Category: Nanotechnology

A five-stage, and very demanding protocol, for taking a nanoscience discovery to a consumer nanotechnology product has been outlined by engineer Michael Kelly of the University of Cambridge. Kelly, who is also based at the MacDiarmid Institute for Advanced Materials and Nanotechnology, at Victoria University of Wellington, New Zealand, explains how a clear understanding of how and why experimental silicon semiconductor and liquid crystal technology took so long to move from the laboratory bench to the manufacturing plant and mass production and consumption should underpin predictions about current nanoscience.

Kelly also explains why once a technology, such as the silicon chip, is in place it is very difficult to usurp even with advances such as conducting polymers and novel forms of carbon from buckyballs (fullerenes) and nanotubes to graphene despite the hyperbole that surrounds such novel materials. He points out that too little attention is paid to the many hurdles facing the nanoscientist hoping to be revolutionary nanotechnologist. But, his systematic protocol reveals what the aspirational need to know in making that quantum leap.

If one is working towards nanotechnology, then one must first identify the environment in which a new nanomaterial will be superior to the current state-of-the art material, otherwise the science becomes a solution looking for a problem. There are a few examples of fundamental science, the laser being a rare example, where uses are found after the fact, but, Kelly suggests that, in a burgeoning field with myriad projects and experiments final outcomes do not commonly justify the initial effort.

Secondly, it is important to identify the critical properties of the new nanomaterial and to be able to reproduce them absolutely in different samples with values to within better than 10 percent of the mean or there is no possibility of mass production. He points out that semiconductor tunnelling devices have only very recently addressed this problem.

Thirdly, a way to make the material or device with pre-specified performance and at high yield is essential from an early stage of development or again wasted raw materials will keep end product costs too high for a product to be commercially viable.

Kelly’s fourth commandment asserts that for a product, one must be able to simulate its performance from first principles and to readily invert properties at any stage of development so that it might be reverse engineered and adapted to resolve discrepancies where a device deviates from design.

Fifth and finally, even if the first four steps of the protocol are addressed adequately lifetime performance must be demonstrated as being superior to any current state-of-the art technology. He cites multi-heterojunction tandem solar cell technology as being on the cusp of serious development in this regard, one might also mention organic light emitting diodes (OLEDs) and their development from unstable devices in the early 1990s to fully fledged commercial technology today.

The shift from traditional manufacturing to the current developments based on novel and even designer materials means that industry now places great emphasis on product development taking place at the laboratory bench and expects much more than a one-off result before adopting new science and converting it into technology, nano or otherwise.

Kelly M.J. (2014). From nanoscience to nanotechnology: what can and what cannot be manufactured, International Journal of Nanotechnology, 11 (5/6/7/8) 441. DOI: http://dx.doi.org/10.1504/ijnt.2014.060563

UPDATE: My original article on this subject is now online with Materials Today.

It was almost inevitable that the naysayers and scaremongers would start to express concerns about graphene, the new wonder material that won its developers a Nobel prize for their work with sticky tape and HB pencils. It’s sensible to look at graphene if there are risks and Ken Donaldson, a respiratory toxicologist at the University of Edinburgh, and his colleagues have been among the first to raise the warning flag on graphene, at least for nanoscopic platelets of the stuff. In case you didn’t know graphene is essentially a single, monolayer, of graphite, the carbon allotrope found in soot, charcoal and, yes, the “lead” in an HB pencil.

Donaldson’s work seems to suggest that flakes of graphene if they get into the lungs might cause health problems. However, I, and some of my contacts in the field of nanotechnology and safety are not so sure it will ever be a real health problem even for scientists working with graphene nano-flakes.

Andrew Maynard of 2020Science.org is Director of the Risk Science Center at the University of Michigan and had this to say of the Donaldson work:

“This is an interesting area of health impact speculation and research. Donaldson’s work certainly demonstrates the potential for graphene flakes to present a health risk if they are able to be inhaled and enter the lungs, or penetrate to the region surrounding the lungs,” Maynard says. He then went on to tell me that this is a big ‘if’. “Pharyngeal aspiration delivers particles – or platelets in this case – to the lungs within liquid droplets – the droplets determining where the material is deposited,” he added. “It allows early experimentation on what could occur if the material could enter the lungs under handling and use. But it doesn’t provide information in the plausibility of exposure occurring. And without knowing whether graphene flakes can become airborne and inhaled in a form that is dangerous during use, questions concerning health risks – while important – remain speculative.”

