- Memristor chip could lead to faster, cheaper computers
- Latest 3D TV Technology Offers Interactive Control
- Carbon Nanotube Artificial Muscles for Extreme Temperatures (+video)
- Watch, Listen, and Feel Movies with a Haptics Jacket
- Glass you can build with: Metallic glass that's stronger and lasts longer
Memristor chip could lead to faster, cheaper computersMarch 17th, 2009
(PhysOrg.com) -- The memristor is a computer component that offers both memory and logic functions in one simple package. It has the potential to transform the semiconductor industry, enabling smaller, faster, cheaper chips and computers.
A University of Michigan electrical engineer has taken a step toward this end by building a chip composed of nanoscale memristors that can store up to 1 kilobit of information.
Previously, only a few memristor circuits had been demonstrated, rather than such a large-scale array, due to reliability and reproducibility issues. While 1 kilobit is not a huge amount of information, the researchers consider it a leap that will make it easier to scale the technology so it can store much more data.
"We demonstrated CMOS-compatible, ultra-high-density memory arrays based on a silicon memristive system. This is an important first step." said Wei Lu, an assistant professor in the Department of Electrical Engineering and Computer Science. CMOS stands for complementary metal oxide semiconductor. It is the technology used in modern microchips.
The density of a memristor-based memory chip could be at least an order of magnitude—a factor of 10—higher than current transistor-based chips. Such high density circuits can also be very fast, Lu says. You could save data to a memristor memory three orders of magnitude faster than saving to today's flash memory, for example.
Another benefit of memristor memory is that it's not volatile, as today's DRAM memory is. DRAM, which stands for dynamic random access memory, is part of your computer's quick-access memory that helps the machine run faster. DRAM is overwritten multiple times a second because it fades with time. Memristor memory would not have to be overwritten. It is more stable.
Lu says memristors could open the door to universal memory. And because of how densely they can be crammed onto integrated circuits, memristors also offer hope for robust biologically-inspired logic circuits. Each neuron in the human brain is connected to 10,000 other neurons through synapses, Lu says. Engineers can't achieve that kind of connectivity with today's transistor-based circuits. But memristor circuits could potentially overcome this problem. source
My comment: For you Peter Hamilton fans :) An for those who don't know what I'm referring to, it's very simple. In one of his books, you can read that about the simultaneous development of two technologies that changed the world-the discovery of say wormhole drive and the discovery of chips big enough to write all the humans memories. Thus, when one gets old, you can clone a new body and just transfer the personality stored the chip into the new body-a practical immortality! So, these memristors could serve that purpose one day. Isn't this cool!
Latest 3D TV Technology Offers Interactive ControlMarch 19th, 2009 By Lisa Zyga
(PhysOrg.com) -- Three-dimensional TV is now closer than ever to becoming a reality for consumers. In a recent study, researchers at the University of Tokyo and Hitachi, Ltd., have presented a 3D TV system that captures a live scene in real time and reproduces it on an autostereoscopic display. The system also offers interactive control, allowing viewers to adjust viewing parameters such as cropping a scene and reproducing an appropriate amount of depth.
“The greatest advantage of our system is to provide interactive control of the viewing parameters,” lead author of the study Yuichi Taguchi, a Ph.D. student at the University of Tokyo, told PhysOrg.com. “The interactive control is essential for reproducing a dynamic 3D scene with desirable conditions, which depend on the contents of the scene, the viewer's preference, and the display specifications.”
The 3D TV system, called TransCAIP, captures a live scene using an array of 64 video cameras that are all connected via Ethernet cables to one PC, which converts images from all the video cameras into images for the display. Each video camera contains a built-in HTTP server, which sends motion JPEG sequences to the PC.
