13. Large Scale Energy Storage
• Zinc-air
– 3x Li-ion enengy for hald the cost.
• Sodium-ion
– Thousands of discharge cycles with no loss of capacity
• Lithium-ion
– Proven technology that can scale but costly
• Iron-copper nanoparticles
• Sodium sulfur
– In use (Texas)
• Lead Acid
One of the limiting factors on chip density is the wiring between components. Advances in wiring and interconnect are part of what is necessary for Moore's Law to continue. One approach to the problem is doing with less wires and using optical interconnect where possible. But you can't get rid of all wires. Fortunately wiring technology is not standing still.The smallest wires ever developed in silicon - just one atom tall and four atoms wide - have been shown by a team of researchers from the University of New South Wales, Melbourne University and Purdue University to have the same current-carrying capability as copper wires. http://www.purdue.edu/newsroom/research/2012/120105KlimeckPhosphorus.html * For engineers it could provide a roadmap to future nanoscale computational devices where atomic sizes are at the end of Moore's law. The theory shows that a single dense row of phosphorus atoms embedded in silicon will be the ultimate limit of downscaling. * For computer scientists, it places donor-atom based silicon quantum computing closer to realization. * And for physicists, the results show that Ohm's Law, which demonstrates the relationship between electrical current, resistance and voltage, continues to apply all the way down to an atomic-scale wire.Pizoelectric effects in nanowires. are potentially very important for energy harvesting applications.http://nextbigfuture.com/2012/01/individual-gan-nanowires-exhibit-strong.htmlSemiconductor GaNNWs are promising components in next generation nano- and optoelectronic systems. In addition to their direct band gap, they exhibit piezoelectricity, which renders them particularly attractive in energy harvesting applications for self-powered devices. Experimental results reveal that GaNNWs exhibit strong piezoelectricity in three dimensions, with up to six times the effect in bulk. Based on finite element modeling, this finding has major implication on the design of energy harvesting systems exhibiting unprecedented levels of power density production. The presented method is applicable to other piezoelectric NW materials as well as wires manufactured along different crystallographic orientations.Reconfigurablenanowire based transistorshttp://pubs.acs.org/doi/abs/10.1021/nl203094hThis novel nanotransistor technology makes way for a simple and compact hardware platform that can be flexibly reconfigured during operation to perform different logic computations yielding unprecedented circuit design flexibility.
Reconfigurablenanowire based transistorshttp://pubs.acs.org/doi/abs/10.1021/nl203094hThis novel nanotransistor technology makes way for a simple and compact hardware platform that can be flexibly reconfigured during operation to perform different logic computations yielding unprecedented circuit design flexibility.For the past 30 years electronic applications have been dominated by complementary metal oxide semiconductor (CMOS) devices. These combine p- and n-type field effect transistors (FETs) to reduce static power consumption. However, CMOS transistors are limited to static electrical functions, i.e., electrical characteristics that cannot be changed. Here we present the concept and a demonstrator of a universal transistor that can be reversely configured as p-FET or n-FET simply by the application of an electric signal. This concept is enabled by employing an axial nanowireheterostructure (metal/intrinsic-silicon/metal) with independent gating of the Schottky junctions.
Figure 3 Critical current density of the developed fullerene nanowhisker superconductor (5K). The critical current density remains constant over a wide range of field intensities, showing that this material has excellent superconducting properties.http://www.nims.go.jp/eng/news/press/2011/12/p201112270.htmlThe National Institute for Materials Science (NIMS; President: SukekatsuUshioda) succeeded in realizing superconductivity in fullerene nanowhiskers, which are a nanosized carbon material that is lightweight and has a fine fibrous shape. Among the conventional superconducting materials, superconductors with comparatively high superconducting transition temperatures were mainly intermetallic compounds or ceramics, and those were often heavy, hard materials. This research will enable development of new thread-like and cloth-like superconducting materials called “Flexible, lightweight superconductors.”
