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3D Nanostructure for Cathodes in Batteries Could Mean Cell Phones that Charge in Seconds

No sooner do I discuss University of Illinois researchers who have created 3D antennas for mobile phones using nanotechnology than another group of researchers at the University of Illinois (this time at Urbana-Champaign) have developed 3D material for batteries that combines the qualities of supercapacitors with those of batteries and could change the entire battery paradigm. 

Professor Paul Braun and his colleagues just published in the March 20th edition of the journal Nature Nanotechnology their results that showed ultra fast charge and discharge rates by “using cathodes made from a self-assembled three-dimensional bicontinuous nanoarchitecture consisting of an electrolytically active material sandwiched between rapid ion and electron transport pathways.”

What this could mean, according to the excited science and technology press, are electric cars that could be charged in five minutes, a laptop in just a couple of minutes and a cell phone in seconds.

While thin film technology has allowed faster charging capabilities than seen in your typical li-ion batteries but it can’t store the energy well, meaning that a mobile device would run out of power in mere seconds.

What Braun and his team have done essentially is to take the thin film technology but built it up through self-assembly into a three-dimensional structure thereby increasing its surface area and its ability to store energy.

The actual structure apparently resembles a lattice of tightly packed spheres. Metal is used to fill in the spaces around the spheres and then it is all melted leaving a 3D scaffold that appears like a sponge. Then the structure is electropolished that increases the size of the pores.

The result is that lithium ions can move rapidly through the material with a high electrical conductivity.

According to Braun this could revolutionize the battery. "We like that it's very universal,” Braun is quoted as saying in a number of articles covering the report. “This is not linked to one very specific kind of battery, but rather it's a new paradigm in thinking about a battery in three dimensions for enhancing properties."

Nanoparticles Enable 3D Printing for Cell Phone Antennas

After nanotechnology manages to develop a solution for mobile devices so that they don’t need to be charged every day, I would like if nanotech could lead to a solution for the dropped call.

Mobile phones where the batteries run down in a few hours are really annoying but I think dropped calls from bad reception runs a close second in my annoyance scale.

I may not have to wait that long if research at the University of Illinois in making a 3D antenna for mobile phones can successfully make it commercially available cell phones.

The research, which was initially published in the Wiley journal Advanced Materials, employed an ink jet printing method that used silver nanoparticles and were sprayed on the inside or the ourside of a small hemispherical dome.

“To our knowledge, this is the first demonstration of 3D printed antennas on curvilinear surfaces,” Jennifer A. Lewis, the Hans Thurnauer Professor of Materials Science and Engineering and director of the Frederick Seitz Materials Research Laboratory at Illinois is quoted as saying in the University press release. “Omnidirectional printing of metallic nanoparticle inks offers an attractive alternative for meeting the demanding form factors of 3D electrically small antennas (ESAs).”

The functionality of antennas for mobile phones has not fared well in the overall miniaturization of the gadgets with characteristics such as gain, efficiency, bandwidth, and range all suffering.

According Jennifer T. Bernhard, a professor of electrical and computer engineering at Illinois, the 3D antennas that the research team has developed are an order of magnitude better in performance metrics than the typical monopole designs.

“There has been a long-standing problem of minimizing the ratio of energy stored to energy radiated—the Q—of an ESA,” Bernhard explains in the article. “By printing directly on the hemispherical substrate, we have a highly versatile single-mode antenna with a Q that very closely approaches the fundamental limit dictated by physics (known as the Chu limit).”

The researchers claim that this design can be quickly adapted to conform to different specifications, such as operating frequencies, device sizes or encapsulated designs. 

Phones that can last a month on a charge or don’t even need a battery because they can run own their own mechanical energy and no more dropped calls…mobile phones are beginning to sound a lot more attractive.

Nanomaterial Offers New Heat Management for Advanced Electronics

Researchers at GE Global Research under a DARPA contract have announced a new thermal material system for dissipating heat in advanced electronics that is far more effective than traditional copper.

According to the Dr. Tao Deng, the lead researcher on the project at GE, the new material is a phase-change material that was used in a prototype as a substrate for a chip.

With the all the work that is currently being done in the development of novel nanoscale materials for heat management of electronics (see, here and here) it seems that GE has set aside electronics for aviation as a market they are targeting with this technology.

