Tag Archives: Alberto Bianco

Human lung enzyme can degrade graphene

Caption: A human lung enzyme can biodegrade graphene. Credit: Fotolia Courtesy: Graphene Flagship

The big European Commission research programme, Grahene Flagship, has announced some new work with widespread implications if graphene is to be used in biomedical implants. From a August 23, 2018 news item on ScienceDaily,

Myeloperoxidase — an enzyme naturally found in our lungs — can biodegrade pristine graphene, according to the latest discovery of Graphene Flagship partners in CNRS, University of Strasbourg (France), Karolinska Institute (Sweden) and University of Castilla-La Mancha (Spain). Among other projects, the Graphene Flagship designs based like flexible biomedical electronic devices that will interfaced with the human body. Such applications require graphene to be biodegradable, so our body can be expelled from the body.

An August 23, 2018 Grapehene Flagship press release (mildly edited version on EurekAlert), which originated the news item, provides more detail,

To test how graphene behaves within the body, researchers analysed how it was broken down with the addition of a common human enzyme – myeloperoxidase or MPO. If a foreign body or bacteria is detected, neutrophils surround it and secrete MPO, thereby destroying the threat. Previous work by Graphene Flagship partners found that MPO could successfully biodegrade graphene oxide.

However, the structure of non-functionalized graphene was thought to be more resistant to degradation. To test this, the team looked at the effects of MPO ex vivo on two graphene forms; single- and few-layer.

Alberto Bianco, researcher at Graphene Flagship Partner CNRS, explains: “We used two forms of graphene, single- and few-layer, prepared by two different methods in water. They were then taken and put in contact with myeloperoxidase in the presence of hydrogen peroxide. This peroxidase was able to degrade and oxidise them. This was really unexpected, because we thought that non-functionalized graphene was more resistant than graphene oxide.”

Rajendra Kurapati, first author on the study and researcher at Graphene Flagship Partner CNRS, remarks how “the results emphasize that highly dispersible graphene could be degraded in the body by the action of neutrophils. This would open the new avenue for developing graphene-based materials.”

With successful ex-vivo testing, in-vivo testing is the next stage. Bengt Fadeel, professor at Graphene Flagship Partner Karolinska Institute believes that “understanding whether graphene is biodegradable or not is important for biomedical and other applications of this material. The fact that cells of the immune system are capable of handling graphene is very promising.”

Prof. Maurizio Prato, the Graphene Flagship leader for its Health and Environment Work Package said that “the enzymatic degradation of graphene is a very important topic, because in principle, graphene dispersed in the atmosphere could produce some harm. Instead, if there are microorganisms able to degrade graphene and related materials, the persistence of these materials in our environment will be strongly decreased. These types of studies are needed.” “What is also needed is to investigate the nature of degradation products,” adds Prato. “Once graphene is digested by enzymes, it could produce harmful derivatives. We need to know the structure of these derivatives and study their impact on health and environment,” he concludes.

Prof. Andrea C. Ferrari, Science and Technology Officer of the Graphene Flagship, and chair of its management panel added: “The report of a successful avenue for graphene biodegradation is a very important step forward to ensure the safe use of this material in applications. The Graphene Flagship has put the investigation of the health and environment effects of graphene at the centre of its programme since the start. These results strengthen our innovation and technology roadmap.”

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

Degradation of Single‐Layer and Few‐Layer Graphene by Neutrophil Myeloperoxidase by Dr. Rajendra Kurapati, Dr. Sourav P. Mukherjee, Dr. Cristina Martín, Dr. George Bepete, Prof. Ester Vázquez, Dr. Alain Pénicaud, Prof. Dr. Bengt Fadeel, Dr. Alberto Bianco. Angewandte Chemie https://doi.org/10.1002/anie.201806906 First published: 13 July 2018

This paper is behind a paywall.

A 2nd European roadmap for graphene

About 2.5 years ago there was an article titled, “A roadmap for graphene” (behind a paywall) which Nature magazine published online in Oct. 2012. I see at least two of the 2012 authors, Konstantin (Kostya) Novoselov and Vladimir Fal’ko,, are party to this second, more comprehensive roadmap featured in a Feb. 24, 2015 news item on Nanowerk,

In October 2013, academia and industry came together to form the Graphene Flagship. Now with 142 partners in 23 countries, and a growing number of associate members, the Graphene Flagship was established following a call from the European Commission to address big science and technology challenges of the day through long-term, multidisciplinary R&D efforts.