Step-and-repeat nanoimprint lithography delivers single digit nanostructuresResearchers at aBeam Technologies and the Molecular Foundry have developed a novel strategy for fabricating imprint templates with sub-10 nm patterns by combining electron beam lithography and atomic layer deposition. The nanostructures are replicated by step-and-repeat nanoimprint lithography and successfully transferred into a functional material with high fidelity. This process demonstrates for the first time the ability of step-and-repeat nanoimprint lithography as a single digit nanofabrication method.http://nanotechweb.org/cws/article/lab/48111The step-and-repeat process is performed at room temperature and at low pressure (force &lt30 N) with an Imprio 55 press (Molecular Imprints). Low viscous resist films are pre-spin coated on six-inch wafers and are imprinted with ultraviolet light. Patterns down to 7 nm can be successfully imprinted with a variation of less than 1 nm between the mold and the final structures. Thanks to a high control over the residual layer underneath the imprinted features, the patterns are easily transferred with high aspect ratio into silicon."We believe that our nanoimprint process has not yet reached its limit in terms of resolution, especially for reducing the pitch of gratings," commented Peroz and Dhuey.
Metal-assisted chemical etching uses two steps. First, a thin layer of gold is patterned on top of a semiconductor wafer with soft lithography (left). The gold catalyzes a chemical reaction that etches the semiconductor from the top down, creating three-dimensional structures for optoelectronic applications (right).Creating semiconductor structures for high-end optoelectronic devices just got easier, thanks to University of Illinois researchers.http://news.illinois.edu/news/11/1222etching_XiulingLi.htmlThe team developed a method to chemically etch patterned arrays in the semiconductor gallium arsenide, used in solar cells, lasers, light emitting diodes (LEDs), field effect transistors (FETs), capacitors and sensors. Led by electrical and computer engineering professor Xiuling Li, the researchers describe their technique in the journal Nano Letters.While silicon is the most ubiquitous material in semiconductor devices, materials in the III-V (pronounced three-five) group are more efficient in optoelectronic applications, such as solar cells or lasers.Unfortunately, these materials can be difficult to dry etch, as the high-energy ion blasts damage the semiconductor’s surface. III-V semiconductors are especially susceptible to damage.To address this problem, Li and her group turned to metal-assisted chemical etching (MacEtch), a wet-etching approach they had previously developed for silicon. Unlike other wet methods, MacEtch works in one direction, from the top down. It is faster and less expensive than many dry etch techniques, according to Li. Her group revisited the MacEtch technique, optimizing the chemical solution and reaction conditions for the III-V semiconductor gallium arsenide (GaAs).The process has two steps. First, a thin film of metal is patterned on the GaAs surface. Then, the semiconductor with the metal pattern is immersed in the MacEtch chemical solution. The metal catalyzes the reaction so that only the areas touching metal are etched away, and high-aspect-ratio structures are formed as the metal sinks into the wafer. When the etching is done, the metal can be cleaned from the surface without damaging it.“It is a big deal to be able to etch GaAs this way,” Li said. “The realization of high-aspect-ratio III-V nanostructure arrays by wet etching can potentially transform the fabrication of semiconductor lasers where surface grating is currently fabricated by dry etching, which is expensive and causes surface damage.”
http://www.eurekalert.org/pub_releases/2011-12/ific-tpi121811.phpKyoto, Japan -- Researchers at Kyoto University have announced a breakthrough with broad implications for semiconductor-based devices. The findings, announced in the December 20 issue of the journal Nature Communications, may lead to the development of ultra-high-speed transistors and high-efficiency photovoltaic cells.Working with standard semiconductor material (gallium arsenide, GaAs), the team observed that exposing the sample to a terahertz (1,000 gigahertz) range electric field pulse caused an avalanche of electron-hole pairs (excitons) to burst forth. This single-cycle pulse, lasting merely a picosecond (10^-12 s), resulted in a 1,000-fold increase in exciton density compared with the initial state of the sample."The terahertz pulse exposes the sample to an intense 1 MV/cm^2 electric field," explains Hideki Hirori, team leader and Assistant Professor at Kyoto University's Institute for Integrated Cell-Material Sciences (iCeMS). "The resulting exciton avalanche can be confirmed by a bright, near-infrared luminescence, demonstrating a three-order of magnitude increase in the number of carriers."
