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Steep Slope Transistors Provide Benefit of Longer Battery Life for Mobile Phones

On Wednesday I covered the announcement from Ecole Polytechnique Fédérale de Lausanne (EPFL) and IBM that they along with host of other European research institutes were intending to develop better transistors that would eliminate the wasted current that drips through transistor gates.

The project has been dubbed Steeper based on its intentions to create steep slope transistors that exhibit an abrupt change when switching between on and off states.

I focused primarily on its addressing of the issue of vampire energy consumption and how this project could account for much greater energy conservation.

Oddly, considering my recent preoccupation with improving mobile phone batteries and rechargeable batteries in general, I neglected to point out that one of the side benefits of conserving power in electronic devices is that the batteries will last longer. This was pointed out to me in a flurry of tweets on Twitter claiming “Cellphone Battery Life to Improve 10x Thanks to Nanotechnology”.

In my defense for not pointing this out in my original blog entry, I should note that the technology will not improve battery technology, but just improve the electronic devices that the batteries are charging so that they use less energy and drain less power from the batteries.

EU Project Aims at Stemming the Tide of Wasted Energy for Our Electronic Devices

I have made the point on a couple of occasions that when nanotechnology is applied to energy its major impact right at the moment is in helping to conserve energy rather than helping in generating it.

This I am sure is not appealing to those who cheerlead for solar power or fuel cells, but nanotechnology’s significant contribution to the world’s energy woes at the moment is more about better insulation.

Along these lines, Ecole Polytechnique Fédérale de Lausanne (EPFL) and IBM announced a major research initiative, dubbed Steeper, that aims to improve the energy efficiency of the electronic devices we use every day.

Maybe you’re not getting as excited about this as some new advance in photovoltaics, but you should. To give you the magnitude of the problem, here is some data from a press release sent out for the announcement.

“According to the International Energy Agency (IEA), electronic devices currently account for 15 percent of household electricity consumption, and energy consumed by information and communications technologies as well as consumer electronics will double by 2022 and triple by 2030 to 1,700 Terawatt hours -- this is equal to the entire total residential electricity consumption of the in US and Japan in 2009.”

Finding a way to reduce this energy consumption is a big deal and it seems the scientists in a recently formed consortium of research institutes and universities in Europe will be employing nanotechnology to reach a solution.

The nanotechnology of which we speak will come in the form of semiconducting nanowires that the researchers will be investigating along with tunnel field effect transistors (TFETs) to not only close the gates of transistors more tightly but also see if they can find a method for opening and closing the gate for maximum current flow and fewer turns.

To give you a sense of how serious this project is they started it back in June and are just now letting people know what they’re doing. And some of the key individuals in the project are speaking confidently about its prospects.

“Our vision is to share this research to enable manufacturers to build the Holy Grail in electronics, a computer that utilizes negligible energy when it's in sleep mode, which we call the zero-watt PC," Professor Adrian Ionescu of the Nanolab at EPFL is quoted as saying in the above referenced article.

"By applying our collective research in TFETs with semiconducting nanowires we aim to significantly reduce the power consumption of the basic building blocks of integrated circuits affecting the smallest consumer electronics to massive, supercomputers," says Dr. Heike Riel, head of the nanoscale electronics group at IBM's Zurich research facility.

Batteries the Size of a Grain of Salt Enabled by Nanowires

I have made clear my interest in seeing nanotechnology employed so as to improve the current state of batteries.

Let us make no mistake, nanotechnology, primarily in the form of nanofibers, is being used in batteries today. In fact it was estimated as far back 2005 that nearly 60% of batteries used nanofibers.

But what I am after, and I think your average consumer is looking for too, are rechargeable batteries for our portable devices that will last longer than a few hours (laptops) or a day or two (mobile phones and MP3 players), and instead will last weeks or months on a charge, and also significantly increase the number of times we can recharge those batteries without them progressively getting worse at holding that charge.

So I was intrigued by research funded by DARPA that looked as though it was pushing battery technology a bit further.The results of a portion of that research conducted at UCLA were reported last week at the AVS 57th International Symposium & Exhibition, which was held at the Albuquerque Convention Center in New Mexico, (The abstract of the presentation can be found here).

The UCLA researchers were involved in developing an electrolyte that would be used in batteries the size of a grain of salt and would not only be able to power portable electronic devices but also micro- and nano-scale devices.

