Recent research offers a new spin on using nanoscale semiconductor structures to build faster computers and electronics. Literally.
University of Pittsburgh and Delft University of Technology researchers reveal in the Feb. 17 online issue of Nature Nanotechnology a new method that better preserves the units necessary to power lightning-fast electronics, known as qubits (pronounced CUE-bits). Hole spins, rather than electron spins, can keep quantum bits in the same physical state up to 10 times longer than before, the report finds.
“Previously, our group and others have used electron spins, but the problem was that they interacted with spins of nuclei, and therefore it was difficult to preserve the alignment and control of electron spins,” said Sergey Frolov, assistant professor in the Department of Physics and Astronomy within Pitt’s Kenneth P. Dietrich School of Arts and Sciences, who did the work as a postdoctoral fellow at Delft University of Technology in the Netherlands.
Whereas normal computing bits hold mathematical values of zero or one, quantum bits live in a hazy superposition of both states. It is this quality, said Frolov, which allows them to perform multiple calculations at once, offering exponential speed over classical computers. However, maintaining the qubit’s state long enough to perform computation remains a long-standing challenge for physicists.
“To create a viable quantum computer, the demonstration of long-lived quantum bits, or qubits, is necessary,” said Frolov. “With our work, we have gotten one step closer.”
Thankfully, an explanation of the hole spins vs. electron spins issue follows,
The holes within hole spins, Frolov explained, are literally empty spaces left when electrons are taken out. Using extremely thin filaments called InSb (indium antimonide) nanowires, the researchers created a transistor-like device that could transform the electrons into holes. They then precisely placed one hole in a nanoscale box called “a quantum dot” and controlled the spin of that hole using electric fields. This approach- featuring nanoscale size and a higher density of devices on an electronic chip-is far more advantageous than magnetic control, which has been typically employed until now, said Frolov.
“Our research shows that holes, or empty spaces, can make better spin qubits than electrons for future quantum computers.”
“Spins are the smallest magnets in our universe. Our vision for a quantum computer is to connect thousands of spins, and now we know how to control a single spin,” said Frolov. “In the future, we’d like to scale up this concept to include multiple qubits.”
This graphic displays spin qubits within a nanowire. [downloaded from http://www.news.pitt.edu/connecting-quantum-dots]
From the news release,
Coauthors of the paper include Leo Kouwenhoven, Stevan Nadj-Perge, Vlad Pribiag, Johan van den Berg, and Ilse van Weperen of Delft University of Technology; and Sebastien Plissard and Erik Bakkers from Eindhoven University of Technology in the Netherlands.
The big news is that a multinational team has managed to spin carbon nanotubes (after 10 years of work) into threads that look like black cotton and display both the properties of metal wires and of carbon fibers. Here’s more from the Jan. 10, 2013 news item on ScienceDaily,
“We finally have a nanotube fiber with properties that don’t exist in any other material,” said lead researcher Matteo Pasquali, professor of chemical and biomolecular engineering and chemistry at Rice. “It looks like black cotton thread but behaves like both metal wires and strong carbon fibers.”
The research team includes academic, government and industrial scientists from Rice; Teijin Aramid’s headquarters in Arnhem, the Netherlands; the Technion-Israel Institute of Technology in Haifa, Israel; and the Air Force Research Laboratory (AFRL) in Dayton, Ohio.
The phenomenal properties of carbon nanotubes have enthralled scientists from the moment of their discovery in 1991. The hollow tubes of pure carbon, which are nearly as wide as a strand of DNA, are about 100 times stronger than steel at one-sixth the weight. Nanotubes’ conductive properties — for both electricity and heat — rival the best metal conductors. They also can serve as light-activated semiconductors, drug-delivery devices and even sponges to soak up oil.
Unfortunately, carbon nanotubes are also the prima donna of nanomaterials [emphasis mine]; they are difficult to work with, despite their exquisite potential. For starters, finding the means to produce bulk quantities of nanotubes took almost a decade. Scientists also learned early on that there were several dozen types of nanotubes — each with unique material and electrical properties; and engineers have yet to find a way to produce just one type. Instead, all production methods yield a hodgepodge of types, often in hairball-like clumps.