Caption: A picosecond terahertz pulse causes an avalanche of excitons to burst forth from semiconductor GaAs.Credit: Courtesy Tanaka Lab, Kyoto University iCeMS.Research in Kyoto using terahertz waves is led by Professor Koichiro Tanaka, whose lab at the iCeMS pursues numerous applications including the development of new biological imaging technologies."Since terahertz waves are sensitive to water, our goal is to create a microscope that will allow us to look inside living cells in real time," says Prof. Tanaka. "These just-released results using semiconductors are an entirely different field of science, but they demonstrate the rich potential that lies in the study of terahertz waves."The article, "Extraordinary carrier multiplication gated by a picosecond electric field pulse" by H. Hirori, K. Shinokita, M. Shirai, S. Tani, Y. Kadoya, and K. Tanaka was published online in the December 20, 2011 issue of Nature Communications.
Image 1This transmission electron microscope image shows a graphene quantum dot with zigzag edges. The quantum dots can be created in bulk from carbon fiber through a chemical process discovered at Rice University. (Credit: Ajayan lab/Rice University)Image 2Green-fluorescing graphene quantum dots created at Rice University surround a blue-stained nucleus in a human breast cancer cell. Cells were placed in a solution with the quantum dots for four hours. The dots, each smaller than 5 nanometers, easily passed through the cell membranes, showing their potential value for bioimaging. (Credit: Ajayan lab/Rice University)http://www.media.rice.edu/media/NewsBot.asp?MODE=VIEW&ID=16612&SnID=1286683387http://en.wikipedia.org/wiki/Quantum_dotGraphene quantum dots: The next big small thing Rice University-led team creates tiny materials in bulk from carbon fiberA Rice University laboratory has found a way to turn common carbon fiber into graphene quantum dots, tiny specks of matter with properties expected to prove useful in electronic, optical and biomedical applications.The Rice lab of materials scientist PulickelAjayan, in collaboration with colleagues in China, India, Japan and the Texas Medical Center, discovered a one-step chemical process that is markedly simpler than established techniques for making graphene quantum dots. The results were published online this month in the American Chemical Society's journal Nano Letters.Quantum dots, discovered in the 1980s, are semiconductors that contain a size- and shape-dependent band gap. These have been promising structures for applications that range from computers, LEDs, solar cells and lasers to medical imaging devices. The sub-5 nanometer carbon-based quantum dots produced in bulk through the wet chemical process discovered at Rice are highly soluble, and their size can be controlled via the temperature at which they're created.
Writing and reading a magnetic byte: this image shows a magnetic byte imaged 5 times in different magnetic states to store the ASCII code for each letter of the word THINK, a corporate mantra used by IBM since 1914. The team achieved this using 96 iron atoms − one bit was stored by 12 atoms and there are eight bits in each byte.
PRESS RELEASE: Researchers at Chalmers have for the first time demonstrated a novel subharmonicgraphene FET mixer at microwave frequencies. The mixer provides new opportunities in future electronics, as it enables compact circuit technology, potential to reach high frequencies and integration with silicon technology.http://www.chalmers.se/en/news/Pages/Graphene-mixer-can-speed-up-future-electronics.aspxA mixer is a key building block in all electronic systems – a device that combines two or more electronic signals into one or two composite output signals. Future applications at THz frequencies such as radar systems for security and safety, radio astronomy, process monitoring and environmental monitoring will require large arrays of mixers for high-resolution imaging and high-speed data acquisition. Such mixer arrays or multi-pixel receivers need new type of devices that are not only sensitive but also power-efficient and compact.The ability in graphene to switch between hole or electron carrier transport via the field effect enables a unique niche for graphene for RF IC applications. Thanks to this symmetrical electrical characteristic, the researchers at Chalmers have managed to build the G-FET subharmonic resistive mixer using only one transistor. Hence, no extra feeding circuits are required, which makes the mixer circuit more compact as opposed to conventional mixers. As a consequence, the new type of mixer requires less wafer area when constructed and can open up for advanced sensor arrays, for example for imaging at millimetre waves and even sub millimetre waves as G-FET technology progress.- “The performance of the mixer can be improved by further optimising the circuit, as well as fabricating a G-FET device with a higher on-off current ratio”, says Jan Stake, professor of the research team. “Using a G‐FET in this new topology enables us to extend its operation to higher frequencies, thereby exploiting the exceptional properties of graphene. This paves the way for future technologies operating at extremely high frequencies.”
