Showing Spotlights 1225 - 1232 of 2140 in category (newest first):
Steel is one of the most widely used engineering materials in the world. Its pre-eminent position amongst the engineering materials arises due to the abundance and low cost of its main constituent, i.e. iron, and its amenability to produce a wide variety of engineered microstructures with superior properties, and recyclability. Currently, there is a growing awareness about the potential benefits of nanotechnology in the modern engineering industry, and a number of leading research institutes and companies are pursuing research in the area of nanostructured steels. The focus of the ongoing efforts has been largely manipulation of microstructures at the nano-scale through innovative processing techniques and adoption of novel alloying strategies.
May 10th, 2010
Cultured mammalian cells prefer growing on structured rather than on completely flat surfaces. In regenerative medicine, in which human cells must grow on artificial scaffolds to replace damaged tissue, appropriate biological signals, such as growth factors, but also mechanic stimuli should be provided at the nano and microscales for cell attachment and proliferation, mimicking the natural cell matrices in organic tissues. The straightforward fabrication of nanostructured surfaces as scaffolds for tissue engineering is complex, but instead, micro- and nanorugosities can be easily generated on flat surfaces by either top-down or bottom-up approaches. Researchers have demonstrated that bacterial inclusion bodies formed by biologically irrelevant polypeptides are convenient biomaterials for the bottom-up decoration of substrates for mammalian cell growth.
May 7th, 2010
OLEDs - organic light-emitting diodes - are full of promise for a range of practical applications. OLED technology is based on the phenomenon that certain organic materials emit light when fed by an electric current and it is already used in small electronic device displays in mobile phones, MP3 players, digital cameras, and also some TV screens. With more efficient and cheaper OLED technologies it will possible to make ultra flat, very bright and power-saving OLED televisions, windows that could be used as light source at night, and large-scale organic solar cells. In contrast to regular LEDs, the emissive electroluminescent layer of an OLED consists of a thin-film of organic compounds. Exciton quenching and photon loss processes still limit OLED efficiency and brightness. Organic light-emitting transistors (OLETs) are alternative, planar light sources combining, in the same architecture, the switching mechanism of a thin-film transistor and an electroluminescent device. Thus, OLETs could open a new era in organic optoelectronics and serve as test beds to address general fundamental optoelectronic and photonic issues.
May 6th, 2010
One of the greatest current environmental concerns both for the near term as well as for the future is global warming caused by man-made carbon emissions and its well-recognized impact on climate change. The various strategies which can be adopted to combat global warming are classified under the following three categories: 1) Reducing energy consumption by employing more efficient technologies that minimize use of fossil fuels; 2) Adopting technologies that utilize renewable energy and energy storage technologies; 3) Addressing carbon management issues that involve separation, capture, sequestration and conversion to useful products. The present article will specifically address the first two topics.
May 4th, 2010
An intriguing novel approach to extract the energy from the photosynthetic conversion process has been demonstrated by researchers at Stanford and Yonsei Universities. They have inserted ultrasharp gold nanoelectrodes into living algae cells and extracted electrons, thereby harnessing an - albeit very tiny - electrical current. This is electricity production that doesn't release carbon into the atmosphere. The results demonstrate the feasibility of collecting high-energy electrons in steps of the photosynthetic electron transport chain and prior to the downstream processes associated with energy loss. In addition, the system allows direct monitoring of specific charge transfer reactions in live cells, leading to broad applications for investigating developmental processes and the responses of cells and organelles to light and chemical stimuli.
May 3rd, 2010
One of the most neglected aspects in the nanoelectronics field is the problem of wiring. How do we wire individual nanoelectronic devices within a nanointegrated circuit together? Furthermore, how do we extract and input information from such a circuit - i.e. how do we let it communicate with the outside world? Researchers at Caltech present a method for multiplexing the electrical signals from potentially tens of thousands of nanoscale sensors onto a single optical output, using piezoelectric nanoscale mechanical resonators. This work is a step closer to building miniscule, highly integrated sensor arrays that are untethered from the external environment.
Apr 30th, 2010
A European project has completed an extensive five-year study of the needs and opportunities for coordinating future research and development in nanomaterials science and nanotechnology for the advancement of technologies ranging from communication and information, health and medicine, future energy, environment and climate change to transport and cultural heritage. Based on the collaborative work of more than 600 experts from all over the world, the project has compiled an overall picture of the present and future developments in the large spectrum of nanomaterials. Although one of the foci was to highlight the important roles of advanced analytical equipment at European research infrastructures, especially at synchrotron radiation, laser and neutron facilities, the 500-page project report provides an excellent overview of the nanomaterials revolution that is upon us. This is one of the best, up-to-date primers on nanotechnologies!
Apr 29th, 2010
Hydrogels have been in development for several decades and are being used as parts in biology-based microdevices and medical diagnostic technologies, for drug delivery, and in tissue engineering. These gels are networks of water-insoluble polymer chains that are attractive for tissue engineering since their physical and biological properties can be tailored to mimic tissues. Researchers have found that the encapsulation of cells within cell-laden microgels is an attractive approach for engineered tissue formation. Scientists have now developed a technique for the self-assembly of cell-laden microgels on the interface of air and hydrophobic solutions to fabricate three-dimensional tissue constructs with controllable microscale features.
Apr 28th, 2010