In Dr. Teng’s blog discussing the technology a good deal of the description is devoted to how it performs in high gravity environments.

"In demonstrations, the prototype system has functioned effectively in a variety of electronics and application environments. We also subjected it to harsh conditions during testing and found it could successfully operate in extremely high gravity applications. More specifically, the prototype has operated in conditions that simulate more than 10 times the normal force of gravity! By comparison, this gravity force is more than four times greater than what someone would experience on the Mission Space ride at Disney."

I don’t recall any other new materials that were intended for heat management in computer chips spending so much time highlighting their functionality in high G’s without mentioning much in the way how much better their heat management is.

This preoccupation along with the DARPA contract leads me to suspect that we will likely see this in aerospace before we see in laptops. 

 

Report on Potential Risks of Nanotechnology in Electronics Needs a Second Draft

I have encountered both hopeless ideologues and blinded cheerleaders on either side of the nanotechnology and toxicity debate, and in my experience it is the environmentalists who are just unreachable.

Like Pavlovian Dogs, they see the term “nanotechnology” and bark back “What about the environment?”. They don’t really discern between microscopy tools and nanoparticles, never mind delineate among the vast amount of different nanoparticles. They just know that nanotechnology is untested and being foisted upon them as unsuspecting consumers by some evil industry.

At least with the nanotech cheerleaders you can temper their enthusiasm if you explain the situation a little bit. After all greed has as its close relative fear, but ideology’s closest kin is ignorance. There is a little you can do to overcome that, certainly the force of argument doesn’t help.

In both observing this debate and covering the issue, I have not come across any organization that has presented more faulty thinking on the subject than the Silicon Valley Toxics Coalition (SVTC).

So egregious is their thinking in these matters that I am torn between believing that it must be a deliberate misrepresentation of the issues or they just don’t know or understand them. The latest insult to our collective intelligence is their white paper entitled “Nanotechnology in Electronics: The Risk to Human Health”.

Let’s take a look at it. It starts out with a definition of nanotechnology in the first sentence that is not too bad as these definitions go. But in the next sentence manages to confuse the concept of molecular nanotechnology with the nanomaterials variety that they are no doubt railing against. This is just an introduction to the confused thinking we find further.

For instance, in the second page we are provided a glossary. At the top of the list, I guess because the list is alphabetical, are “brominated flame retardants” (BFRs). Okay, but why? What does this have to with nanotechnology or nanoparticles? In fact, if anything, it demonstrates why we should hardly be concerned about nanoparticles in electronics when 2.5 million tons of BFRs are used annually in polymers.

After presenting BFRs and explaining they have been shown to be detrimental to both human and environmental health, we are given “engineered nanoparrticles” next in the glossary. A somewhat facile definition is provided “ENPs are so small they cannot be seen with a regular light microscope” but no detrimental effects are attributed to them, except, of course, that it is listed right under BFRs. Guilt by association? I am beginning to lean towards deliberate misrepresentation.

On the same page, we get the question “How Small is Small?” (Poorly informed pieces such as these spend a lot of time providing definitions, no doubt because of the author’s need for them). And for the first time, we get the term that is supposed to connote the Evil Empire: The Nanotechnology Industry. I challenge anyone, including misguided environmentalists, to tell me what the nanotechnology industry is, or is supposed to be.

Of course, having a monolithic nanotechnology industry planning to do us harm for profit is a lot more satisfying and can produce amusing banners that say stuff like this: “Nano, it’s not green, it’s totalitarian”. Sigh.

Next in the SVTC report we get the questions of why nanoparticles are important and why they would be used in electronics. The answers are more or less accurate, but it’s not clear why the use of nano lithium iron oxide in rechargeable batteries is presented so ominously when it is explained that they may replace conventional batteries in laptops and cell phones.

Are conventional batteries, filled as they are with all sorts of toxic materials, any less of a threat? Or maybe the SVTC wants to eliminate laptops and cell phones all together? I ask this because when I recently suggested that nanotech research might eliminate the need for batteries in cell phones, I was met with the Pavlovian response: What about the environment?

Just as a note to the SVTC the next time you put one of these together you should know that a majority of today’s Li-ion batteries already use nanofibers.

