Science & Technology News (1121)
Posted: December 1, 2015 05:43AM
We are likely all familiar with rainbow holograms, as they are used to help secure currencies and credit cards. Making these holograms is somewhat difficult, but researchers at ITMO University have managed to significantly simplify the process by bringing it to inkjet printers.
The process of creating a rainbow hologram starts with making a master hologram using a laser to record onto a photosensitive polymer. This polymer is then dried and the unexposed parts are washed out, leaving a stencil that is transferred to a metallic matrix that can emboss the hologram onto a transparent film. All told, this can several days, especially as temperature control and vibration isolation is necessary for creating the master hologram. This new printing method takes just minutes as it only requires printing a nanocrystalline ink onto a microembossed surface, which is later covered by a varnish. The ink has a high refractive index across the visible portion of the spectrum, so even under a varnish or polymer layer the hologram is preserved.
Naturally this discovery could dramatically reduce the cost of these holograms, but also make it possible to create holograms of any size.
Source: ITMOP University
Posted: November 30, 2015 02:40PM
Ever since it was discovered, researchers have been thinking of more and more applications for graphene, with a heavy focus on electrical and optical systems. This is because the material has many useful electrical and optical properties, but it also has beneficial mechanical properties. Now researchers at the University of Belgrade, Serbia, as reported by the Institute of Physics, have successfully used graphene in a microphone.
Graphene is an atom-thick sheet of carbon that is transparent, flexible, strong, and highly conductive. Its high strength and flexibility is what the researchers are taking advantage of, along with its light weight, by making an acoustic membrane out of it. This is the part of a condenser microphone that actually converts sound into an electrical current. The membrane is about 60 layers of graphene thick and the researchers placed it into the housing of a commercial microphone for testing. Compared to a typical nickel-based microphone, the graphene-based version demonstrated a 15 dB higher sensitivity at frequencies up to 11 kHz. In theory adding more layers to the membrane will allow it to perform well in the ultrasonic range of the spectrum.
While it is impressive as is, the graphene-based microphone is just a proof of concept, especially as graphene is difficult to produce. As manufacturing obstacles are knocked down though, we could see these more sensitive microphones appearing at lower costs.
Source: Institute of Physics
Posted: November 30, 2015 05:38AM
For many people, understanding superconductor is an ultimate goal as these materials could revolutionize much of the modern world. This is much easier said than done though, as the physics behind superconductivity is quite complicated and crosses many fields. Now researchers at Aalto University have made an unexpected discovery that links superconductivity and topology by solving a curious paradox.
Back in 1928 theories on the motions of electrons in crystals were developed and it was found that electrons in a crystal will act like electrons in free space, thanks to quantum mechanics. In the crystal though, the ordered array of atoms will make the electrons behave like they have more or less mass than normal. In superconductors, where electrons can flow without resistance, it is actually possible for the electrons to appear to have infinite mass, which is contrary to expectations as infinite mass would stop a normal particle. Under quantum mechanics though, electrons are both particles and waves and by including something called the quantum metric to characterize the electrons, the answer appears. While the apparent mass of the electrons increase within the superconductor, this metric also increases, making the electrons seem to spread across the crystal. The greater the quantum metric is, the greater the supercurrent that can be carried.
The quantum metric has a relation to the Chern number from topology, where it is an invariant. That means that without breaking the object, the value will not vary, like the number of twists in a belt. By having a nonzero value for the electrons, the electron waves will be forced to overlap, which ensures superconductivity. The next step for this research could be to test the prediction in ultracold gases.
Source: Aalto University
Posted: November 25, 2015 05:28AM
A somewhat common concept in science fiction is the mining of asteroids and other airless bodies for various materials. In the coming decades this could become a reality, and researchers at Vanderbilt and Fisk Universities, NASA's Jet Propulsion Laboratory, and the Planetary Science Institute have recently created something that should help. They have developed a new gamma ray detector that is extremely efficient compared to current systems.
Gamma rays are very high energy photons and are also well known in science fiction. The current gold standard for gamma-ray spectroscopy is high purity germanium, but these systems require a lot of power and cryogenic cooling. Space missions are not really able to supply these needs, but a sensor based on europium-doped strontium iodide (SrI2)is far easier to work with. This newly discovered material is transparent and when a gamma ray hits it, a flash is created that can be seen and recorded. The idea is that a spacecraft of lander could have one of these gamma ray detectors on board and use it to pick up the gamma rays emanating from subsurface materials after they are struck by omnipresent cosmic rays.
