Metamaterials
Latest
Magic Leap is experimenting with light-bending nanomaterials
Mixed reality company Magic Leap is cagey with its tech, to say the least. However, it has released a research paper in conjunction with Berkeley Lab that hints on what it's doing. The team developed new materials that can take in light from more angles than before and redirect it with minimal losses. That could aid not only its mixed reality (MR) headset, which reportedly uses wave-guiding tech similar to the Hololens, but spark breakthroughs in holograms, invisibility cloaks and more.
'Metamaterial' can switch from soft to hard - and back again
University of Michigan researchers have developed a technique for a new 'metamaterial' that can change its level of solidness, but without damaging or changing the material itself. Metamaterials are man-made materials whose properties come from the way it's constructed rather than what it's composed from. Scientist can then tinker with its structure to affect its properties. Those effects can be very broad: researchers were able to create a camera that doesn't require a lens to work using different man-made materials. This one's different again.
We're getting closer to real invisibility cloaks
We've been inching closer to real-life invisibility cloaks for a bit now, but going full on Harry Potter in the Hogwarts library is probably still a ways off. The latest advancement in metamaterial-based vanishing tech from Iowa State University guards whatever it's placed on from cameras, according to a paper published in Nature. The naked eye? Not so much. And even those cameras can't hide it from a human viewing a video feed, only other machines or perhaps radar. The researchers achieved this by embedding split ring resonators filled with galinstan into silicone sheets. Stretching those sheets is a form of tuning of sorts, and allowed the scientists to suppress certain radar waves up to about 75 percent. This type of tech could be used in a stealth fighter jet for example, as everything RF notes.
3D-printed material can carry 160,000 times its own weight
Researchers from MIT and Lawrence Livermore have created a new class of materials with the same density as aerogels (aka frozen smoke) but 10,000 times stiffer. Called micro-architected metamaterials, they can withstand 160,000 times their own weight, making them ideal for load-bearing, weight-sensitive applications. To do it, the team created microscopic lattice molds using a 3D printer and photosensitive feedstock (see the video below), then coated them with a metal 200 to 500 nanometers thick. Once the lattice material was removed, it left an ultralight metal material with a very high strength-to-weight ratio. The process also works with polymers and ceramics -- with the latter, they created a material as light as aerogel, but four orders of magnitude stiffer. In fact, it was 100 times stronger than any known aerogel, making it ideal for use in the aerospace industry. Given that it was funded by DARPA, it could also end up on robots, drones or soldiers.
Metamaterial camera needs no lens, could herald cheaper imaging tech
Metamaterials are proving to be quite useful for toying with the electromagnetic spectrum, whether for technology previously thought to be the stuff of science fiction, or for boring real-world applications. Engineers at Duke University have come up something that falls more into the latter category: a metamaterial imaging sensor that doesn't require a lens to generate a picture. The sensor is a flexible copper-plated sheet patterned with small squares that capture various light frequencies all at once, functioning like one big aperture. Add a few circuits with a pinch of software and the sensor-only camera can produce up to ten images per second, but the catch is Duke's only works at microwave frequencies. Microwave imaging is used plenty, however, and due to its flexibility and lack of moving parts, the sensor could be used to build better integrated, cheaper airport scanners and vehicle collision avoidance technology -- making you safer however you choose to travel. Unless you take the train. Then you're on your own.
Intellectual Ventures launches Kymeta spinoff, promises slim satellite broadband hotspots
Intellectual Ventures is best known for its tendency to sue everyone, but it's going some distance to mend that bruised image through a newly spun out company, Kymeta. The startup hopes to improve the quality of satellite broadband through mTenna-branded, Ka-band hotspots made from metamaterials -- substances that can boost and manipulate a satellite signal while occupying virtually no space, leading to self-pointing transceivers that are just a fraction of the size of what we use today. That still amounts to equipment the size of a laptop running at a peak 5Mbps, although it's small enough that Kymeta sees hotspots reaching individual customers who want access from a boat, a car or the field. We'd just advise against tossing out the MiFi too quickly. Kymeta doesn't expect the hotspot to be ready before late 2014 at the earliest, and that leaves many questions about how much of a hit we'll take to the pocketbook.
