Imagine printing out molecules that can respond to their surroundings. A research project at the Univ. of Washington merges custom chemistry and 3D printing. Scientists created a bone-shaped plastic tab that turns purple under stretching, offering an easy way to record the force on an object.
Artists, print designers and interior decorators have long had access to a broad palette of paint and ink colors for their work. Now, researchers have created a broad color palette of electrochromic polymers, materials that can be used for sunglasses, window tinting and other applications that rely on electrical current to produce color changes.
Anyone who has ever toasted the top of their legs with their laptop or broiled their ear on a cell phone knows that microelectronic devices can give off a lot of heat. These devices contain a multitude of transistors, and although each one produces very little heat individually, their combined thermal output is significant and can damage the device.
A novel approach to growing nanowires promises a new means of control over their light-emitting and electronic properties. In a recent issue of Nano Letters, scientists from Lawrence Berkeley National Lab demonstrated a new growth technique that uses specially engineered catalysts. These catalysts, which are precursors to growing the nanowires, have given scientists more options than ever in turning the color of light-emitting nanowires.
Scientists discovered in 1937 that liquid helium-4, when chilled to extremely low temperatures, became a superfluid that could leak through glass, overflow its containers or eternally gush like a fountain. Future Nobel laureate Lev Landau came along in 1941, predicting that superfluid helium-4 should contain an exotic, particle-like excitation called a roton.
Proteins are the building blocks of all living things, and they exist in virtually unlimited varieties, most of whose highly complex structures have not yet been determined. Those structures could be key to developing new drugs or to understanding basic biological processes. But figuring out the arrangement of atoms in these complicated, folded molecules usually requires getting them to form crystals large enough to be observed in detail.
A breakthrough by a team of researchers could lead to the more precise transfer of information in computer chips, as well as new types of optical materials for light emission and lasers. The researchers were able to control light at tiny lengths around 500 nm, smaller than the light’s own wavelength, by using random crystal lattice structures to counteract light diffraction.
A team of Caltech chemists has discovered a method for producing a group of silicon-containing organic chemicals without relying on expensive precious metal catalysts. Instead, the new technique uses as a catalyst a cheap, abundant chemical that is commonly found in chemistry labs around the world, potassium tert-butoxide, to help create a host of products ranging from new medicines to advanced materials.
When a metal tube lines an oil well thousands of feet below the surface of the ocean, that metal had better be solid and reliable. Unfortunately, the environment in such deep wells is often rich in hydrogen, a gas that can penetrate high-tech alloys and make them brittle, making fractures and leaks more likely. Now researchers have figured which characteristics of a metal structure foster this embrittlement in the presence of hydrogen.
The delivery of tiny biodegradable microstructures to heart tissue damaged by heart attack may help repair the tissue and prevent future heart failure. A team led by cardiovascular researchers at the Medical College of Wisconsin bioengineered the microstructures to be the same size, shape and stiffness as adult heart muscle cells, or cardiomyocytes, with the goal of releasing biologically active peptides that act as cardioprotective agents.
While the mysterious, unseen forces magnets project are now (mostly) well understood, they can still occasionally surprise us. For instance, thin films of cobalt have been observed to spontaneously switch their poles: something that typically doesn’t happen in the absence of an external magnetic field. Physicists at NIST and the Univ. of Maryland have measured this phenomenon on the largest scale yet.
Researchers at Virginia Commonwealth Univ. and universities in China and Japan have discovered a new structural variant of carbon called "penta-graphene", a very thin sheet of pure carbon that has a unique structure inspired by a pentagonal pattern of tiles found paving the streets of Cairo.
Lawrence Berkeley National Laboratory researchers have developed a nano-sized optical antenna that can greatly enhance the spontaneous emission of light from atoms, molecules and semiconductor quantum dots. This advance opens the door to light-emitting diodes (LEDs) that can replace lasers for short-range optical communications, including optical interconnects for microchips, plus a host of other potential applications.
Researchers at The Univ. of Texas at Austin have created the first transistors made of silicene, the world’s thinnest silicon material. Their research holds the promise of building dramatically faster, smaller and more efficient computer chips. Made of a one-atom-thick layer of silicon atoms, silicene has outstanding electrical properties but has until now proved difficult to produce and work with.
Far from being a defect, a winding thread of odd rings at the border of two sheets of graphene has qualities that may prove valuable to manufacturers, according to Rice Univ. scientists. Graphene rarely appears as a perfect lattice of chicken wire-like six-atom rings. When grown via chemical vapor deposition, it usually consists of “domains,” or separately grown sheets that bloom outward from hot catalysts until they meet up.
The editors of R&D Magazine are looking for speakers to participate in a webinar on “Using Multiple Materials in 3D Printing.” Candidates are asked to give a 15-min PowerPoint-based talk over the phone on their experiences in fabricating 3D printed products using multiple materials or developing the processes and/or technologies to accomplish this.
The lowly roundworm is the star of an ambitious Rice Univ. project to measure the toxicity of nanoparticles. The low-cost, high-output study measures the effects of many types of nanoparticles not only on individual organisms but also on entire populations. The researchers tested 20 types of nanoparticles and determined that five, including the carbon-60 molecules (“buckyballs”) discovered at Rice in 1985, showed little to no toxicity.
Efficiency is big in the tiny world of thermoelectric nanowires. Researchers at Sandia National Laboratories say better materials and manufacturing techniques for the nanowires could allow carmakers to harvest power from the heat wasted by exhaust systems or lead to more efficient devices to cool computer chips.
If you can’t find the ideal material, then design a new one. Northwestern Univ.’s James Rondinelli uses quantum mechanical calculations to predict and design the properties of new materials by working at the atom-level. His group’s latest achievement is the discovery of a novel way to control the electronic band gap in complex oxide materials without changing the material’s overall composition.
Researchers at the Univ. of Liverpool and Univ. College London have shown a new way to use a single molecule as a magnetic field sensor. In a study, published in Nature Nanotechnology, the team shows how magnetism can manipulate the way electricity flows through a single molecule, a key step that could enable the development of magnetic field sensors for hard drives that are a tiny fraction of their present size.
Engineers are shining new light on an emerging family of solar-absorbing materials that could clear the way for cheaper and more efficient solar panels and LEDs. The materials, called perovskites, are particularly good at absorbing visible light, but had never been studied in their purest form: as perfect single crystals.
Imagine eyeglasses that can go quickly from clear to shaded and back again when you want them to, rather than passively in response to changes in light. Scientists report a major step toward that goal, which could benefit pilots, security guards and others who need such control, in ACS Applied Materials & Interfaces.
In Science, Los Alamos National Laboratory researchers reveal a new solution-based hot-casting technique that allows growth of highly efficient and reproducible solar cells from large-area perovskite crystals. The researchers fabricated planar solar cells from pervoskite materials with large crystalline grains that had efficiencies approaching 18%.
Earth’s magnetic field is crucial for our existence, as it shields the life on our planet’s surface from deadly cosmic rays. It is generated by turbulent motions of liquid iron in Earth’s core. Iron is a metal, which means it can easily conduct a flow of electrons that makes up an electric current. New findings show a missing piece of the traditional theory explaining why metals become less conductive when they are heated.
In today’s world, in which the threat of terrorism looms, there is an urgent need for fast, reliable tools to detect the release of deadly chemical warfare agents (CWAs). In ACS Macro Letters, scientists are reporting new progress toward thin-film materials that could rapidly change colors in the presence of CWAs.