It is important to point out that any safety issues with regards to graphene will be very dependent on the shape and surface of the particles. Lab tests can make all kinds of claims but do not necessarily reflect how the flakes would behave when in contact with living tissue or whether there is actually a mechanism for problematic exposure at all. It might be that graphene would not be a problem at all, after all macrophages can usually cope with particles up to about 10 micrometres in diameter. Platelets of this size shouldn’t be a challenge and any larger would suggests that they wouldn’t be able to get into the lungs anyway.

Intriguingly, the Nobel-winning studies on graphene simply used pencil lead and sticky tape to produce the material, countless generations have been exposed to such materials for many years, could we have unwittingly been exposed to graphene flakes all this time?

Schinwald, A., Murphy, F., Jones, A., MacNee, W., & Donaldson, K. (2012). Graphene-Based Nanoplatelets: A New Risk to the Respiratory System as a Consequence of Their Unusual Aerodynamic Properties ACS Nano, 6 (1), 736-746 DOI: 10.1021/nn204229f

Adamantane, the invincible molecule, was discovered in petroleum in 1933 and stimulated a whole new field in chemistry, that of research into polyhedral organic compounds. It might be thought of as the tiniest possible building block of diamond, which is after all an infinite 3D network of carbon atoms essentially pinned on the adamantane structure minus the hydrogens. Adamantane itself has been modified for practical applications in the pharmaceutical industry, in polymer science for heat-stable lubricants and others uses, and as molecular building blocks in nanotechnology. But, this “diamondoid” and its chemical cousins might also be the molecular mavens we need to guide hydrocarbon exploration.

Underground fossil fuel reservoirs including natural gas, gas condensate, petroleum and coal are the natural resources of hydrocarbons we rely on the most and commonly contain diamondoid hydrocarbons, says Patricia Lopes Barros de Araujo of the Federal Rural University of Pernambuco in Brazil, Ali Mansoori of the University of Illinois, USA and Elmo Silvano de Araujo of the Federal University of Pernambuco also in Brazil, who have reviewed the state of the art recently in the journal IJOGCT (full reference below).

Fundamentally, the team explains, diamondoids can act as geochemical tools for petroleum characterisation, their presence on fossil fuel fluids also gives researchers a way to evaluate petroleum sample quality, to determine its origin, investigate the degree of biodegradation and thermal maturity and event to help find and assess new sources of petroleum. “The presence of diamondoids in petroleum has become much more than a chemical curiosity,” they explain.

Patricia Lopes Barros de Araujo, Elmo Silvano de Araujo, & Ali Mansoori (2012). Diamondoids: occurrence in fossil fuels, applications in petroleum exploration and fouling in petroleum production. A review paper Int. J. Oil, Gas and Coal Technology, 5 (4), 316-367

Safety in the nano sphere – The safety of nanotechnology is high on the scientific and political agenda. Qualifying and quantifying the issues remains difficult. An Italia team has now devised and tested what they describe as a "systematic and reproducible evaluation of nanoparticle toxicology in living systems". Their approach is based on a physical assessment and quantification of the toxic effects of nanoparticles (NPs). Andrew Maynard, Director, University of Michigan Risk Science Center, in the USA, points out that, "It remains unclear what the results mean for human exposure to engineered nanoparticles, or what the basis might be for deciding relative levels of potential toxicity". He adds that "It is even less clear how their results relate to inhalation exposure to nanoparticles, where a suite of inhalation-specific mechanisms may lead to very different results to those predicted by fruit flies eating the material." An interesting development but perhaps not quite the last word on nano safety.

Is the “nano” label just marketing buzz and PR puff? You might think so given the huge number of products and press releases that exist where this little prefix, from the Greek meaning dwarf, is used instead of a more everyday description. Particles become far more interesting to consumers and grant-awarding peers when they become nanoparticles. Atomic clusters are so 1970s, but nanoclusters? Now, you’re talking. And, not to ignore that tubular field of single-walled carbon nanotubes (SWCNTs) and copper nanotubes…where would we be without them? Unfortunately, marketing executives have hijacked the prefix for countless non-nano products, hoping to exploit the buzz.

Of course, nanoscience and nanotechnology really are likely to be revolutionary as our understanding of entities that lie between the molecular and the bulk scales improves and our skills in designing and constructing such entities evolves. Some pundits suggest that nano could be bigger than steam or penicillin. However, for that to happen, we probably need a better definition of nano and to exclude those developments and products that are irrelevant to the endeavour.

There are already several legitimate nano products that are increasingly in widespread use. For instance, the textiles industry is using conducting polyaniline nanocoating to reduce static cling in artificial fibres, silver nanoparticles show improved efficacy as antibacterial agents and other precious metals in nanoparticulate form are much improved catalysts than their traditionally powdered counterparts. Titania and zinc oxide nanoparticles are also used and marketed for their enhanced UV filtering and antibacterial capacity.

