Author: Richard Jones

New routes to solar energy: the UK announces more research cash

The agency primarily responsible for distributing government research money for nanotechnology in the UK, the Engineering and Physical Sciences Research Council, announced a pair of linked programmes today which substantially increase the funding available for research into new, nano-enabled routes for harnessing solar energy. The first of the Nanotechnology Grand Challenges, which form part of the EPSRC’s new nanotechnology strategy, is looking for large-scale, integrated projects exploiting nanotechnology to enable cheap, efficient and scalable ways to harvest solar energy, with an emphasis on new solar cell technology. The other call, Chemical and Biochemical Solar Energy Conversion, is focussed on biological fuel production, photochemical fuel production and the underpinning fundamental science that enables these processes. Between the two calls, around £8 million (~ US $16 million) is on offer in the first stage, with more promised for continuations of the most successful projects.

I wrote a month ago about the various ways in which nanotechnology might make solar energy, which has the potential to supply all the energy needs of the modern industrial world, more economically and practically viable. The oldest of these technologies – the dye sensitised nano-titania cell invented by EPFL’s Michael Grätzel – is now moving towards full production, with the company G24 Innovations having opened a factory in Wales, in partnership with Konarka. Other technologies such as polymer and hybrid solar cells need more work to become commercial.

Using solar energy to create, not electricity, but fuel, for example for transportation, is a related area of great promise. Some work is already going on developing analogues to photosynthetic systems for using light to split water into hydrogen. A truly grand challenge here would be to devise a system for photochemically reducing carbon dioxide. Think of a system in which one took carbon dioxide (perhaps from the atmosphere) and combined it with water with the aid of a couple of photons of light to make, say, methanol, which could directly be used in your internal combustion engine powered car. It’s possible in principle, one just has to find the right catalyst….

The limits of public engagement

Over on Nanodot, Christine Peterson picks up on some comments I made about public engagement in the Foreword to the final report of the Nanotechnology Engagement Group – Democratic technologies?. Having enumerated some of the problems and difficulties of seeking public engagement about nanotechnology, I finished with the positive words “I believe that the activities outlined in this report are just the start of a very positive movement that seeks to answer a compelling question: how can we ensure that the scientific enterprise is directed in pursuit of societal goals that command broad democratic support?”

“That last question is a tough one,” Christine writes. She raises two interesting questions on the back of this. “Public research funds should go toward goals supported by the public, and our representative governmental systems are supposed to ensure that. Do they?” The record is mixed, of course, but I’m not convinced that science and conventional politics interact terribly well. The paradox of science is that its long term impacts may be very large, but in the short term there are always more urgent matters to deal with, and it is these issues, healthcare or economics, for example, that will decide elections. The elected politicians nominally in charge of public science budgets typically have many other responsibilities too, and their attention is often diverted by more immediate problems.

She goes on to ask “How about private research funds: can they pursue goals not supported by the majority? We don’t want a system where the public votes on how private science dollars are spent, do we?” In a way she then goes on to start to answer her own question “Unless they are violating a specific law, presumably” – there are some goals of science that in most countries are outlawed, regardless of who is funding the work, most notably human reproductive cloning. But there are some interesting discussions to be had about less extreme cases. One of the major sources of private science dollars are the charitable foundations, such as the UK’s Wellcome Foundation, which has £13 billion to play with, and the $33 billion of the Bill and Melinda Gates Foundation. One could certainly imagine in principle a situation in which a foundation pursued a goal with only minority support, but in practise the big foundations seem to be commendably sensitive to public concerns, more so in many ways than government agencies.

Much applied science is done by public companies, and there it is the shareholders who have an obvious interest and responsibility. It’s interesting, for example, that in the UK one of the major driving forces behind the development of a “Responsible NanoCode” for business is a major asset manager, which manages investments in public companies by institutions such as pension funds and insurance companies. There is considerable less clarity, of course, in the case of companies owned by venture capital and private equity, and these could be involved in research that may well turn out to be very controversial (one thinks, for example, of Synthetic Genomics, the company associated with Craig Venter which aims to commercialise synthetic biology). Irrespective of their ownership structure, the mechanisms of the market mean that companies can’t afford to ignore public opinion. There’s a tension, of course, between the idea that the market provides a sensitive mechanism by which the wants and needs of the public are met by private enterprise, and the view that companies have become adept at creating new consumer wants and desires, sometimes against the better interests both of the consumers themselves and wider society. The Nanodialogues project reports a very interesting public engagement exercise with a multinational consumer products company that explores this tension.