To do this the name of the game is working in three dimensions rather than two in order to increase the energy densities but shrink the size of the battery. In this case, with the electrolyte element, the UCLA researchers coated “well-ordered micro-pillars or nano-wires -- fabricated to maximize the surface-to-volume ratio, and thus the potential energy density…” 

While the overall DARPA research is still at its early stages, it now has an electrolyte and other components, such as the electrodes, already developed. But nobody at this point has started to join the various components to create an actual battery. So, I’m still waiting.

Does Hype Surrounding Nanotechnology Even Matter?

There is often an odd schizophrenic nature to articles that set out to bemoan the phenomenon of nanotechnology hype. The latest article of this variety over at Industry Week is a typical example. It starts out explaining how the market has been hyped and then proceeds for the majority of the article to list all the new and unexpected ways nanotechnology is impacting commercial products.

We get the usual complaints of how molecular-level manufacturing is still 10 years away (perpetually so it would seem) disappointing those who thought we would building products from the bottom-up by now, the $1 trillion market number by 2015 is hype and is closer to $26 billion, according to one market research firm and environmental and regulatory concerns are poised to tip over the picnic cart.

As bad as it all appears at least we can take comfort in the fact that Industry Week has taken a real (and welcomed) interest in nanotechnology by running near monthly columns from Scott E. Rickert, who pens their “Taking the NanoPulse” column, which I have commented on before.

Plus I feel myself in agreement with much of their perspective on the state of nanotechnology’s commercial development. However, when I take a step back it always has this initial cautionary tone and then seems to exhort us towards its bright and limitless future.

I guess I am just as conflicted as they are. Nanotechnology is no doubt already being integrated into commercial products to such an extent that in the article, BASF spokesman, Rudiger Iden, explains, “Now that nanotechnology has progressed as a cross-technology used in many products across the company, there is no longer a way to place a figure on nano-related investment.” It’s just too pervasive to separate it out it would seem.

But at the same time we get a pretty regular stream of anti-hype articles like this one, or those who reduce the entire nanotechnology enterprise to “vaporware”. So what brings on this odd split personality when we look at nanotechnology’s prospects?

It’s probably just because it’s prospects still lie so much in the future. We look at the future with both dread and longing. On the one hand, fear that it won’t meet our expectations or be something far worse and on the other hand hope that all our worries will be quelled and better days are ahead. 

So, what of the state of nanotechnology? Has it not met our expectations? Well since “nanotechnology” has been foisted upon as an investment opportunity or worse an industry, I suppose it was bound to disappoint us.

But I am becoming more and more content with just the notion that our ability to manipulate and examine materials at the nanoscale is going to have an enormous impact on the world, and already is doing so. And best of all, will likely do it in ways that we can’t even imagine right now.

Nanoscale Analysis of Rechargeable Batteries Pinpoints Cause of their Demise

It is my fervent belief that nanotechnology’s ability to push the lowly battery to new heights will be one of the field’s biggest achievements in the not-too-distant future. Sure expanding the water supply and better harvesting the sun’s energy are no doubt big achievements. But from a very personal level, I want my cell phone, MP3 player and laptop to last a lot longer on charge than they currently do.

To this end, researchers at Ohio State University, in cooperation with both Oak Ridge National Laboratory and the National Institute of Standards Technology, have thrown just about ever microscopy tool in the arsenal to sort out why rechargeable lithium-ion batteries begin to lose their ability to hold their charges.

Researchers Bharat Bhushan, Suresh Babu and Lei Raymond Cao first started with infrared thermal imaging of each electrode and soon progressed to using scanning electron microscopy, atomic force microscope, scanning spreading resistance microscopy, Kelvin probe microscopy, transmission electron microscopy all to get different length scale resolutions. (This various length scale issue is a big one as I have pointed out before. While we are working out making batteries, let’s see if we can’t get an equivalent to Google Earth for microscopy tools.)

What they discovered was that “the finely-structured nanomaterials on these electrodes that allow the battery to rapidly charge and discharge had coarsened in size.”

They also found out with neutron depth profiling that most of the lithium was no longer available for charge transfer. Now the researchers have not yet connected the coarsening of the nanomaterials on the electrodes with this loss of lithium, but their future research may establish this connection.

