Science & Technology News (606)
Posted: October 1, 2014 11:05AM
Mistakes happen to everyone, so what is important is to learn from the mistake and move on. A student at the University of Massachusetts at Amherst learned this lesson perhaps better than most as a mistake led to quite a discovery. Researchers at the university have been looking for a way to produce the optimal polymer architecture for organic solar cells, and by a student accidentally using the wrong substrate, they have found it.
Organic solar cells are a promising technology that could potentially out compete modern, inorganic solar cells with comparable or better efficiency, but at a lower cost and greater flexibility. They do have problems though, such as discontinuous pathways that cause energy loss. This can be overcome with the right architecture though and a student produced it while trying to grow polymer crystals, on the wrong substrate. By accident the student had used graphene as the substrate, and the mistake was not realized for over a week, when the sample was put under a scanning electron microscope. At that time not only was the mistake found but so were vertically stacked crystals, resembling blades of grass.
This vertically stacked structure addresses the problem of discontinuous pathways because of how electrons prefer to travel in certain directions through the crystals. This discovery may not just impact solar cells, but could find applications in batteries and vertical transistors as well.
Posted: October 1, 2014 05:34AM
In science classes the concept of 'ideal conditions' can often be invoked, because under ideal conditions, complex systems can be made simpler. Outside of classes complex systems are still simplified by removing complicating terms, but such a sacrifice can also make a mathematical model inaccurate. Researchers at Brown University are working to repair these inaccuracies by adding uncertainty to the models for some very complex systems.
Predicting the weather is not easy, evidenced by the number of times a forecast is wrong, and part of the process for doing that is modelling how pressure waves interact, which we do have equations for. While those generalized equations do successfully model the interactions, they fail to consider other variables that also impact the waves, such as the geography beneath them, for the sake of simplicity. The Brown researchers are trying to correct that by adding a random term to the model as a random forcing. This will result in the model producing a range of values, instead of a single answer, and will make it more realistic.
This work is part of a mathematical field called uncertainty quantifications, which tries to recover some degrees of freedom removed by simplification, as a random forcing. The reason this is only being done now is that computing power has only recently reached the level needed for this work.
Source: Brown University
Posted: September 30, 2014 02:32PM
In many ways, we are used to one-way reactions, such as glass breaking and not healing, and fire consuming, not restoring a material. Under the right circumstances though, many reactions can be reversed, at least in part. Among these is converting carbon dioxide back into a fuel using artificial photosynthesis, and researchers at Berkeley Lab have recently made a discovery that could greatly impact that process.
Actually reducing carbon dioxide to create a fuel is very difficult, so researchers have been looking for an efficient and selective catalyst to ease the process. To that end, the Berkeley researchers investigate bimetallic nanoparticles made of gold and copper. Typically nanocatalysts are comprised of a single element, but by using two instead, the researchers were able to tune their electronic properties. Also, by virtue of being nanoparticles, the researchers were able to control their geometry in monolayers. From this the researchers were able to determine the electronic effect and geometric effect on the production of intermediates; materials that are created during the catalyzed process.
Though the work was done with gold-copper nanoparticles, its results should extend to other potential carbon dioxide reduction catalysts. From that it may be possible to engineer superior catalysts that will make it possible to capture carbon dioxide from the air, and create useable fuels from it.
Source: Berkeley Lab
Posted: September 30, 2014 10:07AM
When one envisions a solar power device, they likely picture a silicon panel that directly converts light into electricity. Just like skinning a cat though, there are many ways to harness the power of the Sun. Researchers at MIT have recently created a material that may greatly advance one of these alternatives.
Solar-thermophotovoltaic (STPV) devices work by collecting Sunlight to heat up a material. This material then glows, due to this heat, and that glow is what is converted into electricity. Under ideal circumstances, the material absorbs just the frequencies of light in Sunlight, so as to reduce the amount of energy it may radiate away. That is exactly what the MIT researchers have achieved with this new material, thanks to an idea about a previous study. Some of the team members had previously worked on a STPV device that used hollow cavities in the collector, to help capture and hold light. At the time these cavities were just filled with air, but now the researchers have filled them with a dielectric material, and that resulted in some interesting properties.
