Nanoclast iconNanoclast

Now that 3D Chips Are Here, What Does the Next Generation Hold?

Now that Intel will definitely be introducing its 22-nm Tri-Gate transistor—referred to as a 3-D chip due its 3-D ridge (or fin, thus the alternative name, FinFET) in which electrons runs through—it seems the era of 3-D chips are here sooner than expected. (Read and watch this interesting interview with Intel Senior Fellow Mark Bohr on how we got to this point.)

With this as its context, Dutch researchers from MESA+ Institute at the University of Twente, University of Eindhoven, ASML company and TNO Institute have developed processes by which they can rapidly fabricate “large 3-D photonic in mono-crystalline silicon using CMOS compatible processes”  that should enable novel fabrication methods for computer chips.

The researchers have published their work in a series of three papers and in the one published by the Journal of Vacuum Science and Technology have been able to fabricate a 3-D nanostructure in silicon by making etch marks on two sides of s wafer.

"There are many advantages of our fabrication route" says Willem Tjerkstra, a researcher at the MESA+ Institute in an interview with Nanowerk. "A complex 3-D structure can be made in only two etching steps, instead of tediously making such a structure by stacking layer-by-layer, as in standard CMOS-compatible fabrication. In our paper, we propose that our method allows the realization of 3-D computer chips that have more functional units concentrated on the same area. We also predict the realization of chips on different sides of liquid channels for microfluidic, or for cooling purposes."

In the two succeeding papers, the researchers described a “3D etch-masking method to realize a complex 3-D periodic array (a crystal structure) of pores in silicon” and then in the third paper observed for the first time the long-predicted phenomenon of the spontaneous emission of light from quantum dots in a 3-D photonic band gap.

It will be interesting to see if techniques such as these find their way into the next generation of 3-D chips when dimensions go down to 14nm and then 10nm.

Aircraft Nanocomposites that Provide Early Warning System for Structural Failures

Nanotechnology is already having an impact on air travel, as evidenced by EasyJet’s testing of a nanocoating that will reduce wind drag and fuel consumption.

But if current research into new adhesives based on nanomaterials proves effective, the future of aircraft manufacturing could be altered significantly beyond just coatings and into the actual structures of the aircraft.

Researchers at the University of Toronto are looking into the use of multifunctional nanocomposites and adhesives that would be used in joining techniques for primary flight load structures and serve a double purpose of providing an early warning system for stresses on these structures and possible future failures.

This line of research builds on the already developing practice of using composites and adhesive bonding in the place of mechanical fastening or welding, such as with the new Airbus A380.

The University of Toronto researchers are working with carbon nanotubes to develop their multifunctional adhesives (smart adhesives) due to their electrical conductivity.

Earlier this year, I covered research coming out of MIT that would use carbon nanotubes in a method for detecting internal damage to composites.

In the MIT research, an electrical current would be applied to the composites that would heat up the carbon nanotubes and allow the use of thermographic camera for detecting flaws without the cumbersome need for heating the entire surface of the aircraft. 

The Canadian researchers are attempting something a bit more ambitious in that the method "employs a novel network recognition approach to determine current continuity and critical percolation level."

Can Nanomaterials Bring Down the Costs of Polymer Solar Cells?

Last week when I criticized the New York Times’ Paul Krugman for emphasizing big-oil conspiracies rather than looking at the material science obstacles to solar power, I remarked that the issue for photovoltaics was not overcoming plots by oil companies but instead developing a material that can be produced cheaply and still produce high conversion rates.

Professor Richard Jones has addressed this issue in a new post over at Soft Machines. Jones examines the technical and economic issues in getting polymer solar cells to compete with everything from fossil fuels to nuclear energy and makes it clear that solving the technical issues can resolve the economic ones as well.

Jones uses as his embarkation point a paper authored by Brian Azzopardi from Manchester University in the journal Energy & Environmental Science entitled “Economic assessment of solar electricity production from organic-based photovoltaic modules in a domestic environment”.

According to Jones, Azzopardi reveals in the paper that “the so-called “levelised power cost” – i.e. the cost per unit of electricity, including all capital costs, averaged over the lifetime of the plant, comes in between €0.19 and €0.50 per kWh for 7% efficient solar cells with a lifetime of 5 years, assuming southern European sunshine.”

This is clearly more expensive than both fossil fuels and nuclear and is even short of conventional solar.

