure of the S-proteins of covid-19 was revealed using cryogenic electron microscopy (EM) methods (Fig. 1a).² To realize this, 3,207 micrographs were taken and combined into a three-dimensional (3D) reconstructed model with a resolution of 0.35 nm. The results show that a stochastic conformation change of the S-protein moves the receptor-binding site to an upward position, making it accessible for binding to the cell. This information could be used to develop an antiviral drug using a molecule that binds to the receptor or prevents the conformation change.

After attachment and entry into a cell, viruses typically release their genetic material, use the cell machinery to replicate it, reassemble their shell around the fresh replicated DNA or RNA, and exit. Blocking any of these steps would prevent the infection, but it has been challenging to image the processes inside the cell once the virus has entered. A study showed that entire cells and their interiors could be imaged in 3D with a resolution of 8 nm.³ To achieve this, a cell was first labelled with fluorescent markers, vitrified by high pressure freezing to preserve its structure, and imaged by cryogenic light microscopy. This provided a chemical mapping of the cell. The frozen specimen was then mounted onto a cryogenic scanning electron microscope stage and milled selectively with focused-ion-beam to image the topography of the interior of the cell. The images gathered from the two microscopic methods were then combined to create the 3D tomographic view of the cell. Applying this method to infected cells could reveal the mode of action of the virus inside the cell and open further avenues for drug development.

        See the MRS Bulletin December 2019 theme on Cryogenic Electron Microscopy in Materials Science

Figure 1. (a) Schematics of a coronavirus and three-dimensional reconstructed views of the structure of its spike protein (S) showing a trimer structure. White or grey areas show the electron density obtained using cryogenic electron microscopy (cryo-EM) and colored areas represent protein conformations, where green corresponds to the receptor-binding domain. Reprinted with permission from References 1,2 ©2020 Springer Nature, ©2020 AAAS. (b) Repeat units of organotin polymers acting as antiviral agents. R and R₁ represent side chains. Reprinted with permission from Reference 4 ©2019 Springer Nature. (c) Schematics of a smartphone-based imaging device and quantum-dot (QD) -based fluorescent reader developed for Zika virus detection, with one stripe indicating its presence (test line) and one stripe indicating the test is working (control line using an established antibody; goat anti-mouse IgG). Reprinted with permission from Reference 6 ©2019 Elsevier. (d) Electron micrographs of electrospun membranes containing 8 wt% poly(acrylonitrile) (PAN, top) and 10 wt% ammonium tetrathiomolybdate (ATTM/PAN, bottom) and the virus removal efficiency as a function of the PAN concentration. TEOS stands for tetraethyl orthosilicate. Reprinted with permission from Reference 7 ©2019 Elsevier.

Developing antiviral drugs and effective treatments

In the current absence of a vaccine, the symptoms of covid-19, which are similar to those of pneumonia and other forms of influenza, are being tackled. Viral infections can be treated by drugs made of molecules with special binding properties. For example, water-soluble polymers containing metals and aromatic rings can interact with the receptor-binding sites of the virus and prevent its entry inside the cell. Some of those polymers, termed organotin polymers, can also bind to the viral DNA or RNA inside the cell, preventing replication of the virus. Three examples of the repeat units of such polymers are presented in Figure 1b. The three structures derive from acyclovir, a molecule that is already included in treatments against herpes viruses. It was found that under the form of an organotin polymer, the antiviral efficiency of acyclovir could be increased and used also against other viruses, such as Zika.⁴ Could it also be an effective treatment for infections by other viruses?

        See the MRS Bulletin November 2006 theme on Pharmaceutical Materials Science

Detecting the virus and diagnosing patients at an early stage

The first step to diagnose patients is to look at the symptoms and the contact history with other infected patients. However, the incubation time for a virus may reach several days during which the infected patient has no symptoms but can still spread the disease. It is crucial to develop an early stage detection method that is precise, reliable, easy, fast, and cheap. This is challenging since the most accurate and low detection method uses polymerase chain reaction (PCR), a technique that takes one DNA or RNA segment and synthesizes a billion copies of it. This method however requires precise temperature control and expensive equipment.