A Feb.  24, 2015 University of Cambridge news release, which originated the news item, describes the roadmap in more detail,

In an open-access paper published in the Royal Society of Chemistry journal Nanoscale, more than 60 academics and industrialists lay out a science and technology roadmap for graphene, related two-dimensional crystals, other 2D materials, and hybrid systems based on a combination of different 2D crystals and other nanomaterials. The roadmap covers the next ten years and beyond, and its objective is to guide the research community and industry toward the development of products based on graphene and related materials.

The roadmap highlights three broad areas of activity. The first task is to identify new layered materials, assess their potential, and develop reliable, reproducible and safe means of producing them on an industrial scale. Identification of new device concepts enabled by 2D materials is also called for, along with the development of component technologies. The ultimate goal is to integrate components and structures based on 2D materials into systems capable of providing new functionalities and application areas.

Eleven science and technology themes are identified in the roadmap. These are: fundamental science, health and environment, production, electronic devices, spintronics, photonics and optoelectronics, sensors, flexible electronics, energy conversion and storage, composite materials, and biomedical devices. The roadmap addresses each of these areas in turn, with timelines.

Research areas outlined in the roadmap correspond broadly with current flagship work packages, with the addition of a work package devoted to the growing area of biomedical applications, to be included in the next phase of the flagship. A recent independent assessment has confirmed that the Graphene Flagship is firmly on course, with hundreds of research papers, numerous patents and marketable products to its name.

Roadmap timelines predict that, before the end of the ten-year period of the flagship, products will be close to market in the areas of flexible electronics, composites, and energy, as well as advanced prototypes of silicon-integrated photonic devices, sensors, high-speed electronics, and biomedical devices.

“This publication concludes a four-year effort to collect and coordinate state-of-the-art science and technology of graphene and related materials,” says Andrea Ferrari, director of the Cambridge Graphene Centre, and chairman of the Executive Board of the Graphene Flagship. “We hope that this open-access roadmap will serve as the starting point for academia and industry in their efforts to take layered materials and composites from laboratory to market.” Ferrari led the roadmap effort with Italian Institute of Technology physicist Francesco Bonaccorso, who is a Royal Society Newton Fellow of the University of Cambridge, and a Fellow of Hughes Hall.

“We are very proud of the joint effort of the many authors who have produced this roadmap,” says Jari Kinaret, director of the Graphene Flagship. “The roadmap forms a solid foundation for the graphene community in Europe to plan its activities for the coming years. It is not a static document, but will evolve to reflect progress in the field, and new applications identified and pursued by industry.”

I have skimmed through the report briefly (wish I had more time) and have a couple of comments. First, there’s an excellent glossary of terms for anyone who might stumble over chemical abbreviations and/or more technical terminology. Second, they present a very interesting analysis of the intellectual property (patents) landscape (Note: Links have been removed. Incidental numbers are footnote references),

In the graphene area, there has been a particularly rapid increase in patent activity from around 2007.45 Much of this is driven by patent applications made by major corporations and universities in South Korea and USA.53 Additionally, a high level of graphene patent activity in China is also observed.54 These features have led some commentators to conclude that graphene innovations arising in Europe are being mainly exploited elsewhere.55 Nonetheless, an analysis of the Intellectual Property (IP) provides evidence that Europe already has a significant foothold in the graphene patent landscape and significant opportunities to secure future value. As the underlying graphene technology space develops, and the GRM [graphene and related materials] patent landscape matures, re-distribution of the patent landscape seems inevitable and Europe is well positioned to benefit from patent-based commercialisation of GRM research.

