The new double-walled silicon nanotube anode is made by a clever four-step process: Polymer nanofibers (green) are made, then heated (with, and then without, air) until they are reduced to carbon (black). Silicon (light blue) is coated over the outside of the carbon fibers. Finally, heating in air drives off the carbon and creates the tube as well as the clamping oxide layer (red). (Image courtesy Hui Wu, Stanford, and Yi Cui)
A clever new method for making hollow silicon nanostructures produces a battery anode that is not quickly destroyed by the stress of repeated charging and discharging. A hat tip to PhysOrd.com for reprinting this SLAC National Accelerator Laboratory news release written by Mike Ross “New nanostructure for batteries keeps going and going“:
For more than a decade, scientists have tried to improve lithium-based batteries by replacing the graphite in one terminal with silicon, which can store 10 times more charge. But after just a few charge/discharge cycles, the silicon structure would crack and crumble, rendering the battery useless.
Now a team led by materials scientist Yi Cui of Stanford and SLAC has found a solution: a cleverly designed double-walled nanostructure that lasts more than 6,000 cycles, far more than needed by electric vehicles or mobile electronics.
“This is a very exciting development toward our goal of creating smaller, lighter and longer-lasting batteries than are available today,” Cui said. The results were published March 25 in Nature Nanotechnology [abstract].
Lithium-ion batteries are widely used to power devices from electric vehicles to portable electronics because they can store a relatively large amount of energy in a relatively lightweight package. The battery works by controlling the flow of lithium ions through a fluid electrolyte between its two terminals, called the anode and cathode.
The promise – and peril – of using silicon as the anode in these batteries comes from the way the lithium ions bond with the anode during the charging cycle. Up to four lithium ions bind to each of the atoms in a silicon anode – compared to just one for every six carbon atoms in today’s graphite anode – which allows it to store much more charge.
However, it also swells the anode to as much as four times its initial volume. What’s more, some of the electrolyte reacts with the silicon, coating it and inhibiting further charging. When lithium flows out of the anode during discharge, the anode shrinks back to its original size and the coating cracks, exposing fresh silicon to the electrolyte.
Within just a few cycles, the strain of expansion and contraction, combined with the electrolyte attack, destroys the anode through a process called “decrepitation.”
Over the past five years, Cui’s group has progressively improved the durability of silicon anodes by making them out of nanowires and then hollow silicon nanoparticles. His latest design consists of a double-walled silicon nanotube coated with a thin layer of silicon oxide, a very tough ceramic material.
This strong outer layer keeps the outside wall of the nanotube from expanding, so it stays intact. Instead, the silicon swells harmlessly into the hollow interior, which is also too small for electrolyte molecules to enter. After the first charging cycle, it operates for more than 6,000 cycles with 85 percent capacity remaining.
Cui said future research is aimed at simplifying the process for making the double-wall silicon nanotubes. Others in his group are developing new high-performance cathodes to combine with the new anode to form a battery with five times the performance of today’s lithium-ion technology.
In 2008, Cui founded a company, Amprius, which licensed rights to Stanford’s patents for his silicon nanowire anode technology. Its near-term goal is to produce a battery with double the energy density of today’s lithium-ion batteries.
With a clever new method to produce novel nanostructures, a material like silicon, which has been very well studied for half a century as the basis for an important technology, can fill unexpected new roles. A few decades from now, when atomically precise manufacturing provides a general method for making arbitrarily complex nanostructures, we can expect many more surprising developments.
—James Lewis, PhD
Dmitri Lapotko. (Credit: Jeff Fitlow/Rice University)
In yet another wrinkle in the rapidly developing area of using nanotechnology to enhance cancer chemotherapy, targeted nanoparticles were used to produce “nanobubbles” inside cancer cells instead of to deliver a chemotherapy drug to the cancer cells. In laboratory tests, the nanobubbles proved to be much more efficient in specifically killing cancer cells while sparing neighboring healthy cells. A hat tip to ScienceDaily for reprinting this Rice University news release with its embedded video “‘Nanobubbles’ plus chemotherapy equals single-cell cancer targeting“:
Using light-harvesting nanoparticles to convert laser energy into “plasmonic nanobubbles,” researchers at Rice University, the University of Texas MD Anderson Cancer Center and Baylor College of Medicine (BCM) are developing new methods to inject drugs and genetic payloads directly into cancer cells. In tests on drug-resistant cancer cells, the researchers found that delivering chemotherapy drugs with nanobubbles was up to 30 times more deadly to cancer cells than traditional drug treatment and required less than one-tenth the clinical dose.