Physical chemists Simon Forster, Sandro Olveira and Stefan Seeger of the University of Zurich, Switzerland, have published a backgrounder on the world of nano, which they say provides both scientific background information and market data about the nano-enabled products and could help mesh chemical insights with economic analyses. Their case studies show that some commercialised technologies have several application fields, whereas others are only found in one market but it is the pharmaceutical sector that is currently the most important of today’s nanotechnology markets.

The researchers point to several potential applications of nano materials, among them: functionalised nanomagnets for extracting molecules from blood, drug delivery with nanocapsules for targeting disease sites in the body more precisely, controlled release of “active” cosmetic agents on the skin, nanoparticles of iron and zinc for food supplementation that
increase bioavailability of iron without affecting colour or taste. They also highlight how carbon nanotubes might be woven into to composite yarns to create multifunctional textiles that are bullet-proof, lightweight and highly conductive, silicone nanofilaments might render a clothing material self-cleaning through the super-hydrophobic effect. They point out that nanotechnology could boost power delivery from rechargeable batteries while nano incorporated into smart windows might generate electricity for the building and keep it cool in summer and warm in winter. Many of these developments are research nanoscience and not yet marketable nanotechnology, although as mentioned there are nano products on the market, and probably too many non-nano marketed inappropriately with that tag. Most common abuse is referring to micro (1-100 micrometre dimensions) entities as nano (1-100 nm).

The table shows a range of nano products and their application sectors as defined by Forster and colleagues.

 

 

According to Lux Research, the total market for nanotechnology was about US$238 billion in 2008 and is predicted to grow to US$3100 billion in 2015, bullish and bearish estimates lie either side of that value depending on whether or not the research agency offering them is optimistic or pessimistic about the world economy. The US National Science Foundation (NSF) suggests turnover will be less than a third that prediction at closer to US$1000 billion by 2015 (Cientifica Ltd provides an estimate of US$1500 million for 2015). It is likely that pharma and food will have the greatest share of this market irrespective of its size. The cosmetic industry may have taken out lots of nano patents, but its activities in exploiting the technology are limited by its inherent need to avoid efficacy that might be construed as medicinal by the regulatory authorities. Textiles, automotive and construction while often seen as innovative in many ways are unlikely to take anything but a relatively small portion of the nano market pie.

The emergence and growth of the nano market will, of course, depend almost entirely on strong research efforts that will tap its potential. Whether scientists and technologist will truly catch the buzz is a different matter. The evolution of the field might also pivot on how nano and non-nano are defined ultimately and the growing public awareness and perception of nano and the safety of such products especially given ludicrous remarks about the discipline turning the world into a grey goo.

Simon P. Forster, Sandro Olveira, & Stefan Seeger (2011). Nanotechnology in the market: promises and realities Int. J. Nanotechnol., 8 (6/7), 592-613

An open or shut case for nanotechnology secrets

Should nanotechnology R&D be more open to allow it to thrive in the commercial world, or should companies working in this field be more secretive? Paradoxically, the answer seems to be that keeping secrets stifles innovation and reduces patent success. According to Associate Professor of Management at Pennsylvania State University Abington, Steven McMillan, companies should adopt an open policy towards publication of their R&D results as is common in research institutes, university research departments and academia in general.

McMillan points out that his team’s earlier research has demonstrated that for the pharmaceutical industry, openness is rather important. In that arena, companies are keen to put results into the public domain, to collaborate with academia, and to publish in the open literature. Of course, the patent work is usually undertaken in parallel and “open” publication is done in such a way that patent protection is not compromised by publication in a scientific journal.

Nevertheless, openness is the convention and the research suggests that those companies who are more secretive tend not to fare as well as their open counterparts when it comes to profitable outcomes from their innovations. McMillan and colleagues previously developed a game-theory model akin to the well-known Prisoner’s Dilemma that demonstrated how openness is superior to secrecy.

McMillan has turned to the emerging, burgeoning and positively thriving field of nanotechnology (also known as nanotech and nano) with a view to uncovering parallel phenomenon among the open and secret companies in that area. He has analysed the NSF funded Nanobank with its database of some 600,000 scientific papers, 250,000 patents, and over 50,000 grants to see if any patterns emerge and demonstrated once again that those nano companies that publish openly seem to be the ones that succeed in terms of their R&D performance. Conversely, eschewing open publication is generally to the detriment of the nano company that takes that stance.

G. Steven McMillan (2010). Openness vs. secrecy in nanotechnology International Journal of Technology Intelligence and Planning, 6 (3), 205-209