Posts belonging to Category electronics



Nano Light Consumes Hundred Times Less Than A LED

Scientists from Tohoku University in Japan have developed a new type of energy-efficient flat light source based on carbon nanotubes with very low power consumption of around 0.1 Watt for every hour‘s operation — about a hundred times lower than that of an LED. Electronics based on carbon, especially carbon nanotubes (CNTs), are emerging as successors to silicon for making semiconductor materials, And they may enable a new generation of brighter, low-power, low-cost lighting devices that could challenge the dominance of light-emitting diodes (LEDs) in the future and help meet society’s ever-escalating demand for greener bulbs.
nanolightPlane-lighting homogeneity image of a planar light source device through a neutral density filter
Our simple ‘diode’ panel could obtain high brightness efficiency of 60 Lumen per Watt, which holds excellent potential for a lighting device with low power consumption,” said Norihiro Shimoi, the lead researcher and an associate professor of environmental studies at the Tohoku University. “We have found that a cathode with highly crystalline single-walled carbon nanotubes and an anode with the improved phosphor screen in our diode structure obtained no flicker field emission current and good brightness homogeneity,” Shimoi said.
Source: http://www.aip.org/

Electric Car: Hydrogen Fuel Cells 40 Times Cheaper

Researchers from Umea University – Sweden – and chinese collegues show how a unique nano-alloy composed of palladium nano-islands embedded in tungsten nanoparticles creates a new type of catalysts for highly efficient oxygen reduction, the most important reaction in hydrogen fuel cells. Fuel cell systems represent a promising alternative for low carbon emission energy production. Traditional fuel cells are however limited by the need of efficient catalysts to drive the chemical reactions involved in the fuel cell. Historically, platinum and its alloys have frequently been used as anodic and cathodic catalysts in fuel cells, but the high cost of platinum, due to its low abundance, motivates researchers to find efficient catalysts based on earth-abundant elements. The explanation for the very high efficiency is the unique morphology of the alloy. It is neither a homogeneous alloy, nor a fully segregated two-phase system, but rather something in between.

hydrogen fuel cellsCaption: A schematic model of the unique morphology of the alloy. The Pd-islands (light-brown spheres) are embedded in an environment of tungsten (blue spheres). Oxygen are represented by red spheres, and hydrogen by white spheres.

In our study we report a unique novel alloy with a palladium (Pd) and tungsten (W) ratio of only one to eight, which still has similar efficiency as a pure platinum catalyst. Considering the cost, it would be 40 times lower,” says Thomas Wågberg, Senior lecturer at Department of Physics, Umeå University.
The unique formation of the material is based on a synthesis method, which can be performed in an ordinary kitchen micro-wave oven purchased at the local supermarket. If we were not using argon as protective inert gas, it would be fully possible to synthesize this advanced catalyst in my own kitchen! ,” says Thomas Wågberg.
The findings are published in the scientific journal Nature Communications.

Source: http://www.teknat.umu.se/

Electric Car Batteries Recharge in Two Minutes

Scientists from Nanyang Technological University (NTU Singapore) have developed a new battery that can be recharged up to 70 per cent in only 2 minutes. The battery will also have a longer lifespan of over 20 years.
Electric vehicles are currently inhibited by long recharge times of over 4 hours and the limited lifespan of batteries.
This next generation of lithium-ion batteries will enable electric vehicles to charge 20 times faster than the current technology. With it, electric vehicles will also be able to do away with frequent battery replacements. The new battery will be able to endure more than 10,000 charging cycles20 times more than the current 500 cycles of today’s batteries.
NTU Singapore‘s scientists replaced the traditional graphite used for the anode (negative pole) in lithium-ion batteries with a new gel material made from titanium dioxide, an abundant, cheap and safe material found in soil.
Invented by Associate Professor Chen Xiaodong from the School of Materials Science and Engineering at NTU Singapore, the science behind the formation of the new titanium dioxide gel was published in the latest issue of Advanced Materials.

2014 Renault

While the cost of lithium-ion batteries has been significantly reduced and its performance improved since Sony commercialised it in 1991, the market is fast expanding towards new applications in electric mobility and energy storage,” said Prof Yazami.
There is still room for improvement and one such key area is the power density — how much power can be stored in a certain amount of space — which directly relates to the fast charge ability. Ideally, the charge time for batteries in electric vehicles should be less than 15 minutes, which Prof Chen’s nanostructured anode has proven to do.“.
Source: http://news.asiaone.com

