Sorry, this entry is only available in Brazilian Portuguese.
Author: Verónica Savignano
Postdoctoral fellowship at the Federal University of Santa Catarina (Brazil).
The Graduate Program in Physics of Federal University of Santa Catarina – PPGFSC/UFSC, Florianópolis, announces the vacancy of 1 (one) postdoctoral scholarship from the (Programa Nacional de Pós-doutorado da Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – PNPD/CAPES), to the period of 2 (two) years, it can be renewed annually at a maximum of 60 months.
The monthly amount of the scholarship is R$ 4.100.00 (four thousand one hundred reais) beyond the values destined to assets.
The candidate has to act in THEORETICAL or EXPERIMENTAL research lines at one of the following areas of research: Astrophysics, Atomic and Molecular Physics, Condensed Matter Physics and Statistical Mechanics, Mathematical Physics and Quantum Field Theory and Nuclear Physics and Hadrons.
The complete regulation of the Graduate Program (Programa Nacional de Pós-Doutorado – PNPD) is described at: Portaria nº 086, de 03 de julho de 2013.
To make your application: click here
B-MRS Newsletter. Year 6, issue 8.
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From idea to market: nanotechnology for wellness.
A mix of entrepreneurial spirit, born in childhood, and scientific training, developed in the university stage, led Brazilian Amanda Luizetto dos Santos to create Nanomed two years after completing her doctorate. “The foundation of Nanomed was a natural thing, I always wanted to undertake it, I just needed some time to mature the concept as I imagined,” Amanda states.
Early on in her childhood, Amanda used to set up a street stall to sell her drawings. “From an early age entrepreneurship aroused my heart,” she says. Time passed and pastimes became a life goal. At the end of her undergraduate years in Pharmacy, she participated in an initiative to train young entrepreneurs, in which she opened, maintained and closed (with a positive balance, she explains) a decorative candles company. “This experience was very enriching and, in fact, revived my interest in the world of entrepreneurship,” she recalls.
From her undergraduate degree, Amanda went straight to a doctorate in Analytical Chemistry, at the São Carlos Institute of Chemistry (USP), where she dealt with research in essential oils. The doctorate program included a scientific internship in the United States at Cleveland State University. Then, working closely with the cosmetics industry, Amanda noted this market’s demand for innovation and managed to design a first version of the company. “I found what I had been looking for since I was a young girl,” she says.
Located in São Carlos, in the state of São Paulo (Brazil), Nanomed is dedicated to developing and marketing innovative nanosystems, designed to solve specific challenges of the industry segments such as cosmetics, health and wellness. An example of Nanomed’s technology is nanocapsules that protect substances of interest (skin moisturizing molecules, medicine flavorings, insect repellents), transport them in minimal doses and deliver them to the desired location. Nanomed’s nanocapsules and other nanoparticles, Amanda emphasizes, undergo scientific evaluations to check for toxicity to living tissues and the environment.
In addition to developing nanosystems for other companies, the startup is building its product portfolio. The first products, two nanotechnology-based cosmetic lines, will enter the market (via e-commerce) soon. And between the end of this year and the beginning of next, new products of the food and sanitizing segments will be launched.
Nanomed was formally created in 2012 following the approval of a project in the PIPE program of the São Paulo Research Foundation (Fapesp). PIPE supports scientific and technological research in small companies in the state of São Paulo. Shortly after its creation, Nanomed was incubated in the São Carlos Technology Park (ParqTec), where it remained until 2017.
Since its inception, the startup has been dedicated to R&D of its technologies and products and, at the same time, has taken advantage of its ability to perform analysis and testing to provide services, especially to companies in the cosmetics and pharmaceutical segment. Thanks to the provision of services, Nanomed today is self-sustaining, states Amanda, who is the company’s CEO. “However, profit is still being reinvested,” she says.
For its R&D and service activities, Nanomed has equipment at the company’s headquarters, some of them acquired in projects supported by Fapesp and the Brazilian federal agencies Finep and CNPq. In addition, the startup hires specific assays at university labs and other partners.
