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What's Old Is New Again in Nanotechnology

Last week while watching the BBC News, I saw a brief text report that said how a nanoparticle coating had been invented that could make clothes clean themselves just by exposing them to the sun.

I found this brief report shocking not because of how inventive or amazing a breakthrough it was, but because to my knowledge this invention occurred some years back.

The use of titanium dioxide in the form of nanoparticles that are used with textiles to create a “self-cleaning” mechanism is not new. The characteristic of TiO2 as a photo catalyst could hardly be described as an invention.

Even the humble Nano&Me, which I contributed to nearly three years ago and was aimed at those absolutely uninformed about nanotechnology, talks about reports of TiO2 used as a self-cleaning agent in textiles.

So, was this just invented as the BBC seems to indicate, or not? We have to say, no.

But maybe if we go to the ACS journal Applied Materials and Interfaces in which the research was published we can sort out how there is this confusion.

Just by reading the first sentence of the abstract, we get it. This is not just cotton treated with TiO2 but cotton treated with a mix of silver iodide (Agl) along with Nitrogen (N)-TiO2. This combination increased the photocatalytic activities of the material.

So, this is what I find so infuriating about coverage of nanotechnology. Couldn’t someone (besides me) have said that researchers had found a way of improving the photocatalytic performance of TiO2 in textiles so as to make their self-cleaning properties X times better than previous methods?

Again, it seems the answer is no.

The Nanotechnology and GMO Link Repeated…Again

There are two main groups hard at work trying to establish similarities between nanotechnology and genetically modified organisms (GMOs): the press and NGOs.

In the case of the press, their motivation is quite simple. It’s about selling papers and establishing or re-establishing, as the case may be, the particular media outlet’s hard-hitting investigative journalism credentials.

For NGOs the explanation is somewhat more obscure simply because we can’t see the traces of greed on it. Instead what we get with NGOs is what one might call, in psychological terms, transference.

What they are really angry about involves wars and their loss of privacy, but, most importantly, the threat of big business doing something for profit that puts them somehow at risk. Nanotechnology just happens to be a good scapegoat for them to address those fears and concerns.

So in line with this, we get from the venerable Atlantic a kind of amalgam of these two in an abysmal piece entitled “Is Nanotechnology the New GMO?" I say amalgam because on the one hand it is written for the mainstream press, but on the other hand it is authored by someone who is not just a journalist but a professor of food with book titles to her credit such as: "Food Politics: How the Food Industry Influences Nutrition and Health." I don't think I am extrapolating too much by thinking that the title draws comparisons to the sentiments of your typical NGO.

Anyway, let’s start with the question in the title of this piece. If I may offer a question in response: In what way could nanotechnology be like GMO? Of course, at the very end of the article we discover it’s the usual idea that nanotechnology has been somehow thrust upon people and as soon as they find out about it, they will reject it—in some regions of the world.

As worn thin as this idea is in the mainstream media, the general public keeps on dismissing it as a source of concern. No harm in beating a dead horse, I guess, though some may feel it to be a bit unseemly.

But there are other shockers in this piece. For instance, we get the unequivocal statement: “Nanotechnology science is new, and the industry is unregulated.”

Oh dear, where to begin? First off, nanotechnology is not an industry and never will be an industry any more than silicon is an industry.  Nanotechnology enables products. All of these products must meet consumer guidelines for safety, i.e. they are highly regulated.

Now if you want to discuss regulations of nanomaterials and not a “nanotechnology industry” (which one would expect to include AFMs and STMs), then that’s an interesting discussion. But even there the so-called “industry” has been working under the regulations that have governed the chemical industry for decades. To say that the use of these nanomaterials is unregulated is just misleading, if not ignorant.

Since the author is a supposed expert on the food industry, she gets to cleverly play on the emotional responses of the readers here by discussing nanotechnology in relation to food.

Of course, the food one eats triggers a highly emotional response, like discovering what’s really in your hot dog. So playing on speculation and fear mongering really gets you a long way on that subject.