The PC then converts the 64 input views captured by the cameras to an “integral photography image” made of 60 views, which correspond to the viewing directions of the display. Using an image-based rendering technique, the PC converts the images in real-time, and then arranges the pixels to produce the integral photography image. The entire process, called light field conversion, is implemented on the single PC in real-time, requiring a few hundred milliseconds per frame.Like all autostereoscopic displays, the new 3D TV system doesn’t require viewers to wear special glasses. Instead, the display reproduces various viewpoint images, allowing viewers to see a different image in each eye or by moving their head (the parallax effect). Although the basic principles of autostereoscopic 3D displays were developed more than a century ago, only with recent technological advances has it been possible to actually build autostereoscopic displays since they require such a large number of light rays (the resolution of a view times the number of viewpoints).
The researchers’ light field conversion method, which converts the different viewpoint layouts between the input and output devices, also offers advantages. For one thing, it enables viewers to control the viewing parameters based on their individual preferences or to help sharpen a scene. Using only the software, viewers can control the amount of depth on the display as well as choose a smaller viewing angle to view only a targeted location. Also, the light field conversion technique doesn’t require the capture system to have large lenses or long imaging distances, as some existing systems do.
As the researchers explain, the main technical challenge for their 3D TV system is the fast and flexible conversion of the input images from the 64 cameras to the 60 images in the integral photography format. In this study, their light field conversion method shows that real-time conversion is possible. In the future, the researchers plan to improve the visual quality of the system, such as by reducing blur and other unwanted artifacts caused by depth reproduction.source
My comment: That is so exciting! I honestly cannot imagine something cooler than such auto3D device. Just imagine being able to stop the scene and explore the details any way you want! Of course, that will require a complete change of the way movies are made and stores(obviously, the amount of information for any frame will be 60 times larger, so well, that makes a lot more information into one dvd or whatever they will use). The article said it will happen in 5-10 years time but I so hope it comes sooner. It's simply absolutely gorgeous. I'm starting to save money from now :)
Carbon Nanotube Artificial Muscles for Extreme TemperaturesMarch 20th, 2009
(PhysOrg.com) -- Researchers at the UT Dallas Alan G. MacDiarmid NanoTech Institute have demonstrated a fundamentally new type of artificial muscle, which can operate at extreme temperatures where no other artificial muscle can be used -- from below the temperature of liquid nitrogen (-196° C) to above the melting point of iron (1538° C).
Once actuated (or put into motion) in a certain direction, these new artificial muscles can elongate 10 times more than natural muscles and at rates 1,000 times higher than a natural muscle. In another direction, when densified, they can generate thirty times the force of a natural muscle having the same cross-sectional area. While natural muscles can contract at about 20 percent per second, the new artificial muscles can contract at about 30,000 percent per second.
These artificial muscles are carbon nanotube aerogel sheets made by a novel solid-state process developed at UT Dallas. Sometimes called frozen smoke, aerogel is a low-density solid-state material derived from a gel in which the liquid component of the gel has been replaced with gas. Aerogels are comprised mostly of air. The starting material is an array of vertically aligned carbon nanotubes manufactured under a chemical heat process. Because of the special arrangement of these nanotube arrays, which are called forests because they look like a bamboo forest, the carbon nanotubes can be pulled into sheets at speeds of up two meters per second. The sheets have such low density that an ounce would cover an acre.
When scientists apply a voltage to the carbon nanotube aerogel sheets, the nanotubes repulse, or push away from one another, which in effect works the muscle. These transparent sheets have strange properties that are important for muscle operation. While having about the density of air, in one direction, they have higher specific strength (strength/density) than a steel plate. When stretched in another direction, they provide rubber-like stretchability, but by a mechanism quite different than for ordinary rubber. Because of their nanoscale and microscale structure, they amplify a percent stretch in the nanotube orientation direction to a percent 15 times larger than the percent they contract laterally.
In addition, because no other artificial muscle can actuate at such extreme low and high temperatures, applications for these muscles might develop for use in space exploration, where a hostile environment prohibits use of any other actuating material. source
My comment: Check the video from NewScientist: . Also a stunning report! Just see it on the video, it's like a magic, but it's not. It's pure science! Again, can't wait to see what will come out of this. Just imagine having an arm implant with such muscles! Quite scary, huh :)
Watch, Listen, and Feel Movies with a Haptics JacketMarch 23rd, 2009 by Lisa Zyga
PhysOrg.com) -- Sometimes you may feel a shiver go up your spine as you're watching a chilling movie scene, but a new jacket can actually give you a real shiver. The haptics jacket, designed by scientists at Philips Electronics, can enable movie viewers to feel movies through a sense of touch, in an attempt to provide full emotional immersion in a film.