Fifteen people currently work at Nanomed – partners, employees, fellows and consultants. Most of the team consists of masters and doctors with degrees in Pharmacy, Chemistry, Engineering and Physics, who work in product development and service provision. The startup also has professionals working in the legal and administrative areas.
Below is our interview with Amanda Luizetto dos Santos, founding partner and CEO of Nanomed.
B-MRS Newsletter: What were the most important factors that enabled the creation and development of the startup?
Amanda Luizetto dos Santos: The key factors that enabled Nanomed include the support of Fapesp and ParqTec. Since the beginning of Nanomed, Fapesp has been a fundamental pillar in technology and product developments by financing innovative and high risk projects. ParqTec, which is the oldest incubator in Latin America and is located in São Carlos, was very important because it allowed immersing in the environment of innovative entrepreneurship, as well as supporting the business construction.
B-MRS Newsletter: What were the most important moments for you in the history of the startup?
Amanda Luizetto dos Santos: The most important moment was participating in a meeting at Anvisa’s parliamentary meeting to defend a grade 2 cosmetic product developed by Nanomed and which will be launched and marketed later this year.
[Editor´s Note: Grade 2 products are toiletries or cosmetics whose characteristics require proof of safety and/or efficacy, as well as information on use mode and restrictions].
B-MRS Newsletter: What were the main difficulties the startup has faced thus far?
Amanda Luizetto dos Santos: The main difficulty, still encountered, is the slowness and regulatory bureaucracy that is related to the fact we work in the health area.
B-MRS Newsletter: What do you think is the main contribution of the startup to society?
Amanda Luizetto dos Santos: The main contribution is to offer safe and innovative products to society and contribute to the population’s quality of life.
B-MRS Newsletter: What is your goal/dream for the startup?
Amanda Luizetto dos Santos: Nanomed’s goal is to make people happy and satisfied by offering a line of innovative and high performance products in the domestic and international market.
B-MRS Newsletter: Leave a message to our newsletter readers and social media followers who are considering starting a startup.
Amanda Luizetto dos Santos: I believe we need to be realistic when we think about the future, especially when it comes to opening a business of our own. The idea that to undertake is to have no boss does not exist, in fact, you have thousands of bosses, such as client, employee, government, and many others. So, entrepreneurship means working hard and in all sectors of the business (all of them!). Creating a startup and keeping it alive requires a great deal of work (quite a lot), dedication, resilience and a cool head.
The universe of entrepreneurship is a constant adrenaline rush, particularly addictive, while it brings immense satisfaction to see things come to fruition, that cold feeling in the belly is inevitable. I can’t live without it (I still don’t know if fortunately or unfortunately!).
Featured paper: Nanorods to develop new anti-inflammatory drugs.
[Paper: Characterization of the structural, optical, photocatalytic and in vitro and in vivo anti-inflammatory properties of Mn2+ doped Zn2GeO4 nanorods. Suzuki, V. Y.; Amorin, L. H. C; Lima, N. M; Machado, E. G; Carvalho, P. E.; Castro, S. B. R.; Souza Alves, C. C.; Carli, A. P.; Li, Maximo Siu; Longo, Elson; Felipe La Porta. J. Mater. Chem. C, 2019, 7, 8216. DOI: 10.1039/c9tc01189g]
A team of researchers from Brazilian universities found, in cylindrical nanostructures known as nanorods, an anti-inflammatory effect equivalent to that achieved by commercial drugs. Researchers have also demonstrated the effectiveness of these nanorods as catalysts (accelerators) in the degradation of a pollutant. These applications are even more relevant considering that the scientific team was able to produce large quantities of the material through a simple and fast process. The work carried out shows the potential of these nanorods for the development of new medicines and for the treatment of effluents.