Finally, by the fifth page we get an answer to the question: How is nanotechnology used in electronics? And who is their source for an answer to this question: The Project on Emerging Technology (PET). Now I almost feel sorry for the SVTC, bad data in bad data out.

Since the PET list offers little explanation of their, shall we say, less than rigorous nanotech product list, the SVTC doesn’t present any specific examples of how nanotechnology is used in electronics either. We are just told that it is found in nearly every form of consumer electronics. You can claim that, but can you show it?

Just to add insult to injury they present “molecular” electronics. Really? Again, this is just poorly informed. Why add molecular electronics to your list of boogey men unless you had no idea of how it really fit into the universe of nanotechnology and electronics. I am leaning back towards not knowing or understanding.

Look, I am in favor of the most rigorous research into determining the risks of nanoparticles in electronics and a host of other applications and products. But if I may take the exhortation at the end of this report and turn it around it somewhat: Be an informed environmentalist. 

Nanotech Research into Improving Cladding of Nuclear Fuel Rods

Last July, Dr. Hongbing Lu, a nanomaterials expert and researcher at the University of Texas at Dallas, received nearly $900,000 from the US Department of Energy (DoE) to begin to look at how it may be possible to improve the materials used for cladding nuclear fuel rods

At the time of the announcement, it seemed the main benefit to come from the research would be a reduction in fuel burn rate and increasing efficiency of nuclear power plants. But now with the unfolding nuclear disaster in Japan one can’t help but wonder if improving the cladding materials of the nuclear rods might have helped avoid leakage when the rods were temporarily exposed.

Lu was planning to first investigate how cracks propagate in the materials and then ultimately to start looking at various materials that could avoid this kind of cracking.

“We’re working on a very general simulation methodology that can be applied to that kind of environment,” Lu said. “It’s more than just crack growth. We need to understand how the material behaves under extreme pressure, temperature, corrosion and irradiation. With the methodology we’re using, we’re taking all of those factors into consideration and incorporating material behaviors into some mathematical models to describe them under very complicated conditions.”

At the time of the article announcing the DoE research grant, Lu expected that the materials research they were conducting would not only be beneficial for the materials cladding the nuclear fuel rods but also for other parts of a nuclear power plant.

Nanotechnology Could Make Batteries in Mobile Devices Obsolete

Beyond making mobile phones and other mobile devices flexible enough to wrap around your wrist, I have been a strong proponent of efforts to improve the battery life of these mobile gadgets

There have been a number of announcements recently reporting on work that improves the li-ion batteries used in mobile phones, or efforts to reduce the amount of energy used by these devices through the use of steep-slope transistors and thereby lengthen the battery life.

It is in this latter area of  seeking to lower power consumption in these devices that  we have our latest breakthrough to extend the battery life of mobile phone from hours to weeks.

Researchers from the University of Illinois’s Beckman Institute for Advanced Science and Technology, led by electrical and computer engineering professor Eric Pop, have reported in Science that they have used carbon nanotubes to control bits and lower power switching in phase change materials (PCM).

Just as a bit of background on PCM, one of the major commercial initiatives with the material in memory applications was the joint venture between Intel and STMicroelectronics with their Swiss-based Numonyx, which Micron Technologies acquired last year. PCM compares quite favorably with NOR-type flash, memory NAND-type flash memory, and RAM or EEpROM. Cost is still high compared to DRAM and read speed is not as good as DRAM, but unlike it DRAM it is non-volatile. You can read more about PCM memory here.

But what the researchers recognized was that one of the drawbacks with PCM memory was that high programming currents have made it difficult to realize low power operation. The researchers overcame this drawback by replacing metal wires with carbon nanotubes.

In a press release prepared by the University of Illinois, graduate student Feng Xiong, the first author of the paper, explains, “The energy consumption is essentially scaled with the volume of the memory bit,” says Xiong. “By using nanoscale contacts, we are able to achieve much smaller power consumption.”

The way the system works is that bits are created by putting a small amount of PCM in the a nanoscale gap located in the middle of a carbon nanotube and then by applying just small currents to the nanotube they can switch the tube on and off.

According to the abstract in Science, the researchers were able to achieve “programming currents as low as 0.5 μA (SET) and 5 μA (RESET), two orders of magnitude lower than state-of-the-art devices.”

