It’s just one atom thick, but carbyne has twice the strength of its two-dimensional cousin, graphene, and three times the stiffness of a diamond. And researchers have just discovered that it can act like a transistor for new tinier electronics.
Category: materials – Page 371
Researchers enable robots to see through solid walls with Wi-Fi (w/ Video)
(Phys.org) —Wi-Fi makes all kinds of things possible. We can send and receive messages, make phone calls, browse the Internet, even play games with people who are miles away, all without the cords and wires to tie us down. At UC Santa Barbara, researchers are now using this versatile, everyday signal to do something different and powerful: looking through solid walls and seeing every square inch of what’s on the other side. Built into robots, the technology has far-reaching possibilities.
“This is an exciting time to be doing this kind of research,” said Yasamin Mostofi, professor of electrical and computer engineering at UCSB. For the past few years, she and her team have been busy realizing this X-ray vision, enabling robots to see objects and humans behind thick walls through the use of radio frequency signals. The patented technology allows users to see the space on the other side and identify not only the presence of occluded objects, but also their position and geometry, without any prior knowledge of the area. Additionally, it has the potential to classify the material type of each occluded object such as human, metal or wood.
The combination of imaging technology and automated mobility can make these robots useful in situations where human access is difficult or risky, and the ability to determine what is in a given occluded area is important, such as search and rescue operations for natural or man-made disasters.
MIT Invented Magnetic Hairs That Can Make Water Flow Uphill
Inspired by the coats of fur on some animals, researchers at MIT have developed a flexible skin-like material covered in thousands of tiny magnetic hairs that can move in varying directions in the presence of a magnetic field. That might not seem particularly useful, until MIT points out that the new material can be used to control how liquids move across its surface, even causing water to flow against the pull of gravity.
It’s a neat trick, for sure, but there are other more useful applications of this new material. The tiny magnetic micro-pillars that make up the hair can be manufactured from a fiber optic-like material allowing them to change the direction of light passing through, facilitating self-darkening windows, or revolutionary new optics for cameras. The material can also be used to create advanced artificial skins, smart waterproofing, and even a precise way to manipulate individual cells. And let’s not forget a potential radical breakthrough in self-combing toupees and wigs. [MIT].
New ‘shape-shifting’ material can reconstruct faces
Called a shape-memory polymer (SMP) and developed by a team at Texas A&M University in the US, this biodegradable material can be used to fill in gaps in a damaged face and act as a scaffold to guide the growth of existing bones.
The researchers made their shape-memory polymer by linking molecules of another material — polycaprolactone, or PCL — and whipping it into a foam. According to Jackie Hong at Motherboard, the material is soft and easy to mould when heated to 60°C (140°F), and sets when it’s cooled to body temperature without becoming brittle. It can be used in 3D printing and moulding, which means it can be shaped into extremely precise models and bone scaffolds, and it’s full of tiny holes like a sponge, which allows bone-producing cells called osteoblasts to collect inside and grow.
According to Hong, the researchers enhanced this osteoblast-growing effect by coating their SMP material in polydopamine — a different kind of polymer substance that helps bind existing bones to the SMP scaffold, and has been shown in previous studies to encourage the growth of osteoblasts. Over a three-day trial, their coated SMP scaffold grew five times more osteoblasts than their uncoated scaffold.
Sand-based batteries could soon power your mobile phone
Researchers at the University of California, Riverside in the US have developed lithium-ion batteries that substitute graphite with silicon extracted from sand and last three times longer than current products.
The negative side of lithium-ion batteries, or anode, is made with graphite, and scientists have been trying to find a substitute material that could make batteries last longer. One of the options is silicon, which can store up to 10 times more energy than current materials, but it’s expensive and hard to produce in large quantities.
But then a very simple but brilliant option revealed itself to graduate student Zachary Favors. As Gizmag reports, Favors was relaxing after surfing when he noticed something quite special: sand. Sand is made of quartz, or silicon dioxide, and other materials, so Favors thought he could extract the silicon and use it to make batteries.
Solar panels as inexpensive as paint?
Fortunately, that is changing because researchers such as Qiaoqiang Gan, University at Buffalo assistant professor of electrical engineering, are helping develop a new generation of photovoltaic cells that produce more power and cost less to manufacture than what’s available today.
One of the more promising efforts, which Gan is working on, involves the use of plasmonic-enhanced organic photovoltaic materials. These devices don’t match traditional solar cells in terms of energy production but they are less expensive and — because they are made (or processed) in liquid form — can be applied to a greater variety of surfaces.
Gan detailed the progress of plasmonic-enhanced organic photovoltaic materials in the May 7 edition of the journal Advanced Materials. Co-authors include Filbert J. Bartoli, professor of electrical and computer engineering at Lehigh University, and Zakya Kafafi of the National Science Foundation.