Creating large-scale objects from these clumps of nanotubes has been a challenge. A threadlike fiber that is less than one-quarter the thickness of a human hair will contain tens of millions of nanotubes packed side by side. Ideally, these nanotubes will be perfectly aligned — like pencils in a box — and tightly packed. Some labs have explored means of growing such fibers whole, but the production rates for these “solid-state” fibers have proven quite slow compared with fiber-production methods that rely on a chemical process called “wet spinning.” In this process, clumps of raw nanotubes are dissolved in a liquid and squirted through tiny holes to form long strands.
Thank you to the writer of the Rice University news release for giving me the phrase “prima donna of nanomaterials.”
The news release goes on to describe the years of work and collaboration needed to arrive at this point,
Shortly after arriving at Rice in 2000, Pasquali began studying CNT wet-spinning methods with the late Richard Smalley, a nanotechnology pioneer and the namesake of Rice’s Smalley Institute for Nanoscale Science and Technology. In 2003, two years before his untimely death, Smalley worked with Pasquali and colleagues to create the first pure nanotube fibers. The work established an industrially relevant wet-spinning process for nanotubes that was analogous to the methods used to create high-performance aramid fibers — like Teijin’s Twaron — which are used in bulletproof vests and other products. But the process needed to be refined. The fibers weren’t very strong or conductive, due partly to gaps and misalignment of the millions of nanotubes inside them.
“Achieving very high packing and alignment of the carbon nanotubes in the fibers is critical,” said study co-author Yeshayahu Talmon, director of Technion’s Russell Berrie Nanotechnology Institute, who began collaborating with Pasquali about five years ago.
The next big breakthrough came in 2009, when Talmon, Pasquali and colleagues discovered the first true solvent for nanotubes — chlorosulfonic acid. For the first time, scientists had a way to create highly concentrated solutions of nanotubes, a development that led to improved alignment and packing.
“Until that time, no one thought that spinning out of chlorosulfonic acid was possible because it reacts with water,” Pasquali said. “A graduate student in my lab, Natnael Bahabtu, found simple ways to show that CNT fibers could be spun from chlorosulfonic acid solutions. That was critical for this new process.”
Pasquali said other labs had found that the strength and conductivity of spun fibers could also be improved if the starting material — the clumps of raw nanotubes — contained long nanotubes with few atomic defects. In 2010, Pasquali and Talmon began experimenting with nanotubes from different suppliers and working with AFRL scientists to measure the precise electrical and thermal properties of the improved fibers.
During the same period, Otto [Marcin Otto, Business Development Manager at Teijin Aramid] was evaluating methods that different research centers had proposed for making CNT fibers. He envisaged combining Pasquali’s discoveries, Teijin Aramid’s know-how and the use of long CNTs to further the development of high performance CNT fibers. In 2010, Teijin Aramid set up and funded a project with Rice, and the company’s fiber-spinning experts have collaborated with Rice scientists throughout the project.
“The Teijin scientific and technical help led to immediate improvements in strength and conductivity,” Pasquali said.
Study co-author Junichiro Kono, a Rice professor of electrical and computer engineering, said, “The research showed that the electrical conductivity of the fibers could be tuned and optimized with techniques that were applied after initial production. This led to the highest conductivity ever reported for a macroscopic CNT fiber.”
The fibers reported in Science have about 10 times the tensile strength and electrical and thermal conductivity of the best previously reported wet-spun CNT fibers, Pasquali said. The specific electrical conductivity of the new fibers is on par with copper, gold and aluminum wires, but the new material has advantages over metal wires.
Here’s an explanatory video the researchers have provided,
“Our carbon nanotube fibers combine high thermal and electrical conductivity, like that seen in metals, with the flexibility, robust handling and strength of textile fibers”, explained Marcin Otto, Business Development Manager at Teijin Aramid. “With that novel combination of properties it is possible to use CNT fibers in many applications in the aerospace, automotive, medical and (smart) clothing industries.”
Teijin’s cooperation and involvement was crucial to the project. Twaron technology enabled improved performance, and an industrially scalable production method. That makes it possible to find applications for CNT fibers in a range of commercial or industrial products. “This research and ongoing tests offer us a glimpse into the potential future possibilities of this new fiber. For example, we have been very excited by the interest of innovative medical doctors and scientists exploring the possibilities to use CNT fiber in surgical operations and other applications in the medical field”, says Marcin Otto. Teijin Aramid expects to replace the copper in data cables and light power cables used in the aerospace and automotive industries, to make aircraft and high end cars lighter and more robust at the same time. Other applications could include integrating light weight electronic components, such as antennas, into composites, or replacing cooling systems in electronics where the high thermal conductivity of carbon nanotube fiber can help to dissipate heat.