By needing less power, weighing less, and being cheaper to make, SrI2 detectors could prove invaluable when an asteroid mining economy starts up. Before then though, we may see them appear on various spacecraft with the purpose of studying make-up of objects throughout the Solar System.
Source: Vanderbilt University
Posted: November 24, 2015 02:26PM
Many devices today have cameras integrated into them for a number of reasons, from capturing images to motion tracking. All of these systems utilize lenses for focusing light onto the sensor, and those lenses add to the bulk and cost of the camera. Researchers at Rice University, however, have developed a new, lens-less solution called FlatCam.
Traditional digital cameras are like cubes in that the surface area of the sensor is tied to the system's thickness. If you want greater surface area for better low-light performance, you will also have to increase the thickness of the camera. FlatCam decouples these parameters though by placing a grid-like mask directly over the sensor. This mask is like a great number of pinhole cameras, which do not use lenses, and restricts the light data that strikes the sensor. The raw data from the sensor is then sent to a processor to build an image, and like a light field camera, the picture can be focused after taking it. In addition to this, FlatCams can be flexible and cost less than traditional cameras, by leaving out the assembly steps for integrating lenses.
The prototypes of FlatCam were hand-built with off-the-shelf sensors and create 512x512 images in seconds with a desktop computer, while being thinner than a dime. With better algorithms and manufacturing methods, it should be possible to increase both the resolution and speed of the system.
Source: Rice University
Posted: November 24, 2015 07:03AM
There has been a great interest for a long time now to make cars more efficient and one way this is being achieved is by downsizing the engine. This can be a tricky tactic though, because the pressures and temperatures the engine components must endure increase. To continue downsizing and increasing engine power, harder steels must be made and researchers at Karlsruhe Institute of Technology have recently found a more efficient means of making such a steel.
Low-alloy steels contain less than five mass percent of metals other than iron and can be made to have a hard surface with a soft core. One way to process these steels is low-pressure carbonitration, which enriches the surface with carbon and nitrogen at temperatures between 800 and 1050 ºC, but at low pressure. The low pressure is necessary to limit surface oxidation but it also has the effect of making a more consistent hardness profile. Normally this process uses ammonia as a nitrogen donor and a carbon donor like ethyne or propane, but the KIT researchers found they could replace these two gases with just one. Methylamine (CH3NH2) and dimethylamine ((CH3)2NH2) can both supply the carbon and nitrogen, which simplifies and accelerates the process. This is because the carbon and nitrogen are able to enter the material in parallel, and methylamine can also be used at higher temperatures, speeding up the process even more. Plus the gas is used better, so less is needed.
Now the researchers are working on optimizing the process and then bringing the process out of the lab and to the pilot scale.
Posted: November 23, 2015 02:35PM
Fairly often a tradeoff must be made between protection and sight, as the eyes must be uncovered to see, exposing them to danger. It appears one species managed to get around this issue by having eyes within its hard shells, as researchers at MIT have discovered.
Acanthopleura granulate, a species of chiton, can be found around the world, if you know how to distinguish them from the rocks they live on. For a while we have known that they have eyes in their hard armor, but did not know if these were true eyes or just photoreceptive areas. The MIT researchers were able to isolate the lenses and found that they actually could focus light and produce images. What makes these eyes so interesting is that they are made of the same tough, ceramic material as their shells, unlike the primarily protein eyes of almost everything else. This means the eyes are just as tough as the whole of the chiton's shell, without sacrificing sight. Beyond that, the lenses can focus light in both air and water, as the species lives in intertidal zones, spending time both in the air and underwater.
This discovery could lead to advances in armor for the military and those who work in hazardous areas, since we now have an example of a vision being fully integrated into armor.
Posted: November 23, 2015 05:12AM
Quantum mechanics has many unusual phenomena and entanglement is near the top of the list, as it allows two systems to be so strongly linked that manipulating one can affect the other. Creating entangled systems at the macroscale is very difficult as it often requires very low temperatures and very powerful magnet fields, or chemical reactions. Researchers at the University of Chicago though have successfully entangled particles in a semiconductor at room temperature with a small magnetic field.
