Thermal considerations are rapidly becoming one of the most serious design constraints in microelectronics, especially on submicron scale lengths. A study by researchers from the Univ. of Illinois at Urbana-Champaign has shown that standard thermal models will lead to the wrong answer in a 3-D heat-transfer problem if the dimensions of the heating element are on the order of one micron or smaller.
Droplets are simple spheres of fluid, not normally considered capable of doing anything on their own. But now researchers have made droplets of alcohol move through water, even moving through complex mazes. The droplets can be led to certain targets, using a surprisingly simple impetus. In the future, such moving droplets may deliver medicines, moving entire chemistries to targets.
In a rare case of having their cake and eating it too, scientists from NIST and other institutions have developed a toolset that allows them to explore the complex interior of tiny, multi-layered batteries they devised. It provides insight into the batteries’ performance without destroying them, which results in both a useful probe for scientists and a potential power source for micromachines.
A novel x-ray technique used at the U.S. Department of Energy’s Advanced Photon Source has revealed surprising dynamics in the nanomechanics of operating batteries and suggests a way to mitigate battery failures by minimizing the generation of elastic energy. The method could open a path to wider use of these batteries in conjunction with renewable energy sources.
A little change in temperature makes a big difference for growing a new generation of hybrid atomic-layer structures, according to scientists. Rice Univ. scientists led the first single-step growth of self-assembled hybrid layers made of two elements that can either be side by side and one-atom thick or stacked atop each other. The structure’s final form can be tuned by changing the growth temperature.
The key to creating a material that would be ideal for converting solar energy to heat is tuning the material’s spectrum of absorption just right: It should absorb virtually all wavelengths of light that reach Earth’s surface from the sun—but not much of the rest of the spectrum, since that would increase the energy that is reradiated by the material, and thus lost to the conversion process.
Confined photons have many potential applications, such as efficient miniature lasers, on-chip information storage, or tiny sensors on pharmaceuticals. Making a structure that can capture photons is difficult, but scientists in the Netherlands have recently devised a new type of resonant cavity inside a photonic crystal that imprisons light in all three dimensions.
Electricity and magnetism rule our digital world. Semiconductors process electrical information, while magnetic materials enable long-term data storage. A Univ. of Pittsburgh research team has discovered a way to fuse these two distinct properties in a single material, paving the way for new ultrahigh density storage and computing architectures.
Concrete can be better and more environmentally friendly by paying attention to its atomic structure, according to researchers at Rice Univ., the Massachusetts Institute of Technology and Marseille Univ. The international team of scientists has created computational models to help concrete manufacturers fine-tune mixes for general applications.
If it's true that good things come in small packages, then NIST can now make anyone working with nanoparticles very happy. The institute recently issued Reference Material (RM) 8027, the smallest known reference material ever created for validating measurements of man-made, ultrafine particles between 1 and 100 nm in size.
Scientists at the U.S. Naval Research Laboratory have introduced a new one-step process using, for the first time in these types of syntheses, potassium superoxide to rapidly form oxide nanoparticles from simple salt solutions in water. An important advantage of this method is the capability of creating bulk quantities of these materials, more than 10 g in a single step.
using an aberration-corrected scanning transmission electron microscope, researchers have recently understood how defects in 2-D crystals such as tungsten disulphide can move, or dislocate, to other locations in the material. Understanding how atoms "glide" and "climb" on the surface of 2-D crystals may pave the way for researchers to develop materials with unusual or unique characteristics.
Princeton Univ. researchers have developed a new method to increase the power and clarity of light-emitting diodes (LEDs). Using a new nanoscale structure made from flexible carbon-based sheet, the researchers increased the brightness and efficiency of LEDs made of organic materials by 57%.
Diamonds aren’t just a girl’s best friend, they’re also R&D’s best friend—or at least a new acquaintance. Many laboratories and companies are embracing synthetic diamond for its elevated super properties in applications ranging from analytical instruments and biomedical sensors to electronics and lasers to water purification.
In experiments using graphene, researchers in Switzerland have been able to demonstrate a phenomenon predicted by a Russian physicist more than 50 years ago. The observation of the Lifshitz transition, which describes a change in topology, depended on the creation of a double-layer graphene sample of unprecedented quality.
A common complaints about solar power is that solar panels are still too expensive. Efforts at making them more efficient or longer-lasting have been limited. A new method developed in Okinawa could solve the expense problem: A hybrid form of deposition is being used to create perovskite solar cells from a mixture of inexpensive organic and inorganic raw materials, eliminating the need for expensive crystallized silicon.
A Rice Univ. team led by bioengineer Jeffrey Jacot and chemical engineer and chemist Matteo Pasquali have created new pediatric heart-defect patches infused with conductive single-walled carbon nanotubes that allow electrical signals to pass unhindered. The nanotubes overcome a limitation of current patches in which pore walls hinder the transfer of electrical signals between cardiomyocytes, the heart muscle’s beating cells.
Researchers are developing a robotic fabric that moves and contracts and is embedded with sensors, an approach that could lead to "active clothing" or a new class of "soft" robots. The robotic fabric, developed at Purdue Univ., is a cotton material containing sensors made of a flexible polymer and threadlike strands of a shape-memory alloy that return to a coiled shape when heated, causing the fabric to move.
Nanocomposite oxide ceramics have potential uses as ferroelectrics, fast ion conductors, and nuclear fuels and for storing nuclear waste, generating a great deal of scientific interest on the structure, properties, and applications of these blended materials. Los Alamos National Laboratory researchers have made the first observations of the relationship between the chemistry and dislocation structures of the nanoscale interfaces.
Over a three-year period, Univ. of North Texas researchers developed and tested structured insulated panel building materials made from kenaf, a plant in the hibiscus family that is similar to bamboo. Kenaf fibers are an attractive prospect because they offer the same strength to weight ratio as glass fibers. The researchers found that the kenaf materials, including composite panels, provide up to 20% energy savings.
Researchers have discovered a way to create a highly sensitive chemical sensor based on the crystalline flaws in graphene sheets. The imperfections have unique electronic properties that the researchers were able to exploit to increase sensitivity to absorbed gas molecules by 300 times.
For the first time, scientists led by John V. Badding, a professor of chemistry at Penn State Univ., have discovered how to produce ultra-thin "diamond nanothreads" that promise extraordinary properties, including strength and stiffness greater than that of today's strongest nanotubes and polymers. The core of the nanothreads is a long, thin strand of carbon atoms arranged just like the fundamental unit of a diamond's structure.
Shellfish such as mussels and barnacles secrete very sticky proteins that help them cling to rocks or ship hulls, even underwater. Inspired by these natural adhesives, a team of Massachusetts Institute of Technology engineers has designed new materials that could be used to repair ships or help heal wounds and surgical incisions.
Transforming substances from liquids into gels plays an important role across many industries, but the transformation process, called gelation, is expensive and energy demanding. Instead of adding chemical thickeners and heating or cooling the fluids, as is traditional, researchers in Okinawa are experimenting with microfluidic platforms, adding nanoparticles and biomolecules with used pH, chemical and temperature sensing properties.
For decades, the power conversion efficiency of organic solar cells was hampered by the drawbacks of commonly used metal electrodes, including their instability and susceptibility to oxidation. Now for the first time, researchers at the Univ. of Massachusetts Amherst have developed a more efficient, easily processable and lightweight solar cell that can use virtually any metal for the electrode, effectively breaking the “electrode barrier.”