In terms of real-world applications the article cited above points to this research enabling a faster rollout of electric cars. Electric cars? I would like my iPod to hold a charge for longer than 30 minutes after owning it for a couple of years.

Structural DNA Nanotechnology Facility Gets Funding

If you follow nanotechnology news through aggregators like Google Alerts, you likely have noticed this is government grant season. For the last few months there has been a steady stream of announcements for million-dollar grants going to research facilities throughout the US.

One that has caught my eye is a $1.6 million grant to New York University (NYU) to upgrade its Structural DNA Nanotechnology facility. It would be accurate to describe this grant as being on the smaller scale of the grants that have been going out lately with $4 to $6 million being on the larger end of the spectrum.

(By the way, and in no way specific to this particular grant, scores of relatively small grants like this may do more harm than good. While they may spread the wealth around, they might actually hinder development that a grand focused effort might enable, as Chad Mirkin pointed out at the President’s Council on Science and Technology (PCAST) webcast back in June by noting that currently the NSF has a couple of million dollars set aside for developing new instrumentation technologies, but they are splitting the project between 13 bids.)

But what struck me was not the size of the grant but for whom and for what. The star researcher at NYU is Nadrian Seeman, who has become a sort of savior to the molecular manufacturing (MNT) community, although he may not always adhere to the orthodoxy set down by some of its adherents. 

It could be argued that this grant indicates that the MNT brand of nanotechnology is getting some funding for research after all. It may not be the diamondoid mechanosynthesis (DMS) variety that has enjoyed so many computer simulations but more the biological kind but is a step towards nanoscale machines making other machines.

While not a staggering large grant, and really targeted at improving the lab at NYU rather than funding specific research, perhaps this will begin to allay fears that the concept of MNT has been blackballed by government funding institutions and the aspirations of MNT admirers can be lifted.

New Nanomaterial is Latest Solution to Overcoming Heat Issues in Chips

While nanotechnology tools have enabled the shrinking of chip features well below the somewhat arbitrary 100nm threshold that often defines nanotechnology, this continuing reduction of chip features is causing a lot of problems brought on from excessive heat.

Carbon nanotubes that offer a pumpless liquid cooling system and a design for graphene that manages heat in electronics application are a few of the nanomaterials to be offered recently as a solution to this problem.

The latest report  is that researchers at Tyndall National Institute in collaboration with Stokes Research Institute and the University of Limerick in Ireland have developed a novel nanomaterial based on a nanowire that reportedly provides at least a 50% better thermal performance than any other material on the market.

The nanowire-based material achieves its performance by reducing the thermal contact resistance between the chip itself and its heatsink by filling in the voids that are typically created when two materials come in contact. 

The context in which this research was announced is interesting since it was presented at the International Power Supply on Chip Workshop in Cork, Ireland, in which big names like Damien Callaghan, Investment Director of Intel Capital and Chairman of the Advisory Board of the recently announced 500-million-dollar Investment Ireland Fund, were present. Based on that it would seem this research might receive some funding to further its commercialization.

A Treasure Trove of Nanotechnology-Related Videos

Almost from the time YouTube launched there have been at least a scattering of videos related to nanotechnology to be found on it. Some have been good and some less so, but certainly the number of videos has expanded over the years.

With this increase, there have been those who have uploaded and collected nano-based videos and I recently came across a fairly new aggregator of these nanotechnology-related videos on YouTube called the NISE (Nanoscale Informal Science Education) Network, or at least new to me

I haven’t really looked at a wide variety of videos that NISE has collected, but the ones that come from a DVD NISE Network produced called “Talking Nano” contains some real gems. In particular, I enjoyed a seminar George Whitesides gave educators and journalists back in 2007 at the Museum of Science in Boston on what they should know and consider important when relating the subject of nanotechnology either to their students or their audience.

Whitesides, of course, is a renowned scientist at Harvard University, and someone who I’ve come to appreciate for his unique perspectives on how nanotechnology will develop.

I really recommend watching all four parts of the video below, but this one alone, the first in the series, has so many pearls of wisdom at least watch this one. For instance, he believes that nanotechnology will have its biggest impact in an area he terms “commodity infrastructure”, which to Whitesides includes things like energy, water and environmental maintenance. 

Okay, this is a presentation for lay people with long explanations about the scale of nanotechnology, but even the engineers and scientists who read Spectrum will enjoy it. 

