Tag Archives: Institut national de la recherche scientifique

Promising new technique for controlled fabrication of nanowires

This research is the result of a collaboration between French, Italian, Australian, and Canadian researchers. From a Jan. 5, 2016 news item on *phys.org,

An international team of researchers including Professor Federico Rosei and members of his group at INRS (Institut national de la recherche scientifique) has developed a new strategy for fabricating atomically controlled carbon nanostructures used in molecular carbon-based electronics. An article just published in the prestigious journal Nature Communications presents their findings: the complete electronic structure of a conjugated organic polymer, and the influence of the substrate on its electronic properties.

A Jan. 5, 2016 INRS news release by Gisèle Bolduc, which originated the news item, indicates this is the beginning rather than an endpoint (Note: A link has been removed),

The researchers combined two procedures previously developed in Professor Rosei’s lab—molecular self-assembly and chain polymerization—to produce a network of long-range poly(para-phenylene) (PPP) nanowires on a copper (Cu) surface. Using advanced technologies such as scanning tunneling microscopy and photoelectron spectroscopy as well as theoretical models, they were able to describe the morphology and electronic structure of these nanostructures.

“We provide a complete description of the band structure and also highlight the strong interaction between the polymer and the substrate, which explains both the decreased bandgap and the metallic nature of the new chains. Even with this hybridization, the PPP bands display a quasi one-dimensional dispersion in conductive polymeric nanowires,” said Professor Federico Rosei, one of the authors of the study.

Although further research is needed to fully describe the electronic properties of these nanostructures, the polymer’s dispersion provides a spectroscopic record of the polymerization process of certain types of molecules on gold, silver, copper, and other surfaces. It’s a promising approach for similar semiconductor studies—an essential step in the development of actual devices.

The results of the study could be used in designing organic nanostructures, with significant potential applications in nanoelectronics, including photovoltaic devices, field-effect transistors, light-emitting diodes, and sensors.

About the article

This study was designed by Yannick Fagot-Revurat and Daniel Malterre of Université de Lorraine/CNRS, Federico Rosei of INRS, Josh Lipton-Duffin of the Institute for Future Environments (Australia), Giorgio Contini of the Italian National Research Council, and Dmytro F. Perepichka of McGill University. […]The researchers were generously supported by Conseil Franco-Québécois de coopération universitaire, the France–Italy International Program for Scientific Cooperation, the Natural Sciences and Engineering Research Council of Canada, Fonds québécois de recherche – Nature et technologies, and a Québec MEIE grant (in collaboration with Belgium).

Here’s a link to and a citation for the paper,

Quasi one-dimensional band dispersion and surface metallization in long-range ordered polymeric wires by Guillaume Vasseur, Yannick Fagot-Revurat, Muriel Sicot, Bertrand Kierren, Luc Moreau, Daniel Malterre, Luis Cardenas, Gianluca Galeotti, Josh Lipton-Duffin, Federico Rosei, Marco Di Giovannantonio, Giorgio Contini, Patrick Le Fèvre, François Bertran, Liangbo Liang, Vincent Meunier, Dmitrii F. Perepichka. Nature Communications 7, Article number:  10235 doi:10.1038/ncomms10235 Published 04 January 2016

This is an open access paper.

*’ScienceDaily’ corrected to ‘phys.org’ on Tues., Jan. 5, 2016 at 1615 PST.

An enzyme’s atoms are in a subtle dance that can affect protein function

This research comes from Québec’s Institut national de la recherche scientifique (INRS) according to a Dec. 10, 2015 news item on ScienceDaily,

Infinitesimal fluctuations occurring on the milli- and even nano-second time scales within the three-dimensional structure of enzymes may be one of the keys to explaining protein function. Professor Nicolas Doucet’s team at INRS has demonstrated that even when certain amino acids are far from the active site of an enzyme, a change in their flexibility and atomic fluctuations can significantly impact enzyme activity. This phenomenon, which has been underestimated up to now, could explain certain protein engineering failures and help improve the way synthetic functional enzymes are designed.

A Dec. 10, 2015 INRS news release on EurekAlert, which originated the news item, provides an explanation of an enzyme’s functions and what the researchers found out,

Enzymes are nanomachines that are exceptionally efficient at catalyzing a chemical reaction. They play a role in all cellular mechanisms. Like all proteins, they are made up of amino acid chains that are folded and assembled in a very precise 3D structure. Some enzymes, like ribonuclease A, are so efficient that they catalyze the transformation of chemical molecules thousands of times per second.