“We are delivering cancer drugs or other genetic cargo at the single-cell level,” said Rice’s Dmitri Lapotko, a biologist and physicist whose plasmonic nanobubble technique is the subject of four new peer-reviewed studies, including one due later this month in the journal Biomaterials and another published April 3 in the journal PLoS ONE [Open Access research article]. “By avoiding healthy cells and delivering the drugs directly inside cancer cells, we can simultaneously increase drug efficacy while lowering the dosage,” he said. …
Rice’s nanobubbles are not nanoparticles; rather, they are short-lived events. The nanobubbles are tiny pockets of air and water vapor that are created when laser light strikes a cluster of nanoparticles and is converted instantly into heat. The bubbles form just below the surface of cancer cells. As the bubbles expand and burst, they briefly open small holes in the surface of the cells and allow cancer drugs to rush inside. The same technique can be used to deliver gene therapies and other therapeutic payloads directly into cells.
This method, which has yet to be tested in animals, will require more research before it might be ready for human testing, said Lapotko, faculty fellow in biochemistry and cell biology and in physics and astronomy at Rice. …
To form the nanobubbles, the researchers must first get the gold nanoclusters inside the cancer cells. The scientists do this by tagging individual gold nanoparticles with an antibody that binds to the surface of the cancer cell. Cells ingest the gold nanoparticles and sequester them together in tiny pockets just below their surfaces.
While a few gold nanoparticles are taken up by healthy cells, the cancer cells take up far more, and the selectivity of the procedure owes to the fact that the minimum threshold of laser energy needed to form a nanobubble in a cancer cell is too low to form a nanobubble in a healthy cell
A given molecular targeting strategy can only achieve a certain ratio of entering cancer cells to entering healthy cells. As the cancer evolves to become more resistant to the drug, that ratio becomes inadequate to kill cancer cells while sparing healthy cells. But because the laser pulse can be precisely controlled, the ratio of gold nanoparticles in cancer cells to the amount in healthy cells is sufficient to ensure that nanobubbles only form in cancer cells, so the drug can only enter the cancer cells. If this approach works as well in an animal model as it does in laboratory cell cultures, it might develop into an effective therapy to kill drug-resistant tumor cells.
—James Lewis, PhD
In what way, and on what basis, should we attempt to steer the development of technology? This is the fundamental question that underlies at least two discussions that I keep coming back to here – how to do industrial policy and how to democratise science. But some would simply deny the premise of these discussions, and argue that technology can’t be steered, and that the market is the only effective way of incorporating public preferences into decisions about technology development. This is a hugely influential point of view which goes with the grain of the currently hegemonic neo-liberal, free market dominated world-view. It originates in the arguments of Friedrich Hayek against the 1940′s vogue for scientific planning, it incorporates Michael Polanyi’s vision of an “independent republic of science”, and it fits the view of technology as an autonomous agent which unfolds with a logic akin to that of Darwinian evolution – what one might called the “Wired” view of the world, eloquently expressed in Kevin Kelly’s recent book “What Technology Wants”. It’s a coherent, even seductive, package of beliefs; although I think it’s fatally flawed, it deserves serious examination.
Hayek’s argument against planning (his 1945 article The Use of Knowledge in Society makes this very clearly) rests on two insights. Firstly, he insists that the relevant knowledge that would underpin the rational planning of an economy or a society isn’t limited to scientific knowledge, and must include the tacit, unorganised knowledge of people who aren’t experts in the conventional sense of the word. This kind of knowledge, then, can’t rest solely with experts, but must be dispersed throughout society. Secondly, he claims that the most effective – perhaps the only – way in which this distributed knowledge can be aggregated and used is through the mechanism of the market. If we apply this kind of thinking to the development of technology, we’re led to the idea that technological development would happen in the most effective way if we simply allow many creative entrepreneurs to try different ways of combining different technologies and to develop new ones on the basis of existing scientific knowledge and what developments of that knowledge they are able to make. When the resulting innovations are presented to the market, the ones that survive will, by definition, the ones that best meet human needs. Stated this way, the connection with Darwinian evolution is obvious.
