Exotic artificial composite materials called metamaterials can be engineered with certain electromagnetic properties that allows them to act as invisibility cloaks. These materials bend all light or other electromagnetic waves around an object hidden inside a metamaterial cloak, to emerge on the other side as if they had passed through an empty volume of space. Researchers have already been experimenting with cloaking devices for various, usually longer wavelengths such as microwave or infrared waves. Recently, even graphene has been added to the family of cloaking materials. Now, for the first time, a team of scientists at UC Berkeley have devised an invisibility cloak material that hides objects from detection using light that is visible to humans.
Structural color - where the color results from interferences, not pigments - is a natural fit for new display technologies and writing substrates since it can provide vivid colors in environments of high intensity light (e.g. sunlight) without the need for additional illuminating power. Most existing display technologies such as LCDs and LEDs require power to actively project colors and often suffer from performance degradations in these reflective environments. Recognizing this, researchers have developed a number of techniques for dynamically and spatially modulating the colors reflected off of photonic crystal-like substrates. In new work, researchers have demonstrated an electrical-power-free infusion technique that allows them to draw multi-color images on colloidal photonic crystal substrates using transparent imaging oils.
Single-molecule magnets (SMM) are fascinating nanoscale structures with unique functional properties showing promise for high-density electronic data storage devices, solid state quantum computers, spintronic devices such as spin valves, and other advanced technological applications. Despite a flurry of research in this area - since an individual magnetic molecule represents the ultimate size limit to storing and processing information - the main challenge related to harnessing properties of SMM remained unsolved. A new study by a group of European researchers reports the successful encapsulation of single-molecule magnets in carbon nanotubes, yielding a new type of hybrid nanostructure that combines all the key single-molecule magnet properties of the guest molecules with the functional properties of the host CNT.
To build microprocessors with more than one billion transistors, manufacturers still use the same technique - photolithography, the high-tech, nanoscale version of printing technology - that they have been using for the past 50 years. State-of-the-art photolithography processes use 193 nm light to produce diffraction-limited features as small as 32 nm. Going beyond 32 nm, the cost and complexity rises significantly, posing massive technological and economic challenges for chip manufacturers. This provides plenty of incentives for researchers to explore alternative manufacturing technologies for chipmakers. One novel approach is based on the use of DNA nanostructures to pattern a silicon wafer.
For more than 5000 years, noble metals have been known to be impervious to magnetic fields. Significant scientific breakthroughs in the recent past have led to making either 13 atoms clusters of platinum or organic molecule capped noble metal nanoparticles magnetic. By carefully controlling the size, shape, and composition of noble metals - especially in confined nanoscale systems - their properties can be modified, potentially leading to significantly advanced nanomaterial-based applications such as catalysis, self-assembly, novel metamaterials, improved MRI research, and spintronics. Now, researchers have developed simple method to make nano- and macro-particles of noble metals magnetic.
It is not often that the prefix multipliers kilo and nano come together, and when they do, it usually is in the opening chapters of physical sciences textbooks where the point is made that the universe around us spans enormous space and time scales while operating in unimaginably small ones. We are truly awestruck and inspired by the tension. Kilometer-long nanowires do have a similar eponymous echo. Researchers have now reported the first successful fabrication of arrays of millions of ordered indefinitely long nanowires and nanotubes in a flexible polymer fiber. The results are kilometer-long nanowires - a novel approach to nanowire fabrication that might bring with it fresh solutions.
Radiation damage to materials is a major issue for builders of nuclear power plants as well as spacecraft engineers. The former have to worry about material failure due to the destructive radiation created within the reactor; the later are concerned about the exposure to space radiation of both materials and humans during long-term space missions. There is a consensus that interface engineering is the way to go to to improve resistance to extreme conditions in general and to reach radiation tolerance in particular - interfaces are places where defects created by energetic collision in solids can annihilate each other and thus render the material immune to irradiation. All kind of interfaces are being explored, in particular those formed by the contact between two different solid state phases.
The future of your shirts, socks and gloves will be electronic. In years to come, wearable electronics will look nothing like even your smallest iPod or mobile phone today. Not only will such devices be embedded on textile substrates, but an electronics device or system could become the fabric itself. Here is some recent work that demonstrates the kind of issues scientists are working on today and that will help improve the performance of electronic textile structures. Using atomic layer deposition (ALD), researchers have grown coatings of inorganic materials on the surface of textiles like woven cotton and nonwoven polypropylene. By fabricating an all-fiber capacitor, they show that their coated materials are sufficiently conductive to perform in simple device architectures.