So, how is the gap to be closed? Not surprisingly the majority of the cost of the a photovoltaic system based on polymer solar cells comes from the modules, and the main cost of the modules stems from the cost of the materials, which account for anywhere between 60-80% of the modules.

One thing we can quickly see from numbers like this is that we need to find some cheaper materials and as Jones points out a good place to start is with the transparent conducting electrodes, which currently use a thin layer of indium tin oxide (ITO) and represents half of the material costs.

As we know, ITO is rare and expensive and is going to become more so as time goes on. The nanomaterials we have been looking at for providing both transparency and conductivity, like carbon nanotubes and graphene, have not presented any clear solutions as of yet. Jones does provide us with a useful link that provides us with a good summary of nanomaterial contenders for replacing ITO.

But the message is clear: We still have some technological obstacles to overcome to make the economics of polymer solar cells--and, by extension, photovoltaics in general--compete favorably with fossil fuels, no matter what conspiracy you want to blame on the lack of a wider adoption of solar.

Carbon Nanotubes and Graphene: Rival Rock Stars?

The best summation I’ve seen of a recent article that states that graphene has achieved a “rock star” status was a Tweet from Cientifica: “Graphene is Elvis & Nanotubes are Carl Perkins?”

That sounds about right. And as I recall Carl Perkins wrote and first recorded “Blue Suede Shoes” that Elvis eventually made into such a hit. Playing second fiddle to the younger upstart seems about how the relationship between carbon nanotubes and graphene is developing.

There seems to be an informed opinion out there that graphene is never going to go anywhere in electronics because of its lacking a band gap. But I am not so easily swayed by this line of argument because companies like IBM are investing so much time and effort in developing the material for electronics.

That said, it might be more likely that graphene will find its first applications outside of electronics, not unlike carbon nanotubes, which is still struggling to make an impact in electronics.

In fact, this is the point made by one of the Cornell University researchers who is cited in the initial article linked to at the top of this page.

"People often focus on the electronic applications of graphene, and they don't really think as much of its mechanical applications," said Robert A. Barton, graduate student and lead author of an American Vacuum Society online review article, Sept. 9, about graphene's present and future.

As rival rock stars go, it should be interesting to see how the relationship between the two stars of carbon nanotubes and graphene plays out over time.
 

Thermoelectric Materials Turn to Nanotechnology

After yesterday’s post  in which once again I tried pulling someone back down to earth from the nanotechnology/photovoltaic ethereal heights, I am pleased to blog on research that proves once again that when it comes to nanotech and energy, it’s the mundane that’s interesting.

Thermoelectric materials have been a tantalizing possibility for exploiting all the energy that is lost in waste heat. With their ability to generate an electrical charge simply from temperature differences, it boggles the imagination how much electricity could be generated with these materials.

Researchers at the University of Oslo in Norway cooperation with SINTEF (the Foundation for Scientific and Industrial Research at the Norwegian Institute of Technology) are looking towards nanotechnology to provide an environmentally friendly and more efficient method to produce thermoelectric materials to generate electricity.

The thermoelectric materials that are currently in use employ the elements Lead and Tellurium, but both of which are toxic. In addition to being toxic, the thermoelectric materials are only able to recover 10% of the energy that is loss as waste heat.

But, according to Ole Martin Løvvik, who is both an associate professor in the Department of Physics at the University of Oslo and a senior scientist at SINTEF, nanotechnology could provide both an environmentally friendly alternative and improve its ability to recover energy by 50%.

"I think we will manage to solve this problem with nanotechnology. The technology is simple and flexible and is almost too good to be true. In the long run, the technology can utilise all heat sources, such as solar energy and geothermal energy. The only limits are in our imagination," Løvvik is quoted as saying in the research magazine Apollon at the University of Oslo.

First applications for their solution have already been targeted at automobiles and the researchers are already in discussion with the US car manufacturer General Motors on the technology.

"Modern cars need a lot of electricity. By covering the exhaust system with thermoelectric plates, the heat from the exhaust system can increase the car's efficiency by almost ten per cent at a single stroke,” says Løvvik. “If we succeed, this will be a revolution in the modern automotive industry."

The researchers’ method for balancing between the need for thermoelectric materials to have both high thermal resistance and high current flow is to grind down semi-conductor materials into nano-sized particles by freezing them to minus196 degrees. After breaking the semi-conductor material into nanoparticles they are glued back together, which results in a material that can reflect the heat waves but not reflect the current.