One objection to this viewpoint is essentially moral in character. The market certainly aggregates the preferences and knowledge of many people, but it necessarily gives more weight to the views of people with more money, and the distribution of money doesn’t necessarily coincide with the distribution of wisdom or virtue. Some free market enthusiasts simply assert the contrary, following Ayn Rand. There are, though, some much less risible moral arguments in favour of free markets which emphasise the positive virtues of pluralism, and even those opponents of libertarianism who point to the naivety of believing that this pluralism can be maintained in the face of highly concentrated economic and political power need to answer important questions about how pluralism can be maintained in any alternative system.
What should be less contentious than these moral arguments is an examination of the recent history of technological innovation. This shows that the technologies that made the modem world – in all their positive and negative aspects – are largely the result of the exercise of state power, rather than of the free enterprise of technological entrepreneurs. New technologies were largely driven by large scale interventions by the Warfare States that dominated the twentieth century. The military-industrial complexes of these states began long before Eisenhower popularised this name, and existed not just in the USA, but in Wilhelmine and Nazi Germany, in the USSR, and in the UK (David Edgerton’s “Warfare State: Britain 1920- 1970″ gives a compelling reinterpretation of modern British history in these terms). At the beginning of the century, for example, the Haber-Bosch process for fixing nitrogen was rapidly industrialised by the German chemical company BASF. It’s difficult to think of a more world-changing innovation – more than half the world’s population wouldn’t now be here if it hadn’t been for the huge growth in agricultural productivity that artificial fertilisers made possible. However, the importance of this process for producing the raw materials for explosives ensured that the German state took much more than a spectator’s role. Vaclav Smil, in his book Enriching the Earth, quotes an estimate for the development cost of the Haber-Bosch process of US$100 million at 1919 prices (roughly US$1 billion in current money, equating to about $19 billion in terms of its share of the economy at the time), of which about half came from the government. Many more recent examples of state involvement in innovation are cited in Mariana Mazzucato’s pamphlet The Entrepreneurial State. Perhaps one of the most important stories is the role of state spending in creating the modern IT industry; computing, the semiconductor industry and the internet are all largely the outcome of US military spending.
Of course, the historical fact that the transformative, general purpose technologies that were so important in driving economic growth in the twentieth century emerged as a result of state sponsorship doesn’t by itself invalidate the Hayekian thesis that innovation is best left to the free market. To understand the limitations of this picture, we need to return to Hayek’s basic arguments. Under what circumstances does the free market fail to aggregate information in an optimal way? People are not always rational economic actors – they know what they want and need now, but they aren’t always good at anticipating what they might want if things they can’t imagine become available, or what they might need if conditions change rapidly. There’s a natural cognitive bias to give more weight to the present, and less to an unknowable future. Just like natural selection, the optimisation process that the market carries out is necessarily local, not global.
So when does the Hayekian argument for leaving innovation to the market not apply? The free market works well for evolutionary innovation – local optimisation is good at solving present problems with the tools at hand now. But it fails to be able to mobilise resources on a large scale for big problems whose solution will take more than a few years. So, we’d expect market-driven innovation to fail to deliver whenever timescales for development are too long, or the expense of development too great. Because capital markets are now short-term to the point of irrationality (as demonstrated by this study (PDF) from the Bank of England by Andrew Haldane), the private sector rejects long term investments in infrastructure and R&D, even if the net present value of those investments would be significantly positive. In the energy sector, for example, we saw widespread liberalisation of markets across the world in the 1990s. One predictable consequence of this has been a collapse of private sector R&D in the energy sector (illustrated for the case of the USA by Dan Kammen here – The Incredible Shrinking Energy R&D Budget (PDF)).