Hybrid Bio-Electronics

Scientists from the University of Leeds have taken a crucial step forward in bio-nanotechnology, a field that uses biology to develop new tools for science, technology and medicine. The study, published in the journal Nano Letters, demonstrates how stable ‘lipid membranes’ – the thin ‘skin’ that surrounds all biological cells – can be applied to synthetic surfaces. Importantly, the new technique can use these lipid membranes to ‘draw’ – akin to using them like a biological ink – with a resolution of 6 nanometres (6 billionths of a meter), which is much smaller than scientists had previously thought was possible.
bioelectronics-
This is smaller than the active elements of the most advanced silicon chips and promises the ability to position functional biological molecules – such as those involved in taste, smell, and other sensory roles – with high precision, to create novel hybrid bio-electronic devices,” said Professor Steve Evans, from the School of Physics and Astronomy at the University of Leeds and a co-author of the paper.
The ability to controllablywrite’ and ‘position’ lipid membrane fragments with such high precision was achieved by Mr George Heath, a PhD student from the School of Physics and Astronomy at the University of Leeds and the lead author of the research paper.
Mr Heath said: “The method is much like the inking of a pen. However, instead of writing with fluid ink, we allow the lipid molecules – the ink – to dry on the tip first. This allows us to then write underwater, which is the natural environment for lipid membranes. Previously, other research teams have focused on writing with lipids in air and they have only been able to achieve a resolution of microns, which is a thousand times larger than what we have demonstrated. “
source: http://www.leeds.ac.uk/

Towards The Bionic Brain

RMIT University (Australia) researchers have brought ultra-fast, nano-scale data storage within striking reach, using technology that mimics the human brain. The researchers have built a novel nano-structure that offers a new platform for the development of highly stable and reliable nanoscale memory devices, useful for nanocomputers. Project leader Dr Sharath Sriram, co-leader of the RMIT Functional Materials and Microsystems Research Group, said the nanometer-thin stacked structure was created using thin film, a functional oxide material more than 10,000 times thinner than a human hair.

Brain Cells
The thin film is specifically designed to have defects in its chemistry to demonstrate a ‘memristive‘ effect – where the memory element’s behaviour is dependent on its past experiences,” Dr Sriram said. “With flash memory rapidly approaching fundamental scaling limits, we need novel materials and architectures for creating the next generation of non-volatile memory. “The structure we developed could be used for a range of electronic applications – from ultrafast memory devices that can be shrunk down to a few nanometers, to computer logic architectures that replicate the versatility and response time of a biological neural network. “While more investigation needs to be done, our work advances the search for next generation memory technology can replicate the complex functions of human neural system - bringing us one step closer to the bionic brain.

The pioneering work will be published in the journal Advanced Functional Materials (11 November).

Source: http://www.rmit.edu.au

How To Produce Massively Nanoparticles In One-Step

Scientists at the U.S. Naval Research Laboratory (NRL) Materials Science and Technology Division have developed a novel one-step process using, for the first time in these types of syntheses, potassium superoxide (KO2) to rapidly form oxide nanoparticles from simple salt solutions in water. An important advantage of this method is the capability of creating bulk quantities of materials. NRL has demonstrated that large quantities (over 10 grams) of oxide nanoparticles can be prepared in a single step, which is approximately four orders of magnitude higher yield than many other methods.
oxidenanoparticleOxide nanoparticles are crucial components in numerous applications to include electronic and magnetic devices, energy storage and generation, and medical applications such as magnetic nanoparticles for use in magnetic resonance imaging (MRI). In all of these applications, particle size is critical to the utility and function of oxide nanoparticle
Typically, the synthesis of oxide nanoparticles involves the slow reaction of a weak oxidizing agent, such as hydrogen peroxide, with dilute solutions of metal salts or complexes in both aqueous and non-aqueous solvent systems,” said Dr. Thomas Sutto, NRL research chemist. One exciting aspect of this technique is that it can also be used to produce blends of nanoparticles. This has been demonstrated by preparing more complex materials, such as lithium cobalt oxide — a cathode material for lithium batteries.

Source: http://www.nrl.navy.mil/

Extremely Bendable Electronics

As tech company LG demonstrated this summer with the unveiling of its 18-inch flexible screen, the next generation of roll-up displays is tantalizingly close. Researchers are now reporting in the journal ACS Nano a new, inexpensive and simple way to make transparent, flexible transistors — the building blocks of electronics — that could help bring roll-up smartphones with see-through displays and other bendable gadgets to consumers in just a few years.
Yang Yang and colleagues note that transistors are traditionally made in a multi-step photolithography process, which uses light to print a pattern onto a glass or wafer. Not only is this approach costly, it also involves a number of toxic substances. Finding a greener, less-expensive alternative has been a challenge. Recently, new processing techniques using metal oxide semiconductors have attracted attention, but the resulting devices are lacking in flexibility or other essential traits. Now Yang’s team developed inks that create patterns on ultrathin, transparent devices when exposed to light.
transparent transistorsThis transparent transistor, which functions even when wrapped around a thin pen, could help make flexible electronics widely accessible.
The main application of our transistors is for next-generation displays, like OLED or LCD displays,” said Yang. “Our transistors are designed for simple manufacturing. We believe this is an important step toward making flexible electronics widely accessible.
Source: http://www.acs.org/

How to “Grow” Billions Of Light Dots Directly On Chips

Researchers from the University of California, Santa Barbara (UCSB), in collaboration with the DARPA, succeeded to grow lasers directly on microchips, a breaktrhrough that will enable the mass-production of inexpensive and robust microsystems that exceed the performance capabilities of current technologies.