Conspiracy Theories Immaterial to Nanomaterial Science for Photovoltaics

Noted New York Times columnist and Nobel Prize winner, Paul Krugman has weighed in on the subject of solar power with somewhat mixed results.

He somehow believes that maintaining Moore’s Law over the past half century does not indicate an impressive “mastery of the material world”:

“Moore’s Law — in which the price of computing power falls roughly 50 percent every 18 months — has powered an ever-expanding range of applications, from faxes to Facebook.

Our mastery of the material world, on the other hand, has advanced much more slowly. The sources of energy, the way we move stuff around, are much the same as they were a generation ago.”

I suppose Prof. Krugman believes that the doubling of the number of transistors on a chip every two years comes solely from software developments.

But all of this the Nobel laureate presents to us only so he can introduce the concept of “Moore’s law in solar energy,” which a regular reader of Spectrum will know has not tracked as regularly as some pundits have suggested and may have fallen completely out of sight in the views of most.

Nonetheless Prof. Krugman is correct that the overall trend in the last 25 years has been a reduction in the costs of photovoltaics. But he runs afoul of sound reasoning when he chalks up the lack of greater adoption of solar power with this decreasing price trend—especially within the power grid—to the good old fossil fuel conspiracy.

I am afraid it is a bit more complex than that and part of it leads back to the subject he made a hash of at the beginning of his editorial: material science.

The problem has been to develop a material that produces high conversion rates at a reasonable cost. And a review of just this blog will reveal how much time and resources have been devoted to developing that material with everything from dye-sensitized solar cells to the use of quantum dots.

There is even a vocal segment that believes the nanotechnology solutions that could offer a cheap and highly efficient material for converting the sun’s energy into electricity should be banned because they cause more harm than good. So much for appealing to the sensibility of the so-called environmentalist.

I would like to suggest to Prof. Krugman that instead of railing against the evil intentions of oil producers, he look at some new proposals for ensuring that the technological innovations we need are developed rather than merely promised for some point in the future or their absences blamed on flimsy conspiracy theories.

When Promises from Nanotechnology Go Horribly Wrong

The modern-day snake oil pedaled by the less scrupulous among us sometimes consists of alternative energy and some little known emerging technology, and occasionally the potent mix of both of them together.

We need only look at the cautionary tale of Solyndra to see how desperate the US government was to give it money in the hope that they could make solar power just a little bit better than it is.

Combining precise amounts of desperation, greed and ignorance can really do people in as we can see from the latest bit of news coming out of India that follows along these lines.

The Kerala High Court in India has been investigating some outfit that calls itself Nano Excel Pvt Ltd after documents revealed that investors were promised high returns for a project that was touted as the “first nanotechnology-based hydroelectric power generation plant in the country”.

Reports estimate that the company “swindled” Rs350 crores ($71 million) from investors after claiming that they had a memorandum of understanding with the government to build a power plant with initial generation capacity of “100 MW, which would be scaled up to 10,000 MW by 2015.” Instead the only agreement Nano Excel had with the government was to build “a 14 MV small scale power plant.”

It seems Nano Excel was also claiming that they had deals in place with low-cost solar cell maker Nanosolar  as well as Korea-based inorganic chemical component manufacturer Biocera Co.

It’s not clear whether there were in fact deals in place with those companies, or not, but when you fudge the facts on this scale it’s hard to believe anything the company might have said.

High Energy-Conversion Rates for Dye-Sensitized Solar Cells Made Easier

Earlier this year I had the opportunity to do an interview with the discover of dye-sensitized solar cells (DSSCs), Michael Grätzel, in which he indicated that we should expect to see DSSCs capable of 10% conversion efficiency mass produced quite soon.

This is pretty impressive since Sony only demonstrated a module capable of 10% conversion efficiency in 2010.

But, according to some researchers a the Chinese Academy of Sciences, reaching this high conversion efficiency comes with the high price tag of needing resource-limited materials such as ruthenium. So the researchers, led by Yu Bai, have developed a method by which they can attain those efficiency levels with DSSCs without the use of ruthenium.

The research, which was published in the journal of the American Chemical Society,  used an all-organic dye that can be used with cobalt in the place of the ruthenium.

To replace the use of ruthenium dyes researchers have been experimenting with so-called ‘push-pull’ dye sensitizers, which are molecules that contain “electron-accepting and –donating groups linked together by a conjugated bridge.”

The researchers took the push-pull dye sensitizers that had been tried thus far and incorporated an aromatic–sulfur bridging group. What resulted was a push-pull dye that reached an energy conversion efficiency of 9.4%, breaking the record for ruthenium-free DSCs just slightly behind the best ruthenium-based systems.