The contrast is clear if we compare two different cases of innovation – the development of new apps for the iPhone, and the development of innovative new passenger aircraft, like the composite-based Boeing Dreamliner and Airbus A350. The world of app development is one in which tens or hundreds of thousands of people can and do try out all sorts of ideas, a few of which have turned out to fulfil an important and widely appreciated need and have made their developers rich. This is a world that’s well described by the Hayekian picture of experimentation and evolution – the low barriers to entry and the ease of widespread distribution of the products rewards experimentation. Making a new airliner, in contrast, involves years of development and outlays of tens of billions of dollars in development cost before any products are sold. Unsurprisingly, the only players are two huge companies – essentially a world duopoly – each of whom is in receipt of substantial state aid of one form or another. The lesson is that technological innovation doesn’t just come in one form. Some innovation – with low barriers to entry, often building on existing technological platforms – can be done by individuals or small companies, and can be understood well in terms of the Hayekian picture. But innovation on a larger scale, the more radical innovation that leads to new general purpose technologies, needs either a large company with a protected income stream or outright state action. In the past the companies able to carry out innovation on this scale would typically have been a state sponsored “national champion”, supported perhaps by guaranteed defense contracts, or the beneficiary of a monopoly or cartel, such as the postwar Bell Labs.
If the prevalence of this Hayekian thinking about technological innovation really does mean that we’re less able now to introduce major, world-changing innovations than we were 50 years ago, this would matter a great deal. One way of thinking about this is in evolutionary terms – if technological innovation is only able to proceed incrementally, there’s a risk that we’re less able to adapt to sudden shocks, we’re less able to anticipate the future and we’re at risk of being locked into technological trajectories that we can’t alter later in response to unexpected changes in our environment or unanticipated consequences. I’ve written earlier about the suggestion that, far from seeing universal accelerating change, we’re currently seeing innovation stagnation. The risk is that we’re seeing less in the way of really radical innovation now, at a time when pressing issues like climate change, peak cheap oil and demographic transitions make innovation more necessary than ever. We are seeing a great deal of very rapid innovation in the world of information, but this rapid pace of change in one particular realm has obscured much less rapid growth in the material realm and the biological realm. It’s in these realms that slow timescales and the large scale of the effort needed mean that the market seems unable to deliver the innovation we need.
It’s not going to be possible, nor would it be desirable, for us to return to the political economies of the mid-twentieth century warfare states that delivered the new technologies that underlie our current economies. Whatever other benefits the turn to free markets may have delivered, it seems to have been less effective at providing radical innovation, and with the need for those radical innovations becoming more urgent, some rethinking is now urgently required.
The Oxford University spin-out Oxford Nanopore Technologies created a stir last month by announcing that it would be bringing to market this year systems to read out the sequence of individual DNA molecules by threading them through nanopores. It’s claimed that this will allow a complete human genome to be sequenced in about 15 minutes for a few thousand dollars; the company also is introducing a cheap, disposable sequencer which will sell for less that $900. Speculation has now begun about the future of the company, with valuations of $1-2 billion dollars being discussed if they decide to take the company public in the next 18 months.
It’s taken a while for this idea of sequencing a single DNA molecule by directly reading out its bases to come to fruition. The original idea came from David Deamer and Harvard’s Dan Branton in the mid-1990s; from Hagen Bayley, in Oxford, came the idea of using an engineered derivative of a natural pore-forming protein to form the hole through which the DNA is threaded. I’ve previously reported progress towards this goal here, in 2005, and in more detail here, in 2007. The Oxford Nanopore announcement gives us some clues as to the key developments since then. The working system uses a polymer membrane, rather than a lipid bilayer, to carry the pore array, which undoubtedly makes the system much more robust. The pore is still created from a pore forming protein, though this has been genetically engineered to give greater discrimination between different combinations of bases as the DNA is threaded through the hole. And, perhaps most importantly, an enzyme is used to grab DNA molecules from solution and feed them through the pore. In practise, the system will be sold as a set of modular units containing the electronics and interface, together with consumables cartridges, presumably including the nanopore arrays and the enzymes. The idea is to take single molecule analysis beyond DNA to include RNA and proteins, as well as various small molecules, with a different cartridge being available for each type of experiment. This will depend on the success of their program to develop a whole family of different pores able to discriminate between different types of molecules.