Overall, the graphene patent landscape is growing rapidly and already resembles that of sub-segments of the semiconductor and biotechnology industries,56 which experience high levels of patent activity. The patent strategies of the businesses active in such sub-sectors frequently include ‘portfolio maximization’56 and ‘portfolio optimization’56 strategies, and the sub-sectors experience the development of what commentators term ‘patent thickets’56, or multiple overlapping granted patent rights.56 A range of policies, regulatory and business strategies have been developed to limit such patent practices.57 In such circumstances, accurate patent landscaping may provide critical information to policy-makers, investors and individual industry participants, underpinning the development of sound policies, business strategies and research commercialisation plans.

It sounds like a patent thicket is developing (Note: Links have been removed. Incidental numbers are footnote references),,

Fig. 13 provides evidence of a relative increase in graphene patent filings in South Korea from 2007 to 2009 compared to 2004–2006. This could indicate increased commercial interest in graphene technology from around 2007. The period 2010 to 2012 shows a marked relative increase in graphene patent filings in China. It should be noted that a general increase in Chinese patent filings across many ST domains in this period is observed.76 Notwithstanding this general increase in Chinese patent activity, there does appear to be increased commercial interest in graphene in China. It is notable that the European Patent Office contribution as a percentage of all graphene patent filings globally falls from a 8% in the period 2007 to 2009 to 4% in the period 2010 to 2012.

The importance of the US, China and South Korea is emphasised by the top assignees, shown in Fig. 14. The corporation with most graphene patent applications is the Korean multinational Samsung, with over three times as many filings as its nearest rival. It has also patented an unrivalled range of graphene-technology applications, including synthesis procedures,77 transparent display devices,78 composite materials,79 transistors,80 batteries and solar cells.81 Samsung’s patent applications indicate a sustained and heavy investment in graphene R&D, as well as collaboration (co-assignment of patents) with a wide range of academic institutions.82,83

 

image file: c4nr01600a-f14.tif
Fig. 14 Top 10 graphene patent assignees by number and cumulative over all time as of end-July 2014. Number of patents are indicated in the red histograms referred to the left Y axis, while the cumulative percentage is the blue line, referred to the right Y axis.

It is also interesting to note that patent filings by universities and research institutions make up a significant proportion ([similar]50%) of total patent filings: the other half comprises contributions from small and medium-sized enterprises (SMEs) and multinationals.

Europe’s position is shown in Fig. 10, 12 and 14. While Europe makes a good showing in the geographical distribution of publications, it lags behind in patent applications, with only 7% of patent filings as compared to 30% in the US, 25% in China, and 13% in South Korea (Fig. 13) and only 9% of filings by academic institutions assigned in Europe (Fig. 15).

 

image file: c4nr01600a-f15.tif
Fig. 15 Geographical breakdown of academic patent holders as of July 2014.

While Europe is trailing other regions in terms of number of patent filings, it nevertheless has a significant foothold in the patent landscape. Currently, the top European patent holder is Finland’s Nokia, primarily around incorporation of graphene into electrical devices, including resonators and electrodes.72,84,85

This may sound like Europe is trailing behind but that’s not the case according to the roadmap (Note: Links have been removed. Incidental numbers are footnote references),

European Universities also show promise in the graphene patent landscape. We also find evidence of corporate-academic collaborations in Europe, including e.g. co-assignments filed with European research institutions and Germany’s AMO GmbH,86 and chemical giant BASF.87,88 Finally, Europe sees significant patent filings from a number of international corporate and university players including Samsung,77 Vorbeck Materials,89 Princeton University,90–92 and Rice University,93–95 perhaps reflecting the quality of the European ST base around graphene, and its importance as a market for graphene technologies.

There are a number of features in the graphene patent landscape which may lead to a risk of patent thickets96 or ‘multiple overlapping granted patents’ existing around aspects of graphene technology systems. [emphasis mine] There is a relatively high volume of patent activity around graphene, which is an early stage technology space, with applications in patent intensive industry sectors. Often patents claim carbon nano structures other than graphene in graphene patent landscapes, illustrating difficulties around defining ‘graphene’ and mapping the graphene patent landscape. Additionally, the graphene patent nomenclature is not entirely settled. Different patent examiners might grant patents over the same components which the different experts and industry players call by different names.