Despite the reporter’s expertise on the food industry, what I would like to know is what the reporter was thinking when she states: “Food companies often don't know whether or not they are using these materials.”

What?! The food industry is made up all sorts of scientists devising processes and ingredients for producing food. If you think for one minute that nobody along the entire food production chain knows exactly what is in the food they are selling to the public, you have been misinformed.

What we seem to have here in this piece is what was revealed as the real cause of the Friends of the Earth’s concerns about nanotechnology in food: “What it comes down to, I’d recommend that consumers veer away from processed foods.”

A preaching nanny hardly seems to be helpful on this issue.

 

 

A Little Nanotechnology Discipline, Please!

Mainstream media often makes a hash out of reporting nanotechnology.

The latest on the long list of how perfectly respectable journalists typically turn in the most misleading copy on nanotechnology comes from the International Herald Tribune (IHT).

In the very first sentence we get: “the world of nanotechnology involves shrinking things down to a whole new level ie [sic] where things are a billion times smaller than the world of meters that we live in.”

Of course, you can imagine a reader of this thinking that nanotechnology involves “shrinking things down” not unlike the 1960s movie “Fantastic Voyage” to where white blood cells attack your miniaturized submarine.

And what does it mean: “a billion times smaller than the world we live in.”? Cells, molecules, atoms and subatomic particles all inhabit the world we live in.

But if that was bad, the next paragraph loses all connections to any kind of rational thought: “But, at present, we cannot really think about basic concepts like width, breadth, depth and height or even bigger problems like poverty and global warming on a scale which is 1,000 times smaller than a fly’s eye – they all lose meaning on the nanoscale.”

I am simply dumbfounded. Even when I can’t understand what they have written I can guess at what they might be thinking. But this really stretches me to the limits of my imagination.

As depressing as this is, I have become inured over the years to reading some pretty rough stuff from journalists when it comes to nanotechnology. But what really sent me over the edge on this one was the rather irresponsible manner in which the expert, Dr Abdul Qadeer from the Federal Urdu University of Arts, Science and Technology, presents the future of nanotechnology.

“In the future, there is a possibility to make nanorobots,” Qadeer is quoted as saying in the IHT piece. “These can be injected into our bodies to carry out repairs.”

Is it any wonder then that the journalist starts his piece with the idea of “shrinking things” straight from Fantastic Voyage imagery?

It’s one thing for journalists not to do their homework on an assignment, but it’s quite another when the experts advising them lead them astray.

Carbon Nanotube-Enabled Flexible Backplanes Promise Smart Device Ubiquity

Researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) have developed a material that uses carbon nanotubes to create a flexible backplane for an artificial electronic skin (e-skin).

“With our solution-based processing technology, we have produced mechanically flexible and stretchable active-matrix backplanes, based on fully passivated and highly uniform arrays of thin film transistors made from single walled carbon nanotubes that evenly cover areas of approximately 56 square centimeters,” says Ali Javey, a faculty scientist in Berkeley Lab’s Materials Sciences Division and a professor of electrical engineering and computer science at the University of California (UC) Berkeley in Berkeley Lab press release. “This technology, in combination with inkjet printing of metal contacts, should provide lithography-free fabrication of low-cost flexible and stretchable electronics in the future.”

It seems carbon nanotubes and artificial skin is becoming a popular research area as researchers at nearby Stanford University also looked at how carbon nanotubes could be used in flexible electronics and started demonstrating the usefulness of the method with an artificial skin.

Javey and his colleagues have published their work in the ACS journal Nano Letters in a paper entitled “Carbon Nanotube Active-Matrix Backplanes for Conformal Electronics and Sensors”.

Curiously the researchers bemoan the general problem that has existed in this are of flexible electronics of not being able to attain a pure single-walled carbon nanotube (SWNT) solution to create your flexible electronic devices. I say curious because Zhenan Bao—the same researcher at Stanford who developed the artificial skin—also developed in cooperation with researchers from the University of California Davis a method by which to come up with the exact mix of SWNTs you want.