What will the impact of this development be, if everything works as well as is being suggested? (The prudent commentator should stress the if here, as we haven’t yet seen any independent trials of the technology). Much has already been written about the implications of cheap – less than $1000 – sequencing of the human genome, but I can’t help wondering whether this may not actually be the big story here. And in any case, that goal may end being reached with or without Oxford Nanopore, as this recent Nature News article makes clear. We still don’t know whether the Oxford Nanopore technique will be yet competitive on accuracy and price with the other contending approaches. I wonder, though, whether we are seeing here something from the classic playbook for a disruptive innovation. The $900 device in particular looks like it’s intended to create new markets for cheap, quick and dirty sequencing, to provide an income stream while the technology is improved further – with better, more selective pores and better membranes (inevitably, perhaps, Branton’s group at Harvard reported using graphene membranes for threading DNA in Nature last year). As computers continue to get faster, cheaper and more powerful, the technology will automatically benefit from these advances too – fragmentary and perhaps imperfect sequence information has much greater value in the context of vast existing sequence libraries and the data processing power to use them. Perhaps applications for this will be found in forensic and environmental science, diagnostics, microbiology and synthetic biology. The emphasis on molecules other than DNA is interesting too; single molecule identification and sequencing of RNA opens up the possibility of rapidly identifying what genes are being transcribed in a cell at a given moment (the so-called “transcriptome”).
The impact on the investment markets for nanotechnology is likely to be substantial. Existing commercialisation efforts around nanotechnology have been disappointing so far, but a company success on the scale now being talked about would undoubtedly attract more money into the area – perhaps it might also persuade some of the companies currently sitting on huge piles of cash that they might usefully invest some of this in a little more research and development. What’s significant about Oxford Nanopore is that it is operating in a sweet spot between the mundane and the far-fetched. It’s not a nanomaterials company, essentially competing in relatively low margin speciality chemicals, nor is it trying to make a nanofactory or nanoscale submarine or one of the other more radical visions of the nanofuturists. Instead, it’s using the lessons of biology – and indeed some of the components of molecular biology – to create a functional device that operates on the true single molecule level to fill real market needs. It also seems to be displaying a commendable determination to capture all the value of its inventions, rather than licensing its IP to other, bigger companies.
Finally, not the least of the impacts of a commercial and technological success on the scale being talked about would be on nanotechnology itself as a discipline. In the last few years the field’s early excitement has been diluted by a sense of unfulfilled promise, especially, perhaps, in the UK; last year I asked “Why has the UK given up on nanotechnology?” Perhaps it will turn out that some of that disillusionment was premature.
Molecules can be delivered through a tiny channel templated by one strand of DNA.
The developers are using this to deliver precise amounts of chemicals through the membrane of individual cells. This is highly cool, with all sorts of research implications. And eventually, perhaps therapeutic implications - they're talking about scaling it up to process 100,000 cells at a time.
So I got to wondering: If someone loaded up these reservoirs with two kinds of molecules, that would stick to each other but not to themselves, could this be used as an ink-jet printer at the nanoscale?
For starters, use one kind of molecule that will stick to a surface. Squirt it on and see if it worked. Then, scan the tip while you squirt.
Once you start using multiple kinds of molecules, you can perhaps build 3D structures. And with a patterned surface, it might be possible to get atomic precision.
With a million addressible reservoirs, and 10 ms per 1-nm voxel, it would be possible to build the volume of a human cell in a few hours.
Hat tip to Next Big Future.
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| Image Credit - DebateitOut.com |
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| "Quantum Tunneling, by Orfescu |
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| "NanoMaiastra, Brancusi - In Memoriam", by Orfescu |
Display technology is currently realizing the benefits of nanotechnology in lighting support for the displays and the display construction itself. One of the new display technologies is the Mirasol display from Qualcomm. This MEMS (microelectromechanical-system)-on-glass device targets low-power, daylight-readable color displays for portable-system applications.