What this may translate to for your mobile phone is that a smart phone will consume so little energy that it may not even need a battery but could run on its own thermal or mechanical energy. (Battery manufacturers are not going to like that part).

“I think anyone who is dealing with a lot of chargers and plugging things in every night can relate to wanting a cell phone or laptop whose batteries can last for weeks or months,” Pop is quoted as saying in the University of Illinois press release.

New Technique Allows for Single Atomic Layer Patterning of Graphene

Last month when I suggested an imagined rivalry between graphene and molybdenite for replacing silicon in future transistors, I was pleased with the comments the piece received.

It would seem some are looking more towards the memristor replacing the transistor all together rather than just looking at how to improve transistors, and considering that a paper in IEEE Computer Magazine inspired an article in the New York Times maybe this will be the case.

But getting back to the transistor and graphene, it seems that researchers at Rice University have stumbled upon a way to pattern a single atomic layer of graphene.

The research, which was published last week in the journal Science, provides a technique for controlling the number of layers that are removed when patterning graphene, which previous techniques could not achieve.

“One cannot make a layer thinner than a single atomic layer. That’s it,” explains James Tour, Rice's T.T. and W.F. Chao Chair in Chemistry in the video below. “We have hit the bottom.” 

According to Ayrat Dimiev, a postdoctoral scientist in Tour's lab, the discovery of the patterning technique was a complete accident. “We had no idea that we would be removing a single carbon layer from graphene,” he says in the video. “We were trying to reduce the graphene in a new way using zinc and hydrochloric acid.”

While the patterning technique may not have a bottom on the vertical dimension, the researchers recognize that the ideal would be to achieve the same precision on the horizontal dimension. 

So graphene can be imbued with a band gap and it’s possible to achieve single atomic layer patterning so when can we expect to see someone making an electronic device out of the stuff?

High-throughput Analyzer Provides Size and Concentration Measurements of Nanoparticles

I have detailed in the past how biologists have felt forlorn in the world of imaging on the nanoscale.

Dejected biologists have continued to seek out some tools to aid them in seeing the nanoscale world. This search found some sympathetic researchers at the University of California Santa Barbara.

In an article over at Nanowerk, which delves into the details of the research that was first published in Nature Nanotechnology, the lead researcher on the project explains the motivation for developing what is being described as a “high-throughput label-free nanoparticle analyzer”.

"Our collaborators informed us of the significant need for similar technologies for particle analysis on the nanoscale for studying blood and other potential clinical applications, and we set to work," explains Jean-Luc Fraikin, the first author of the paper. "Only once we became more deeply involved in the project did we begin to appreciate the broader context for this work, given the range of applications for which nanoparticles in this size range are being developed, and the lack of practical sizing technologies that were available."

The device they developed is able to measure both the size of nanoparticles and their concentration in solution at a rate of 100,000 particles per second. This stands in stark contrast to the other methods that have been available for measuring these metrics, namely averaging and electron microscopy. With averaging there was no way of determining the varying sizes of the particles and electron microscopy was time consuming and expensive.

"The low-cost, scalable fabrication method, as well as the simple readout electronics, make this analyzer potentially useful in a wide range of applications," noted Fraikin in the Nanowerk article.

The analyzer is a micro-fluidic design with a micro channel that leads the analyte through a sensor consisting of “two voltage-bias electrodes and a single, optically lithographed readout electrode embedded in the microchannel.”

"Together, these components form a fluidic voltage divider that yields wide-bandwidth electrical detection of particles as they pass through the nanoconstriction," Fraikin explains in his Nanowerk interview. "The sensing electrode is embedded in the channel between the fluidic resistor and the nanoconstriction. As a particle enters the nanoconstriction, it alters the ionic current and, because of the voltage division between the fluidic resistor and the nanoconstriction, changes the electrical potential of the fluid in contact with the sensing electrode."

It would seem the time is right for having a cheap and easy-to-use device for measuring the size and concentration of nanoparticles in all sorts of solutions, not just biological ones. If Geoffrey Ozin is correct in his estimation that nanomaterials are at a saturation point where some more measurement of what we have is needed, then this could be tool to help in that regard.

