Researchers from Northeastern University are among the many scientists helping NASA use the weightlessness of space to design stronger materials here on Earth. Researchers say by observing the solidification process in a microgravity environment—in this case, the International Space Station—they were able to study how this morphological instability develops in three dimensions to shape the structure of materials on a micron scale.
Over the past three decades, researchers have found various applications of a method for attaching molecules to gold; the approach uses chemicals called thiols to bind the materials together. But while this technique has led to useful devices for electronics, sensing and nanotechnology, it has limitations. Now, a Massachusetts Institute of Technology team has found a new material that could overcome many of these limitations.
A new version of solar cells created by laboratories at Rice and Pennsylvania State universities could open the door to research on a new class of solar energy devices. The photovoltaic devices are based on block copolymers, self-assembling organic materials that arrange themselves into distinct layers. They easily outperform other cells with polymer compounds as active elements.
Scientists at the University of California, San Diego have designed tiny spherical particles to float easily through the bloodstream after injection, then assemble into a durable scaffold within diseased tissue. An enzyme produced by a specific type of tumor can trigger the transformation of the spheres into net-like structures that accumulate at the site of a cancer.
Paper is known for its ability to absorb liquids, making it ideal for products such as paper towels. But by modifying the underlying network of cellulose fibers, etching off surface “fluff” and applying a thin chemical coating, researchers have created a new type of paper that repels a wide variety of liquids—including water and oil.
What may be the ultimate heat sink is only possible because of yet another astounding capability of graphene. The one-atom-thick form of carbon can act as a go-between that allows vertically aligned carbon nanotubes to grow on nearly anything. That includes diamonds. A diamond film/graphene/nanotube structure was one result of new research carried out by scientists at Rice University and the Honda Research Institute USA.
Pushing gold exploration to the nanoscale, scientists used SLAC National Accelerator Laboratory's Linac Coherent Light Source X-ray laser to produce a series of 3D images that detail a ringing effect in tiny gold crystals. The technique provides a unique window for studying why smaller is better for some specialized materials, including those used in chemical reactions and electronic components.
When an object slides on another, the advancement may occur through a “stop and go” series in the characteristic manner which scientists call "stick-slip", a pervasive phenomenon at every scale. Researchers in Italy have studied and gained on the conditions in which, at the nanoscopic level, the switch from smooth sliding to stick-slip regime occurs, simulating the “toy-like” systems of “cold ions”.
In a move that would make the alchemists of King Arthur’s time green with envy, scientists have unraveled the formula for turning liquid cement into liquid metal. This makes cement a semiconductor and opens up its use in the profitable consumer electronics marketplace for thin films, protective coatings, and computer chips.
There has been great interest in using quantum dots to produce low-cost, easily manufactured, stable photovoltaic cells. But, so far, the creation of such cells has been limited by the fact that in practice, quantum dots are not as good at conducting an electric charge as they are in theory. Something in the physical structure of these cells seems to trap their electric-charge carriers. Now researchers may have found the key.
Researchers at North Carolina State University have developed a new technique for creating high-quality semiconductor thin films at the atomic scale—meaning the films are only one atom thick. The technique can be used to create these thin films on a large scale, sufficient to coat wafers that are two inches wide, or larger.
Rice University scientists have unveiled a robust new method for arranging metal nanoparticles in geometric patterns that can act as optical processors that transform incoming light signals into output of a different color. The team used the method to create an optical device in which incoming light could be directly controlled with light via a process known as “four-wave mixing.”
An international team of researchers may have found what cause a dramatic cooling near the end of the last major Ice Age more than 12,000 years ago. The recently published study, which involved the study of rock melted into carbon spherules, describes evidence of a major cosmic event near the end of the Ice Age. The ensuing climate change forced many species to adapt or die.
Meeting the demand for more data storage in smaller volumes means using materials made up of ever-smaller magnets, or nanomagnets. One promising material for a potential new generation of recording media is an alloy of iron and platinum with an ordered crystal structure.
A fried breakfast food popular in Spain provided the inspiration for the development of doughnut-shaped droplets that may provide scientists with a new approach for studying fundamental issues in physics, mathematics, and materials. The doughnut-shaped droplets, a shape known as toroidal, are formed from two dissimilar liquids using a simple rotating stage and an injection needle.
Waterproof fabrics that whisk away sweat could be the latest application of microfluidic technology developed by bioengineers at the University of California, Davis. The new fabric works like human skin, forming excess sweat into droplets that drain away by themselves, says inventor Tingrui Pan.
Through experiments and simulations, a team of Lawrence Livermore National Laboratory scientists have found that twin boundaries with good electrical conductivity and a strengthening mechanism in materials may not be so perfect after all.
These days, aerospace engineering is all about the light stuff. Advanced carbon-fiber composites have been used in recent years to lighten planes’ loads. For the next generation of commercial jets, researchers are looking to even stronger and lighter materials, such as composites made with carbon fibers coated with carbon nanotubes. However, a significant hurdle to achieving such composites has existed, until now.
Nearly everyone is familiar with the polytetrafluoroethylene (PTFE), otherwise known as Teflon. Famous for being “non-sticky” and water repellent, PTFE is a dry lubricant used on machine components everywhere. Recently, engineering researchers at the University of Arkansas found a way to make the polymer even less adhesive.
Graphene has dazzled scientists ever since its discovery more than a decade ago. But one long-sought goal has proved elusive: how to engineer into graphene a property called a band gap, which would be necessary to use the material to make transistors and other electronic devices. New findings by Massachusetts Institute of Technology researchers are a major step toward making graphene with this coveted property.
With the hand of nature trained on a beaker of chemical fluid, the most delicate flower structures have been formed in a Harvard University laboratory—and not at the scale of inches, but microns. These minuscule sculptures, curved and delicate, don't resemble the cubic or jagged forms normally associated with crystals, though that's what they are. Rather, fields of flowers seem to bloom from the surface of a submerged glass slide.
In the wake of the sobering news that atmospheric carbon dioxide is now at its highest level in at least three million years, an important advance in the race to develop carbon-neutral renewable energy sources has been achieved. Scientists with Lawrence Berkeley National Laboratory have reported the first fully integrated nanosystem for artificial photosynthesis.
Injectable nanoparticles developed at Massachusetts Institute of Technology may someday eliminate the need for patients with Type 1 diabetes to constantly monitor their blood-sugar levels and inject themselves with insulin. The nanoparticles were designed to sense glucose levels in the body and respond by secreting the appropriate amount of insulin.
Inspired by the structure of moth eyes, researchers at North Carolina State University have developed nanostructures that limit reflection at the interfaces where two thin films meet, suppressing the “thin-film interference” phenomenon commonly observed in nature. This can potentially improve the efficiency of thin-film solar cells and other optoelectronic devices.
In a quest to develop low-friction components for ever smaller mechanical systems, a team of physicists in Germany has recently discovered a previously unknown type of friction that they call “desorption stick.” The researchers examined how and why single polymer molecules in various solvents slide over or stick to certain surfaces. They found that an unexpected factor was responsible for the friction they observed.