Along with the excellent absorption spectrum, this new material can be produced with modern manufacturing techniques on silicon wafers up to a foot on a side. Now the researchers are searching for other materials that this device can be made with, to help cut costs. They predict we may see a commercially viable product in just five years.
Posted: September 30, 2014 06:28AM
Our computers contain electronics to process data and magnetic systems to store data, because that is what typically works best. This is not necessarily the ideal arrangement though, as magnetically stored information is not immediately usable by electronic devices. At the University of Pittsburgh however, researchers have discovered a material that may combine data storage and processing into a single device.
The material is comprised of a thick layer of the oxide strontium titanate, and a thin layer of lanthanum aluminate. The researchers found that the interface between these two layers can have magnetic properties at room temperature. Obviously that would make it useful for data storage, but the researchers also found that when it is magnetic, it is also insulating. It is made this way by applying a voltage that removes the electrons at the interface. When the electrons are still there, the interface is conducting.
As magnetic materials normally only react to magnetic fields, finding one that also reacts to electricity could lead to some interesting technologies for electronics and future spintronics. This material also could be the first of a family of such hybrids, with other members potentially exhibiting more properties.
Source: University of Pittsburgh
Posted: September 29, 2014 02:00PM
Vision is easily one of our most used and elide upon senses, but it is also one of the hardest to replicate, in its entirety. Of course we have cameras we can connect computers to, so they can see the world, but machines have a very hard time recognizing objects. Now researchers at Virginia Tech are working on a machine vision system that will use cartoons to teach computers what they see.
For computers to understand what they are looking at, it can be necessary to describe each object in great detail. Describing some concepts can be very difficult though, which is why the researchers are turning to visual abstractions or cartoons. Instead of just having a computer look at an image, the plan is to crowd-source new images that replicate the originals using clipart. This way, computers can learn to recognize objects more like how humans do.
To help with this work, Google has awarded the researchers $92,000 of unrestricted funds.
Posted: September 29, 2014 10:08AM
Normally in school, we are shown the right way to do something then left to do it the right way, and expand what we learn to a general practice. While this method does work, is it necessarily the best method? Researchers at the University of Eastern Finland are investigating that question by showing programming students animations with mistakes in them, that the students must identify.
The idea for this method came from a discussion about Jeliot 3, a programming visualization tool. It was realized that students do not necessarily pay attention to the animations presented by Jeliot 3, which have no mistakes. By introducing errors into the animations though, the students will become more engaged with the animation, as they try to identify the mistakes, which will help them understand the topics involved.
Exactly how useful Jeliot ConAn is, has yet to be determined as, so far, it has had mixed results. Only with more time and study can it be fully evaluated, but before even now teachers are learning new activities for their students, which leverage the fun of searching for mistakes.
Source: University of Eastern Finland
Posted: September 29, 2014 05:54AM
Measurements are critically important in the sciences, so it is also important that measurements can be trusted. To prove just how trustworthy a measurement is, reference materials can be analyzed, since we know what any measurements of them should be. Researchers at NIST have recently created a new reference material that is the smallest ever at roughly 2 nm in diameter.
To create the new Reference Material 8027 (RM 8027), the researchers start by etching nanocrystals from a silicon wafer. This allows them to ensure the nanocrystals are of the correct size. They are then separated with ultrasound and acquire an organic shell, to ensure stability. To prove RM 8027 is what it should be, its size and composition are determined by dynamic light scattering, analytical centrifugation, electron microscopy, and inductively coupled plasma mass spectrometry (ICP-MS).
Along with ensuring that studies concerning materials with dimensions at or below 5 nm, RM 8027 could also help with studying silicon nanoparticles for use in solar cells, solid state lighting, and more. This is because silicon nanoparticles like it could be used in those applications, replacing the current standards.
Posted: September 26, 2014 04:28PM
One of the grander aspects of the General Theory of Relativity is that spacetime can be warped by objects and events. At the time, this was an unbelievable concept, but thanks to many experiments over the decades, we know it to be true and seek out some of the theory's consequences. Among them is the gravitational wave and now researchers, having reexamined the theory, have developed a new way to detect them, which has been published in the Monthly Notices of the Royal Astronomical Society: Letters.