In this study, Donald Gagné, a researcher in Professor Doucet’s lab holding a PhD in biology from INRS, analyzed the impact of removing a methyl group located near a loop distant from the reaction site of ribonuclease A–a very slight change that presumably would have no effect. The mutation does not perturb the 3D structure of the enzyme. However, it did result in a four-fold reduction in the affinity of ribonuclease A for nucleotides (molecules to which it must bind to carry out its function). How is this possible?

Using crystallography techniques and nuclear magnetic resonance to examine the enzyme at atomic resolution, Donald Gagné compared normal ribonuclease A with the mutated enzyme. He observed that when ribonuclease A is modified, the nucleotides do not position themselves correctly and have a harder time binding to the active site. It appears that this repositioning is due to an increase in enzyme fluctuations caused by the elimination of this distant methyl group, which we can picture as creating vibrations that spread through the enzyme structure all the way to the site of catalysis.

This demonstration of the importance of enzyme dynamics could change our understanding of protein and enzyme mechanisms. While it remains a challenge to measure fluctuations at this atomic scale, researchers have studied the three-dimensional structure of proteins to understand how they function. Despite the staggering complexity of this phenomenon, we now know that proteins are increasingly regulated by the subtle dance of their atoms.

Here’s a link to and a citation for the paper,

Perturbation of the Conformational Dynamics of an Active-Site Loop Alters Enzyme Activity by Donald Gagné, Rachel L. French, Chitra Narayanan, Miljan Simonović, Pratul K. Agarwal, Nicolas Doucet. Structure Volume 23, Issue 12, p2256–2266, 1 December 2015 DOI: http://dx.doi.org/10.1016/j.str.2015.10.011

This paper is behind a paywall.

Canadian nanoscientist, Federico Rosei, picks up a new honour (this one is from China)

I covered two of Federico Rosei’s awards last year in a Jan. 27, 2014 post about his Canadian Society for Chemistry award and in a Feb. 4, 2014 post about his E.W.R. Steacie Memorial Fellowship from Canada’s Natural Sciences and Engineering Research Council. This year, China has honoured the Dr. Rosei with a scholar’s award that requires regular visits to China. From a Jan. 28, 2015 news item on Azonano,

Professor Federico Rosei of the INRS Énergie Matériaux Télécommunications Research Centre has won the Chang Jiang Scholars Award, a highly prestigious distinction for world-class researchers given by the Chinese government. Professor Rosei was honoured for his work in the field of organic and inorganic nanomaterials. This is the first time the award has been given to an INRS faculty member. [INRS is Québec’s Institut national de la recherche scientifique; the Université de Québec’s research branch]

A Jan. 23, 2015 INRS news release by Gisèle Bolduc, which originated the news item, fills in some more details about the award and Dr. Rosei,

As a Chang Jiang scholar, Professor Rosei will make regular visits to the University of Electronic Science and Technology of China (UESTC) over the next three years, where he will help set up an R&D platform in nanomaterials and electronic and optoelectronic devices. In addition to these joint research projects, Professor Rosei will train young Chinese researchers, make scientific presentations, and forge international academic ties.

Federico Rosei’s tenure as a Chang Jiang scholar will complement and enhance his work as UNESCO Chair on Materials and Technologies for Energy Conversion, Saving and Storage (MATECSS). This INRS research chair is part of a North-South/South-South initiative to promote the international sharing of technical and scientific knowledge in the areas of renewable energies and sustainable development.

“Dr. Federico Rosei is an outstanding professor and researcher, and a true world leader in his field,” noted Yves Bégin, vice president (or principal) of research and academic affairs. “INRS is extremely proud to have Professor Rosei among its professors. Beyond his major scientific advances in his field, his presence in our institution helps build invaluable bridges between the local team of professors and large-scale international research projects.”

About the Chang Jiang Scholars Awards

Founded in 1998 by the Chinese Ministry of Education, the Chang Jiang Scholars program annually brings some 50 eminent international scholars, mainly in science and technology, to Chinese universities. The program’s aim is to raise standards of research in Chinese universities through collaboration with leading scientists from the world over.