You Can't Coat a Nanosphere Like You Can a Macro One

Imagine you were given the task of coating a spherical object, and you were handed a tennis ball, a can of paint and a paintbrush. After thinking for a minute, you figured you could dispense with the paintbrush and just dip the tennis ball in the paint and  not only make a much quicker job of it but also probably cover the tennis ball in paint more completely.

In that circumstance you would be very clever and be given a pat on your back for your ingenuity. However, if you tried that on the nanoscale you might discover that the coating wasn’t covering your sphere.

Researchers Matthew Lane and Gary Grest at Sandia National Laboratories have determined through the use of computer simulations that when attempting to coat a nanoparticle the coating drops off the sphere, leaving what is described as “louvres” and a not a complete protective coating.

This would appear to be a problem. To prevent nanoparticles from aggregating in an undesired way, the method used has been covering them in a coating so they don’t stick together. It seems this research shows that those coatings may very well have the opposite effect.

In the article cited above, Carlos Gutierrez, manager of Sandia’s Surfaces and Interface Sciences Department, said, “It’s well-known that aggregation of nanoparticles in suspension is presently an obstacle to their commercial and industrial use. The simulations show that even coatings fully and uniformly applied to spherical nanoparticles are significantly distorted at the water-vapor interface.”

The research, which was originally published back in June in the journal Physical Review Letters, demonstrated through simulations that with nanoparticles because the diameter of the sphere is smaller than the thickness of the coating the curvature of the sphere causes the coating to drop off leaving the louvre-like surface.

While this phenomenon may soothe those chemical engineers who had been pulling their hair out trying to get nanoparticles to fully disperse in a solution, they may be worse off than where they started from, now lacking the simple tool of coating the nanoparticles to prevent aggregation.

But the good news is that the characteristics of the patchy coatings are particular to each nanoparticle. As the article describes it, “Though each particle is coated asymmetrically, the asymmetry is consistent for any given set. Said another way, all coated nanoscopic sets are asymmetric in their own way.”

The article goes on to argue that by having predictable variations for each member of a nanoset there is a possibility for new applications.

Unfortunately, what those applications might be is not provided. Instead we get a summation of what this simulation has given us, “What we’ve done here is to put up a large ‘dead end’ sign to prevent researchers from wasting time going down the wrong path,” Lane said. “Increasing surface density of the coating or its molecular chain length isn’t going to improve patchy coatings, as it would for larger particles.” And then a small bit of encouragement, “But there are numerous other possible paths to new outcomes when you can control the shape of the aggregation.”

Nanotechnology Sweeps Nobel Prizes

Okay, maybe nanotechnology didn’t win the Nobel Peace Prize, but one could argue that the manipulation of matter at the nanoscale did have a good showing in Physics and Chemistry.

For chemistry the Nobel Prize Committee selected Richard F. Heck, University of Delaware, Ei-ichi Negishi, Purdue University, and Akira Suzuki, Hokkaido University for their development of palladium-catalyzed cross coupling. This technique is widely used now both in the pharmaceutical and electronics industry for building complex carbon molecules that require working with the rather non-reactive carbon atom when in the presence of one of their own.

And the other winner: Graphene. Andre Geim and Konstantin Novoselov, now both at the University of Manchester, won for their research into single atom-thick sheets of carbon, called graphene back in 2004.

This was just a matter of time really considering all the excitement over the last few years with the material. A list of some of the research being done with graphene that has been covered here on the pages of IEEE Spectrum is compiled in this article.

 

One article that was missing from the lists was an interview I did with Phaedon Avouris at IBM’s IBM T.J. Watson Research Center, about IBM’s breakthrough in developing a new method for creating a band gap with graphene.

Discovering new materials and material phenomenon are sometimes revolutionary. But personally I am always impressed by the scientists who make these discoveries into something useful not unlike the way Stuart Parkin at IBM did with giant magnetoresistance (GMR)  (which also won a Nobel Prized for its discoverers) or Phaedon Avouris in creating a band gap that could lead to graphene to be used in electronics.

Anyway, these prizes are a good showing for the much-maligned field of science and technology that works on the nanoscale, let’s call it nanotechnology.

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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.

 
Editor
Dexter Johnson
Madrid, Spain
 
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Rachel Courtland
Associate Editor, IEEE Spectrum
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