Materials scientists have long known that introducing defects into 3-D materials can improve their mechanical and electronic properties. Now a new Northwestern Univ. study finds how defects affect 2-D crystalline structures, and the results hold information for designing new materials.
A new theoretical study shows the conductivity conditions under which graphene nanoribbons can become switches in externally controlled electronic devices. The results, obtained by researchers in Argentina and Brazil, yield a clearer theoretical understanding of conductivity in graphene samples of finite size, which have applications in externally controlled electronic devices.
Navy researchers have recently demonstrated sustained flight of a radio-controlled P-51 fighter replica fueled by a new gas-to-liquid process that uses seawater as carbon feedstock. The fuel is made using an innovative and proprietary electrolytic cation exchange module that separates gases from water at 92% efficiency. Catalysis converts the gases to liquid hydrocarbons.
Solid-state dye-sensitized solar cells have shown their potential in achieving high efficiency with a low cost of fabrication. Degradation of these cells shortens lifespan dramatically, however, and the causes of this are not well understood. After a detailed analysis, researchers in Okinawa have determined which material in the cells was degrading, and why.
Chemists have found that cellulose, the most abundant organic polymer on Earth, can be heated in a furnace in the presence of ammonia and turned into the building blocks for supercapacitors. The new process produces nitrogen-doped, nanoporous carbon membranes, which act as the electrodes of a supercapacitor. The only byproduct is methane, which could be used immediately as a fuel or for other purposes.
Carbon nanotubes are reinforcing bars that make 2-D graphene much easier to handle in a new hybrid material grown by researchers at Rice Univ. The Rice laboratory of chemist James Tour set nanotubes into graphene in a way that not only mimics how steel rebar is used in concrete but also preserves and even improves the electrical and mechanical qualities of both.
A combined computational and experimental study of self-assembled silver-based structures known as superlattices has revealed an unusual and unexpected behavior: arrays of gear-like molecular-scale machines that rotate in unison when pressure is applied to them.
A research team has developed a small electronic sensing device that can alert users wirelessly to the presence of chemical vapors in the atmosphere.
As the properties and applications of graphene continue to be explored in laboratories all over the world, a growing number of researchers are looking beyond the one-atom-thick layer of carbon for alternative materials that exhibit similarly captivating properties.
Engineers have demonstrated thin, soft stick-on patches that stretch and move with the skin and incorporate commercial, off-the-shelf chip-based electronics for sophisticated wireless health monitoring.
A medical device, once its job is done, could harmlessly melt away inside a person’s body. Or, a military device could collect and send its data and then dissolve away, leaving no trace of an intelligence mission. Or, an environmental sensor could collect climate information, then wash away in the rain. It’s a new way of looking at electronics.
In the future, the clothes you wear could be made from sugar. Researchers have discovered a new chemical process that can convert adipic acid directly from sugar.
A novel ultrathin collagen matrix assembly allows for the unprecedented maintenance of liver cell morphology and function in a microscale "organ-on-a-chip" device that is one example of 3-D microtissue engineering.
Researchers are turning some of the basic tenets of chemistry and physics upside down to cut a trail toward the discovery of a new set of materials. They’re called “polar metals” and, according to many scientific principles, they probably shouldn’t exist.
Biomedical engineers have grown living skeletal muscle that looks a lot like the real thing. It contracts powerfully and rapidly, integrates into mice quickly, and for the first time, demonstrates the ability to heal itself both inside the laboratory and inside an animal.
In the ongoing search for new materials for fuel cells, batteries, photovoltaics, separation membranes, and electronic devices, one newer approach involves applying and managing stresses within known materials to give them dramatically different properties.
Biomass is a good alternative for fossil fuels, but converting biomass into useful chemicals and fuels is difficult in practice. The metal oxide CeO2 can help the process by activating water, but until recent research in the Netherlands, it was not clear in which form the reactivity of this catalyst was highest.
Pharmaceutical researchers in California, in collaboration with materials scientists, engineers and neurobiologists, have discovered a new mechanism for using near-infrared light to activate polymeric drug-delivering nanoparticles and other targeted therapeutic substances inside the body. This discovery represents a major innovation; up to now only a handful of strategies using light-triggered release from nanoparticles have been reported.
Recent research in Japan, China and U.S. has revealed through theoretical simulations that the molecular mechanism of carbon nanotube growth and hydrocarbon combustion actually share many similarities. In studies using acetylene molecules as feedstock, a highly reactive molecular intermediate was found to play an important role in both processes forming CNTs and soot, which are two distinctively different structures.
Germanium monosulfide (GeS) is emerging as one of the most important class "IV–VI" semiconductor materials with potential in optoelectronics applications for telecommunications and computing. Adding a new element of control to preparation of this material, researchers in China have found a convenient way to selectively prepare GeS nanostructures, including nanosheets and nanowires, that are more active than their bulk counterparts
Using an acoustic metadevice that can influence the acoustic space and can control any of the ways in which waves travel, engineers have demonstrated, for the first time, that it is possible to dynamically alter the geometry of a 3-D colloidal crystal in real time. The crystals designed in the study, called metamaterials, are artificially structured materials that extend the properties of naturally occurring materials and compounds.
Stem cells have the potential to repair human tissue and maintain organ function in chronic disease, but a major problem has been how to mass-produce such a complex living material. Scientists in the U.K. have now developed a new substance which could simplify the manufacture of therapeutic cells by allowing both self-renewal of cells and evolution into cardiomyocyte cells.
Combatting the tissue degrading enzymes that cause lasting damage following a heart attack is tricky. Each patient responds to a heart attack differently and damage can vary from one part of the heart muscle to another, but existing treatments can’t be fine-tuned to deal with this variation. Univ. of Pennsylvania researchers have developed a way to address this problem via a material that can be applied directly to the damaged heart tissue.
Researchers in Sweden have designed a paper filter which is capable of removing virus particles with the efficiency matching that of the best industrial virus filters. The paper filter, which is manufactured according to traditional paper making processes, consists of 100% high purity cellulose nanofibers directly derived from nature.
The fundamental laws of thermodynamics do not apply to objects on the nanoscale to the extent they do in our macroscopic world, and researchers are working to accurately describe the differences. A team of scientists have recently made progress in this area by determining how heat transfers from cold to hot objects in the nanoworld.