The researchers entangled electrons and nuclei within SiC, a semiconductor, using infrared laser light and electromagnetic pulses. The laser ordered the magnetic states of the particles and then the electromagnetic pulses, like those of an MRI machine, actually entangled them. The volume the entangled particles occupied is about 40 cubic micrometers, or the size of a red blood cell. It has been known for some time that defects in semiconductors, like SiC, have excellent quantum properties that will preserve quantum states for long periods of time, and can be controlled by photonics and electronics.
For now the technique could be used to create quantum sensors that can break through the sensitivity limit of traditional sensors. Eventually though, especially if the entangled states could be made across different SiC chips, this macroscopic entanglement could be used to create advanced and secure communication networks.
Source: University of Chicago
Posted: November 20, 2015 03:07PM
The backbone of the Internet is light, as optical signals transmit information across the globe at very high speeds. With an ever increasing demand for greater bandwidths though, many are seeking new means of improving the technologies involved. As reported by The Optical Society, researchers have created a new tunable filter that could help push the Internet to new boundaries.
Filters are a necessary part of optical communications, as they are what allow us to isolate specific frequencies and channels. Traditionally optical networks have frequencies and channels predetermined and fixed, but by moving to a flexible design, the amount of data transmitted could grow by orders of magnitude. Key to such networks are filters that can be quickly and efficiently tuned, and that is what the researchers have built. It uses periodic nanostructures to separate different light frequencies and micro-heaters to alter these structures and tune the filter. The filter can operate over any range of frequencies, is of excellent filter quality, and has the widest tuning span ever demonstrated on a silicon chip.
The filter was built on a CMOS-compatible platform, so it could be quickly and cheaply manufactured by leveraging existing CMOS techniques. Naturally it could also be integrated into other CMOS-compatible chips, which would further support its adoption.
Source: The Optical Society
Posted: November 20, 2015 04:57AM
Humans need fresh water to survive, and the supply is not unlimited so numerous technologies have been developed to purify saltwater. Many of these methods can require a lot of energy or filters that can clog up, so other means are still being developed. Researchers at MIT have developed an interesting new approach that separates salt and fresh water using a shockwave.
This process is called shock electrodialysis and uses a porous material with membranes or electrodes sandwiching it. If a current is pushed through the system, salty water will separate into areas with more and less salt. If the current is high enough though, a shockwave will be created between these areas as a very strong gradient between salt and fresh water. These two regions can then be separated with a physical barrier. While membranes can be used in this setup, the water flows over them, instead of through them so they will not be fouled up with particles or damaged by the water pressure.
Beyond separating out fresh water, this approach could also kill off any bacteria in the water, due to the powerful electric fields used. Currently the method will not compete with established techniques, like reverse osmosis, but as it scales up, this may change. It could find other cleanup uses though, and it requires very little infrastructure, so it could be deployed in remote areas or emergency situations.
Posted: November 19, 2015 02:42PM
Computer hardware manufacturers have been pushing towards smaller component sizes for a long time, as smaller sizes can bring with them improve energy efficiency and performance. Eventually they want to make devices on the scales of atoms, but in this domain there are new problems needing new solutions. Researchers at Brookhaven National Laboratory have found one possible solution for imperfections in atom-wide wires.
At just an atom wide, these wires are effectively one dimensional and could be exceptional conductors. The catch is that imperfections in the wire can easily cause electron waves to reflect back down its length, and it is impossible to remove all imperfections. The Brookhaven researchers have developed an interesting solution though that ties the direction the electrons are moving to their spin. The spin of an electron is a fundamental characteristic of the particle and can be very resilient to changes. The researchers bind the spin and direction of the electron by embedding magnetic moments along the atom-wide path.
For now this is just a theory and will need to be tested very carefully, but because this is the only proposed solution and both laboratories and industry want to reach the atomic-scale, it will certainly be tested thoroughly.
Source: Brookhaven National Laboratory
Posted: November 19, 2015 05:11AM
Light emitting diodes can be found almost anywhere, and with their great efficiency, many want to see them used in even more places. The problem is that LEDs tend to be considerably more expensive than their more traditional counterparts. That may be changing soon though, thanks to researchers at Florida State University who have created a perovskite with exceptional performance.