What isn’t in doubt is that global science and technology can seem a complex, unpredictable and perhaps uncontrollable force. The science fiction writer William Gibson puts this well in a recent interview: “I think what scares people most about new technologies — it’s actually what scares me most — is that they’re never legislated into being. Congress doesn’t vote on the cellular telephony initiative and create a cellphone system across the United States and the world. It just happens and capital flows around and it changes things at the most intimate levels of our lives, but we never decided to do it. Somewhere now there’s a team of people working on something that’s going to profoundly impact your life in the next 10 years and change everything. You don’t know what it is and they don’t know how it’s going to change your life because usually these things don’t go as predicted.”

Nanomechanical computers

A report on the BBC News website yesterday – Antique engines inspire nano chip – discussed a new computer design based on the use of nanoscale mechanical elements, which it described as being inspired by the Victorian grandeur of Babbage’s difference engine. The work referred to comes from the laboratory of Robert Blick of the University of Wisconsin, and is published in the New Journal of Physics as A nanomechanical computer—exploring new avenues of computing (free access).

Talk of nanoscale mechanical computers and Babbage’s machine inevitably makes one think of Eric Drexler’s proposals for nanocomputers based on rod logic. However, the operating principles underlying Blick’s proposals are rather different. The basic element is a nanoelectromechanical single electron transistor (a NEMSET, see illustration below). This consists of a silicon nano-post, which oscillates between two electrodes, shuttling electrons between the source and the drain (see also Silicon nanopillars for mechanical single-electron transport (PDF)). The current is a strong function of the applied frequency, because when the post is in mechanical resonance it carries many more electrons across the gap, and the paper demonstrates how coupled NEMSETS can be used to implement logical operations.

Blick stresses that the speed of operation of these mechanical logic gates is not competitive with conventional electronics; the selling points are instead the ability to run at higher temperature (particularly if they were to be fabricated from diamond) and their lower power consumption.

Readers may be interested in Blick’s web-site nanomachines.com, which demonstrates a number of other interesting potential applications for nanostructures fabricated by top-down methods.

The nanoelectromechanical single electron transistor
A nano-electromechanical single electron transistors (NEMSET). From Blick et al., New J. Phys. 9 (2007) 241.

Save the planet by insulating your house

A surprisingly large fraction of the energy used in developed countries is used heating and lighting buildings – in the European Union 40% of energy used is in buildings. This is an obvious place to look for savings if one is trying to reduce energy consumption without compromising economic activity. A few weeks ago, I reported a talk by Colin Humphreys explaining how much energy could be saved by replacing conventional lighting by light emitting diodes. A recent report commissioned by the UK Government’s Department for Environment, Food and Rural Affairs, Environmentally beneficial nanotechnology – Barriers and Opportunities (PDF file) ranks building insulation as one of the areas in which nanotechnology could make a substantial and immediate contribution to saving energy.

The problem doesn’t arise so much from new buildings; current building regulations in the UK and the EU are quite strict, and the technologies for making very heat efficient buildings are fairly well understood, even if they aren’t always used to the full. It is the existing building stock that is the problem. My own house illustrates this very well; its 3 foot thick solid limestone walls look as handsome and sturdy as when they were built 150 years ago, but the absence of a cavity makes them very poor insulators. To bring them up to modern insulating standards I’d need to dryline the walls with plasterboard with a foam-filled cavity, at a thickness that would lose a significant amount of the interior volume of the rooms. Is their some magic nanotechnology enabled solution that would allow us to retrofit proper insulation to the existing housing stock in an acceptable way?

The claims made by manufacturers of various products in this area are not always crystal clear, so its worth reminding ourself of the basic physics. Heat is transferred by convection, conduction and radiation. Stopping convection is essentially a matter of controlling the drafts. The amount of heat transmitted by conduction is proportional to the difference of temperature, the thickness of the material, and a material constant called the thermal conductivity. For solids like brick, concrete and glass thermal conductivities are around 0.6 – 0.8 W/m.K. As everyone knows, still air is a very good thermal insulator, with a thermal conductivity of 0.024 W/m.K, and the goal of traditional insulation materials, from sheeps’ wool to plastic foam, is to trap air to exploit its insulating properties. Standard building insulation is made from materials like polyurethane foam, are actually pretty good. A typical commercial product has a value of thermal conductivity of 0.021 W/m.K; it manages to do a bit better than pure air because the holes in the foam are actually filled with a gas that is heavier than air.