In the Berkeley Lab press release it is made clear that the researchers used “a SWNT solution enriched to be 99-percent semiconductor tubes”, but it doesn’t indicate how they were able to get that level of purity. Maybe they can give Bao a shout out and try and use her method.

In any case, it will be interesting to see if the two research groups can move this initial work that uses  artificial skin as a demonstration of the methods into broader uses for furthering the development of flexible electronics.

US Nanotechnology Initiative Responds to Presidential Committee's Recommendations

Approximately 20 months after the President's Council of Advisors on Science and Technology’s (PCAST) biennial review of the National Nanotechnology Initiative (NNI) in which it offered some suggestions on how to improve the US’s competitiveness in nanotechnology, the various representatives of the NNI provided their response.

The webcast of this November 2 hearing can be viewed from here.  If you prefer a brief written summary of the four speakers, you can find that here in a report from the American Institute of Physics.  All of the materials from the meeting, including the presentations, can be found here.

My take on the PCAST recommendations is that they wanted to start seeing more commercial products from the $14 billion that has been invested in nanotech research over the last 10 years, and they wanted the issue of environmental, health and safety (EHS)…shall we say…adequately addressed.

The answer for these calls has been to increase the number of public/private partnerships and improving tech transfer mechanisms to shorten the timescale of moving from fundamental research to commercial products.

That sounds fine, but the test of time will determine whether these measures can actually make an impact in the commercial development of nanotech research.

As far as EHS issue, we are told in the presentation that $500 million has been invested thus far into addressing this issue. I am not sure that a little over 3.5% of the overall nanotech research budget is enough to address the EHS concerns surrounding nanotechnology, or, more importantly, satisfy the groups who have placed themselves in opposition to nanotechnology and called on a moratorium of all research.

Whatever your opinion is of the PCAST recommendations to the NNI, or the NNI’s response to those suggestions, you have to be impressed with the transparent way that the US government operates in its nanotechnology initiative. For someone like myself who spends some time in looking into the nanotech initiatives of other countries, it is impressive.

The Troubled Teen Years of Nanotechnology

I have always enjoyed the voice of Kristen Kulinowski, whose blog, Nanorisk, I have linked to on this blog.

After a year of no blog entries from Nanorisk I was beginning to wonder if it might not be better to remove it from the blog list as it appeared to be another addition to the growing number of now moribund nanotech-related blogs.

But last week, it came alive and provided a video to a panel discussion that Dr. Kulinowski participated in entitled “Nanotechnology in 2010’s: The Teen Years."

I was struck at the very beginning of the video how the moderator, David Kestenbaum, a journalist from the National Public Radio, launched into one of the typical nanotech-bashing poses: “After billions of dollars where are the nanotech products?”

It was another sigh moment for me, but thankfully the panel gave him a proper smack down, explaining to him—one hopes—the real nature of nanotechnology as an enabling technology not a product in and of itself.

After being provided a number of technologies that nanotech is enabling, the moderator decided it might be better to go after the number one most boring question about nanotechnology: “Can you define nanotechnology?

I suppose, depending on the audience, this question can be almost required. But I am hard pressed to believe that a meeting sponsored by the American Chemical Society really needs to bog itself down into tedious definitions of nanotechnology. After offering his own definition—which really should have sufficed (for its comic relief qualities alone)—he goes through the panelists who mightily attempt to keep the skeptical journalist satisfied, and thankfully nearly completely ignore the question.

Perhaps part of Mr. Kestenbaum’s skepticism and admitted frustration comes from some odd ideas he has about quantum effects. For instance, he says at one point: “All chemistry is a quantum effect.” The panelists begin to look uncomfortable at this point, barely able to maintain their polite smiles. And as a viewer, you begin to ask yourself: Which Wiki entry did Mr. Kestenbaum read before coming out to moderate this panel?