The dimensional aspect of existence is associated with the dimensions of space and time.
The dimensionless aspect, since it has no dimensions, is outside of space and time. This is the key aspect to existence: an aspect outside of space and time perpetually interacting dialectically with an aspect inside space and time. All of the weird and wonderful phenomena of the universe are the products of this ultimate dichotomy.
Does this sound crazy? Then consider the evidence provided by black holes.
The R = 0 Universe.
Black holes are objects where gravity is so strong that light itself cannot escape the gravitational pull. They are the most mysterious objects in the universe and hold the key to the nature of reality. They open the door to understanding the fundamental composition of the universe.
Their hypothetical existence was first predicted in Einstein’s famous theory of General Relativity, but Einstein himself believed it was impossible for them to become real objects in the universe. The reason for that is that they exhibit a feature that physics cannot cope with or comprehend.
Einstein’s equations contain a term that involves dividing the mass of the black hole by the distance “r” from the black hole. The question is what happens when r=0? Division by zero gives a result of infinity. To physicists, it is impossible for infinity to appear in the real world, so they consider r = 0 to be the point at which physics breaks down. At r = 0, the centre of a black hole, gravity is infinite and time itself stops: all of the mass of the black hole is contained within an infinitely small point where the concept of space no longer makes any sense. The point takes up precisely no space at all. Since this point is outside space and time, it is dimensionless. The physical universe collapses into an ineffable twilight state at this point. This apparently impossible object of infinite density and infinite gravity is known as the singularity. No predictions can be made about it, or about what might emerge from it. At the singularity, physicists’ understanding of nature fails completely. Therefore, they believe that there is a fatal flaw in the formulation of Einstein’s theory of general relativity, despite its immense success.
The one thing no physicist has ever contemplated is this: there is no flaw whatsoever. The reason why physics seems to disintegrate at r = 0 is for the extremely simple reason that r = 0 is not in the physical universe. It is in the mental universe, the universe of mind, as we have described in the previous section.
Ultrathin ‘Invisibility Cloak’ Can Match Any Background
Invisibility cloaks are designed to bend light around an object, but materials that do this are typically hard to shape and only work from narrow angles — if you walk around the cloaked object, for instance, it’s visible. But a new cloak avoids that problem, and is thin and flexible enough to be wrapped around an object of any shape, the researchers said. It can also be “tuned” to match whatever background is behind it — or can even create illusions of what’s there, they added.
Led by Xiang Zhang, director of materials science at Lawrence Berkeley National Laboratory, the group constructed a thin film consisting of a 50-nanometer-thick layer of magnesium fluoride topped by a varying pattern of tiny, brick-shaped gold antennas, each 30 nanometers thick. (For comparison, an average strand of human hair is about 100,000 nanometers wide.) The “bricks” were built in six different sizes, ranging from about 30 to 220 nanometers long and 90 to 175 nanometers wide. [Now You See It: 6 Tales of Invisibility in Pop Culture]
The scientists then wrapped up a tiny, irregularly shaped object measuring about 36 microns across, or a bit more than one-thousandth of an inch. Shining a light, with a wavelength of 730 nanometers, or near-infrared, they found that it reflected back almost perfectly. The light scattering from the cloak still bounced off the object, but without revealing where the object was — as though there were just a flat mirror in its place, the researchers said.
Making 3-D objects disappear: Researchers create ultrathin invisibility cloak
Invisibility cloaks are a staple of science fiction and fantasy, from Star Trek to Harry Potter, but don’t exist in real life, or do they? Scientists at the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley have devised an ultra-thin invisibility “skin” cloak that can conform to the shape of an object and conceal it from detection with visible light. Although this cloak is only microscopic in size, the principles behind the technology should enable it to be scaled-up to conceal macroscopic items as well.
Working with brick-like blocks of gold nanoantennas, the Berkeley researchers fashioned a “skin cloak” barely 80 nanometers in thickness, that was wrapped around a three-dimensional object about the size of a few biological cells and arbitrarily shaped with multiple bumps and dents. The surface of the skin cloak was meta-engineered to reroute reflected light waves so that the object was rendered invisible to optical detection when the cloak is activated.
“This is the first time a 3D object of arbitrary shape has been cloaked from visible light,” said Xiang Zhang, director of Berkeley Lab’s Materials Sciences Division and a world authority on metamaterials — artificial nanostructures engineered with electromagnetic properties not found in nature. “Our ultra-thin cloak now looks like a coat. It is easy to design and implement, and is potentially scalable for hiding macroscopic objects.”
New Solar Panels That Work At Night
Despite the enormous untapped potential of solar energy, one thing is for sure- photovoltaics are only as good as the sun’s rays shining upon them. However, researchers at the Idaho National Laboratory are close to the production of a super-thin solar film that would be cost-effective, imprinted on flexible materials, and would be able to harvest solar energy even after sunset!