The work originated about three years ago when Professor Felipe de Almeida La Porta, who had recently joined the faculty of the Federal Technological University of Paraná (UTFPR), Londrina campus, was implementing a research group on nanotechnology and computational chemistry at this university. “Our laboratory was investigating some classes of emerging materials, with the perspective of aligning theory and practice, thus driving new discoveries and applications,” says La Porta. One of the materials studied by the group was zinc germanate (Zn2GeO4), a versatile semiconductor with well-known applications in sensors, catalysts, batteries and other devices.
Together with undergraduate researcher Victor Yuudi Suzuki, the professor started a project in which he synthesized pure Zn2GeO4 nanorods at the UTFPR laboratory with very small percentages of manganese ions. To produce this series of nanorods, they used “microwave assisted hydrothermal synthesis.” The method consists, in broad lines, of mixing aqueous solutions containing certain compounds, heating the final solution in a microwave oven and allowing the compounds to react for a certain period of time at controlled pressure and temperature. In this study, the manganese ion-doped Zn2GeO4 was prepared, and the reactions were performed at 140 °C for 10 minutes. The resulting material from these reactions was collected at room temperature, then washed and dried, which generate the nanorods.
Professor La Porta and his research group were able to optimize one of the process steps, the crystallization of materials, thus reducing the synthesis time from hours to a few minutes, but maintaining the quality of the material and the possibility to control its shape.
After preparing the samples, they traveled from Londrina (state of Paraná) to São Carlos (São Paulo state) to characterize the materials at the Center for Functional Materials Development (CDMF) at the Federal University of São Carlos (UFSCar) and at the Institute of Physics at the University of São Paulo (USP). Together with the local researchers, they were able to analyze the shape, structure and luminescence of the four types of nanorod compositions produced: manganese-free and with 1, 2 and 4% of this element incorporated into the structure of Zn2GeO4.
Finally, knowing that compounds containing zinc, germanium or manganese exhibit considerable effects on living things, the team contacted some collaborators to investigate these properties in the nanorods. Thus, several experiments were performed at the Departments of Chemistry and Pharmacy of the Federal University of Juiz de Fora and at the Federal University of Vales do Jequitinhonha and Mucuri, both in the state of Minas Gerais.
To study the anti-inflammatory action, the team performed in vitro tests (in contact with cells in laboratory containers) and also in vivo tests (using rats with paw edema, within the norms of the Brazilian code for laboratory animal use). Both types of experiments revealed that nanorods with about 4% manganese were the most effective in controlling inflammation. The in vitro tests showed these nanostructures were able to modulate molecules that regulate inflammation without causing cell death (without cytotoxicity). In the in vivo experiments, the nanorods reduced the induced rat paw edema with results similar to that of the application of dexamethasone, a well-known drug of the corticoid group.
“At first, we thought that combining these elements to form a ternary oxide could somehow potentiate these effects. But we had no idea the results would be so significant. Given that the drugs currently available in therapy are proving to be less effective every day, these results may encourage the use of these nanorods, for example in the production of a new pharmaceutical formulation, especially for cases of inflammation,” says Felipe La Porta, who is the corresponding author of the paper that was recently published by the research team in the Journal of Materials Chemistry C (impact factor 6,641).
In addition to proving the potential of the material for this application in the health area, the authors of the paper have experimentally verified the ability of nanorods to degrade a chemical dye widely found in industrial effluents, known as methylene blue. For this application, 2% manganese nanostructures were the most efficient, completely decomposing the dye in 10 minutes. “Due to the manufacture simplicity of this system, coupled with its excellent properties, this material is also promising for cleaning various environmental pollutants, and can be easily recovered at the end of this process,” adds Prof La Porta.
The superior properties that the Brazilian scientific team found in the nanorods with manganese can be related to the structural defects observed in these samples. In fact, the three-dimensional network of atoms that forms zinc germanate is crystalline, that is, organized in regular patterns. The introduction of manganese generates irregularities, and new properties emerge.
The scientific paper that reports this work was selected to be part of the Materials and Nano Research in Brazil collection, prepared by the Royal Society of Chemistry in celebration of the 18th B-MRS Meeting, and can therefore be accessed free of charge until October 15 of this year, here.