Perovskites are an interesting class of organic-inorganic materials characterized by their crystal structure. Others have tried to build LEDs from them before, but these tended to perform more poorly than expected. The Florida researchers felt that by tweaking the material, they could improve performance, and they did to the point of surprising themselves. For a computer monitor, LEDs typically need to glow at around 400 nits, or candelas per square meter, but the perovskite LEDs they made were coming in at 10,000 nits from just 12 V.
Beyond the impressive luminance of the material, it is also relatively inexpensive and the researchers were able to make it in their lab in an hour, with the full device completed and tested in half-a-day. Also perovskites are typically unstable in humid air, but the nanostructures used here demonstrated great environmental stability, which can further cut costs by requiring less sophisticated manufacturing infrastructure.
Source: Florida State University
Posted: November 18, 2015 02:31PM
For a long time now, researchers have been working towards quantum computers that exploit quantum mechanics to perform operations traditional computers would take millennia to complete. We are still working on the technologies and components that will be necessary to construct these computers though, but are continually making important steps. Now researchers at the University of New South Wales have successfully built two qubits into a silicon microchip and written quantum computer code to them.
While traditional computers utilize bits with values of zero and one, quantum computers use qubits that can be both zero and one at the same time, thanks to superposition. By also entangling these qubits with each other, quantum code that has no analogy in normal computers can be encoded. With qubits made from an electron and nucleus of phosphorus atoms embedded into silicon chips, the New South Wales researchers were able to achieve write this code. Further the design they used passes a measure of locality with the highest 'score' ever recorded in an experiment. Locality means that objects are only influenced by those around them, and not remotely as quantum mechanics can allow. A high score means the system is indeed quantum mechanical in nature.
By achieving this with qubits in silicon chips similar to modern microchips, this work is a tremendous step forward for creating full quantum computers. It also provides a platform to work with quantum computer code and algorithms.
Posted: November 18, 2015 06:22AM
At some point we may have very secure communications thanks to the nature of quantum mechanics. When a quantum, like a photon is observed its properties can be altered, so any eavesdropping on optical telecommunications can be detected. Researchers at RMIT University in Melbourne have recently found a way to create the necessary photons directly on CMOS chips, which throws open the door to networks secured by quantum encryption.
Typically creating the single photons or photon pairs needed for quantum encryption is complicated by the need of gases or complex micro-structured fibers. This new design though uses a micro-ring resonator, which is a ring the photons will travel around and around in, causing classical effects to be suppressed and quantum processes to be amplified. Two laser beams of different wavelengths are what feed the system, but there is normally a risk that these beams will collapse the desired quantum state, and the photons will normally have the polarization of the original lasers. By exploiting nonlinear optics though, the researchers were able to bake everything they needed directly onto a chip.
As these chips can be made with the techniques at existing CMOS foundries, they can be made on a large scale easily and eventually be integrated into computer chips. Both of these achievements could drive quantum encryption to be very rapidly adopted.
Source: RMIT University
Posted: November 17, 2015 05:48AM
Lasers are a really cool technology that enables all kinds of other technologies and experiments. One thing fairly consistent with lasers is that they heat the targeted object up as the beam continues to strike it. Researchers at the University of Washington have changed that though, by actually cooling water by 36 ºF with an infrared laser.
This refrigeration effect was first demonstrated at Los Alamos National Laboratory in 1995, but in that case vacuum conditions were required. What the Washington researchers have achieved is under real-world conditions though, so it has many possible applications. It works by aiming the laser at a microscopic crystal that has been suspended in the water, or other liquid. When the crystal is hit by the light, it emits a glow, but this glow puts out more energy than the laser is providing. The extra energy therefore comes from the crystal's environment; the liquid it is suspended in.
This discovery has many applications, including in biology as it could allow lasers to precisely cool various cells when undergoing different processes. It could even be deployed to cool objects like computer chips. Currently though, the process takes a lot of energy, so the researchers are going to continue to work on ways to improve its efficiency.
Source: University of Washington
Posted: November 16, 2015 02:28PM
When quantum mechanics was still in its infancy, many scientists took up positions for and against it, with Albert Einstein initially against it. The reason he was against it is because he and another scientist worked out a scenario that would require "spooky action at a distance" to be possible under the new rules. Today we know that phenomenon to be quantum entanglement, but we have still been checking that there are no non-quantum answers, and researchers at NIST have settled the question.