This is just the first 15 minutes of the over hour-long video in which the panelists get the opportunity to go into depth on their own research. While this may have actually been interesting to the chemists and chemical engineers one would imagine made up the audience, it’s hard to see how this addressed the implied question of the panel’s title: Where is nanotechnology 10 years into the National Nanotechnology Initiative?

I was left wondering—as I often do with these panels on nanotechnology—who is this panel discussion supposed to be targeting? I just couldn’t get a sense of who they expected to be listening to this.

I think for next time maybe they might ask Dr. Kulinowski to moderate such a panel. Then it might get interesting.

Molybdenite Moves From Potential Silicon Replacement to a Transistor Prototype

You may recall my coverage at the beginning of the year of work conducted by researchers at Ecole Polytechnique Federale de Lausanne’s (EPFL) Laboratory of Nanoscale Electronics and Structures (LANES) in using “the humble and abundant mineral molybdenite (MoS2) as an attractive alternative to silicon as a two-dimensional material (like graphene is) for replacing the three-dimensional silicon in transistors.”

Well, after publishing at the beginning of the year on the mere potential for molybdenite, the researchers have just published in the journal ACS Nano on their success at building a prototype transistor using the mineral.

In a press release prepared by EPFL, Andras Kis, the director of LANES, explains, “We have built an initial prototype, putting from two to six serial transistors in place, and shown that basic binary logic operations were possible, which proves that we can make a larger chip.”

With silicon it has not proven possible to reduce its thickness below two nanometers “because of the risk of initiating a chemical reaction that would oxidize the surface and compromise its electronic properties.” Molybdenite offers the ability to reduce the thickness of layers down to just three atoms. This translates into a reduction in size of nearly three times.

“The main advantage of MoS2 is that it allows us to reduce the size of transistors, and thus to further miniaturize them,” explains Kis.

It would also seem that molybdenite combines the 2D qualities of graphene with the inherent band gap of silicon.

The researchers still seem intent on downplaying molybdenite’s possible role as competitor to graphene, but I for one am not entirely convinced by the argument of it merely being a complement to graphene.

Nonetheless, back at the beginning of the year “applications that require thin transparent semiconductors, such as optoelectronics and energy harvesting” were highlighted, and now those applications have been somewhat expanded to include “…flexible electronics, such as eventually in the design of flexible sheets of chips.”

IEEE Meeting Plays Host to the Nanomaterials that Aim to Displace Silicon

The place to be this first week of December, if you follow nanotechnology in electronics, is at the IEEE International Electron Devices Meeting (IEDM) in Washington, DC. Hopefully with better planning on my part I can find myself at next year’s meeting.

The news from this year’s event has contained some real eye-openers. Intriguingly, at least some of the news centers around research that is a reaction to Intel’s introduction of its 3D 22-nm Tri-Gate transistor.

In collaborative research between Purdue and Harvard Universities,  researchers are looking into new materials for these 3D chips that will improve electron mobility in these devices and enable the further advancement of this 3D approach.

The researchers are focusing their search on III-V materials, in particular, indium-gallium-arsenide, with which they will make nanowires.

"Industry and academia are racing to develop transistors from the III-V materials," said Pied “Peter” Ye, a professor of electrical and computer engineering at Purdue in the story that covers this research for the university news service. "Here, we have made the world's first 3-D gate-all-around transistor on much higher-mobility material than silicon, the indium-gallium-arsenide."

According to Ye, as the 3D Tri-Gate transistor moves from its current gate length down to 14nm by 2015, silicon will not be able perform. However, Ye believes that nanowires made from III-V materials will get us to the 10nm range.

There’s another approach from the IEDM that is aiming at the 10nm threshold that also has been getting a lot of coverage. Publications from the New York Times to the Wall Street Journal have devoted pixels this week to the work IBM is doing with using carbon nanotubes to create transistors that should keep them performing at and below the 10nm threshold.

The IBM researchers reported at the IEDM on their work at making “the first transistor with sub-10 nm channel lengths, outperforming the best competing silicon-based devices at these length scales.”