The best known thermal insulators are the fascinating materials known as aerogels. These are incredibly diffuse foams – their densities can be as low as 2 mg/cm3, not much more than air – that resemble nothing as much as solidified smoke. One makes an aerogel by making a cross-linked gel (typically from water soluble polymers of silica) and then drying it above the critical point of the solvent, preserving the structure of the gel in which the strands are essentially single molecules. An aerogel can have a thermal conductivity around 0.008 W/m.K. This is substantially less than the conductivity of the air it traps, essentially because the nanscale strands of material disrupt the transport of the gas molecules.

Aerogels have been known for a long time, mostly as a laboratory curiousity, with some applications in space where their outstanding properties have justified their very high expense. But it seems that there have been some significant process improvements that have brought the price down to a point where one could envisage using them in the building trade. One of the companies active in this area is the US-based Aspen Aerogels, which markets sheets of aerogel made, for strength, in a fabric matrix. These have a thermal conductivity in the range 0.012 – 0.015 W/m.K. This represents a worthwhile improvement on the standard PU foams. However, one shouldn’t overstate its impact; this means to achieve a given level of thermal insulation one needs an insulating sheet a bit more than half the thickness of a standard material.

Another product, from a company called Industrial Nanotech Inc, looks more radical in its impact. This is essentially an insulating paint; the makers claim that three layers of this material – Nansulate will provide significant insulation. If true, this would be very important, as it would easily and cheaply solve the problem of retrofitting insulation to the existing housing stock. So, is the claim plausible?

The company’s website gives little in the way of detail, either of the composition of the product or, in quantitative terms, its effectiveness as an insulator. The active ingredient is referred to as “hydro-NM-Oxide”, a term not well known in science. However, a recent patent filed by the inventor gives us some clues. US patent 7,144,522 discloses an insulating coating consisting of aerogel particles in a paint matrix. This has a thermal conductivity of 0.104 W/m.K. This is probably pretty good for a paint, but it is quite a lot worse than typical insulating foams. What, of course, makes matters much worse is that as a paint it will be applied as a very thin film (the recommended procedure is to use three coats, giving a dry thickness of 7.5 mils, a little less than 0.2 millimeters. Since one needs a thickness of at least 70 millimeters of polyurethane foam to achieve an acceptable value of thermal insulation (U value of 0.35 W/m2.K) it’s difficult to see how a layer that is both 350 times thinner than this, and with a significantly higher value of thermal conductivity, could make a significant contribution to the thermal insulation of a building.

More on synthetic biology and nanotechnology

There’s a lot of interesting recent commentary about synthetic biology on Homunculus, the consistently interesting blog of the science writer Philip Ball. There’s lots more detail about the story of the first bacterial genome transplant that I referred to in my last post; his commentary on the story was published last week as a Nature News and Views article (subscription required).

Philip Ball was a participant in a recent symposium organised by the Kavli Foundation “The merging of bio and nano: towards cyborg cells”. The participants in this produced an interesting statement: A vision for the convergence of synthetic biology and nanotechnology. The signatories to this statement include some very eminent figures both from synthetic biology and from bionanotechnology, including Cees Dekker, Angela Belcher, Stephen Chu and John Glass. Although the statement is bullish on the potential of synthetic biology for addressing problems such as renewable energy and medicine, it is considerably more nuanced than the sorts of statements reported by the recent New York Times article.

The case for a linkage between synthetic biology and bionanotechnology is well made at the outset: “Since the nanoscale is also the natural scale on which living cells organize matter, we are now seeing a convergence in which molecular biology offers inspiration and components to nanotechnology, while nanotechnology has provided new tools and techniques for probing the fundamental processes of cell biology. Synthetic biology looks sure to profit from this trend.” The writers divide the enabling technologies for synthetic biology into hardware and software. For this perspective on synthetic biology, which concentrates on the idea of reprogramming existing cells with synthetic genomes, the crucial hardware is the capability for cheap, accurate DNA synthesis, about which they write: “The ability to sequence and manufacture DNA is growing exponentially, with costs dropping by a factor of two every two years. The construction of arbitrary genetic sequences comparable to the genome size of simple organisms is now possible. “ This, of course, also has implications for the use of DNA as a building block for designed nanostructures and devices (see here for an example).