The scenario Einstein helped develop was that two quanta could be made to share a state, such that revealing the state of one would instantly affect the other. That problem is that instant effect because according to Relativity, information cannot travel faster than the speed of light, so some 'spooky action' must be involved. While on paper entanglement is the answer, in reality there are other ways to replicate the phenomenon without invoking quantum mechanics, such as by having sampling biases, not having detection separated enough. The NIST experiment was able to rule out these loopholes though, thanks to new technologies that can efficiently detect photons faster than light-speed communication could reach from one detector to another, and with settings picked by random number generators.
The results technically do not prove quantum mechanics is the answer, but leave only a one in 170 million chance that some local hidden action is the solution. This exceeds the five sigma confidence level needed to declare a discovery to the particle physics community.
Posted: November 16, 2015 05:48AM
Among the promises of Cloud Computing is that an underpowered thin client, like a smartphone, can use the power of remote servers to perform processes that would take too long to do locally. To manipulate images taken by a phone, this requires uploading the original image, the instructions for the manipulation, and then downloading the image again. MIT researchers, however, have devised a new method that dramatically cuts the down on the data transmitted, the power consumed, and the time needed.
Instead of sending the original image to the servers, this new method has the phone send a low resolution JPEG version. As one pixel in this image represents an average of pixels in the original, high-frequency noise is added to the image. This effectively increases the resolution of the image by adding random data, which is there to prevent the image manipulation algorithms from using color consistency too heavily. Now the server applies the manipulation to the noisy image and breaks it into pieces. These pieces are then analyzed by a machine-learning algorithm to characterize the manipulation in just 25 parameters. Now instead of transmitting multiple pieces, say 64x64 (4096 pixels) in size, just 25 numbers are sent for each piece, cutting bandwidth consumption by 98% to 99%. Using those parameters, the phone can apply the manipulation itself far more easily than if it tried to do it all on its own. In fact, the power it consumes performing these manipulations is less than the power it would take to upload and download the original and manipulated images.
This method is only applicable in some situations, such as applying filters to an entire image and not removing and replacing parts of it, but when you consider the savings it brings with it, that is hardly a concern. Also the resulting image is technically not quite what applying the manipulation directly to the original image would get you, but it is close enough to be acceptable.
Posted: November 13, 2015 01:59PM
There has been a somewhat recent change in medical science as technologies and techniques have been enabling treatments to become individualized to the patient. This generally means the treatments will be more effective and can come with fewer side effects. Now this personalization can be extended to some medical devices, thanks to researchers at Northeastern University.
Additive manufacturing, especially 3D printing has become pretty famous of late as it enables interesting and unusual structures to be created quickly and cheaply. The Northeastern researchers decided to try applying 3D printing to the creation of catheters, especially for premature babies. Every premature baby has its own set of unique problems, so the standardized sizes and shapes of catheters can be problematic. By printing catheters designed for the patient's needs, the risks of traditional catheters can be minimized and removed. This requires a new 3D printing technique though, as the reinforcing ceramic fibers in the composite mix making the catheter, must be precisely arranged. To achieve this, the researchers applied very small amounts of iron oxide to the ceramic fibers, so that ultralow magnetic fields can manipulate them. Then a laser can be used to harden the plastic surrounding the ceramic fibers
Beyond the creation of better catheters for neonatal care, this research could lead to many other medical devices, but also better designed materials. This opens the door to not only theorizing the best fiber architecture for something, but actually testing the architecture.
Source: Northeastern University
Posted: November 13, 2015 06:04AM
Researchers at North Carolina State University have discovered a new way to create ideal geometric phase holograms from any optical pattern. These holograms could be applied to make new kinds of displays, imaging systems, telecommunication tech, and more.
Geometric phase holograms are thin films that can focus, disperse, reorient, and manipulate light in even more ways, while ideal version do all of this very efficiently. Making ideal geometric phase holograms is difficult though, because the molecules or structures within them must be smaller than the wavelength of light. Naturally this has limited their applications, but the North Carolina researchers have developed two methods that grant the necessary control, while also being simpler. They work by creating a high-fidelity light pattern on a substrate with a tightly focused laser or by exploiting how the waves interfere with each other. The molecules in the substrate orient themselves based on the polarization of the light that hits them, giving the researchers the control they require. The light pattern can then be transferred to the liquid crystal layer that actually forms the hologram.