The work was carried out with funding from Brazilian research support agencies: the federal CNPq and Capes, and the state Araucaria Foundation, Fapesp and Fapemig.
Royal Society of Chemistry put together a collection of paper of Brazilian authors in honour of XVIII B-MRS Meeting.
The Royal Society of Chemistry (RSC) has prepared an online collection of articles by Brazilian authors in celebration of the XVIII B-MRS Meeting (Balneário Camboriú, September 22-26, 2019). The Royal Society of Chemistry is a supporter of this edition of B-MRS’s annual event.
Titled Materials and Nano Research in Brazil, the collection brings together 55 articles published in RSC journals between 2017 and 2019. All selected articles are open access until October 15, 2019.
The collection is available at www.rsc.li/brazil-mrs-2019
Postdoctoral fellowship opportunity in Brazil (Sao Paulo).
Abstract
The Institute of Chemistry of São Carlos (IQSC) of University of São Paulo (USP) is offering a postdoctoral fellowship linked to the Project “Study and application of electrochemical technology for the analysis and degradation of endocrine interferents: materials, sensors, processes and scientific dissemination” coordinated by Prof. Dr. Marcos Lanza (Grant 2017/10118-0).
The project aims at the production of new materials with electrocatalytic activity and their application in electrochemical analysis sensors and in advanced effluent treatment processes. In addition to the publication of the scientific knowledge through scientific articles, the dissemination of results will also occur through scientific popularization. Through the production of didactical material to improve the teaching of physicochemistry in Basic Education and the realization of interactive expositions open to students and the general population, it is hoped to arouse interest in science, especially among school-age youth.
Requirements
The candidate will work on the development and application of new carbon matrix (electrocatalytic) materials for the electrogeneration of H2O2 in situ, from the oxygen reduction reaction, to be applied to cells and reactors electrochemical processes aimed at the degradation of organic compounds with endocrine interference activity.
The desirable requirements for the candidate are: (1) knowledge of morphological-structural analysis techniques and electrochemical techniques for the analysis of electrocatalysts; (2) knowledge of advanced oxidative electrochemical processes (PEOA) of degradation of organic compounds, as well as the notion of instrumental techniques of chemical analysis.
The candidate must have immediate availability to reside in São Carlos / SP / Brazil and have completed his doctorate for less than 7 years.
If selected, the candidate will have a FAPESP postdoctoral fellowship (www.fapesp.br/270) in the monthly amount of R $ 7,373.10 (approximately US$ 1,800.00/month) for up to 24 months, with the possibility of financial assistance for the displacement and installation. It is noteworthy that there is no income tax levied on the scholarship amount and it corresponds to the amount with legal discounts of a newly hired lecturer of public university from the State of Sao Paulo. As a reference, the minimum salary in Brazil is US$ 250.00.
São Paulo Research Foundation – FAPESP – is an independent public foundation with the mission to foster research and the scientific and technological development of the State of São Paulo (Brazil).
More information on FAPESP postdoctoral fellowships:
http://www.fapesp.br/en/postdoc
The inscriptions should be made through the email marcoslanza@usp.br to the supervisor Prof. Dr. Marcos Lanza until September 10, 2019. The following documents must be attached to the e-mail:
1) Curriculum Vitae containing the academic training and publications (maximum of 4 pages). Experience in the areas of Materials Chemistry (and related areas) and Electrochemistry must be proven through publications in international scientific journals.
2) Letter of the candidate justifying the interest on the vacancy (maximum of 200 words).
3) Two (2) letters of recommendation.
4) Work plan with its own title describing one (1) research proposal involving the following topic: Production and characterization of new electrocatalyst materials supported in carbon for the electrogeneration of H2O2, from the oxygen reduction reaction, aiming the application in Electrochemical Advanced Oxidative Processes (EAOP) of degradation of organic compounds with endocrine interference activity.
The proposal should include a brief introduction and a description of the strategies for obtaining results, bibliographical references and international journals of interest for submission (maximum of 10 pages).