Gravity, according to General Relativity, is the warping of spacetime around an object. Particularly energetic events, such as supernovae, binary neutron star systems, and the merging of neutron stars and black holes should create large ripples in spacetime, which will travel across the Universe. Using experiments on Earth and in space, we have been trying to detect these waves, to further prove Einstein correct, but have had no luck so far. The new method being proposed is to watch for stars to changes in brightness. The idea is that stars that oscillate could absorb energy from a gravitational wave, if the frequency of the wave were the same as the star's oscillations.
Another result of this research is that stars, including the sun, could interfere with gravitational waves, effectively eclipsing their sources. The researchers are now working to determine how long it would take to observe these effects.
Posted: September 26, 2014 06:38AM
Water is one of the most important materials on Earth for the role it plays in supporting life. For this reason we try to look for it when searching for other planets that potentially also have life on them. To help with the search, knowing where the Solar System's water originated would be useful, and now researchers at the Carnegie Institution think they know the source.
There are only two options for where the water could have come from and those are the planetary nebula that the Solar System developed from, or chemical processes the Sun triggered, after it came to life. To determine which is correct, the researchers had to find out the ratio of hydrogen isotopes in water on Earth and in comets and asteroids. Unlike the dynamic Earth, the water (as ice) held by comets and asteroids has been in unchanged since the beginning of the Solar System, and is, in effect, a time capsule of that earlier time. The researchers also created a model to see if a newly formed star could produce the ratios observed today.
The results of the model do not match what has been found in the Solar System, which indicates that much of the water in the Solar System actually predates it. This conclusion is of immense importance as this option would put more water on other planets than if the local stars had to produce it all. Also the water and ices contained in planetary nebulae have organic molecules with them, which could impact life forming.
Source: Carnegie Institution
Posted: September 25, 2014 04:04PM
Nanoparticles are interesting materials with many applications from energy storage to medical uses, but can be a little tricky to make. Chemical reactions must be used and they are not always the fast or efficient. Researchers at the Naval Research Laboratory have recently discovered a new process for synthesizing oxide nanoparticles that can produce very large quantities, very quickly.
Traditionally the synthesis of oxide nanoparticles relies on an oxidizing agent like hydrogen peroxide. While these agents work, they are somewhat weak and slow at reaction with solutions of metal salts. What the NRL researchers have done though is demonstrated that potassium superoxide (KO2) could be used instead. Its use results in a rapid exothermic reaction that produces insoluble oxide or hydroxide nanoparticles. The researchers have already managed to produce over 10 grams in a single step, which is 10,000 times more than many other methods after four steps.
One catch to this KO2 method is that the concentration of metal in the solution cannot be too great, or else large clusters of the nanoparticles will be made. It is able to create more complex materials though, including a cathode used in lithium batteries, a multiferroic material, and even a superconductor.
Source: Naval Research Laboratory
Posted: September 25, 2014 12:36PM
I am not actually sure about how many LEDs there are around me presently, but there are definitely many. While these light sources are all fairly efficient, compact, and have a long lifespan, they do have an emission problem. Most of the light an LED actually produces can be trapped inside of it, but researchers at Princeton University have recently developed a new LED design that lets the light out.
Believe it or not, but some simple LEDs only emit 2-4% of the light they create. The remainder of the light stays trapped within the LED, producing heat that will actually shorten the light's lifespan. By adding reflectors, lenses, and other structures, more of the light will be emitted, but a display using such LEDs could then reflect ambient light, reducing its contrast. The solution to that has been to add a light-absorbing material to the display, which cuts the brightness by as much as half. The Princeton researchers have a new design in mind though that uses a nanotechnology structure called plasmonic cavity with subwavelength hole-array (PlaCSH). This puts a metal mesh on top of the LED that guides photons out of the LED and to a viewer.
The researchers predict that this system, which will work with both organic and inorganic LEDs, could increase efficiency by 58% and display contrast by 400%, while also being flexible. Producing organic LEDs with the PlaCSH is also a simple affair with nanoimprint technology, which allows the structures to be produced like printing newspapers.