Technically there is a limit to the scale of the patterns this method can work with, but the researchers have not run into it yet as they experiment with practical applications. Next the researchers want to try making a hologram that works with both visible and infrared frequencies.
Source: North Carolina State University
Posted: November 12, 2015 02:30PM
There are several components that make up batteries and each influences its performance in various situations. The electrolyte, which carries the ions between the electrodes, is a critical component and its properties can determine the safe operating temperatures for the battery. Researchers at Rice University have recently developed a new electrolyte made of clay that could significantly improve batteries for extreme situations.
The normal organic electrolyte used in batteries has a boiling point around 60 ºC, so if the temperatures around the battery exceed that, vapors can form that can explode. Solid-state electrolytes address this problem well, but do not make very good contact with the electrodes, decreasing the battery's performance. This new electrolyte achieves the best of both worlds because it is made out of clay. For it to work in a battery, the researchers first dry it, removing the water that could react poorly with lithium, and then combine it with an ionic liquid and lithium salt. That produces a peanut butter-like slurry that has the request ions needed to be a viable electrolyte, but it can be spread onto the electrodes, making a good connection.
When tested the electrolyte demonstrated good performance at temperatures up to 120 ºC, which could find it uses in space, defense, and oil and gas applications. Next the researchers want to see just how far they can push the electrolyte, both in terms of temperatures and types of batteries. The material's nature could prove useful in thin film and commercial-scale batteries.
Source: Rice University
Posted: November 12, 2015 05:34AM
Many people have been tricked by thinking that iron pyrite, or fool's gold is the rare precious metal. Instead they have a material of less value, but it could be finding new use soon. Researchers at Vanderbilt University have discovered that quantum dots of iron pyrite could improve lithium ion batteries.
It has already been found that quantum dots of different materials can speed up the charging of lithium ion batteries, but the effect only lasts for a few cycles. However, quantum dots made of iron pyrite, if they are the proper size, can provide the rapid-charging effect while also lasting for dozens of cycles. This is because the iron pyrite becomes directly involved in the electrochemistry of the battery. Instead of the lithium entering the electrode to store energy, the fool's gold breaks down into iron and sulfur, and the lithium combines with the sulfur to store energy. Normally it is just the lithium that has to diffuse in a battery, but in this scenario, the iron must also diffuse, which is why the size of the quantum dots is important. By keeping the size beneath the diffusion length of iron, the iron atoms can more easily diffuse, increasing energy storage.
More work needs to be done before fool's gold enters our batteries, but we could see this being one way to create batteries capable of charging in just seconds. The researchers believe a deeper study of the chemical storage mechanisms involved will significantly help with developing these batteries.
Source: Vanderbilt University
Posted: November 11, 2015 02:40PM
We may not think about it much, but one aspect of modern life is having a lot of transmissions piercing our bodies all the time to bring our various devices the latest information. Sometimes these transmissions run into each other, causing interference that slows things down significantly. Researchers at Northwestern University have devised a clever way to ease this congestion by looking to FM transmissions.
Unless you are living far removed from your neighbors, there is a good chance that you have wireless networks that bump against each other, and transmissions for one network can affect those of others. To address this issue, the researchers have developed a scheduling system that takes advantage of how common and penetrating FM signals are. These signals are able to pass through walls and other obstacles without much loss, and are comprised of blocks 104 bits long. Because these bits will arrive at neighboring networks at nearly the same time, they can be used to synchronize schedules between the networks. By monitoring transmissions at different times, the Wi-FM system can determine what parts of the schedule are free and only transmit at those times, preventing congestion, and all without direct communication between the networks.
This technology could actually be deployed relatively easily as in many cases it only requires a software update. Many wireless devices already have FM components integrated into the Wi-Fi and Bluetooth chips.
Source: Northwestern University
Posted: November 11, 2015 05:09AM
With the various components in our computers, there are a number of places that slowdowns can occur because some hardware simply operates slower than the rest. For a long time magnetic hard drives would hold back loading times, and while Flash-based SSDs have accelerated things a lot, they are not without faults. Now researchers at the University of Sheffield have discovered a means to improve racetrack memory, a possible future memory solution.