The authors are much more cautious on the software side. “Less clear are the design rules for this remarkable new technology—the software. We have decoded the letters in which life’s instructions are written, and we now understand many of the words – the genes. But we have come to realize that the language is highly complex and context-dependent: meaning comes not from linear strings of words but from networks of interconnections, with its own entwined grammar. For this reason, the ability to write new stories is currently beyond our ability – although we are starting to master simple couplets. Understanding the relative merits of rational design and evolutionary trial-and-error in this endeavor is a major challenge that will take years if not decades. “

The new new thing

It’s fairly clear that nanotechnology is no longer the new new thing. A recent story in Business Week – Nanotech Disappoints in Europe – is not atypical. It takes its lead from the recent difficulties of the UK nanotech company Oxonica, which it describes as emblematic of the nanotechnology sector as a whole: “a story of early promise, huge hype, and dashed hopes.” Meanwhile, in the slightly neophilic world of the think-tanks, one detects the onset of a certain boredom with the subject. For example, Jack Stilgoe writes on the Demos blog “We have had huge fun running around in the nanoworld for the last three years. But there is a sense that, as the term ‘nanotechnology’ becomes less and less useful for describing the diversity of science that is being done, interesting challenges lie elsewhere… But where?”

Where indeed? A strong candidate for the next new new thing is surely synthetic biology. (This will not, of course, be new to regular Soft Machines readers, who will have read about it here two years ago). An article in the New York Times at the weekend gives a good summary of some of the claims. The trigger for the recent prominence of synthetic biology in the news is probably the recent announcement from the Craig Venter Institute of the first bacterial genome transplant. This refers to an advance paper in Science (abstract, subscription required for full article) by John Glass and coworkers. There are some interesting observations on this in a commentary (subscription required) in Science. It’s clear that much remains to be clarified about this experiment: “But the advance remains somewhat mysterious. Glass says he doesn’t fully understand why the genome transplant succeeded, and it’s not clear how applicable their technique will be to other microbes. “ The commentary from other scientists is interesting: “Microbial geneticist Antoine Danchin of the Pasteur Institute in Paris calls the experiment “an exceptional technical feat.” Yet, he laments, “many controls are missing.” And that has prevented Glass’s team, as well as independent scientists, from truly understanding how the introduced DNA takes over the host cell.”

The technical challenges of this new field haven’t prevented activists from drawing attention to its potential downsides. Those veterans of anti-nanotechnology campaigning, the ETC group, have issued a report on synthetic biology, Extreme Genetic Engineering, noting that “Today, scientists aren’t just mapping genomes and manipulating genes, they’re building life from scratch – and they’re doing it in the absence of societal debate and regulatory oversight”. Meanwhile, the Royal Society has issued a call for views on the subject.

Looking again at the NY Times article, one can perhaps detect some interesting parallels with the way the earlier nanotechnology debate unfolded. We see, for example, some fairly unrealistic expectations being raised: ““Grow a house” is on the to-do list of the M.I.T. Synthetic Biology Working Group, presumably meaning that an acorn might be reprogrammed to generate walls, oak floors and a roof instead of the usual trunk and branches. “Take over Mars. And then Venus. And then Earth” —the last items on this modest agenda.” And just as the radical predictions of nanotechnology were underpinned by what were in my view inappropriate analogies with mechanical engineering, much of the talk in synthetic biology is underpinned by explicit, but as yet unproven, parallels between cell biology and computer science: “Most people in synthetic biology are engineers who have invaded genetics. They have brought with them a vocabulary derived from circuit design and software development that they seek to impose on the softer substance of biology. They talk of modules — meaning networks of genes assembled to perform some standard function — and of “booting up” a cell with new DNA-based instructions, much the way someone gets a computer going.”

It will be interesting how the field of synthetic biology develops, to see whether it does a better of job of steering between overpromised benefits and overdramatised fears than nanotechnology arguably did. Meanwhile, nanotechnology won’t be going away. Even the sceptical Business Week article concluded that better times lay ahead as the focus in commercialising nanotechnology moved from simple applications of nanoparticles to more sophisticated applications of nanoscale devices: “Potentially even more important is the upcoming shift from nanotech materials to applications—especially in health care and pharmaceuticals. These are fields where Europe is historically strong and already has sophisticated business networks. “

Enough talk already

Nature this week carries an editorial about the recent flurry of activity around public engagement over nanotechnology. This is generally upbeat and approving, reporting the positive side of the messages from the final report of the Nanotechnology Engagement Group, and highlighting some of the interesting outcomes of the Nanodialogues experiments. The Software Control of Matter blog even gets a mention as a “taste of true upstream thinking by nanoscientists”.

As usual, the editorial castigates the governments of the USA and the UK for not responding to the results of this public engagement, particularly in failing to get enough research going on potential environmental and health risks of nanoparticles. “These governments and others not only need to act on this outcome of public engagement, but must also integrate such processes into their departments’ and agencies’ activities.” To be fair, I think we are beginning to see the start of this, in the UK at least.