Researchers from the NUS Nanoscience and Nanotechnology Initiative (NUSNNI) have developed the world's first energy-storage membrane, answering the need for cost-effective and environmentally friendly energy storage and delivery solutions. http://newshub.nus.edu.sg/headlines/0911/membrane_30Sep11.phpThe research team, led by Principal Investigator Dr Xie Xian Ning, used a polystyrene-based polymer to deposit the soft, foldable membrane converted from organic waste which, when sandwiched between and charged by two graphite plates, can store charge at 0.2 farads per square centimetre. This capability was well above the typical upper limit of 1 microfarad per square centimetre for a standard capacitor. The cost involved in energy storage is also drastically reduced with this invention, from about US$7 to store each farad using existing technologies based on liquid electrolytes to about US$0.62 per farad. Dr Xie said: "Compared to rechargeable batteries and supercapacitors, the proprietary membrane allows for very simple device configuration and low fabrication cost. Moreover, the performance of the membrane surpasses those of rechargeable batteries, such as lithium ion and lead-acid batteries, and supercapacitors."
Energy storage is especially important for maximizing solar power. Until now: “It’s cheaper to generate an electron than to store one,” said Jim Greenburger, executive director of the US-based National Alliance for Advanced Technology Batteries. “The function of storage is to help the generator to deliver steady power.”Zinc-AirThese batteries use a porous electrode allowing air inside the battery where a catalyst helps form hydroxyl ions at an oxygen-electrolyte interface. The ions help oxidize a zinc electrode, creating current. During recharging, zinc oxide is converted back to zinc and oxygen is released. Aside from its stability and planet-healthy lack of toxic metals, zinc air batteries have promise for electrical vehicles as well.Sodium-IonAquion Energy, based in Pittsburgh, Pennyslvania, is developing what it calls a low-cost, ambient temperature sodium-ion battery. It uses an electro-chemical couple said to be capable of thousands of deep discharge cycles with little or no loss of capacity and an efficiency of more than 85%. It uses thicker electrodes (carbon anode and sodium cathode), a sodium-based aqueous electrolyte and less-expensive separators and current collector materials. The battery uses no hazardous materials. The plan is to build units with a capacity between 10 kWh and 100 kWh that can perform for more than two hours. Aside from being 100% recyclable, the battery is expected to withstand discharge abuse, incur low maintenance costs and can be assembled in open-air environments. It is expected to cost less than a third of lithium-ion technology. Aquion hopes to release a commercial grid-enabled battery in 2012.Lithium-IonPaul Denholm, a systems analyst for the National Renewable Energy Laboratory (NREL) said that while lithium-ion (li-ion) batteries have been primarily used for electric vehicles and smaller applications, the technology is gaining interest from companies looking to develop them for the grid. The primary issue is their high cost.Researchers at the University of Leeds in the UK have licensed a new material and process that could simplify the manufacture of li-ion cells to Livermore, California-based PolyStor Energy Corporation. Electrovaya Inc., a Canadian manufacturer of nano-structured polymer li-ion battery platforms started work in late 2011 on a project to build a 1.2 mWh storage system at a Manitoba research facility using end-of-life li-ion batteries from electric vehicle (EVs).Iron-copper nanoparticlesYi Cui, a materials science and engineering professor at Stanford University, recently developed nanowire anodes for li-ion batteries. The electrode is said to be 99% efficient and offer 10 times higher specific charge capacity of existing carbon anodes, maintaining 83% of their charge after 40,000 cycles. (Lead-acid batteries last for just hundreds of cycles, while li-ion batteries typically last for 1,000.) The new electrode uses the same principle as li-ion, but accomplishes it using abundant and inexpensive elements. Yi Cui says the new battery will use a water-based electrolyte rather than the solvent typically used in li-ion batteries.Sodium sulfur“There are a wide range of maturities for the sodium sulfur (NaS) battery,” according to Denholm of the NREL, explaining that NGK Insulators, based in Japan, builds cells for grid-tied systems. A 4 mWh system currently provides transmission backup for an almost 70-year-old infrastructure in the event of a line outage for about 4,000 people in Presidio, Texas. It’s the first of its kind in Texas and the largest in the US. This molten-metal type of battery has high energy density, high efficiency (89–92%) and long cycle life. While made from inexpensive materials, it operates at high temperatures (300 to 350 degrees C) and must be contained in concrete structures.Lead-acid“Even though lead-acid chemistry is over a hundred years old there are people doing some new things with it to make it competitive,” Denholm said. Greenburger agreed, explaining, “Everybody in the business keeps waving their hands, saying lead-acid is the cheapest.”