Teijin Aramid is currently trialing samples of CNT fiber on a small scale with the most active prospective customers. Building up a robust supply chain is high on the project team’s list of priorities. As well as their carbon fiber, aramid fiber and polyethylene tape, this new carbon nanotube fiber is expected to allow Teijin to offer customers an even broader portfolio of high performance materials.
Teijin Group (which is headquartered in Japan) has been mentioned here before notably in a July 19, 2010 posting about a textile inspired by a butterfly’s wing (Morphotex) which, sadly, is no longer being produced as noted in a more recent April 12, 2012 posting about Teijin’s then new fiber ‘Nanofront™’ for use in sports socks.
According to the Dec. 6, 2012 posting by Ben Zevenbergen on Techdirt the European Union will commence a yearlong, starting in 2013, ‘structured stakeholder process’ to discuss copyright reform,
This exercise will assess whether “the market” is able to address the current deficiencies of copyright in the following six topics: “cross-border portability of content, user-generated content, data- and text-mining, private copy levies, access to audiovisual works and cultural heritage.“
Zevenberg goes on to analyze the six topics at more length and he also discusses the politics that led to this develoment but the part I found most interesting focuses on possible ripple effects (Note: I have removed links),
Hopefully the British will now feel supported in implementing the recommendations of the Hargreaves report. Perhaps the Dutch will also feel justified to proceed with the idea to make their copyright system more flexible. Overseas governments may also feel reinforced to open the discussions on their copyright systems and join the EU in finding the new way forward. But will the EU’s move encourage the GOP [US Republican Party] to republish their recent insightful report on copyright reform?
Dr. Michael Geist is a law professor at the University of Ottawa where he holds the Canada Research Chair in Internet and E-commerce Law. He has obtained a Bachelor of Laws (LL.B.) degree from Osgoode Hall Law School in Toronto, Master of Laws (LL.M.) degrees from Cambridge University in the UK and Columbia Law School in New York, and a Doctorate in Law (J.S.D.) from Columbia Law School. Dr. Geist is an internationally syndicated columnist on technology law issues …
I very much enjoyed and appreciated the 2012 S.NET (Society for the Study of Nanoscience and Emerging Technologies) conference in Enschede, Netherlands from Oct. 22-25, 2012. It was my first nano-themed conference and I suffered from an embarrassment of riches so what follows is just a sliver of the available presentation offerings and my opinions.
I’m sad to say that I have no sensible notes from the opening plenary (‘Emerging technologies — From Technology Push to Societal Pull’ with Dave Blank, Christos Tokamanis, and Pat Mooney on a panel moderated by Arie Rip) largely due to the fact that I’d been travelling continuously for about 15 or 16 hours by then and had trouble absorbing information. The next day was much better.
Public risk perceptions: Mary Collins talking about the Nanopants attack (protest) and about scientists’ approaches to public communication about nanotechnology risks ; Frederico Neresini discussing perceptions in Italy; and Craig Cormick providing more details about the nanosunscreen debacle in Australia.
Mary Collins (University of California at Santa Barbara) presented her work analyzing the various points of view from the science and non-science communities regarding discussions of public risk. She noted there is still concern that the GMO (genetically modified organisms) movement could happen again with nanotechnology and scientists are devoutly interested in avoiding this circumstance. By and large, most scientists want to promote some discussion about risks as a means of avoiding a ‘GMO disaster’ although there is no universal agreement as to which groups/social communities should be apprised. Some scientists favour elite groups only while others prefer a more universal dissemination of information. Collins noted that it is very difficult to find any documentation of scientists espousing the belief that communication of risk should be nonexistent. One audience member noted that a policy of suppressing discussion could be inferred by the lack of media coverage for an activist protest known as the ‘Nanopants attack’. Wired Magazine appears to have been the only media outlet to have covered the event by featuring a June 10, 2005 article by Howard Lovy,
On a chilly Chicago afternoon in early May, environmental activists sauntered into the Eddie Bauer store on Michigan Avenue, headed to the broad storefront windows opening out on the Magnificent Mile and proceeded to take off their clothes.