Like traditional hard disks, racetrack memory stores data magnetically, but the medium is tiny wires instead of physical disks. The data is moved along the wires, like cars on a racetrack, for reading and writing, but moving the data requires magnetic fields or electric currents. While these options work, they take more power than is desirable, but the Sheffield researchers have found a new solution. It turns out that surface acoustic waves can also move the data, and the direction the data moves can also be controlled by the frequency of the waves.
Sound waves like this are being used in electronics already, but this is the first time they have been used as part of a memory system. As surface acoustic waves can travel for several centimeters before decaying, it is conceivable that they could be used to affect large arrays of racetrack memory, moving a lot of data very efficiently.
Source: University of Sheffield
Posted: November 10, 2015 05:53AM
Some of the largest and most advanced structures ever built by man have been particle accelerators, because the traditional means of accelerating particles to relativistic speeds require that much room. Recently though, new accelerator designs have been developed that could enable accelerators the size of tables to be built. Now researchers at the University of Maryland have further refined this design to bring the energy requirements down to a fraction of what a lightbulb needs.
Plasma wakefield acceleration works by firing a laser into a plasma. As the laser passes through the ionized gas, it produces a wake behind it that drags electrons along with the pulse, at speeds approaching the speed of light. Normally this requires very powerful laser pulses, but the Maryland researchers decided to try exploiting a phenomenon called relativistic self-focusing. As the laser travels through the plasma, it excites the electrons it hits, making them move back and forth in the laser field, and those at the center of the beam are the most affected. According to Relativity, the faster an object moves, the more its mass will increase, so the electrons at the center of the beam become heavier than those around them. This causes them to slow down and the beam to self-focus, increasing its intensity.
By exploiting this effect, the researchers were able to reduce the energy of the laser pulse to just millijoules, which is how much energy a typical lightbulb uses in a millisecond, while still observing acceleration. This could allow for particle accelerators so small they could be on carts. Also, because of how rapid and violent the acceleration of the particles is, they will radiate gamma rays in ultrashort bursts that could be used for safe medical imaging.
Source: University of Maryland
Posted: November 9, 2015 02:34PM
The human eye is pretty good at finding deviations and variations, but computers struggle to do so, unless the differences are on a large scale. By giving computers the power to spot these differences though, they could help us identify defects and create better looking graphics. Now researchers at MIT have developed a pair of algorithms that are capable of doing just that from still images.
One of the algorithms works by finding repeated shapes in an image and then creates an ideally regular, target version of the image. Next it moves around the pixels of the original image, to approximate the target version, and repeats the earlier process to create a new target image. It continues to iterate these steps until the target images look the same, leaving a surprisingly natural looking image. Reversing this process will amplifying deviations in the original image. The other algorithm looks for color differences to identify shapes, generates idealized versions of these shapes, and then exaggerates the deviations between them and the image.
Potentially these algorithms could be used to identify structural defects, camouflaged objects, and movements our eyes would not normally catch. They can also be applied to create more polished graphics with image-editing software.
Posted: November 9, 2015 05:48AM
The current push for virtual reality systems seems only natural, given the growing capabilities of computers and the desire to become immersed in other worlds, so it is also natural to try to make virtual reality real. To that end, researchers at Queen's University have developed the BitDrones system to allow people to physically interact with virtual objects.
The system uses three kinds of BitDrones that are tracked via reflective markers, so they can be correctly placed in the air. The PixelDrones possess an LED and small dot matrix display while the ShapeDrones have a light-weight mesh around them, giving them a specific shape, and the DisplayDrones carry a curved touchscreen, camera, and Android smartphone board. Together with the motion tracking system, the BitDrones are able to act as an interface for virtual objects, like folders on a computer. When you open a folder, the PixelDrones will form a wheel that you can spin to advance through the contents. With the ShapeDrones virtual structures can be represented and manipulated while the DisplayDrones can be used for Skype calls and will even replicate the caller's motions.
The current system supports dozens of drones, and the BitDrones are about two-and-a-half inches to five inches in size, but the researchers envision shrinking the drones down to half-an-inch and scaling the system up to support thousands of them. On these scales, BitDrones could potentially render high resolution programmable matter for its users.
Source: Queen's University
Posted: November 6, 2015 02:29PM
Despite how common antimatter is in fiction and uncommon it is in reality, it is a real thing that we are still trying to understand. One of the reasons we are trying to understand it is to figure out why there is so little of it in the Universe, compared to normal matter. Some explanations suggest that some properties of antimatter inhibited it from forming (anti)atoms like normal matter did, but researchers at Rice University and Brookhaven National Laboratory have ruled out at least two of these properties.