For anyone new to this blog, I am not a big fan of current patent regimes as they seem to be stifling rather encouraging innovation. Sadly, patents and copyright were originally developed to encourage creativity and innovation by allowing the creators to profit from their ideas. Over time a system designed to encourage innovation has devolved into one that does the opposite. (My Oct. 31, 2011 post titled Patents as weapons and obstacles, details my take on this matter.) I’m not arguing against patents and copyright but suggesting that the system be fixed or replaced with something that delivers on the original intention.

Getting back to the matter at hand, here’s a link to and a citation for the 200 pp. 2015 European Graphene roadmap,

Science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems by Andrea C. Ferrari, Francesco Bonaccorso, Vladimir Fal’ko, Konstantin S. Novoselov, Stephan Roche, Peter Bøggild, Stefano Borini, Frank H. L. Koppens, Vincenzo Palermo, Nicola Pugno, José A. Garrido, Roman Sordan, Alberto Bianco, Laura Ballerini, Maurizio Prato, Elefterios Lidorikis, Jani Kivioja, Claudio Marinelli, Tapani Ryhänen, Alberto Morpurgo, Jonathan N. Coleman, Valeria Nicolosi, Luigi Colombo, Albert Fert, Mar Garcia-Hernandez, Adrian Bachtold, Grégory F. Schneider, Francisco Guinea, Cees Dekker, Matteo Barbone, Zhipei Sun, Costas Galiotis,  Alexander N. Grigorenko, Gerasimos Konstantatos, Andras Kis, Mikhail Katsnelson, Lieven Vandersypen, Annick Loiseau, Vittorio Morandi, Daniel Neumaier, Emanuele Treossi, Vittorio Pellegrini, Marco Polini, Alessandro Tredicucci, Gareth M. Williams, Byung Hee Hong, Jong-Hyun Ahn, Jong Min Kim, Herbert Zirath, Bart J. van Wees, Herre van der Zant, Luigi Occhipinti, Andrea Di Matteo, Ian A. Kinloch, Thomas Seyller, Etienne Quesnel, Xinliang Feng,  Ken Teo, Nalin Rupesinghe, Pertti Hakonen, Simon R. T. Neil, Quentin Tannock, Tomas Löfwander and Jari Kinaret. Nanoscale, 2015, Advance Article DOI: 10.1039/C4NR01600A First published online 22 Sep 2014

Here’s a diagram illustrating the roadmap process,

Fig. 122 The STRs [science and technology roadmaps] follow a hierarchical structure where the strategic level in a) is connected to the more detailed roadmap shown in b). These general roadmaps are the condensed form of the topical roadmaps presented in the previous sections, and give technological targets for key applications to become commercially competitive and the forecasts for when the targets are predicted to be met.  Courtesy: Researchers and  the Royal Society's journal, Nanoscale

Fig. 122 The STRs [science and technology roadmaps] follow a hierarchical structure where the strategic level in a) is connected to the more detailed roadmap shown in b). These general roadmaps are the condensed form of the topical roadmaps presented in the previous sections, and give technological targets for key applications to become commercially competitive and the forecasts for when the targets are predicted to be met.
Courtesy: Researchers and the Royal Society’s journal, Nanoscale

The image here is not the best quality; the one embedded in the relevant Nanowerk news item is better.

As for the earlier roadmap, here’s my Oct. 11, 2012 post on the topic.

Should October 2013 be called ‘the month of graphene’?

Since the Oct. 10-11, 2013 Graphene Flagship (1B Euros investment) launch, mentioned in my preview Oct. 7, 2013 posting, there’ve been a flurry of graphene-themed news items both on this blog and elsewhere and I’ve decided to offer a brief roundup what I’ve found elsewhere.

Dexter Johnson offers a commentary in the pithily titled, Europe Invests €1 Billion to Become “Graphene Valley,” an Oct. 15, 2013 posting on his Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers] website) Note: Links have been removed,

The initiative has been dubbed “The Graphene Flagship,” and apparently it is the first in a number of €1 billion, 10-year plans the EC is planning to launch. The graphene version will bring together 76 academic institutions and industrial groups from 17 European countries, with an initial 30-month-budget of €54M ($73 million).

Graphene research is still struggling to find any kind of applications that will really take hold, and many don’t expect it will have a commercial impact until 2020. What’s more, manufacturing methods are still undeveloped. So it would appear that a 10-year plan is aimed at the academic institutions that form the backbone of this initiative rather than commercial enterprises.