Source: Princeton University
Posted: September 25, 2014 05:57AM
For a handful of years or so, consumers have had access to OLED displays in some devices, and every year the number of devices grows. Now we can even find some OLED displays large enough to monitors and televisions that can be rolled up. As reported by the American Chemical Society, a new method of creating transistors has been developed that may help bring flexible electronics to more consumers in the coming years.
Traditionally transistors are produced using a multi-step photolithography process that etches a pattern into a wafer using light and some rather toxic materials. Metal oxide semiconductors have been attracting attention of late, but do lack certain properties, such as flexibility. The new method described in ACS Nano however uses new inks that can create patterns on ultrathin, transparent devices using light. This avoids the use of the toxic materials and high temperatures with the direct light sensitivity. It also allows for a simpler manufacturing process, and that could drastically help with bringing flexible electronics to more people.
Source: American Chemical Society
Posted: September 24, 2014 02:00PM
The Sun can pour an unbelievable amount of energy onto Earth, which is why so many systems exist to capture and use that energy. The catch is that our energy use patters do not always align with production times. Storage systems help with this, and researchers at the University of Basque Country have recently developed an improved version of one system, that could lead to its increased use.
As their name suggests, solar thermal panels can collect the thermal energy of Sunlight. Often those panels are connected to tanks of water, which store the heat. For optimal performance, these tanks are tall and thin cylinders, but optimal performance is not necessarily optimal convenience. The Basque Country researchers have changed that though by adding a phase change material to the design. Specifically a commercial paraffin was added by encapsulating it in aluminum plates, and arranging the plates to have channels water can flow through. The paraffin will melt at 60 ºC, absorbing heat from the water in the process, and when the water is colder, the paraffin will solidify and transfer heat back to the water.
This design is more compact and even modular, unlike water tanks, which opens up the possibility of it being used in a variety of new places. The researchers are now working on a full-scale prototype to be tested in an experimental facility.
Source: University of the Basque Country
Posted: September 24, 2014 09:22AM
Carbon has long since been considered one of the more amazing elements, but over the past few decades it has been proving this in new ways. One of those ways is graphene, which is exceptionally hard and conductive, yet still flexible and transparent. Graphene also opened up a door to a new realm of materials that can compete with it, and now researchers at the University of Southampton have reached a milestone for one of them.
Molybdenum disuphide (MoS2) is highly conductive and mechanically strong, like graphene, but it and other transition metal dichalcogenides (TMDCs) have properties graphene does not. These include the ability to emit light, so we could see them one day used for LEDs. The methods for producing MoS2 however, result in small flakes and that limits its potential. The Southampton researchers though have managed to fabricate a piece of MoS2 over 1000 mm2 in size, and then transfer it to another substrate.
The ability to create such large pieces will go a long way in finding applications for MoS2. Now the researchers are welcoming enquires from other universities and industry, for potential collaborations.
Source: University of Southampton
Posted: September 24, 2014 07:19AM
We all know that when two people get on a seesaw, the side with the heavier person on it will tip down, until that person pushes up. What if the 'people' were massless? That is like what researchers at the University of Minnesota have investigated when they built a nanoscale seesaw and put photons on either side.
The device itself is just 0.7 microns by 50 microns in size and consists of a seesaw with arrays of holes at both ends. These holes are photonic crystal cavities and will actually hold onto photons from a nearby source. When photons, or a single photon, are in the cavities, their optical force will actually move the seesaw, even though that force is equivalent to one third of a quadrillionth of a pound, and that movement can be measured. The researchers also found that when one side of the cavities had photons and the other side had none, the seesaw would start to oscillate. When that oscillation was strong enough, photons would actually start to be shuttled from one side to the other, and the team was able to achieve about 1000 photons being shuttled with each cycle. A 10 W light bulb produces about 1020 photons every second.
Eventually the researchers would like to see this system used to transport a single photon with each cycle, which would make it useful for quantum mechanical devices. The ability to mechanically control photon movement could lead to other advances as well, including sensitive micromechanical accelerometers and be used in navigational gyroscopes.