To tackle this challenge and allow miniaturization for affordable point-of-care devices, many relevant materials issues can be explored. For example, in lab-on-a-chip devices conducting PCR, phase-changing materials can be used instead of batteries. Indeed, batteries are needed to power the electronic components that will control and maintain the isothermal temperature of 60°C required for the PCR. Instead, a self-heating self-regulating passive system can be developed by exploiting the heat released during the phase change of a metallic alloy like Mg-Fe. When a drop of water is placed on the metal, an exothermic chemical reaction occurs producing temperatures in the range required for the PCR. This metal was used in a PCR chip of a few millimeters only.⁵

Furthermore, visual read-out is the most convenient way to see the result from point-of-care devices, similar to pregnancy tests. Fluorescent dyes are commonly used to generate this optical output. Typically, a fluorescent molecule is attached to an antibody that is specific to a biomarker of the virus. In presence of the virus, the antibodies bind, tagging the sample with fluorophores; in absence, they are washed away. Upon shining light to the samples, the bound fluorophores emit light, indicating the presence of the virus. However, one major drawback is that a large concentration of fluorophores is required to give a strong and reliable signal, hindering the miniaturization and the detection limit.

As an alternative, nanometric quantum dots (QD) can be used. Indeed, QDs are monodisperse nanoparticles that can emit extremely intense fluorescence. In one study, by assembling QDs into microspheres in chip-size immunoassays, Zika viruses were detected in blood samples at concentrations of 0.15 ng/mL and in just 20 minutes (Fig. 1c).⁶ Although QDs fluoresce in a narrow spectrum, they can be excited by a light with a broader spectrum. This means a smartphone could be used to induce a signal, its camera to record it, and its processing power to compute the information. Such a smartphone-based diagnosis method is cheap, portable, user-friendly, and could be a way to proceed with early diagnosis of patients.

        See the MRS Bulletin February 2006 theme on Materials for Micro- and Nanofluidics and the September 2013 theme on Quantum Dot Light-Emitting Devices

Decontaminating and avoiding transmission

Wearing a mask (especially for healthcare professionals) and washing hands correctly and regularly are current recommendations to avoid contracting the virus. Covid-19 is transmissible when it is in the form of an aerosol, that is, liquid droplets in air. However, facemasks have limited pore size and time-efficiency, and decontamination of surfaces and hands using chemicals may irritate and weaken the physical barrier made by the skin. It is therefore necessary to engineer membranes that can filter the virus and its infective form outside a host cell over a long time and in hot and humid environments such as occurs when breathing into a facemask.

In addition, to be used as a facemask, the membrane needs to be strong, flexible, enable air flow, and ideally be affordable, comfortable, and recyclable. An ideal method for fabricating defect-free and highly interconnected porous membranes at an industrial scale is electrospinning. During electrospinning, a high voltage electric field is applied to a polymer solution to form threads that are collected onto a target. In a study using mixtures of poly(acrylonitrile) with tetrathoxysilane and ammonium tetrathiomolybdate salts, membranes were developed that could block more than 98% of Semliki forest virus, another RNA virus of ~50 nm diameter (Fig. 1d).⁷ The efficiency of the membranes was improved by the presence of the salts that increased the surface energy and roughness of the individual polymeric fibers, enabling electrostatic binding of the virus in addition to the physical barrier provided by the mesh. Since the size of coronaviruses typically ranges from 50 nm to 200 nm in diameter, exploration of electrospun membranes may yield the next generation of facemasks.⁸

        See the MRS Bulletin January 2008 theme on Advancing Materials and Technologies for Water Purification