Plasmonic cloak makes objects invisible, but only in the microwave region of the spectrum
Okay, so we're not up to USS Pegasus levels yet, but for the first time researchers have been able to cloak a three dimensional object. Don't start planning your first trip to the Hogwarts library restricted section just yet though, the breakthrough is only in the microwave region of the EM spectrum. Using a shell of plasmonic materials, it's possible to create a "photo negative" of the object being cloaked in order to make it disappear. The technique is different to the use of metamaterials, which try to bounce light around the object. Instead, plasmonics try to deceive the light as to what's actually there at the time -- but because it has to be tailored to create a "negative image" of the object you're hiding, it's not as flexible, but it could be an important step on the road to that bank heist we've been planning.
EES packs circuits into temporary tattoos, makes medical diagnostics fashionable
Flexible circuit pioneer John Rogers and his team are at it again. This time he's developing a wearable, ultra-thin circuit that attaches to your skin just like a temporary tattoo. The Epidermal Electronic System (EES) consists of circuits which could contain electrodes capable of measuring brain, heart and muscle activity in the same way an EEG does now, transmitting this data wirelessly to your doctor. Because it's flexible and bonds to the skin, it can be worn for extended periods, unlike traditional diagnostic pads used in hospitals today. In the lab, the devices were solar-powered with embedded photovoltaic cells -- heavier duty circuits would require inductive charging to be practical. Rogers' team also looked into the tech acting as a game controller (they wired it up to someone's throat and played Sokoban with voice commands, still managing to yield a 90 percent accuracy rate), but it's some way off from replacing your SIXAXIS. One of the problems encountered concerned RF communication -- perhaps they should get on the horn to their friends in Oregon and build those fashionable diagnostic pants we're eagerly waiting for.
Metamaterial printing method inches us closer to invisibility cloaks
In theory, metamaterials are all kinds of awesome -- they can boost antenna strength, focus lasers, and create invisibility cloaks. But, they've been limited to day dreams lab experiments because producing the light-interfering materials in any practical quantity has been difficult and time consuming. John Rogers, a professor at the University of Illinois has figured out a way to print a layered, nano-scale mesh that bends near-infrared light in much larger amounts than previously possible. The new method, based around a plastic stamp, has been used to create sheets of metamaterial measuring a few square inches, but Rogers is confident he can scale it up to several feet. Who knows, by the time the second installment of The Deathly Hallows hits theaters in July you could get the best Harry Potter costume -- one that lets you sneak in without shelling out $13. [Thanks, Plum G.]
Scientists finally find a practical use for metamaterials: boosting antenna performance (video)
Metamaterials can do all sorts of cool things in theory, like create invisibility cloaks or focus lasers. In practice, though, they're rather less useful. Or at least they were, before the team at Fractal Antenna figured out that a simple sleeve made out of fractal-based metamaterials triples the bandwidth of a simple monopole antenna and boosts its gain by 3dB. All you need to do is slip the fractal sleeve on and, hey presto, instant super antenna. You can see it demonstrated in the video after the break before reading all the nitty, gritty, infinitely-repeating details in the PR, which is down there too.
Metamaterials used to focus Terahertz lasers, make them useful
Forget old and busted X-rays, T-rays are the future, man! It was only recently that we were discussing Terahertz lasers and their potential to see through paper, clothes, plastic, flesh, and other materials, but that discourse had to end on the sad note that nobody had managed to make them usable in a practical and economically feasible way. The major hurdle to overcome was the diffusion of Terahertz radiation -- which results in weak, unfocused lasers -- but now researchers from the universities of Harvard and Leeds seem to believe they've managed to do it. Using metamaterials to collimate T-rays into a "tightly bound, high powered beam" will, they claim, permit semiconductor lasers (i.e. the affordable kind) to perform the duties currently set aside for sophisticated machinery costing upwards of $160,000. Harvard has already filed a patent application for this innovation, and if things pan out, we might be seeing body scanners (both for medical and security purposes), manufacturing quality checks, and a bunch of other things using the extra special THz stuff to do their work.