Source: University of Minnesota
Posted: September 23, 2014 03:29PM
We all know the classic scenario, and may even have experienced losing our keys, phone, or remote control, leading us to search through our homes, for the missing object. If robots are to ever enter our homes, they will have to be able to search for specific objects, and finding them will not necessarily be any easier for them. That may change though, thanks to the work or researchers at the Georgia Institute of Technology, which uses UHF RFID tags to direct robots to their goals.
Typically a robot will search for objects using its cameras, which can be problematic, depending on the clutter in the area. What the Georgia researchers have done is placed RFID tags onto objects and built an antenna system into a robot, which can then play 'hot-or-cold' to find it. When the antennas are oriented toward the tag, the signal will be stronger than when they are looking in another direction. Using this information, the robot can move to the tagged object, and does so without explicitly estimating the objects 3D location.
Among the potential uses for this technology is marking medication with RFID tags, so a robot can find the correct bottle for the correct person. As RFID tags can uniquely identify potentially billions of objects, and can be quite inexpensive, the possible applications are tremendous.
Source: Georgia Institute of Technology
Posted: September 23, 2014 06:38AM
Silicon is potentially one of the most important elements to certain human societies, with how reliant we are on our electronics. When silicon is eventually replaced with something better though, it will be truly amazing what may be achieved. Researchers at the University of Cambridge, the Singapore A*STAR Data Storage Institute, and the Singapore University of Technology and Design have recently made an important discovery for phase-change materials, which could be one of silicon's replacements.
Semiconductors, like silicon are used in electronics because they can be used to switch electrical signals on and off, and thereby logic devices can be built with them. Phase-change materials, however, actually switch between phases with different electrical properties, using electrical pulses. This switching can take just nanoseconds to happen, and once done, the material will persist in that phase. Naturally this gives PCMs a potential use for storing data, as non-volatile memory, but it could also be used to perform logic operations. Such in-memory logic devices have been demonstrated, but they have been slower than silicon devices and lack stability. However, the researchers have discovered that by reversing the process that had been used, starting from the conducting, crystalline phase and going to the insulating, amorphous phase, the devices could be faster and more stable.
Combining memory and logic operations into a single device could have dramatic impacts on computing, by conserving space and improving speed. Also, as PCM memory devices are non-volatile, there would be energy savings compared to DRAM, which must refresh the data it stores, or risk losing it.
Source: University of Cambridge
Posted: September 22, 2014 03:30PM
According to science fiction, it is cool and futuristic to be able to control devices by waving one's hands. Some technologies already exist to let us do just that, and many of these rely on a device's camera, which works, but is not necessarily the ideal solution. Researchers at the University of Washington have developed a way to use a cellphone's data transmissions to track movement in the area around it for input.
For any number of reasons, our phones broadcast wireless signals that penetrate many materials, including our bodies, very well, but not perfectly. Some of the transmitted signals will be reflected back to the device. With multiple, low-power receivers in a smartphone, the reflection could be picked up and analyzed to track position and movement, and the researchers have aptly named this project SideSwipe.
Compared to camera-based systems, SideSwipe could cut down on battery use, as the data processing involved is much simpler than the video processing cameras require. Also the penetrating nature of wireless transmissions allows SideSwipe to function even when the smartphone would is in a user's pocket or bag.
Source: University of Washington
Posted: September 22, 2014 09:22AM
There are some senses we cannot imagine being without, and touch is definitely one of them. Robots however have only had limited experience with the sense of touch, and they would have as much use for it as we do. Researchers at MIT have recently created a new touch sensor that can give robots touch with impressive accuracy in real time.
The new sensor is actually based on an old design called GelSight, which uses light to measure touch. The sensor consists of a plastic cube with metallic paint on one side, along with multiple lights and detectors. These lights, each a different color, shine through the cube, bouncing around and reflecting off of the paint, until eventually returning to the light detectors. These detectors measure the intensity of the light and feed that data to a computer-vision algorithm that uses it to reconstruct the surface of the cube. The original GelSight sensors could resolve deformations on the micrometer scale, while this version works on the millimeter scale. That is still more sensitive than our fingers though and the loss in resolution does allow the sensor to be smaller and for the processing to be done in real time.