Nanotechnology for solar cells

This month’s issue of Physics World has an useful article giving an overview of the possible applications of nanotechnology to solar cells, under the strapline “Nanotechnology could transform solar cells from niche products to devices that provide a significant fraction of the world’s energy”.

The article discusses both the high road to nano-solar, using the sophistication of semiconductor nanotechnology to make highly efficient (but expensive) solar cells, and the low road, which uses dye-sensitised nanoparticles or semiconducting polymers to make relatively inefficient, but potentially very cheap, materials. One thing the article doesn’t talk about much are the issues of production and scaling, which are currently the main barriers in the way of these materials fully meeting their potential. We will undoubtedly hear much more about this over the coming months and years.

Shot by both sides

Tuesday’s launch event for two new reports in public engagement in nanotechnology – All Talk? Nanotechnologies and public engagement was a packed and interesting day. I didn’t, though, go home in an entirely optimistic frame of mind, and that wasn’t just because of the very real difficulties I had travelling through the flooded English midlands.

The morning was spent in presentations of and discussions arising from the two reports. The Demos project, Nanodialogues (the full report can be downloaded here) is presented as a series of experiments in public engagement, and that’s a very apt way of putting it. Each of the four activities addressed a very different aspect of science policy, and managed to throw a great deal of light on areas that have in the past stayed out of sight. The most straightforward of these exercises concerned a relatively simple and bounded policy choice – should iron nanoparticles be used in environmental remediation? An exercise carried out with the research councils proved problematic, illustrating just how strange and remote the nuts and bolts of government science funding procedures can be when looked at with fresh eyes. The third project was carried out in Zimbabwe, and very graphically illustrated the practical gulf between the rhetoric one sees about how nanotechnology might help the developing world and the reality of the problems that exist there. The fourth experiment found away into the notoriously closed world of business, bringing together focus groups and corporate researchers at the laboratories of Unilever, the multinational behind household brands such as Sunsilk shampoo, Dove soaps, Ponds skincreams and Surf soap-powder. Here what was explored was the tension between the company’s view that they are innovating to respond to consumer demand, and the slightly different view of some of the public that “innovation is not following their needs; it is imagining their wants, fulfilling them and leading them somewhere.”

The final report of the Nanotechnology Engagement Group summarises lessons learnt from the variety of public engagement exercises that have taken place in the UK around nanotechnology in the last couple of years. The report highlights some of the difficulties that have been encountered. Sometimes there has been a lack of clarity of the purpose of public engagement, which has led to frustrations and disappointments by participants and sponsors. It has sometimes not been clear how the results of public engagement feed back into policy. But, being more positive, there is a great deal of evidence from participants of how rewarding these exercises can be. This was underlined at the event by presentations from two of the members of the public who were involved. Bill Cusack, from Halifax, who took part in Nanojury UK, and Deborah Perry, from London, who took part in Nanodialogues, both spoke eloquently about the rewards of taking part, as well as some of the frustrations they felt.

One of the recommendations of the NEG report was that the institutions who commission or participate in public engagement exercises should always be prompt in making a public response. The Research Councils who supported Nanodialogues have made a response, which can be read here. I’m quite optimistic that EPSRC, at least, will be responding in a quite substantial way, and will be developing further public engagement activities that will be feeding directly into policy decisions.

If, after the morning session, I was feeling reasonably optimistic that despite well-recognised difficulties, there was a consensus developing about how to incorporate public engagement into scientific policy making, by the end of the afternoon sessions, “Where next for public engagement in science” and “A new social contract for science?”, I was left thinking that this optimism might be naive and Pollyannish. It became clear that there were some strongly held views in opposition, from both sides, to this comfortable position. On the one hand, there was the view that Science itself provides clear answers to policy questions; for example, given the correct information the need for GM food to feed the world’s population and nuclear energy to power it would become obvious. As for policy, we have a representative democracy to ensure that the people’s views are represented; it is politicians, not opinion polls, who ought to decide these issues, and public engagement is really just a question of the print and broadcast media informing people. On the other hand, we heard that the direct action and controversy-stoking of the social movements are the only way that opposing views can properly be heard, and that irrationality is a legitimate tool in the face of the entrenched hegemony of technoscience.

So, by the end, I was feeling rather lonely in my menshevik position of looking for moderate progress within the bounds of societal and institutional constraints. I wasn’t the only one to be feeling uncomfortable, though, as this account of the meeting from industrial scientist turned policy maker David Bott makes clear.