According to the Big Bang theory, equal parts matter and antimatter should have been created when the Universe was created, but instead we find that matter was more common. Antimatter particles having the opposite charge and spin of their normal-matter counterparts is not enough to explain this discrepancy. Now we know the scattering length and effective range of antiprotons match those of normal protons, so those properties did not lead to the bias either. The scattering length is the measure of how particles, anti- or normal, deviate as they travel a path, while effective range is how close particles must be to magnetically interact with each other. Both of these properties are measured in femtometers.
It took examining data of 500 million particle collisions from Brookhaven National Laboratory's Relativistic Heavy Ion Collider, but finally the data revealed the answers. With the measurements being nearly identical to that of protons, the question remains unanswered, but then researchers had already assumed these properties were the same for decades. This is just the first time that assumption has been confirmed.
Source: Rice University
Posted: November 6, 2015 05:14AM
Welding is a crucial technology for the manufacturing of many objects and structures, but it does have some important limitations. For one thing it can take a lot of energy and many metals cannot be welded together, without the welds being weak. Researchers at Ohio State University have recently developed a new welding technique though, that addresses both issues.
In resistance spot welding, metals are welded together by applying an electric current that heats a metal by their natural resistances. This heat is enough to partially melt the metals involved, creating the welds, but requires a lot of energy and the melting and re-solidification process can weaken the metals. The Ohio researchers' solution solves both problems by vaporizing aluminum foil. The method is called vaporized foil actuator (VFA) welding and works by connecting aluminum foil to a high-voltage capacitor bank. The capacitors release a powerful pulse into the aluminum foil, causing it to vaporize and create a burst of gas. This burst forces the two pieces of metal to be welded together at speeds nearing thousands of miles per hour.
The result of this method is a weld between the metals' atoms, without melting the metals and weakening them, allowing more metals to be welded than previously possible, including steel and aluminum alloys which were previously un-weldable. Vaporizing aluminum foil also takes less energy than spot welding, so the method itself is more efficient. In addition to that, this technique can shape metal parts at the same time, saving a manufacturing step.
Source: Ohio State University
Posted: November 5, 2015 02:18PM
Thanks to their efficient emission of light, LEDs are growing ever more popular in various applications. Sadly these devices are not recyclable currently so many recyclers are just storing them until they can be processed. That may be changing soon though, as researchers at Fraunhofer-Gesellschaft have found a way of separating the components without damaging them.
One of the reasons we want to recycle LEDs is that the lamps and phosphors contain rare elements, and recovering them would reduce costs. Like all recycling processes, an efficient means of separating the various parts is crucial. To achieve this, the researchers are using electrohydraulic comminuntion, which uses electrical pulses in a water bath to break the LEDs apart. By tweaking the parameters of the process, like voltage and the type and amount of fluid, the researchers are able to the break points the LED components separate at. Already they have been able to adapt their setup for separating the components of the LED lamps used to replace more conventional light bulbs.
Posted: November 5, 2015 05:21AM
Lenses can be a big deal, both when it comes to their influence on images and their physical size. This is because traditional lenses use refraction to affect light and require more of a material to affect light more. Fresnel zone plate lenses, however, rely on diffraction and can be very thin, as researchers at the University of Wisconsin, Madison have demonstrated.
Diffraction concerns how light bends when it pass a barrier's edge, and Fresnel lenses take advantage of it by selectively bending the light to focus it like a conventional lens. To achieve this, the lenses consist of concentric rings alternating between light and dark areas. If the dark areas are not dark enough though, the image will be fuzzy. To overcome this problem, the researchers used black silicon, which traps light in a forest of nanowires. They made the lens by patterning aluminum rings onto silicon wafers and then etching the nanowires into the wafer, creating the black silicon rings. Finally a plastic support was applied and the remaining unwanted silicon was etched away, leaving the Fresnel lens in a flexible plastic.
Because Fresnel zone plate lenses can be made so much thinner and smaller than conventional lenses, potential applications include lenses on surgical scopes that can see more without being too large. By rolling an array of these lenses into a cylinder, they can capture an image with a 170º field of view.
Source: University of Wisconsin, Madison