B-MRS Newsletter. Year 6, issue 7.
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Featured paper: Low toxicity magneto-luminescent nanoplatform.
In research carried out in a number of Brazilian laboratories, a multidisciplinary scientific team developed a magnetic, luminescent nanomaterial capable of chemically binding to molecules of interest, such as drugs or proteins. This nanomaterial also showed low toxicity in tests with living organisms. With this set of characteristics, the new material can be seen as a multifunctional nanoplatform that is promising for the development of various applications, especially in the areas of biotechnology, health and environment. The study was reported in an article published in ACS Applied Nano Materials (American Chemical Society journal released in 2018), and featured on the cover of the June issue of the journal.
The properties of this nanoplatform derive from the presence of several compounds and elements with distinct properties: iron oxide (Fe3O4, known as magnetite) nanoparticles responsible for magnetism; lanthanide element ions (Gd3 +, Ce3 + and Tb3 +, known as rare earths) responsible for luminescence or light emission, and chitosan (biopolymer obtained from the crustacean exoskeleton), essential for providing chemical bonds of the nanoplatform surface to the external molecules of interest.
The nanoplatform was developed at the Brazilian National Nanotechnology Laboratory of the National Center for Energy and Materials Research (LNNano – CNPEM). The process used for its synthesis comprises a series of steps. Initially, the iron oxide nanoparticles that form the core of the nanoplatforms are synthesized and coated with silicon dioxide (SiO2). Then the luminescent elements and chitosan are incorporated into the nanoparticles forming an outer layer. The result is nanoplatforms of approximately 170 nm in diameter (on average), called Fe3O4@SiO2/GdOF:xCe3+,yTb3+.
To study the magnetic and luminescent properties of the nanoplatform and to characterize its structure and morphology, research groups from the State University of Campinas (Unicamp) and the University of São Paulo (USP) participated in the study.
In addition, the main authors of the paper decided to evaluate the toxicity of nanoplatforms with relation to living organisms – a key step when thinking about health or environmental applications, and they decided to conduct a well-established in vivo test, in which zebrafish embryos (scientific name Danio rerio) are exposed to the material whose toxicity is to be evaluated. These freshwater fish, in fact, has a high genetic similarity to humans (about 70%) and at the same time is cheaper and easier to study than mice or rats, among other advantages.
In the toxicity test, a few dozen freshly fertilized zebrafish eggs were placed in aqueous medium containing the nanoplatforms at various concentrations. The embryos were examined at different development stages using an optical microscope to check for mortality, malformation, edema or changes in size. Tests included embryos with and without chorion (membrane that protects the embryo in the early stages of development). The test results carried out at LNNano showed that nanoplatforms, even at high concentrations (100 mg/L), have low toxicity for all embryo groups.
“This work brings an unprecedented contribution that involves evaluating the toxicity of hybrid nanomaterials using the zebrafish model, a promising alternative method in nanotoxicology, and the influence of the chorion,” says Diego Stéfani Teodoro Martinez, CNPEM researcher at LNNano and one of the corresponding authors of the article.
The embryos were also analyzed at the Brazilian National Synchrotron Light Laboratory (LNLS – CNPEM) to verify the distribution and concentration of nanoplatforms in the organism of the embryos. To do this, the scientists used the synchrotron light X-ray fluorescence microscopy (SXRF) technique, which can accurately map certain chemical elements in biological systems. This technique is available at one of the LNLS experimental stations, coordinated by the researcher Carlos Alberto Pérez, who is one of the corresponding authors of the article.
SXRF analysis showed that nanoplatforms had accumulated in the embryos as a function of exposure time, with higher concentrations in the gastrointestinal tract in the case of already developed mouth embryos – a result that may be significant, for example in the context of healthcare applications involving oral nanoplatform ingestion.