About Federico Rosei

Professor Federico Rosei’s work in material physics has led to scientific innovations and practical applications in electronics, energy, and the life sciences. He is a Fellow of the Royal Society of Canada, distinguished lecturer at IEEE Nanotechnology Council (NTC), UNESCO Chair on Materials and Technologies for Energy Conversion, Saving and Storage (MATECSS), and recipient of the NSERC 2014 E.W.R. Steacie Memorial Fellowship from NSERC. Professor Rosei has won numerous awards including the 2014 José Vasconcelos World Award of Education from the World Cultural Council, the 2011 Friedrich Wilhelm Bessel award from the Alexander von Humboldt Foundation, the 2013 Herzberg Medal from the Canadian Association of Physicists, and the 2011 Rutherford Memorial Medal in Chemistry from the Royal Society of Canada. Dr. Rosei is a member of the European Academy of Sciences, a senior member of the Institute of Electrical and Electronics Engineers (IEEE) and the Society for Photo-Image Engineers (SPIE), and a Fellow of the American Physical Society; the U.S. Association for the Advancement of Science; the Engineering Institute of Canada; the Institute of Physics; the Royal Society of Chemistry; the Institute of Materials, Minerals and Mining; the Institute of Engineering and Technology; the Institute of Nanotechnology; and the Australian Institute of Physics.

Odd, there’s no mention of the Canadian Society for Chemistry award but since this man seems to be the recipient of many awards, I imagine some hard choices had to be made when writing him up.

For anyone who’d prefer to read about Rosei in French or would like to test their French reading skills, here’s Gisèle Bolduc’s 21 janvier 2015 actualité.

A multiferroic material for more powerful solar cells

A Nov. 12, 2014 INRS (Institut national de la recherche scientifique; Université du Québec) news release (also on EurekAlert), describes new work on solar cells from Federico Rosei’s laboratory (Note: Links have been removed; A French language version of the news release can be found here),

Applying a thin film of metallic oxide significantly boosts the performance of solar panel cells—as recentlydemonstrated by Professor Federico Rosei and his team at the Énergie Matériaux Télécommunications Research Centre at Institut national de la recherche scientifique (INRS). The researchers have developed a new class of materials comprising elements such as bismuth, iron, chromium, and oxygen. These“multiferroic” materials absorb solar radiation and possess unique electrical and magnetic properties. This makes them highly promising for solar technology, and also potentially useful in devices like electronic sensors and flash memory drives. …

The INRS research team discovered that by changing the conditions under which a thin film of these materials is applied, the wavelengths of light that are absorbed can be controlled. A triple-layer coating of these materials—barely 200 nanometres thick—captures different wavelengths of light. This coating converts much more light into electricity than previous trials conducted with a single layer of the same material. With a conversion efficiency of 8.1% reported by [Riad] Nechache and his coauthors, this is a major breakthrough in the field.

The team currently envisions adding this coating to traditional single-crystal silicon solar cells (currently available on the market). They believe it could increase maximum solar efficiency by 18% to 24% while also boosting cell longevity. As this technology draws on a simplified structure and processes, as well as abundant and stable materials, new photovoltaic (PV) cells will be more powerful and cost less. This means that the INRS team’s breakthrough may make it possible to reposition silicon PV cells at the forefront of the highly competitive solar energy market.

Here’s a link to and a citation for the paper,

Bandgap tuning of multiferroic oxide solar cells by R. Nechache, C. Harnagea, S. Li, L. Cardenas, W. Huang,  J. Chakrabartty, & F. Rosei. Nature Photonics (2014) doi:10.1038/nphoton.2014.255 Published online
10 November 2014

This paper is behind a paywall although there is a free preview via ReadCube Access.

I last mentioned Federico Rose in a March 4, 2014 post about a talk (The exploration of the role of nanoscience in tomorrow’s energy solutions) he was giving in Vancouver (Canada).

Quebec nanotechnology researcher received prestigious award

This going to be short and fast: Professor Federico Rosei, an expert from Institut national de la recherche scientifique (Université du Québec) on organic nanoelectronics, has been awarded the 2010 Friedrich Wilhelm Bessel Research Award given by the Alexander von Humboldt Foundation. From the news release on Eureka Alert,

The foundation grants 25 of these awards annually to young, high level researchers around the world. Professor Rosei was selected in recognition of the caliber and scope of his research in the field of nanomaterials.