There are way more phones and increasinglysmartphones than more traditional computers. The majority of human being's first computer and access to the internetworked mind of humanity will be through a cell phone. Increasingly these are smartphones. Android is beating up on Apple and everyone else here. 91.4 million people in the U.S. owned smartphones during the three months ending in November, up 8 percent from the preceding three month period. Google Android ranked as the top smartphone platform with 46.9 percent market share, up 3.1 percentage points from the prior three-month period. Apple maintained its #2 position, growing 1.4 percentage point to 28.7 percent of the smartphone market. RIM ranked third with 16.6 percent share, followed by Microsoft (5.2 percent) and Symbian (1.5 percent).
In November, 72.6 percent of U.S. mobile subscribers used text messaging on their mobile device, up 2.1 percentage points. Downloaded applications were used by 44.9 percent of subscribers (up 3.3 percentage points), while browsers were used by 44.4 percent (up 2.3 percentage points). Accessing of social networking sites or blogs increased 2.1 percentage points to 33.0 percent of mobile subscribers. Game-playing was done by 29.7 percent of the mobile audience (up 1.2 percentage points), while 21.7 percent listened to music on their phones (up 1.0 percentage points).http://www.comscore.com/Press_Events/Press_Releases/2011/12/comScore_Reports_November_2011_U.S._Mobile_Subscriber_Market_Share
There was a commercial in the states that shows a guy looking with shocked envy at a truck unloading a 4D TV at his neighbor's while the truck in front of his house is unloading his brand new 3D TV. His bratty young daughter is skipping around the front yard daunting him with "you got the wrong TV!". Well TVs are moving rapidly. I am chagrined to admit I don't even have a 3D TV. Now here is an 84-inch one! Why don't they cover the wall with a screen and be done with it? Or upload us. Or at least plug our brains directly into the computational/communication/educational/entertainment global brain.http://www.hdtvtest.co.uk/news/lg-uhdtv-passive-3d-201112311594.htmFor those who enjoy watching their favourite movies on a huge screen yet want to ensure that they also get excellent picture quality and crystal clear clarity, there has been some good news from Korean television manufacturer LG Electronics. The technology giant is set to unveil the world’s largest ultra-high-definition (UHD) 3D TV at the Consumer Electronics Show (CES) in Las Vegas next month.LG Electronics Home Entertainment Company’s president and CEO Havis Kwon said that the new advanced UHDTV and the technology used would push “the limits of home entertainment innovation”. He added that the firm is determined to show the CES audience that it is dedicated to being the global leader “for immersive home entertainment in 2012 and beyond.”The LG 3D-capable UDTV will feature a native screen resolution of 3840×2160 – which equates to eight million pixels and four times the resolution of a full HD panel – as well as the company’s passive 3D technology. LG hopes to take home entertainment to a whole new level with this offering, by providing the best immersive viewing experience outside of cinema screens.The ultra-high-definition 3DTV will also grant consumers access to the Smart TV ecosystem from LG, through which they can enjoy a huge range of internet-connected services including over 1200 apps. There is also a 2D-to-3D conversion engine on board, which allows viewers to enjoy limitless extra-dimensional viewing.