According to the IBM press release that went out at the time of the IEDM presentation: “…this breakthrough demonstrates for the first time that carbon nanotubes can provide excellent off-state behavior in extremely scaled devices-- better than what some theoretical estimates of tunneling current suggested.”

IBM’s work with carbon nanotubes here was also accompanied with more reports on the company’s use of graphene to create a CMOS-compatible device for wireless communications.

It would seem that IBM continues to vigorously pursue both graphene and carbon nanotubes to realize the merciless demands of Moore’s Law.

How ever the graphene vs. carbon nanotubes story ultimately plays out, one thing is becoming clear that architecture alone is not going to guide electronics below 10nm and replacing silicon will be required. We'll just have to see which of the nanomaterials wins the day.

"Egg-Carton" Solution to Improving Efficiency of Quantum Dots

The quantum dot has been held out as a potential game-changer in the field solid-state lighting for some time now.

However, if one were to offer a possible knock against quantum dot-based devices in this area, it could be at their lack of efficiency. What happens is that current flow escapes between the quantum dots (QD) in a QD layer rather than through the QDs themselves.

To combat this researchers at Harvard University have developed an atomic layer deposition process that deposits the QDs in a single layer along with an aluminum oxide (Al2O3) insulating layer.  According to Edward Likovich, the best metaphor for the new arrangement is that of a carton of eggs, with the eggs being the QDs.

“The process provides a mechanical and energetic barrier between adjacent quantum dots, so the current tends to flow perpendicularly as opposed to being dissipated among dots in the layer,” says Likovich in the Material Research Society article linked to above. “Also, because we have this mechanical barrier between the dots, we can do post-processing to remove the ligands while holding the dots in place, preventing agglomeration.”

The research, which was published in the journal Advanced Materials, essentially fills the interstices between the QDs with the insulating aluminum oxide forcing the current to flow through the QDs and thereby increasing the light-emission yield.

It will be interesting to see if this process will have an impact on the application of QDs in the areas of LEDs or in photovoltaics.

How Exploratory Engineering Will Lead to Future Nanotechnologies

There is no one more convincing or credible on the subject of advanced nanotechnologies than Eric Drexler.

Not surprisingly since the publishing of his works Engines of Creation and later Nanosystems—which together launched the concept of advanced nanotechnologies—the author has not always shared the views of his colleagues and acolytes.  And while attempting to clarify his views on molecular manufacturing, he has also been hard at work at establishing a roadmap for atomically precise manufacturing (APM), which when it was being formulated acknowledged that it may only be feasibly realized by abandoning the notion of universal assemblers.

With the APM roadmap published, it would seem that Dr. Drexler has taken up a new a book project that we get a glimpse into in the hour-long lecture he recently gave to inaugurate the new Oxford Martin Programme on the Impacts of Future Technology.

In the lecture he gives himself the charge of developing a new kind of predictive mechanism for determining where the future of technology, and, in particular, nanotechnology will take us. Dr. Drexler provides us with an intriguing methodology that fundamentally depends on looking at how the laws of physics determine future engineering.

He further outlines the concept of “exploratory engineering”, which one could see as a hybrid of sorts between science and engineering. To give you an example of how exploratory engineering diverges from the conventional variety, in conventional engineering the basic constraint is manufacturing while in exploratory engineering it’s valid modeling.

In predicting technological change, a great deal of energy is always expended determining when the change will occur. As Dr. Drexler explains near the end of the lecture, this is where the methodology needs to abandon physics and get into the far more problematic field of human behavior.

Despite this indeterminate variable, Dr. Drexler remains optimistic that the potential of advanced nanotechnologies for addressing issues like climate change (you’ll have to watch the video) remains within our grasp given the right dose of will.

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Nanoclast

IEEE Spectrum’s nanotechnology blog, featuring news and analysis about the development, applications, and future of science and technology at the nanoscale.

 
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Dexter Johnson
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