Defense systems for instance, such as radar, communications, imaging and sensing payloads rely on a wide variety of microsystems devices. These diverse devices typically require particular substrates or base materials and different processing technologies specific to each application, preventing the integration of such devices into a single fabrication process. Integration of these technologies, historically, has required combining one microchip with another, which introduces significant bandwidth and latency limitations as compared to microsystems integrated on a single chip. Although many photonic components can now be fabricated directly on silicon, realizing an efficient laser source on silicon has proven to be very difficult.
Now, the engineers at UCSB showed it was possible to “grow” or deposit successive layers of indium arsenide material directly on silicon wafers to form billions of light-emitting dots known as “quantum dots.” This method of integrating electronic and photonic circuits on a common silicon substrate promises to eliminate wafer bonding, and has application in numerous military and civilian electronics where size, weight, power and packaging/assembly costs are critical.
laser on chipsDARPA’s Electronic-Photonic Heterogeneous Integration (E-PHI) program has successfully integrated billions of light-emitting dots on silicon to create an efficient silicon-based laser. The Defense Advanced Research Projects Agency (DARPA) is an agency of the United States Department of Defense responsible for the development of new technologies for use by the military.
This method of integrating electronic and photonic circuits on a common silicon substrate promises to eliminate wafer bonding, and has application in numerous military and civilian electronics where size, weight, power and packaging/assembly costs are critical“.“It is anticipated that these E-PHI demonstrator microsystems will provide considerable performance improvement and size reduction versus state-of-the-art technologies,” said Josh Conway, DARPA program manager for E-PHI. “Not only can lasers be easily integrated onto silicon, but other components can as well, paving the way for advanced photonic integrated circuits with far more functionality than can be achieved today.

Source: http://www.darpa.mil/

Carbon NanoTubes Solar Cells Twice More Efficient

Lighter, more flexible, and cheaper than conventional solar-cell materials, carbon nanotubes (CNTs) have long shown promise for photovoltaics. But research stalled when CNTs proved to be inefficient, converting far less sunlight into power than other methods.

Now a research team led by Mark Hersam, professor of materials science and engineering at the McCormick School of Engineering, Northwestern University, has created a new type of CNT solar cell that is twice as efficient as its predecessors. It is also the first CNT solar cell to have its performance certified by the National Renewable Energy Laboratory.

solar cells
The field had been hovering around 1 percent efficiency for about a decade; it had really plateaued,.” Hersam said. “But we’ve been able to increase it to over 3 percent. It’s a significant jump
The problem is that each nanotube chirality only absorbs a narrow range of optical wavelengths,” Hersam said. “If you make a solar cell out of a single chirality carbon nanotube, you basically throw away most of the solar light.”

Hersam’s team made a mixture of polychiral, or multiple chirality, semiconducting nanotubes. This maximized the amount of photocurrent produced by absorbing a broader range of solar-spectrum wavelengths. The cells significantly absorbed near-infrared wavelengths, a range that has been inaccessible to many leading thin-film technologies.
The research is described in the article “Polychiral Semiconducting Carbon Nanotube-Fullerene Solar Cells” in the August 7 issue of Nano Letters.
Source: http://www.mccormick.northwestern.edu/

Medical Nanorobots

Researchers from the Institute of General Physics, the Institute of Bioorganic Chemistry (Russia, Academy of Sciences) and MIPT have made an important step towards creating medical nanorobots. They discovered a way of enabling nano- and microparticles to produce logical calculations using a variety of biochemical reactions.
biological nanorobotsThe scientists draw on the idea of computing using biomolecules. In electronic circuits, for instance, logical connectives use current or voltage (if there is voltage, the result is 1, if there is none, it’s 0). In biochemical systems, the result can a given substance. For example, modern bioengineering techniques allow for making a cell illuminate with different colors or even programming it to die, linking the initiation of apoptosis to the result of binary operations.

Scientists say logical operations inside cells to be a way of controlling biological processes and creating nano-robots, which can deliver drugs on schedule. Calculations using biomolecules inside cells, a.k.a. biocomputing, are a very promising and rapidly developing branch of science, according to the leading author of the study, Maxim Nikitin, a 2010 graduate of MIPT’s Department of Biological and Medical Physics. Biocomputing uses natural cellular mechanisms.

The study paves the way for a number of biomedical technologies and differs significantly from previous works in biocomputing binary operations in DNA, RNA and proteins for over a decade now, but Maxim Nikitin and his colleagues were the first to propose and experimentally confirm a method to transform almost any type of nanoparticle or microparticle into autonomous biocomputing structures that are capable of implementing a functionally complete set of Boolean logic gates (YES, NOT, AND and OR) and binding to a target (such as a cell) as result of a computation.

The prefix “nano” in this case is not a fad or a mere formality. A decrease in particle size sometimes leads to drastic changes in the physical and chemical properties of a substance. The smaller the size, the greater the reactivity; very small semiconductor particles, for example, may produce fluorescent light. The new research project used nanoparticles (i.e. particles of 100 nm) and microparticles (3000 nm or 3 micrometers).

The new work was published on the website of the journal Nature Nanotechnology.
Source: http://mipt.ru/