This honor will allow him to start collaborating with researchers at the Max Planck Institute in Stuttgart and other German research teams on the cutting edge of nanotechnology. In the years ahead, Professor Rosei will work with his German colleagues to study self-assembly in surface molecules—one of the key concepts of nanotechnology—to develop new materials used for electronics, energy applications, and in the life sciences.

Professor Rosei currently holds the Canada Research Chair in Nanostructured Organic and Inorganic Materials.

There is a copy of the news release on the institute’s website but it is in French. There is an English language version of the website but they don’t seem to have included translations of the news releases. Congratulations to Professor Rosei! (His work in organic nanoelectronics was mentioned in my June 15, 2010 posting.)

One of these days I should attempt an informal province by province analysis of the Canadian nanotechnology scene.  In terms of media coverage, it seems that Alberta and Québec are the most active. More analysis later, I hope.

McGill University researchers get closer to making organic nanoelectronics a reality

You can’t rush out and buy products with organic nanoelectronic components yet but one day you will and you’ll have Dr. Dmitrii Perepichka at McGill University (Montréal, Canada), Dr. Federico Rosei of the Institut national de la recherche scientifique and the members of their international research team to thank for it. From the McGill University news release,

Although they could revolutionize a wide range of high-tech products such as computer displays or solar cells, organic materials do not have the same ordered chemical composition as inorganic materials, preventing scientists from using them to their full potential. But an international team of researchers led by McGill’s Dr. Dmitrii Perepichka and the Institut national de la recherche scientifique’s Dr. Federico Rosei have published research that shows how to solve this decades-old conundrum. The team has effectively discovered a way to order the molecules in the PEDOT, the single most industrially important conducting polymer.

This is an important step forward for anyone who owns a computer or a mobile phone or anything with transistors. In the 1960s a fellow called Gordon Moore (he went on to co-found Intel) made a prediction (from Intel’s Moore’s Law web page),

Intel co-founder Gordon Moore is a visionary. In 1965, his prediction, popularly known as Moore’s Law, states that the number of transistors on a chip will double about every two years. And Intel has kept that pace for nearly 40 years.

We are almost at the physical limits given our current technologies which is why this new type of organic component is important. Perepichka while noting that there’s still a considerable amount of work to be done before being able to create organic nanoelectronic components speculates about future uses,

By using molecular materials instead of silicon semiconductor, we could one day build transistors that are ten times smaller than what currently exists.” The chips would in fact be only one molecule thick.

The groundbreaking technique used to achieve this capability,

… sounds deceptively simple. The team used an inorganic material – a crystal of copper – as a template. When molecules are dropped onto the crystal, the crystal provokes a chemical reaction and creates a conducting polymer. By using a scanning probe microscope that enabled them to see surfaces with atomic resolution, the researchers discovered that the polymers had imitated the order of the crystal surface. The team is currently only able to produce the reaction in one dimension, i.e. to make a string or line of molecules. The next step will be to add a second dimension in order to make continuous sheets (“organic graphite”) or electronic circuits.

Here are images of the polymer with its chemical composition (at the left),

This image shows the polymers that were created at a resolution of 5 nanometres (the average strand of human hair is 80,000 nanometres wide) Source: Dept. of Chemistry, McGill University

I was interested to note that part of the funding for this project comes from the US Air Force since they also recently funded work on integrating memristors in electronic components (my blog posting here). Here’s my last excerpt from the news release details about the researchers’ affiliations, where the study was published, and the funding sources for the work,

Perepichka is affiliated with McGill University’s department of chemistry and Rosei is affiliated with Institut national de la recherche scientifique – Énergie Matériaux Télécommunications Center, a member of the Université du Québec network. Their research was published online by the Proceedings of the National Academy of Sciences and was funded by the Natural Sciences and Engineering Research Council of Canada, the Air Force Office of Scientific Research and Asian Office of Aerospace Research and Development of the USA, the Petroleum Research Fund of the American Chemical Society, the Fonds québécois de recherche sur la nature et les technologies, and the Ministère du Développement économique, de l’Innovation et de l’Exportation of Quebec.