Figure 2. (a) Polarized optical microscopy image of self-assembled M13 bacteriophages membranes at 1000 nM concentration in virus at 0° and 45° rotation of the polarizers. Reprinted with permission from Reference 9 ©2019 Elsevier. (b) Rejection fraction of ion Nd³⁺ as a function of the bacteriophages concentration in the membrane for peptide-modified and unmodified viruses. Reprinted with permission from Reference 9 ©2019 Elsevier. (c) Schematics of an optical sensor using M13 self-assembly. Reprinted with permission from Reference 10 ©2017 American Chemical Society. (d) Comparison of the piezoelectric response of films using M13 viruses, periodically poled lithium niobite (PPLN) and collagen. Reprinted with permission from Reference 11 ©2012 Springer Nature.

In addition

Materials science, then, can clearly contribute to fighting against covid-19 in many ways. Inversely, virology can also contribute to the development of new materials. Indeed, viruses are not only monodisperse, with diverse and complex shapes, and with specific affinity to living organisms, they can also self-assemble and exhibit functional properties other than biological properties. For example, cylindrical M13 bacteriophages can self-assemble into flexible membranes to filter toxic ions of very small dimensions, like Nd³⁺ (Fig. 2a,b).⁹ These self-assembled structures could be used as a template to develop new liquid crystal materials for color-based sensors (Fig. 2c)¹⁰ or even biodegradable piezoelectric biomaterials (Fig. 2d).¹¹ Virus-based materials engineering also offers tremendous potential for targeted cargo delivery of drugs and imaging agents, but immunogenicity remains a challenge.¹² The current urgent focus on covid-19 could be an opportunity for further scientific and engineering breakthroughs.

        See the MRS Bulletin February 2019 theme on Bioinspired Far-From-Equilibium Materials

References:

1. Seah, X. Su, G. Lingam, Eye (2020). doi:10.1038/s41433-020-0790-7
2. Wrapp,N. Wang,K.S. Corbett,J.A. Goldsmith,C.-L. Hsieh, O. Abiona, B.S. Graham, J.S. McLellan, Science (2020). doi:10.1126/science.abb2507
3. P. Hoffman, G. Shtengel, C.S. Xu, K.R. Campbell, M. Freeman, L. Wang, D.E. Milkie, H.A. Pasolli, N. Iyer, J.A. Bogovic, D.R. Stabley, A. Shirinifard, S. Pang, D. Peale, K. Schaefer, W. Pomp, C.-L. Chang, J. Lippincott-Schwartz, T. Kirchhausen, D.J. Solecki, E. Betzig, H.F. Hess, Science (2020) doi:10.1126/science.aaz5357
4. R. Roner, C.E. Carraher Jr., L. Miller, F. Mosca, P.  Slawek, J.E. Haky, J. Frank, Journal of  organic and organometallic polymers and materials (2020) doi:10.1007/s10904-019-01250-9
5. -C. Liao, J. Peng, M.G. Mauk, S. Awasthi, J. Song, H. Friedman, H.H. Bau, C. Liu, Sensors and actuators B 229, 232 (2016) doi:10.1016/j.snb.2016.01.073
6. Rong, Q. Wang, N. Sun, X. Jia, K. Wang, R. Xiao, S. Wang, Analytica Chemica Acta (2019) doi:10.1016/j.aca.2018.12.043
7. Al-Attabi, J. Rodriguez-Andres, J.A. Schütz, M. Bechelany, E. des Ligneris, X. Chen, L. Kong, Y.S. Morsi, L.F. Dumee, Separation and purification technology (2019) doi:10.1016/j.seppur.2019.115806
8. Chen, M. Zhou, X. Dong, J. Qu, F. Gong, Y. Han, Y. Qiu, J. Wang, Y. Liu, Y. Wei, J. Xia, T. Yu, X. Zhang, L. Zhang, The Lancet (2020) doi:10.1016/S0140-6736(20)30211-7
9. Sawada, H. Inomata, T. Serizawa, Journal of membrane science (2020) doi:10.1016/j.memsci.2019.117595
10. H. Lee, B. Fan, T.D. Samdin, D.A. Monteiro, M.S. Desai, O. Scheideler, H.E. Jin, S. Kim, S.-W. Lee, ACS Nano (2017) doi:10.1021/acsnano.6b07942
11. Y. Lee, J. Zhang, C. Zueger, W.-J. Chung, S.Y. Yoo, E. Wang, J. Meyer, R. Ramesh, S.-W. Lee, Nature Nanotechnology (2012) doi:10.1038/nnano.2012.69
12. Wu, H. Wu, S. Nakagawa, J. Gao, Biomaterials Science (2020) doi:10.1039/C9BM01383K