But as the Nanowerk article points out, “While the nanoparticle analyzer discussed here measures two very basic physical properties of nanoparticles – their size and concentration in solution – many other characteristics of nanoparticles, such as surface charge, surface roughness, detailed particle shape and electric or magnetic polarizability are critical to their applications and will require tools for the high-throughput measurement these properties as well.”

Nanotech-enabled Products Face Numerous Obstacles on the Way to Market

It is with great pleasure I can report that I read a really first-rate article on nanotechnology from the mainstream press. It comes from the Irish Times and is based around an interview with Prof Peter Dobson of Oxford University, who had been in Ireland in early February for the Nanoweek conference

I had the pleasure of meeting Prof. Dobson in his role as Academic Director of Oxford University’s Begbroke Science Park when I was helping to give some visiting researchers a tour of UK research facilities. With no other motivation than to share his knowledge and experience, he gave us all some rich insights into how it can be possible to lift mere lab research into really making an impact.

The same too goes for this interview in the Irish Times. What is so intriguing about Dobson’s thoughts on nanotechnology and its commercialization is that he remains one of the few who is both a first-rate scientist with both an academic and industrial background and an accomplished businessman.

For me, the greatest lessons are often learned from failures rather than successes, so it is in his explanation of a recent failure of one of his spinout companies Oxford Biosensors that I found a good one. 

“That is a terribly sad story,” he recalls of Oxford Biosensors in the Irish Times article. Adding it was “too disruptive for any licence deal” and the costs of gaining regulatory approval proved overwhelming. 

“We developed a sensor for substances, in a pinprick of blood, which would be markers of cardiac risk. We were within eight or nine months of having a commercial product on the market, but we ran out of money.”

There are all sorts of ways for a company to fail, especially one that is using an emerging technology, but running out of money seems to be a common complaint. But what can’t be overlooked is that established players in the market, even if their technology is comparatively inferior, are not going to make it easy for anyone to introduce a technology into the market that will make their product obsolete.

As I was quoted in an article on the pages of Spectrum when discussing Nantero’s long-awaited nanotube memory chip: ”It is competing with large companies. Samsung, for instance, has created a $4 billion market for themselves with flash memory. Do you think they are going to idly sit by while some start-up says they are going to make that business obsolete? Not likely; they have their own approach, which they are developing in conjunction with University of Cambridge.”

The important lesson here to me is that even if there is strong market pull for your technology, even if you can bridge any regulatory obstacles, you still have to contend with entrenched market giants who just aren’t going to let you walk off with their business.

Nanostructured Material Promises to Double Li-ion Battery Capacity

Nanosys, the Palo Alto, CA-based nanomaterials company, which has long been touted as the IP King of Nanotech with over 500 patents for nanomaterials, has made an announcement recently about a nanomaterial to improve Li-ion battery capacity.

Yimin Zhu, director, battery & fuel cell, at Nanosys, made the announcement while speaking at the IEEE Bay Area Nanotechnology Council lunch forum last month. While the article is light on specifics, it seems that the company has developed a silicon-based, “architected” material that fills in the voids of the carbon anode material matrix.

According to Nanosys’s claims, the material “remains intact and fully functional after 100% DoD cycle testing.” It also “demonstrated a >2× capacity improvement using 10% additive in a Li+ battery anode.”

I managed to glean from the graphic below that the new material will increase density to 300Wh/kg from 170Wh/kg of a graphite coating, and do so with the addition of cutting costs.

While going through this article and Nanoys' website to get some more information, I noticed one annoying bit about the company's latest marketing copy is the term “architected”. Why create a word like this when there are already quite reasonable real words that would suffice: designed, structured, or fabricated. Just annoying.

Anyway, Nanosys is still in the business of making nanostructured materials (or should that be nanoarchitected materials?) and finding industry partners to apply these materials to some device.

Last year, at the CES show they were demonstrating how a nanomaterial they had developed could make the color of LED lights more vivid. On their website, they have a business unit called “LED backlighting”, but I haven’t heard whether they have started shipping that material to LED device manufacturers in bulk. 

According to the article in which Zhu is quoted, “volume revenue shipments are expected in 2011” for the material that promises to boost Li-ion battery capacity. I would like to hear later how it all works out because over the years I have developed some serious doubts about companies that are just selling nanomaterials rather than actual devices and other products.

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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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