The researchers have already tested a robot with a single one of these sensors by having it plug a USB cable into a plug (something some people even have trouble with). With luck, we may see this prototype developed into a practical device before long.
Posted: September 22, 2014 06:09AM
As we approach the limits of silicon circuitry, more and more replacements are appearing to claim the element's throne. Hopefully silicon's reign will last long enough for a clear successor to be found. Researchers at Harvard though have discovered a new material that could be that successor.
This new material is what is called a correlated oxide and uses quantum mechanics to challenge silicon. The base material is samarium nickelate, but by doping it with hydrogen or lithium, the researchers were able to manipulate its band gap. The band gap is a very important characteristic of many materials as it determines the energy difference between conducting and non-conducting electrons. Silicon transistors require the ratio between conducting and non-conducting, or on/off states, to be 104. Previous attempts with correlated oxides have only had an on/off ratio of 10 or 100, but the Harvard researchers were able to achieve a ratio greater than 105, putting it near state-of-the-art silicon transistors. This ratio is present when the material is at room temperature, or even hundreds of degrees above it.
One would expect that a material to potentially replace silicon would come from a lab investigating such replacements. This discovery actually came out of a fuel cell lab though, where the researcher's experience with thin films and ionic transport was used to create the correlated oxide.
Source: Harvard University
Posted: September 20, 2014 08:15AM
NVIDIA's debut of the GTX 900 Series graphics cards issued in the first wave of Maxwell-based GPUs; an architecture that is pretty damn impressive. Among its many features (such as Dynamic Super Resolution), NVIDIA "designed Maxwell to solve some of the most complex lighting and graphics challenges in visual computing." NVIDIA's game demo team decided to test the capabilities of its new technology in a rather unique way, recreating the moon landing scene in Unreal Engine 4 using one of Maxwell's key technologies – Voxel-Based Global Illumination, or VXGI.
VXGI is a new and improved representation of the way light bounces from one object to another in real time, by breaking a scene's geometry into many thousands of tiny boxes called voxels (essentially a pixel in 3D). Maxwell accelerates the creation of these voxels using a technology called "multi-projection", which lets the GPU process the geometry just once for each box's six sides. So how did the demo team use this technology to prove the legitimacy of the moon landing?
Conspiracy theorists have argued for decades that Buzz Aldrin's suit must have been lit from something other than the sun, since the sun was behind the lunar module. The only explanation was that it was an auxiliary light source... in a studio. The photo was just too perfect. After NVIDIA's demo team "researched the rivets on the lunar lander, identified the properties of the dust coating the moon's surface, and measured the reflectivity of the material used in the astronauts' space suits," NVIDIA got to work on recreating the scene. Not only was the demo team able to reproduce how the light illuminated Aldrin, proving there was no artificial light source, it was also able to prove that the reason there were no stars in the photo was simply due to the exposure level of the camera.
NVIDIA's demonstration is quite the fascinating and unique use of a technology we typically think as only applicable to gaming or rendering. So now that one of the top conspiracy theories has been debunked, what's next for the green team? The Kennedy Assassination?
Source: Press Release and NVIDIA Blog
Posted: September 19, 2014 02:07PM
They say great things can come in small packages, and it appears that may be true, if you can think of a dwarf galaxy as 'small.' Researchers at the University of Utah have discovered that a dwarf galaxy may have at its center a supermassive black hole many times larger than the one at the center of our own Milky Way.
M60-UCD1 is a so-called ultracompact dwarf galaxy orbiting M60, which is one of the larger galaxies in our area. The researchers had previously examined the dwarf galaxy, noting the rate at which it was emitting X-rays. The rate matches that of gas falling into the supermassive black holes of other, much larger galaxies. Using the Gemini North telescope on Hawaii's Mauna Kea, the researchers determined that M60-UCD1 may have at its core a supermassive black hole weighing it at 21 million solar masses. With a total mass of 140 million solar masses, that black hole would make up 15% of the galaxy's mass. For comparison, the black hole at the center of the Milky Way comes in at 4 million solar masses, but our galaxy weighs 50 billion solar masses (50,000 million, to be clear).