Just from a political standpoint the choice of Chalmers University in Sweden as the base of operations for the Graphene Flagship is an intriguing choice. …

I have to agree with Dexter that choosing Chalmers University over the University of Manchester where graphene was first isolated is unexpected. As a companion piece to reading Dexter’s posting in its entirety and which features a video from the flagship launch, you might want to try this Oct. 15, 2013 article by Koen Mortelmans for Youris (h/t Oct. 15, 2013 news item on Nanowerk),

Andre Konstantin Geim is the only person who ever received both a Nobel and an Ig Nobel. He was born in 1958 in Russia, and is a Dutch-British physicist with German, Polish, Jewish and Ukrainian roots. “Having lived and worked in several European countries, I consider myself European. I don’t believe that any further taxonomy is necessary,” he says. He is now a physics professor at the University of Manchester. …

He shared the Noble [Nobel] Prize in 2010 with Konstantin Novoselov for their work on graphene. It was following on their isolation of microscope visible grapheme flakes that the worldwide research towards practical applications of graphene took off.  “We did not invent graphene,” Geim says, “we only saw what was laid up for five hundred year under our noses.”

Geim and Novoselov are often thought to have succeeded in separating graphene from graphite by peeling it off with ordinary duct tape until there only remained a layer. Graphene could then be observed with a microscope, because of the partial transparency of the material. That is, after dissolving the duct tape material in acetone, of course. That is also the story Geim himself likes to tell.

However, he did not use – as the urban myth goes – graphite from a common pencil. Instead, he used a carbon sample of extreme purity, specially imported. He also used ultrasound techniques. But, probably the urban legend will survive, as did Archimedes’ bath and Newtons apple. “It is nice to keep some of the magic,” is the expression Geim often uses when he does not want a nice story to be drowned in hard facts or when he wants to remain discrete about still incomplete, but promising research results.

Mortelmans’ article fills in some gaps for those not familiar with the graphene ‘origins’ story while Tim Harper’s July 22, 2012 posting on Cientifica’s (an emerging technologies consultancy where Harper is the CEO and founder) TNT blog offers an insight into Geim’s perspective on the race to commercialize graphene with a paraphrased quote for the title of Harper’s posting, “It’s a bit silly for society to throw a little bit of money at (graphene) and expect it to change the world.” (Note: Within this context, mention is made of the company’s graphene opportunities report.)

With all this excitement about graphene (and carbon generally), the magazine titled Carbon has just published a suggested nomenclature for 2D carbon forms such as graphene, graphane, etc., according to an Oct. 16, 2013 news item on Nanowerk (Note: A link has been removed),

There has been an intense research interest in all two-dimensional (2D) forms of carbon since Geim and Novoselov’s discovery of graphene in 2004. But as the number of such publications rise, so does the level of inconsistency in naming the material of interest. The isolated, single-atom-thick sheet universally referred to as “graphene” may have a clear definition, but when referring to related 2D sheet-like or flake-like carbon forms, many authors have simply defined their own terms to describe their product.

This has led to confusion within the literature, where terms are multiply-defined, or incorrectly used. The Editorial Board of Carbon has therefore published the first recommended nomenclature for 2D carbon forms (“All in the graphene family – A recommended nomenclature for two-dimensional carbon materials”).

This proposed nomenclature comes in the form of an editorial, from Carbon (Volume 65, December 2013, Pages 1–6),

All in the graphene family – A recommended nomenclature for two-dimensional carbon materials

