Scientists from the European Organization for Nuclear Research and the Italian National Institute of Nuclear Physics, under the experiment banner of OPERA are reporting that sub-atomic particles known as neutrinos have the ability to travel faster than the speed of light, a discovery that if verified, would completely disassemble Einstein’s theory of special as well as general relativity. Or, at the outside these findings – if correct – may force science to re-calculate the speed of light :: Read the full article »»»»
In 1911, Kamerlingh Onnes conducted electrical analysis of pure metals - mercury, tin and lead - at very low temperatures. Onnes found that at 4.2 kelvin the resistance in a solid mercury wire immersed in liquid helium suddenly vanished. Some, such as William Thomson - Lord Kelvin – believed that electrons flowing through a conductor would come to a complete halt or, in other words, metal resistivity would become infinitely large at absolute zero. Onnes however felt that a conductor’s electrical resistance would steadily decrease and drop to nil. On April 8, 1911, Kamerlingh Onnes found that at 4.2 kelvin/-270 degrees celsius, the resistance in a solid mercury wire immersed in liquid helium Suddenly Vanished. Onnes wrote in his note-pad that “Mercury has passed into a new state, which on account of its extraordinary electrical properties may be called the superconductive state“. He published more articles about the phenomenon, initially referring to it as “supraconductivity” and, only later adopting the term “superconductivity”
Fast Forward toSeptember 2011: A study undertaken by researchers at Laboratoire National des Champs Magnetique Intenses – Grenoble and published in Nature on September 7, reveals that superconductivity – the phenomenon where a normally conductive materials lose their electrical resistance when cooled – may be linked to the charge-order within the material, in this case copper dioxide. Researchers reported nuclear magnetic resonance measurements showing that high magnetic fields actually induce charge-order, without spin order. The observed static, unidirectional, modulation of the charge density breaks translational symmetry. These findings suggest that charge-order, although visibly pinned by CuO chains in YBa2Cu3Oy, is an intrinsic propensity of the superconducting planes of high-Tc copper oxides :: Read the full article »»»»
Are we on the brink of a major technology shift, display and electronics technology is shifting from metallic wires to plastic -polymer electronics- with surprising results. Research scientist at UCLA Henry Samueli School of Engineering and Applied Science have demonstrated an amazing form of OLED display material that can be stretched upto 45%. Not quite ready to be rolled up into a ball and bounced around the room this hardy little stretchy display is a breakthrough on the road to fully plastic electronics built into everything clothing to coffee tins.
The OLED display demonstrated by the researches was able to be twisted and stretched then return to its original shape all while still operating unaffected. A number of breakthroughs were made in producing this stretchy little patch of plastic. The use of carbon nanotubes in the polymer electronics gives the display flexibility and negates the need for metallic wiring. The polymer also acts as a framework for the carbon nanotubes to form around, simplifying the manufacturing allowing roll to roll manufacturing. The display -emissive polymer- layer is sandwiched between two electronics -composite electrode- layers. The emissive polymer layer contains a discrete LED chip interconnected with stretchable electrodes giving the displays internals enough flexibility to remain fully functional even when stretched. The two outer composite electrode layers contain the single-walled carbon nanotube polymer composite electrodes. These outer layers are also responsible for returning the display to its permanent shape, this effect is due to the shape-memory properties of the composite electrodes. Read the full article »»»»
The making of three-dimensional nanostructured materials - structures that have distinctive shapes at insane scales of a few billionths of a meter — has become a fertile area of research, producing materials that are useful for electronics, photonics, phononics and biomedical devices. But the methods of making such materials have been limited in the 3-D complexity they can produce. An MIT team has found a way to produce more complicated structures by using a blend of current “top-down” and “bottom-up” approaches.
The work is described in a paper published in June in the journal Nano Letters, co-authored by postdoc Chih-Hao Chang; George Barbastathis, the Singapore Research Professor of Optics and Professor of Mechanical Engineering; and six MIT graduate students.
One approach to making three-dimensional nanostructures — a top-down approach — is called phase-shift lithography, in which a two-dimensional mask shapes the intensity of light shining onto a layer of photoresist material (in the same way a photographic negative controls the amount of light reaching different areas of a print). The photoresist is altered only in the areas reached by the light. However, this approach requires very precisely manufactured phase masks, which are expensive and time-consuming to make. Read the full article »»»»
As science develops new devices for studying the world humanity as a collective gains a new way of looking at the world. The European XFEL - X-ray Free-Electron Laser – is one such facility, allowing scientists to photograph molecules, in real-time 3D of course. This allows scientists for the first time to capture chemical reactions taking place, reactions too fast for previous technologies. This is a very big window to the world of the hyper small, nano. XFEL may never be as well-known as CERN and theyre headline grabbing antics, but it will make an important contribution to science none the less.
Dr Markus Kuster, Group Leader of European XFEL GmbH’s Detector Development says: “The European XFEL will represent a major step forward in equipping Europe with a new generation of research infrastructure that can meet the requirements of the 21st century. STFC’s unique skills are creating an imaging device which will help this remarkable facility realise its vast potential” Read the full article »»»»
JAPAN: Tatsuo Hasegawa of the National Institute of Advanced Industrial Science and Technology – AIST – has developed a new inkjet-based printing technique that allows the maufacture of high-performance, single-crystal thin-film transistors. The room temperature process could be used to make large-area printed electronics, including flexible displays, solar cells, electronic paper and sensor sheets. The use of single crystals has been fundamental to the development of semiconductor microelectronics and solid-state science. Whether based on inorganic or organic materials, the devices that show the highest performance rely on single-crystal interfaces, with their nearly perfect translational symmetry and exceptionally high chemical purity. Attention has recently been focused on developing simple ways of producing electronic devices by means of printing technologies. ‘Printed electronics’ is being explored for the manufacture of large-area and flexible electronic devices by the patterned application of functional inks containing soluble or dispersed semiconducting materials. However, because of the strong self-organizing tendency of the deposited materials, the production of semiconducting thin films of high crystallinity – indispensable for realizing high carrier mobility – may be incompatible with conventional printing processes.
