Graphene is a very interesting nanomaterial with potential for applications in many different fields including nanoelectronics. However, the properties of graphene can vary broadly and depend sensitively on its integration in device structures and the details of its interaction with other materials, such as underlying substrates or gate dielectrics. Unlike other semiconductor electronic devices, where the active layer is buried below the surface and where microscopic details of transport cannot be directly examined, graphene is exposed at a surface and can be directly examined on the atomic scale using scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS). New work now provides microscopic details of graphene interaction with a substrate in the most common device structure used so far.
One area of nanobiotechnology that will have a massive impact on improving the live of disabled people lies at the interface (literally) between artificial functional materials and living neuronal tissues. Neuroprosthetics is an area of neuroscience that uses artificial microdevices to replace the function of impaired nervous systems or sensory organs. Different biomedical devices implanted in the central nervous system, so-called neural interfaces, already have been developed to control motor disorders or to translate willful brain processes into specific actions by the control of external devices. One are that has been quite challenging is the communication between biological tissues and artificial sensors - something that is key in building artificial retinas, for instance. Researchers in Italy have now reported the functional interfacing of an organic semiconductor with a network of cultured primary neurons.
Imagine intelligent medical implants that can continuously monitor their condition inside the body and autonomously respond to changes such as infection by releasing anti-inflammatory agents. Thanks to nanotechnology, medical research is moving quickly towards this goal. A new study shows that the use of polypyrrole films as electrically controlled drug release devices on implant surfaces can potentially improve bone implants. By electrodepositing antibiotics or anti-inflammatory drugs in a polymer coating on medical devices, researchers demonstrate that such drugs can be released from polypyrrole on demand - by applying a voltage - and control cellular behavior important for orthopedic applications, i.e. inhibit inflammation and kill bacteria.
Patterns of news coverage on nanotechnology are developing in ways that mirror issue cycles for previous technologies, including agricultural biotechnology. In particular, early coverage of nanotechnology was dominated by a general optimism about the scientific potential and economic impacts of this new technology. This is in part related to the fact that a sizeable proportion of nanotechnology news coverage - at least in newspapers - continues to be provided by a handful of science journalists and business writers. This is an initial draft of an article that what will eventually become a chapter on public attitudes toward nanotechnology in a new book on risk communication and public perception of nanotechnology. It's meant to be a current update and comprehensive overview of what we know (and don't know) at this point.
Traditional anode materials for lithium-ion batteries, like graphite, have a fairly low storage capacity and release rate, so finding alternatives is key to making batteries that last longer and produce more power. Titanium dioxide is regarded as one of the ideal candidates for high-rate anode materials, owing not only to its structural characteristics and special surface activity, but also to its low cost, safety, and relatively low environmental impact. Researchers in Singapore have developed a facile system to fabricate sandwich-like carbon-supported stacked titanium dioxide nanosheets, in which carbon pillars create open channels for fast lithium ion diffusion and the ultrathin framework renders the storage of lithium almost exclusively on the surface. This work provides a new route to design the electrode materials for quick-charging lithium ion batteries.
Thermoelectric materials therefore hold great promise for turning waste heat back into useful power and are touted for use in hybrid cars, new and efficient refrigerators, and other cooling or heating applications. Thermoelectric devices are energy converters - they are based on the fact that when certain materials are heated, they generate a significant electrical voltage; conversely, when a voltage is applied to them, they become hotter on one side, and colder on the other. But they have one big drawback: they are very inefficient. Efficient thermoelectric materials need to be very good at conducting electricity, but not heat - and that's the problem; these materials are not efficient enough to be practical. In most materials, electrical and thermal conductivity go hand in hand. So researchers have to find ways of boosting the performance of thermoelectric materials by separating the two properties.
At the nanoscale, the properties of materials - mechanical, electrical, thermal, optical - often differ significantly from their bulk behavior. And while nanostructured and nanoengineered products are appearing in the marketplace, researchers are still trying to understand all aspects of materials properties of nanostructures and how they can be modified and controlled. Vacancies (also called Schottky defect) play a major role in the electrical and thermal transport as well as the mechanical behavior of materials. A vacancy is the simplest defect which can be created in a material - it corresponds to a lack of an atom in the lattice. New theoretical work calculates the size effect on the vacancy formation energy, the vacancy formation entropy and the vacancy concentration into nanomaterials through a top-down approach by using classical thermodynamics.
Chemotherapeutics generally show a delicate balance between maintaining a high enough dose to kill cancer cells while avoiding a dose so high that it causes severe toxic effects. One of the many promises of nanomedicine is a class of nanoscale drug delivery vehicles that can pinpoint cancer cells and deliver their tumor-killing payload right into cancer cells with high efficiency and no side effects. Based on a novel silica 'nanorattle' structure, a research team further extended their work to fabricate 'all-in-one' multifunctional gold nanoshells on silica nanorattles which combine remote-controlled photothermal therapy with chemotherapy. The results indicate that a combination of hyperthermia and chemotherapeutic agents is an encouraging approach to optimizing cancer therapy for the synergistic effects are greater than the two individual treatments alone.