Most LCD devices operating at low power, such as with mobile phones and tablet PCs, have issues with color representation. In varying light, the color accuracy of the display changes, altering the viewer’s perception of the image. The Mirasol display attempts to overcome these issues.
The display is a front-reflective display rather than a traditional backlit display. The properties of nanoscale materials combine with advanced MEMS-processing techniques, allowing the display to mimic naturally occurring phenomena. The display works by creating a color from an interference pattern on the reflected light that hits the top of the display. This process is the same one that makes a butterfly’s wing shimmer and display different colors.
A new anti-reflective coating developed by researchers at Rensselaer Polytechnic Institute could help to overcome two major hurdles blocking the progress and wider use of solar power. The nanoengineered coating boosts the amount of sunlight captured by solar panels and allows those panels to absorb the entire spectrum of sunlight from any angle, regardless of the sun's position in the sky.
An untreated silicon solar cell only absorbs 67.4 percent of sunlight shone upon it — meaning that nearly one-third of that sunlight is reflected away and thus unharvestable.
After a silicon surface was treated with Lin's new nanoengineered reflective coating, however, the material absorbed 96.21 percent of sunlight shone upon it — meaning that only 3.79 percent of the sunlight was reflected and unharvested. This huge gain in absorption was consistent across the entire spectrum of sunlight, from UV to visible light and infrared, and moves solar power a significant step forward toward economic viability.
In case you haven’t realize, the Nanotechnology Law blog adds a few links in the tabs: Lawfirm Directory and Add Lawfirm.
Lawfirm directory is a new feature aimed at collecting information about lawfirms practising Nanotechnology related issue. If you fill out the form and request a review, we will consider the application subject to further documentation provided by you.
Please note that the review is not an advertorial. If you request an advertorial, we will have to disclose it in the blog post.
Click here to download the list of firms and here (or scroll below) to fill out the form.
Related:
Solo Practicioner Lawyer, a Trend?
The future of work: no cubicle culture, smaller companies, working from home
If you thought nanobots might give us cause for concern when the singularity occurs, how about nanobots made from DNA? U.S. scientists have developed microscopic robots composed of DNA that can follow instructions and work together like an assembly line to make products such as particles of gold.
Reporting in the journal Nature, New York University chemistry professor Nadrian Seeman and colleagues describe a tiny DNA factory consisting of a DNA track for assembly, three molecular forklifts that can deliver parts, and a DNA "walker" that moves around like a car on an assembly line.
The team had produced the first such DNA walker in 2004, knitting together strands of DNA to form a mobile molecule. With the walker working in the nano-factory, the plant can be programmed to produce up to eight different combinations of gold nanoparticle chemical species, according to the researchers.
All our modern technologies from information and communication, energy, and the environment to health and transport depend on the development of materials that can withstand the highest mechanical and thermal load, transfer data at the greatest speeds, safely store data in the smallest dimensions, ensure biocompatible transplants, remove monoxides from car exhausts, or separate protons and electrons in fuel cells.
This has led to great expectations for the future of nanomaterials science and worldwide attention has been drawn to the enormous potential of nanoscience and nanotechnology.
Although Europe’s expertise in nanomaterials science is excellent, it is highly fragmented into scientific disciplines, sectors and national efforts which are on a global level often subcritical. Europe would considerably benefit from a strategic pan-European, multidisciplinary research involving all sectors and the most advanced European research infrastructures.
Image via WikipediaNortheastern to host Global Regulation of Nanotechnologies conference in Boston, May 7 to 8 (Nanowerk News) Leading international experts on the global regulation of nanotechnologies, including scientists, lawyers, ethicists and officials from governments, industry stakeholders, and NGOs will join in a two-day conference May 7-8, 2010 at Northeastern University’s School of Law.
The conference will identify best practices that address the needs of industries, the public and regulators. Speakers include representatives from the U.S. Environmental Protection Agency, the Brazil Ministry of Science and Technology, the Korean governent, the International Conference of Chemicals Management and National Science Foundation-funded university-industry collaborations.
Looks like an interesting conference folks...
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