Coronavirus & materials science

RNA viruses have a high spontaneous mutation rate, which rarely leads to a viable virus. But when they do, the new virus might be transmissible to humans and not be recognized by our immune system. This is how the new coronavirus Covid-19 emerged, causing worldwide fear. Yet, many virologists, biologists, and medics are remaining calm and investigating a vaccine and treatment. As materials researchers, what could we do?

Schematics of the general structure of coronaviruses featuring spike proteins in the outer layer (credit: Nature Publishing group).

Materials science is multidisciplinary, and applies to many fields. Materials can be bio, electronic, dense, porous, passive, active, etc. As a consequence, materials science can play a role in many aspects in the fight against Covid-19, such as in the following areas:

• identification. To be able to elaborate an adequate response to the effects of the virus, it is necessary to know more about it, and in particular its structure. For example, knowing how the proteins forming the virus are folded and assembled in 3 dimensions can help to identify sites where a medical treatment could interact and stop the replication of the virus. Current microscopy methods such as cryogenic electron microscopy (cryo-EM)—where a nanoparticle, a protein assembly, or a virus is frozen and observed under many angles—has already been used to reconstruct with nanometric resolution the complex structure of coronaviruses. The folding of the spike proteins in the outer shell of a feline coronavirus was thus imaged.
• 
  

  3D electron density map recorded by cryo-EM of a spike protein of a coronavirus at 0.33 nm resolution and revealing a trimer structure with 18 nm diameter and 17 nm height (credit: PNAS).

• treatment. The acute symptoms of the coronavirus infection are similar to pneumonia, which is treated by injection of pain relievers and anti-inflammatory drugs. Encapsulating the treatment inside a protective and functional micrometric shell can help deliver the medicine to the infected area more effectively. For example, small microparticles loaded with the drugs were developed to be directly inhaled by the patient. Thanks to the small size of the microparticles, below 10 µm, it is possible to deliver high loads of drugs while reaching the small and deep capillaries in the lungs.
• diagnosis. Regular temperature checks have been implemented to identify infected patients, but other methods may be able to detect the presence of the virus before the appearance of the symptoms. In particular, lab-on-a-chip devices could be used to determine the early presence of the virus. Such chips are only 3 cm long and sequence the genome from infected cells using microfluidics and DNA-assays. It was developed earlier for other coronaviruses. Could such devices be implemented on our smartphones, like demonstrated earlier this year for early detection of malaria?
• prevention of spreading. Wearing a facemask or an N95 respirator is one way to avoid the propagation of droplets containing the virus from a person who carries it to another who is healthy. However, wearing masks is protective for only a couple of hours. Longer than this, the humidity from the breath widens the pores and opens the barrier. Besides, the filtrating capability of such masks is usually limited to particles above 300 nm diameter, whereas the coronavirus may range around 50 to 200 nm diameter only. However, new materials and fabrication technologies might be promising alternatives, such as a recently developed electrospun textile based on silk and graphene. Due to the ultra-high aspect ratio of graphene, a mat with a pore size below 10 nm is created, blocking nano-pollutants including viruses while maintaining the passage of air.