Paul Lemmens, a Philips senior scientist, explains that the jacket isn't meant to make viewers feel the actual punches and blows that the actors are receiving on the screen. Rather, the intentions are more subtle. The jacket's purpose is to make viewers feel anxiety and other emotions through signals such as sending a shiver up the viewer's spine, creating tension in the limbs, and creating a pulse on the chest to simulate a rapid heartbeat.
To produce these emotional sensations, the jacket contains 64 independently controlled actuators, which can cycle on and off 100 times per second. Because of the way the brain perceives touch, only eight actuators on each arm placed six inches apart are enough to cover sensations on the entire arm. The system uses such a small amount of current that two AA batteries could provide power for an hour if 20 motors were operating simultaneously.
The jacket can respond to signals encoded in a DVD, or it can be controlled on the fly, adding another element of reality to entertainment. source
My comment: As said in the source site, just imagine what that can do for an adult movie. Oh! I'd gladly have one of those. Because it's quite smart actually-we really are very sensitive to touch, so, using such device can give a whole new perspective to movie-making.
Glass you can build with: Metallic glass that's stronger and lasts longerMarch 24th, 2009
(PhysOrg.com) -- The normal structure of metals is crystalline. Glass, on the other hand, is amorphous. But it's possible to make amorphous forms of metal, metallic glasses, which can be remarkably strong, having many properties equal to or better than their crystalline metal cousins. The catch is that bulk metallic glasses are highly susceptible to fatigue, a severe problem for their use as structural materials.
Now researchers at the U.S. Department of Energy's Lawrence Berkeley National Laboratory and the University of California at Berkeley, working with colleagues at the California Institute of Technology, have solved the fundamental problem of poor fatigue resistance in bulk metallic glasses. The results are metallic glass alloys that are not only stronger than high-strength steel and aluminum alloys but more resistant to fatigue as well.
Since fatigue is the most widespread mechanism of degradation in metallic structures, low fatigue resistance has impeded the adoption of metallic glasses as structural materials.
"While it has been often thought the fatigue limit was the cyclic stress needed to initiate a crack in a material, there are always small cracks present," Ritchie says. "The fatigue limit is actually the cyclic stress needed to get such a small crack propagating."
In crystalline materials there are many barriers to crack propagation, including grain boundaries, inclusions, and other microstructural obstacles. But metallic glasses have no crystalline structure, so no such barriers exist. "If a crack is present, there's nothing to stop it from propagating," says Ritchie.
Johnson's group at Cal Tech had developed a metallic glass alloy named DH3, made from five elements - roughly a third zirconium, a third titanium, and the remainder niobium, copper, and beryllium. In bulk samples of DH3 the researchers induced a second phase of the metal, which took the form of narrow pathways of crystalline metal permeating the metallic glass in dendritic (treelike) patterns; its growth was carefully controlled by processing a partially molten liquid-solid mixture.
The resulting dendritic phase acts as a local arrest point to any crack that begins to propagate in the glass.
"The process of blocking these shear bands is important not just for fatigue but for toughness as well," Launey says. " What this study shows is that it is their separation that is critical; the spacing of these arrest points has to be small enough to arrest any crack before it becomes large enough to cause catastrophic failure."
So good, in fact, that toughness, ductility, and fatigue resistance - all intimately related properties - of the DH3 alloy improved to the point that the bulk metallic glass was not only stronger than many structural metal alloys but had a fatigue limit more than 30 percent higher than ultra-high-strength steel and aluminum-lithium alloys.source
My comment: Yes, that means even more ugly metal buildings. But on the positive side, it also means tougher spaceships! Or even planes. Although the alloy is made of quite expensive materials, I guess they can overcome that eventually.