The study was carried out in the context of a postdoctoral project by fellow Latif Ullah Khan, also corresponding author of the article. The completion of the project, says Martinez, was made possible by the availability of skills and facilities at CNPEM’s multi-user laboratories. However, partnerships with other laboratories were also crucial, adds the CNPEM researcher. Professor Marcelo Knobel’s group performed the magnetometry studies at Unicamp. The groups of professors Hermi Felinto Brito and Magnus Gidlund carried out the luminescence and functionalization studies at USP. Finally, Professor Diego Muraca (Unicamp) and researcher Jefferson Bettini (CNPEM) contributed to the structural and morphological characterization using transmission electron microscopy techniques.
“This article was the result of integrating the experience of different Brazilian groups; an interdisciplinary study on the frontier of knowledge in nanobiotechnology and nanotoxicology,” says Martinez, adding that one of the main challenges of the work was integrating knowledge and techniques from different areas, such as Materials, Biology and Toxicology, a task that was coordinated by Martinez and Pérez.
The study received financial support from Brazilian agencies CAPES (including through the CAPES-CNPEM agreement), FAPESP and CNPq (including through INCT-Inomat); from the Brazilian Ministry of Science, Technology, Innovations and Communications (MCTIC) through SisNANO, and The World Academy of Sciences for advancement of science in developing countries (TWAS). The study also received financial support from the Brazil-China Nanotechnology Research and Innovation Center (CBC-Nano).
Applications: biotechnology, health and the environment
According to Martínez, the nanoplatform developed opens perspectives for applications in biotechnology, health and the environment, such as biological tissue and cell imaging systems, medical diagnostic kits, and environmental systems for pollutant detection and remediation
The applications would take advantage of the interesting set of nanoplatform properties. Because they are magnetic, using an external magnet, nanoplatforms could be directed and retained in a particular biological tissue or isolated from, for example, contaminated blood or water. In addition, the luminescence of the nanomaterial would allow visualizing the nanoplatforms within the biological tissues and cells of interest. Finally, the presence of chitosan would enable the chemical binding of drugs and other molecules that would serve for the diagnosis and/or treatment of diseases. “However, much study is still needed for real applications and commercialization of this nanoplatform, as it is a new material and needs to be tested on different models in the future,” says Martinez Martinez.
[Paper: Fe3O4@SiO2 Nanoparticles Concurrently Coated with Chitosan and GdOF:Ce3+,Tb3+ Luminophore for Bioimaging: Toxicity Evaluation in the Zebrafish Model. Latif U. Khan, Gabriela H. da Silva, Aline M. Z. de Medeiros, Zahid U. Khan, Magnus Gidlund, Hermi F. Brito, Oscar Moscoso-Londoño, Diego Muraca, Marcelo Knobel, Carlos A. Pérez, Diego Stéfani T. Martinez. ACS Appl. Nano Mater. 2019, 2,6, 3414-3425. https://doi.org/10.1021/acsanm.9b00339.]
Featured scientist: Prof. Julia Greer (California Institute of Technology, USA).
As if she were an architect of the nanoscale, Prof. Julia R. Greer, together with her research group at Caltech (California Institute of Technology) creates three-dimensional structures based on innovatively engineered nanomaterials. The result are metamaterials (artificial materials in which properties depend not only on chemical composition but also on the specific arrangements of nano-sized components into an architected structure) with superior properties. For example, structures with simultaneous extreme lightness and strength or thermal conductivity. Professor Greer and her group develop methods to create such 3D nano-architected materials using an approach called additive manufacturing, and to understand how these properties are generated as a result of multi-scale interactions: atomic, nano and micro scales.