  • Alberto Bianco
    CNRS, Institut de Biologie Moléculaire et Cellulaire, Immunopathologie et Chimie Thérapeutique, Strasbourg, France
  • Hui-Ming Cheng
    Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, China
  • Toshiaki Enoki
    Department of Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology, Tokyo, Japan
  • Yury Gogotsi
    Materials Science and Engineering Department, A.J. Drexel Nanotechnology Institute, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA
  • Robert H. Hurt
    Institute for Molecular and Nanoscale Innovation, School of Engineering, Brown University, Providence, RI 02912, USA
  • Nikhil Koratkar
    Department of Mechanical, Aerospace and Nuclear Engineering, The Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180, USA
  • Takashi Kyotani
    Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
  • Marc Monthioux
    Centre d’Elaboration des Matériaux et d’Etudes Structurales (CEMES), UPR-8011 CNRS, Université de Toulouse, 29 Rue Jeanne Marvig, F-31055 Toulouse, France
  • Chong Rae Park
    Carbon Nanomaterials Design Laboratory, Global Research Laboratory, Research Institute of Advanced Materials, Department of Materials Science and Engineering, Seoul National University, Seoul 151-744, Republic of Korea
  • Juan M.D. Tascon
    Instituto Nacional del Carbón, INCAR-CSIC, Apartado 73, 33080 Oviedo, Spain
  • Jin Zhang
    Center for Nanochemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China

This editorial is behind a paywall.

The yin and the yang of carbon nanotubes and toxicity

 

Illustration courtesy of the University College of London (UCL). Downloaded from http://www.ucl.ac.uk/news/news-articles/0113/130115-chemistry-resolves-toxic-concerns-about-carbon-nanotubes

Illustration courtesy of the University College of London (UCL). Downloaded from http://www.ucl.ac.uk/news/news-articles/0113/130115-chemistry-resolves-toxic-concerns-about-carbon-nanotubes

Researchers at the University College of London (UCL), France’s Centre national de la recherche scientifique (CNRS), and Italy’s University of Trieste have determined that carbon nanotube toxicity issues can be addressed be reducing their length and treating them chemically. From the Jan. 15,2013 news item on ScienceDaily,

In a new study, published January 15 [2013] in the journal Angewandte Chemie, evidence is provided that the asbestos-like reactivity and pathogenicity reported for long, pristine nanotubes can be completely alleviated if their surface is modified and their effective length is reduced as a result of chemical treatment.

First atomically described in the 1990s, carbon nanotubes are sheets of carbon atoms rolled up into hollow tubes just a few nanometres in diameter. Engineered carbon nanotubes can be chemically modified, with the addition of chemotherapeutic drugs, fluorescent tags or nucleic acids — opening up applications in cancer and gene therapy.

Furthermore, these chemically modified carbon nanotubes can pierce the cell membrane, acting as a kind of ‘nano-needle’, allowing the possibility of efficient transport of therapeutic and diagnostic agents directly into the cytoplasm of cells.

Among their downsides however, have been concerns about their safety profile. One of the most serious concerns, highlighted in 2008, involves the carcinogenic risk from the exposure and persistence of such fibres in the body. Some studies indicate that when long untreated carbon nanotubes are injected to the abdominal cavity of mice they can induce unwanted responses resembling those associated with exposure to certain asbestos fibres.

In this paper, the authors describe two different reactions which ask if any chemical modification can render the nanotubes non-toxic. They conclude that not all chemical treatments alleviate the toxicity risks associated with the material. Only those reactions that are able to render carbon nanotubes short and stably suspended in biological fluids without aggregation are able to result in safe, risk-free material.

Here’s a citation and link for this latest  research, from the ScienceDaily news item where you can also read the lead researcher’s comments about carbon nanotubes, safety, and unreasonable proposals to halt production,

Hanene Ali-Boucetta, Antonio Nunes, Raquel Sainz, M. Antonia Herrero, Bowen Tian, Maurizio Prato, Alberto Bianco, Kostas Kostarelos. Asbestos-like Pathogenicity of Long Carbon Nanotubes Alleviated by Chemical Functionalization. Angewandte Chemie International Edition, 2013; DOI: 10.1002/anie.201207664

The article is behind a paywall. I have mentioned long carbon nanotubes and their resemblance to asbestos fibres in several posts. The  Oct. 26, 2009 posting [scroll down about 1/3 of the way] highlights research which took place after the study where mice had carbon nanotubes injected into their bellies; in this second piece of research they inhaled the nanotubes.

ETA Jan. 21, 2013: Dexter Johnson gives context and commentary about this latest research into long multiwalled nanotubes (MWNTs) which he sums up as the answer to this question “What if you kept the MWNTs short?”  in a Jan. 18, 2013 posting on his Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers] website)