Invisibility cloak upgraded to bend infrared light, not to mention our minds
The fabled cloak of invisibility was once considered impossible for modern science, chilling out with perpetual motion up in the clouds, but these days scientists are tilting at blurry windmills with a modicum of success several times a year. The latest advance in theory comes to us from Michigan Tech, which says it can now cloak objects in the infrared spectrum. Previous attempts using metallic metamaterials could only bend microwave radiation, the study claims, but using tiny resonators made of chalcogenide glass arranged in spokes around the object (see diagram at left) researcher Elena Semouchkina and colleagues successfully hid a simulated metal cylinder from 3.5 terahertz waves. While it's hard to say when we might see similar solutions for visible light, even a practical application of infrared cloaking could put your night vision goggles to shame, or perhaps block covert objects from being detected by those newfangled terahertz x-rays.
3D invisibility cloak fashioned out of metamaterials
Those HDTV manufacturers did tell us that 3D was going to be everywhere this year, didn't they? Keeping up with the times, scientists investigating potential methods for rendering physical objects invisible to the human eye have now moved to the full three-dimensional realm. The Karlsruhe Institute of Technology has developed a photonic metamaterial that can make things disappear when viewed from all angles, advancing from previous light refraction methods that only worked in 2D. It sounds similar to what Berkeley researchers developed not too long ago, and just like Berkeley's findings, this is a method that's still at a very early stage of development and can only cover one micrometer-tall bumps. Theoretically unlimited, the so-called carpet cloak could eventually be expanded to "hide a house," but then who's to say we'll even be living in houses by that time?
Electromagnetic invisibility a precursor to the real thing?
This could either be that one giant leap, or just another in a long sequence of multidirectional small steps on the Quixotic quest for undetectability. So-called dc metamaterials are the chief culprit for inciting our interest anew, as researchers from Universitat Autònoma de Barcelona have found a way to use them to render metallic objects invisible to low frequency electromagnetic waves. Composed of irregular networks of superconductors, the metamaterials are capable of granting superpowers altering the magnetic field of materials, and in theory, this advance could aid magnetic imaging in medical settings and also help cloak military vessels from magnetic detection. Of course, there's still the whole "oh, now we need a working prototype" conundrum, but hey, at least we've got the gears turning in the right direction.[Via PhysOrg]
Universal mirrors: more useful, less fun than carnival mirrors
You know those invisibility cloaks scientists have been struggling to master for decades? This here is said cloak's perfect opposite, and it's bending our minds in ways you can hardly fathom. Ulf Leonhardt, a professor at the University of St. Andrews, has worked with a brilliant team of scientists in order to construct what he calls a universal mirror, or if we're being proper, an omnidirectional retroreflector. Unlike conventional mirrors which simply reflect objects at 90 degrees, this concoction reflects objects back at any angle. In other words, a device such as this would make aircraft, boats and satellites entirely easier to track with radar, but it'll have to mature quite a bit before it's ready for that kind of action. The current build is just a single centimeter high and ten centimeters in diameter, and as with invisibility cloaks, the main ingredient here is metamaterials that we won't pretend to fully understand. Just one word of caution, boffins -- don't let Geek Squad get ahold of this stuff.[Image courtesy of Barbara Rich, thanks JR]
Purdue researchers concoct new invisibility cloak, plan Walmart debut
Hate to say it, but we're beyond the point of hope here. We just won't ever, ever see a real-deal invisibility cloak during our relatively brief stint on Earth. That said, researchers at Purdue University are doing their best to prove us wrong, recently developing a new approach to cloaking that is supposedly "simple to manufacture." Unlike traditional invisibility cloaks, which rely on exotic metamaterials that demand complex nanofabrication, this version utilizes a far simpler design based on a tapered optical waveguide. A report from the institution asserts that the team was able to "cloak an area 100 times larger than the wavelengths of light shined by a laser into the device," but for obvious reasons, it's impossible to actually show us it happened. Regardless, for the sake of the kiddos above, we're hoping this stuff gets commercialized, and soon.[Via Digg, Image courtesy of Thomas Ricker (yes, that Thomas Ricker)]
Darpa funds invisible, shoot-through shield
In a move seemingly influenced in equal parts by Halo and David Lynch's film Dune, Darpa has announced that it's ponying up $15 million to develop one-way-invisible, self-healing, shoot-through shields for use in urban combat. While the Pentagon's research division acknowledges that there are "significant technical obstacles" in the process, it's fairly gung-ho about developing a technology combining metamaterials, 'coded' obscurant systems, and a bunch of other stuff no one really understands. Trust us, you'll thank them if the Harkonens try and overthrow your spice-mining operation.[Via Digg]