If this method can be incorporated into the mass production of DSSCs, it's likely the economics of this alternative solar cell could become even more attractive.

Balancing between Skepticism and Optimism in Nanotech

Sometimes the seeming conflict between the overflowing optimism for nanotechnology and then the biting skepticism aimed at it creates confusion in its wake. 

The skepticism surrounding nanotechnology in no small part stems from the belief—as Tim Harper points out—that a new iPhone app constitutes an emerging technology. When people confuse the next generation of an iPod with developing a material that will keep Moore's Law progressing for the next 25 years, there's likely to be some disappointment in nanotechnology.

Plus, isn’t disappointment almost assured when it seems the overriding sentiment within capital markets is “Why bother with hard to understand, risky, expensive and long term stuff like nanotechnology when it only takes a couple of guys with a few laptops to create the next Facebook – and you’ll know whether it will work in 18 months rather than 5 years.”

Indeed. This is why we are seeing the rise of sovereign investment organizations as they come to realize that waiting five years but potentially employing 500 people might make better sense in terms of economic development than employing five people within just a year-and-a-half.

There have been some strong examples within the US of government committing itself to investing in the commercialization of nanotechnology, such as what we have seen in the State of New York

But mainly we have seen that developing economies around the world are ready to step in and make that investment while major economies have waited on the sideline expecting capital markets to fill the gap.

From this state of affairs, one can’t help but wonder whether the inefficiency of markets may be depriving us of needed technological developments that many seem to think are as inevitable as the next iteration of the iPhone, but simply aren’t.

Harper recognizes this shortsightedness in his interview with the Spanish version of Technology Review

And this is certainly a conversation I have had with him before in our nearly ten-year association, but now I recognize a slight new wrinkle in his line of thinking.

It would seem that when he mentions “the creation of shared public-private responsibility for their (emerging technologies) development” as a means for realizing the potential of developed technologies he is not just talking about investment capital, but something more along the lines of public engagement to drive technological development beyond merely the enrichment of the developers.

To Harper it would now seem that the input of the public on what we should be doing with nanotechnology to improve our lives and the planet needs to become integral into how we can best exploit the technology.

Nurturing Basic Nanotech Research for Others to Enjoy the Fruit

It seems the past decade of the United States—along with parts of Europe and Asia—pouring money into nanotechnology research, which led to a few fledgling nanotechnology-based businesses, is finally paying off…for Russia.

Russia, through its RusNano investment organization, is picking up small nanotechnology start-ups from around the world at attractive prices—after other countries have invested billions in supporting the basic research that made some of the companies possible.

The latest announcement is that RusNano will be investing US $25 million in BIND Biosciences and $25 million in Selecta Biosciences, which, according to the RusNano press release, accounts for a total RUSNANO investment of $50 million within the total financing rounds of $94.5 million in the two companies combined.

In the cases of these two companies, I really don’t know to what extent their initial technology was funded or supported by the U.S. government, and I wouldn’t blame them a bit if it was significant. Businesses need capital just to get to production and then later to expand. It hardly matters where it comes from as long as they can survive another day.

We got a pretty stark reminder of this last summer when United Kingdom–based Nanoco let it be known on the pages of the Financial Times that it was fed up with getting no support from the UK government and was open to moving to any country that provided financial support.

It seems that many governments around the world are supportive of basic nanoscientfic research, especially when it involves the construction of a new lab. But when it involves the $25 to $50 million needed to take an advanced prototype into full-scale production, it seems the feeling is that’s the role of market capital.

Indeed it would be if capital were invested in things other than credit-swap defaults. But we know now that it isn’t

So, a country like Russia can set up an investment organization that focuses on nanotechnology and go around the world picking up struggling nanotech start-ups, like Plastic Logic

Here we are 10 years into a massive effort in both time and money to create a new spur to the U.S. economy and just as it’s about to bear fruit we let the crop rot on the vine and let our neighbor buy the entire stock for a song.

I think someone should wake up and realize market capital is not being invested in long-term investments like manufacturing goods with nanomaterials and that sovereign capital from countries like Russia—and they are not alone—are making up the difference. 

Advertisement

Nanoclast

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

 
Editor
Dexter Johnson
Madrid, Spain
 
Contributor
Rachel Courtland
Associate Editor, IEEE Spectrum
New York, NY
Load More