The strip show aimed to expose more than skin: Activists hoped to lay bare growing allegations of the toxic dangers of nanotechnology. The demonstrators bore the message in slogans painted on their bodies, proclaiming “Eddie Bauer hazard” and “Expose the truth about nanotech,” among other things, in light of the clothing company’s embrace of nanotech in its recent line of stain-resistant “nanopants.”
Frederico Neresini, University of Padua (Italy), discussed some of his work polling for attitudes toward nanotechnology risk and his tentative hypothesis that the more public debate there is on the topic, the more important trustworthiness becomes. Trust was discussed many times and in many contexts at the conference and seemed to be an emergent theme.
Craig Cormick, Australian Dept. of Innovation, discussed the surprising results of a recent poll in Australia which showed that 13% of the population doesn’t use any sunscreen due to concern about nanoscale ingredients (this finding was mentioned at more length in my Feb. 9, 2012 posting). He also noted that he was on the receiving end of some very personal attacks once this information was released. I hadn’t realized it was coincidental but, almost simultaneously, there was another project (analyzing sunscreens available on the Australian market for nanoscale ingredients) where they announced findings of many more sunscreens with nanoscale ingredients than were labelled as such. There weren’t many new details for public consumption but it was interesting to hear a first hand account. Cormick did offer a provocative idea during the session, ‘apply the precautionary principle to your risk messages’.
Chris Groves of Cardiff University (Wales) offered a lunchtime plenary talk titled, ‘Horizons of care: from future imaginaries to responsible innovation’. We were treated to a discussion of philosophy which featured Hegel and Deleuze amongst others. What I found most intriguing were Groves’ contentions that ‘vision’ is a problematic metaphor; that living in an ‘age of innovation’ means living in an ‘age of surprises’; and that science interprets the world by looking into the past. His quote from Hannah Arendt, “What we make remakes us” brought home the notion that there is a feedback loop and that science and invention are not unidirectional pursuits, i.e., we do not create the world and stand apart from it; the world we create, in turn, recreates us.
I was particularly taken with one of his last comments, ‘mapping as a metaphor for colonizing the future’. I’ve long been interested by the frequency of ‘mapping’ as a metaphor in scientific pursuits (mapping the genome, amongst many others). His comment reminded me that the great mapping bonanzas are associated with ‘colonizing’ various continents.
A big thank you is due to
US National Science Foundation,
the University of California at Santa Barbara (Valerie Kuan and Barbara Herr Harthorn),
the Canadian Academy of Independent Scholars,
Simon Fraser University,
Debora Gordon, and
all of whose financial support helped me get to the conference. I am deeply grateful.
I want to thank the organizers for a sumptuous conference not only in content but also in execution. They even managed to cater most of our meals, which made life ever so much easier. In particular, I want to thank Marcia Clifford and Evelien Rietberg of the local organizing committee for their patience and help as I fumbled about on my arrival.
Part 2: Yet again, I discover information about Canadian nanotechnology efforts through European sources.
ETA Nov. 1, 2012: I made a minor grammatical correction in the section about Chris Groves’ talk and I should mention that I never did quite grasp the relationship of ‘care’ to the concepts he presented.
In the last week there have been a couple of news releases from Dutch researchers at the University of Twente’s MESA+ Institute for Nanotechnology which feature some metaphors. The first was a Sept. 20, 2012 news item on Nanowerk (Note: I have removed a link),
Nanotechnology researchers develop ‘bed of nails’ material for clean surfaces
Scientists at the University of Twente’s MESA+ Institute for Nanotechnology have developed a new material that is not only extremely water-repellent but also extremely oil-repellent. It contains minuscule pillars which retain droplets. What makes the material unique is that the droplets stay on top even when they evaporate (slowly getting smaller). This opens the way to such things as smartphone screens that really cannot get dirty. The study appears today in the scientific journal Soft Matter (“Absence of an evaporation-driven wetting transition on omniphobic surfaces”).
Water-repellent surfaces can be used as a coating for windows, obviating the need to clean them ever again. These surfaces have an orderly arrangement of tiny pillars less than one-hundredth of a millimetre high (similar to a bed of nails but on an extremely small scale). Water droplets stay on the tips of the pillars, retaining the shape of perfectly round tiny pearls. As a result they can roll off the surface like marbles, taking all the dirt with them.