The obvious question is how could a dwarf galaxy have such a large black hole at its core? The researchers suggest that the dwarf galaxy is possibly what remains of a once larger galaxy, where a supermassive black hole is more expected. When it passed by another galaxy, likely M60, most of the gas and stars were stripped off, leaving what looks like a dwarf galaxy behind. If this is accurate, then other dwarf galaxies may also house similarly large supermassive black holes.
Source: University of Utah
Posted: September 19, 2014 09:18AM
Many children once envisioned that when they grew up, their work attire would be a spacesuit. While it is easy to say that spacesuits are cool, future spacesuits may have a very different look to them in the future. Researchers at MIT are working on a design that could see modern bulky spacesuits replaced with suits that are effectively a second skin.
Spacesuits are really just small spacecraft with life support systems to keep the occupant warm and at a livable pressure. Modern designs achieve that pressure using gases, but the design the researchers are working on would rely on mechanical pressure instead. That pressure would be delivered by coils of a shape-memory alloy. These materials are special metals that can learn a specific shape that they will return to, when heated to a certain temperature. Below that temperature, the alloy is pliable like a paperclip. The idea is to incorporate these coils into the spacesuit, which will be flexible enough for an astronaut to put on, and once on the alloys will be heated to return to their learned shape, which will be smaller, pulling the suit onto the person.
While tests show that such a spacesuit would be able to apply the needed amount of pressure to a body, it does have the problem of requiring temperatures that would eventually cook the astronaut, unless a locking mechanism can be developed. Given the reduction in weight and potential increase in mobility though, you can bet that the flaws will be worked out eventually.
Posted: September 19, 2014 06:50AM
According to quantum mechanics, the quanta that make up the Universe exist in a wave-particle duality. The interpretation that has been traditionally used of this is the Copenhagen interpretation, which treats all particles as waves, and that measuring the wave causes it to collapse down to a particle. This is not the only interpretation though, and one that some of the founders of quantum mechanics is getting new life breathed into it, thanks to a recent experiment at MIT.
Pilot-wave theory presents a very different interpretation of the quantum world as instead of treating particles as the result of observing waves, it keeps them as particles. These particles are on top of some kind of wave though, which influence the particle's trajectory and that explains the wavelike behavior of the particles. The experiment the researchers did involved vibrating a bath of fluid at a rate just below what would cause waves to appear on the surface. A drop of the fluid was then dropped onto the surface, causing waves to radiate from the impact. That droplet was then propelled by those waves, similar to how the pilot-waves would influence the movement of a particle.
As the researchers do point out, there are many quantitatively and qualitative differences between the quantum theory and fluid experiment, which prevent it from being actual evidence of the theory. However, they could be philosophically similar enough to suggest that pilot-wave theory be reexamined with the new tools of chaos theory and the results of this experiment. Perhaps in the future it or another interpretation may become the new standard.
Posted: September 18, 2014 02:00PM
In the quest for a superior battery, researchers at the University of Missouri-Columbia have developed a new long-lasting battery. This battery design is a bit different from what you will find in your devices though, as it is a nuclear battery.
Nuclear materials have seen various energy uses over the years, from large-scale power plants to small thermoelectric systems, like those in some space missions. This battery operates in a different way though, by using betavoltaics instead of any use of thermal energy. In betavoltaics, the nuclear material, in this case strontium-90, emits beta particles into a water-based solution, which increases its electrochemical energy. A titanium dioxide electrode coated in platinum then collects and converts that energy into useable electricity.
With the battery's long life and efficiency, it could see use in automobiles and in space flight. It is likely worth noting that controlled nuclear technologies need not be dangerous, such as those that are used in fire detectors and emergency exit signs.
Source: University of Missouri-Columbia
Posted: September 18, 2014 10:15AM
Some day we may see parts of our computer using photons instead of electrons to carry information. Photons can carry information faster and are more efficient at doing so, but the necessary components, especially emitters, are difficult to make. Researchers at MIT have recently found that one material that could work as a light source can be tuned to produce specific frequencies.