Julia Rosolovsky Greer was born in Moscow (Russia). She began her musical education at the age of 6 and started attending the renowned Gnessin School of Music in Moscow in 5th grade; concurrently in 7th grade she transferred to a Math high school, which in a way served as a foreshadow of her “double-career” as a scientist and a pianist. At 16, she moved with her family to the United States, where she studied and works in three of the top five universities in the world according to the rankings available. For her undergraduate studies she attended the Massachusetts Institute of Technology (MIT), where she obtained in 1997 her major in Chemical Engineering and a minor in Advanced Music Performance. After that, Greer was accepted at Stanford University to undertake graduate studies in Materials Science and Engineering. In 2000, she obtained a M.S. degree, but was discouraged by her at-the-time-supervisor to follow a scientific career. After working for a few years at Intel, Greer decided to return to Stanford to get a Ph.D. Working under the guidance of materials scientist Prof. William D. Nix, who she considers an incredible mentor, Julia made a seminal contribution to nanomechanics and obtained her Ph.D. degree in 2005. After that, she was a postdoctoral fellow at PARC until she joined the faculty of Caltech in 2007, where she is currently a Ruben F. and Donna Mettler Professor of Materials Science, Mechanics, and Medical Engineering.
Professor Greer has an h-index of 56 and over 13,000 citations, according to Google Scholar. She has received a couple of dozen distinctions from scientific institutions, journals and media, and has given more than 100 invited lectures, including named lectures, at scientific events, universities, World Economic Forums and TEDx events. Greer serves as an associate editor for Nano Letters and Extreme Mechanics Letters.
This scientist and concert pianist will be in September in Balneário Camboriú (Brazil), giving a plenary lecture at the XVIII B-MRS Meeting.
See our mini interview with Professor Julia Greer.
B-MRS Newsletter: – In your PhD research, you developed an innovative method to measure mechanical properties of materials at the nanoscale and with it you have made an amazing discovery, right? We would like you to tell us, as briefly as possible, the history of this work, its results and its impact.
When I first arrived at Stanford to start my Ph.D. research with the amazing mentor, Professor W.D. Nix, he vaguely suggested that I should learn how to make small things to test mechanically and see if I could figured out how to use the new-at-the-time instrument, the Focused Ion Beam (FIB). Having worked at Intel for a couple of years, I had learned to do what the Boss tells you to do, so I had learned a very new at the time technique that carves nano-sized shapes by etching the parent material with Ga+ ions. Soon, I had become quite proficient at making nano-cylinders, whose diameters ranged from 1/10,000th of your hair diameter to something like half a thickness of a sheet of paper. I then figured out how to compress them using an instrument called nanoindenter to assess their strength and modulus, and we discovered that as we made those pillars smaller, i.e. reducing the diameter from several microns to a few hundred nanometers, resulted in much higher stresses, i.e. they were able to exhibit much greater strengths. I spent the rest of my 3-year Ph.D. trying to figure out how and why that happened. Together with Prof. Nix, we stumbled upon a pretty impactful finding that smaller was, in fact, stronger, because of the specific behavior and interactions of defects called dislocations within very small, nano- and micro-sized volumes. We did all this work on single crystals of gold, i.e. a relatively malleable metal at the macroscale, whose properties are well understood. When its dimensions were reduced to ~200 nm, it became as strong as steel, exhibiting compressive (and we showed later, tensile, too) stresses close to 800 MPa or even higher; for comparison, the bulk strength of gold is roughly 25 MPa, so it’s 50 times higher! Since then many other research groups have confirmed this type of size effect in many different metals, using different experimental and computational techniques and materials, so it had turned out to be not only a reproducible but seemingly ubiquitous size effect in many different material systems. It has significant implications for how to properly understand material behavior at the nano- and microscale.
B-MRS Newsletter: – In your plenary talk at the B-MRS Meeting, you will talk about three-dimensional nano-architected meta-materials. Could you please choose one of your favorite metamaterials, briefly describe how it is made and mention its (possible) applications?
Well, our meta-materials are like children, I don’t really have a favorite one. What I will do is describe how we usually make these materials, what are their solid constituents – they are all so different: metals, semiconductors, polymers, carbon, ceramics, etc. – and what kind of properties they exhibit. I will describe quite a bit of chemical synthesis, mechanical properties, and show (hopefully 😉 ) interesting visual examples of their response to various stimuli. I am looking forward to the conference!
For more information on this speaker and the plenary talk she will deliver at the XVIII B-MRS Meeting, click on the speaker’s photo and the title of the lecture here https://www.sbpmat.org.br/18encontro/#lectures.