Nanotechnologists at the University of Twente have now managed to create a silicon surface that retains not only water droplets but also oil droplets like tiny pearls …. What makes the material unique is that the droplets remain in place even when they evaporate (get smaller).
With existing materials, evaporating droplets drop down between the pillars onto the surface after a while, changing in shape to hemispheres which can no longer simply roll off the surface. The surface can therefore still get dirty. By modifying the edges and the roughness of the minuscule pillars the UT scientists have managed to create a surface on which the droplets do not drop down even when they evaporate but stay neatly on top.
The Sept. 27, 2012 news item on Nanowerk features another metaphor, one which is well known amongst followers of the nanotechnology scene,
Nanotechnologists create miniscule soccer balls
Nanotechnologists at the University of Twente’s MESA+ research institute have developed a method whereby minuscule polystyrene spheres, automatically and under controlled conditions, form an almost perfect ball that looks suspiciously like a football, but about a thousand times smaller. The spheres organize themselves in such a way that they approach the densest arrangement possible, known as ‘closest packing of spheres’. The method provides nanotechnologists with a new way of creating minuscule 3D structures.
Soccer balls usually reference buckminster fullerenes (bucky balls). The news item explains this new use further,
The method developed by the University of Twente scientists involves placing a drop of water containing thousands of polystyrene spheres one micrometre in size (a thousand times smaller than a millimetre) on a superhydrophobic surface. As the drop is allowed to evaporate very slowly under controlled conditions the distances between the spheres become smaller and smaller and surprisingly they form a highly organized 3D structure. The spheres were found to organize themselves of their own accord in such a way that the ball they form approaches the most compact arrangement possible (‘closest packing of spheres’), with 74% of the space filled by the spheres. Like a football, the structures that form are almost perfectly spherical, consisting of a large number of planes. The researchers have therefore dubbed their material ‘microscopic soccer balls’. The minuscule footballs are a hundred to a thousand micrometres in size, containing from ten thousand to as much as a billion of the tiny polystyrene spheres.
The July 25, 2012 news article by Rachel Carbonell for ABC (Australian Broadcasting Corporation) discusses the current situation in Australia,
The ABC’s revelations that some sunscreen brands are inaccurately promoting themselves as nanotechnology-free have prompted calls for better regulation of nano-materials.
But the push for a mandatory register has suffered a blow, with a Federal Government report labelling it questionable.
The Australian Council of Trade Unions (ACTU) is among those calling for a register, saying the potential risks posed by nano-particles are still unknown.
The Federal Government recently released a study it commissioned to look at the feasibility of a mandatory nanotechnology product register.
The study concluded: “It is clear that some nano-materials behave differently to bulk-form materials and there are associated health, safety and environmental risks.”
“However the challenge presented by nanotechnology can be met through existing regulatory frameworks.
“It is therefore difficult to see a nano-products register delivering a net benefit to the community. The feasibility of a nano-product registry is questionable.”
But groups pushing for a register disagree.
The feasibility report points to the challenge of ensuring safety without stifling innovation, saying nanotechnology is potentially worth $50 billion a year to the Australian economy.
“But the fact that France is already implementing their mandatory register of nano-materials and the Netherlands is following closely, surely demonstrates that it must be possible.” [said Gregory Crocetti from Friends of the Earth]
The discussion presented in Carbonell’s piece is more involved than what I’ve excerpted for this posting so you may want to read her full article.
I don’t believe I’ve come across that information about nanomaterial registries in France and Holland (Netherlands) before. I’ll see if I can find more about them to confirm their existence and exactly what is being documented.
My proposal, Zombies, brains, collapsing boundaries, and entanglements, for the 4th annual S.NET (Society for the Study of Nanoscience and Emerging Technologies) conference was accepted. Mentioned in my Feb. 9, 2012 posting, the conference will be held at the University of Twente (Netherlands) from Oct. 22 – 25, 2012.
Here’s the abstract I provided,
The convergence between popular culture’s current fascination with zombies and their appetite for human brains (first established in the 1985 movie, Night of the Living Dead) and an extraordinarily high level of engagement in brain research by various medical and engineering groups around the world is no coincidence
Amongst other recent discoveries, the memristor (a concept from nanoelectronics) is collapsing the boundaries between humans and machines/robots and ushering in an age where humanistic discourse must grapple with cognitive entanglements.