Printing techniques, such as inkjet technology, show promise for making large-area and flexible electronic devices and work by depositing patterns on a substrate using inks made of semiconductor materials. One major problem with inkjets is that the deposited materials have poor crystalline properties, which reduces charge-carrier mobility in the material and ultimately degrades device performance. Tatsuo Hasegawa has come up with a new printing process that combines a semiconductor ink and a crystallization ink into one. The first is a semiconductor in a solvent and the second, an “antisolvent” – a liquid in which the semiconductor is insoluble. The method produces exceptionally uniform, single-crystal or polycrystalline thin films that grow at the liquid–air interface on a substrate.
The team used a piezoelectric inkjet printing machine with double printing heads that eject droplets of 60 pl at a frequency of 500 Hz. During the process, the antisolvent ink – pure anhydrous dimethylformamide – is printed first and then overprinted with the ink containing the organic semiconductor C8BTBT. The deposited droplets then naturally mix together on the surface of the substrate. Using an optical microscope, the researchers observed tiny floating bodies that begin to form at the liquid surface. Each body seems to act as a nucleus for further crystallization and subsequently grows larger. These bodies eventually cover the entire surface of the droplet to form C8BTBT thin solid-like layers before the solvent evaporates. The solvent evaporates quite slowly, with the final result being films of C8BTBT that are around 30–200 nm thick, sticking tightly to the substrate surface. Researchers used this material to make thin-film transistors with a gold source and drain electrodes and Parylene-C as the gate dielectric layer. The finished devices have average charge-carrier mobilities as high as 16.4 cm2/Vs. Such a value puts the devices into the high performance range, which starts at 10 cm2/Vs. The on-off current ratio is also high, at 105–107. According to Hasegawa, this performance is much higher than previous transistors made from C8BTBT and compares well with other very-high-performance devices, including rubrene single-crystal devices. “We believe the good properties observed come thanks to the fact the single-crystal thin semiconductor film forms slowly. This is because of the fluid nature of the microliquid droplet in which laminar flow dominates over turbulent flow.” The technique should also work for other functional soluble materials, he adds.
The team, which includes researchers from the University of Tokyo and KEK in Tsukuba, now plans to optimize its equipment and device-processing techniques. “For example, there is plenty of scope for improving the source/drain contacts in our transistors,” said Hasegawa. “The next step will then be to exploit the technique for making printed electric metal wires and then ultimately produce all-printed electronic products.”
AIST has conducted significant research and development aimed at achieving a broad range of printable electronics technologies. As part of a semiconductor material suitable for printable electronics technologies, highly soluble in organic solvents, has been developing the study of organic semiconductor devices suitable for processing at room temperature and atmospheric pressure. Organic semiconductors, Crystalline high Materials low-molecular is obtained device performance higher because of the crystallization and random convection inside the droplet, it is difficult to control the deposition of semiconductors from solution in the printing method is usually the formation of the semiconductor layer homogeneous have been extremely difficult.We have developed a double-shot inkjet printing method to print microscopic ink droplets of alternating two types of ink and promote the crystallization of the organic semiconductor ink dissolved organic semiconductors, with the flatness of semiconductor single-molecule level crystal thin films were prepared. Fabrication of organic semiconductor thin films used in semiconductor single crystals C eight -Btbt is provided by Nippon Kayaku Co., Ltd., a semiconductor single crystal thin films X-ray diffraction measurements, the KEK Photon Factory Synchrotron Radiation Laboratory Synchrotron radiation was used.
University of Michigan boffins have discovered, while shooting lasers through glass, that light shining through non conductive materials exhibit strong magnetic characteristics. The magnetic properties of light were thought to be so weak that they could simply be ignored. With this research that has all changed, the assumption as it turns out was drastically wrong. They discovered that extremely powerful light can generate magnetic fields 100 million times stronger than previously estimated. “Strong enough to induce useable voltages and create magnetic batteries.” Professor Stephen Rand says, adding, “Enough sunlight, focused into an optical fiber, could generate electricity – that’s is a simple way to think about it.”
Along with the obvious optical properties of light it also has electric and magnetic qualities. Solar panels take advantage of the electrical properties of light. These new panels will use the magnetic properties of light to create a solar panel, with the potential to produce a similar amount of power as a traditional solar panel - 10% efficiency -. This does raise the interesting idea of hybrid Electric-magnetic panels for twice the power per square meter. Add in Thermal and you have the big three.
Currently the main drawback is the required 10 million watts per square centimeter of light to induce the effect, normal sunlight produces 0.136 watts per centimeter. Research is still in its infancy so these and other hurdles will present themselves but possibilities like clear windows that generate electricity, magnetic batteries and self-powered displays will keep the white coats solving problems. Maybe even more important though is this discovery will change the way we think about light and magnetic fields interacting.
This is a monumental discovery that opens up a whole new field of science, new possibilities. This is a much bigger change than just some new power source, it’s a whole new side to light that we were blinkered to for so long. Longer term this may change how we look at light -no pun intended - this crosses the light and magnetic boundaries. How much of a game changer this is will take time. Solid numbers are required before any solid conclusions can be made. The Journal of Applied Physics this week published the initial paper by Professor Stephen Rand and doctoral student William Fisher. Keep an eye on this one it will get real interesting.