Monolayers of molybdenum disulfide (MoS2) have very good optical properties that could be integrated into optoelectronic chips. These good properties come from, in part, the direct band gap of the material, which makes it easier for excited electrons to drop in energy, emitting a photon in the process. Normally MoS2 is used just as a single layer, but the MIT researchers worked with it in pairs of layers. The presence of the second layer did reduce the intensity of the emitted photons, but it also interfered with where the excited electrons would drop to. Instead of dropping back to the same MoS2 layer, the electrons could drop into the other layer, releasing a photon of a different frequency. The specific frequency could be tuned by controlling the relative angle between the two layers.
With the ability to tune the frequencies of the photons, optoelectronic chips could be designed to carry information along multiple frequencies, like what is done currently to increase bandwidth. Naturally MoS2 does have competition as a light source, but being a thin film keeps it simple and cheap to produce, unlike the 3D, complex systems also being investigated.
Posted: September 18, 2014 07:28AM
Lithium-ion batteries are something of a standard technology now, with them being used in everything from electric cars to cellphones. While the technology has been serving us well for some time, we are approaching its limits and have to look for a replacement. As reported by the American Chemical society, one of these replacements got a big boost recently.
One of the ways to improve a battery is to use better electrodes in it, and for a while it has been known that sulfur would be better for lithium batteries than the current metal oxides. The problem is that lithium sulfur compounds have a tendency to escape, and take what energy they have with them. To address this, researchers have made small, hollow shells of carbon to hold the lithium sulfur compounds, and coated the shells with a polymer.
When tested, the energy storage capacity was 630 milliampere hours per gram, compared to the 200 mAh/g of modern lithium-ion batteries, and that capacity persisted over 600 charging cycles. Theoretically a lithium-sulfur battery could store five to eight times more energy than modern batteries.
Source: American Chemical Society
Posted: September 17, 2014 04:06PM
Quantum mechanics allows for some odd things, such as particles being so strongly coupled, that information about one determines the information about the others. This phenomenon, entanglement, is one that many hope to exploit for quantum computers, but is not particularly easy to work with. Researchers at the University of Waterloo, using single-photon detectors developed by NIST, have recently succeeded in creating entangled photon triplets, which could prove especially useful in future quantum technologies.
To create the triplets the researchers started with a blue photon that was polarized both vertically and horizontally, thanks to superposition, another quantum mechanical phenomenon, and sent it through a special crystal. This crystal converted the single blue photon into two red photons that have the same polarization. One of these daughter photons then entered another special crystal that converted it into two infrared granddaughter photons, which just happen to be at a frequency commonly used in telecommunications. Thus they could actually be transmitted along a fiber optic cable.
As all of these photons have the same polarization, they form an entangled triplet, but this process, called cascaded down-conversion, is hardly efficient. The first stage only works one in a billion times, and the second is one in a million. That is where the NIST single-photon detectors came into play, as they drastically simplified the work of finding the number of triplets, confirming that the system worked at all. Eventually, as the process is improved, the researchers hope to go past triplets and generate four or more entangled photons at a time.
Posted: September 17, 2014 11:11AM
Ice can be quite a problem, even when it is not causing us to slip and fall. When it builds up on radar domes, for example, it can actually interfere with their performance, which is why researchers at Rice University developed a new deicing system. Now they have refined the technology and succeeded in making it optically and radio-frequency transparent.
Originally the researchers created a paint containing graphene nanoribbons, made by splitting carbon nanotubes, mixed with polyurethane. By applying a voltage to the paint, the nanoribbons heat up and melt the ice that may have collected on the paint. What the researchers originally created though had the problem of heating up when exposed to extremely high RF, to the point that it burned up. To correct that, the researchers have made the films in the paint more consistent and coated the nanoribbons in the polyurethane, to prevent them from forming active networks. These changes preserved the films' transparency, so the researchers tried coating a glass slides with it, and then iced them. Even at temperatures of -20 ºC, the ice melted when a voltage was applied.
Naturally this deicing system will still be of use with radar systems, which would otherwise rely on larger, less efficient metal oxide systems, but thanks to being optically transparent, it could also be integrated into windshields and even skyscraper windows. In these situations the RF transparency could also prove useful, as cell transmissions and Wi-Fi would not be blocked.
Source: Rice University