Perceptible only at the level of molecular electronics (nanoelectronics), the memristor was a theoretical concept until 2008. Traditionally in electrical engineering, there are three circuit elements: resistors, inductors, and capacitors. The new circuit element, the memristor, was postulated in a paper by Dr. Leon Chua in 1971 to account for anomalies that had been experienced and described in the literature since the 1950s.
According to Chua’s theory and confirmed by the research team headed by R. Stanley Williams, the memristor remembers how much and when current has been flowing. The memristor is capable of an in-between state similar to certain brain states and this capacity lends itself to learning. As some have described it, the memristor is a synapse on a chip making neural computing a reality and/or the possibility of repairing brains stricken with neurological conditions. In other words, with post-human engineering exploiting discoveries such as the memristor we will have machines/robots that can learn and think and human brains that could incorporate machines.
As Jacques Derrida used the zombie to describe a state that this is neither life nor death as undecidable, the memristor can be described as an agent of transformation conferring robots with the ability to learn (a human trait) thereby rendering them as undecidable, i.e., neither machine nor life. Mirroring its transformative agency in robots, the memristor could also confer the human brain with machine/robot status and undecidability when used for repair or enhancement.
The memristor moves us past Jacques Derrida’s notion of undecidability as largely theoretical to a world where we confront this reality in a type of cognitive entanglement on a daily basis.
You can find the preliminary programme here. My talk is scheduled for Thursday, Oct. 25, 2012 in one of the last sessions for the conference, 11 – 12:30 pm in the Tracing Transhuman Narratives strand.
I do see a few names I recognize, Wickson, Pat (Roy) Mooney and Youtie. I believe Wickson is Fern Wickson from the University of Bergen last mentioned here in a Jul;y 7, 2010 posting about nature, nanotechnology, and metaphors. Pat Roy Mooney is from The ETC Group (an activist or civil society group) and was last mentioned here in my Oct. 7, 2011 posting), and I believe Youtie is Jan Youtie who wss mentioned in my March 29, 2012 posting about nanotechnology, economic impacts, and full life cycle assessments.
There’s a new report from DEEPEN (Deepening ethical engagement and participation in emerging nanotechnologies) from an EU (European Union) funded group. From the news item on Azonano,
DEEPEN received EUR 894,000 in funding from the ‘Science and society’ budget line of the EU’s Sixth Framework Programme (FP6). The three-year project brought together experts in ethics and philosophy and the social and political sciences from Germany, the Netherlands, Portugal and the UK.
According to the report, one major problem is the persistent belief that ‘scientists do science, while society and ethicists deal with any ethical or social implications’. This reflects the assumption that the benefits of nanotechnology need to be pushed, and ethics is a ‘brake on progress’, the project partners argue.
They go on to suggest, amongst other things, that surveys of public opinion need to be rethought as complex attitudes and opinions on emerging technologies such as nanotechnology cannot be captured in a tick box. If you want to look at the project materials, you can go here. I took a look at the video clip and will be taking a look at the report soon (I hope).
Another European (specifically UK) project I mentioned a few months ago is an online public engagement exercise, originally focused on garnering opinions from academics, researchers, and business, which has been expanded (as originally) planned to include the general public. If you want to look at their materials and discussions, go here. The data gathering ends Oct. 31, 2009 and presumably a report will be produced. This is a project for the UK Dept. for Business Innovation and Skills.
Meanwhile, the Project on Emerging Nanotechnologies (PEN) has released data about a survey on US public opinions towards nanotechnology and synthetic biology. From the news item on Nanowerk,
Nanotechnology and synthetic biology continue to develop as two of the most exciting areas of scientific discovery, but research has shown that the public is almost completely unaware of the science and its applications. A groundbreaking poll of 1,001 U.S. adults conducted by Peter D. Hart Research Associates and the Project on Emerging Nanotechnologies (PEN) found 90 percent of Americans think that the public should be better informed about the development of cutting-edge technologies.
There will be a live webcast of the results and panel discussion this morning (9:30 am PST). If you want to click through to the live webcast, you can find the link in yesterday’s posting. More tomorrow after I’ve seen the webcast.