Showing Spotlights 1249 - 1256 of 2204 in category All (newest first):
Metal nanomaterials are often synthesized using the toxic reagent formaldehyde at concentrations thousands of times higher than necessary. Many of these same nanomaterials are being investigated for use in cancer treatment - however, there is a risk that they could do more harm than good. The large excess of formaldehyde that is used originates from methods developed 100 years ago. Because these methods work well, they have stood the test of time. By better understanding the role that formaldehyde plays in nanomaterial synthesis it will become possible to reduce or eliminate this toxic reagent. By eliminating formaldehyde it will become safer to prepare these nanomaterials and safer to use them in cancer treatment.
May 24th, 2010
Electrically conductive composite materials capable of substantial elastic stretch and bending - conductive rubbers - is an industrially important field. The composites are needed for such applications as smart clothing, flexible displays, stretchable circuits, strain gauges, implantable devices, high-stroke microelectromechanical systems, and actuators. A variety of approaches involving carbon nanotubes and elastic polymers have been suggested for the fabrication of conductive elastic composites. Various studies indicated that high loading of CNTs or other conductive additives into the polymer was necessary to obtain a highly conducting composite. A research team has now demonstrated that a combination of high stretchability and high electrical conductivity can be obtained for composites prepared from three-dimensional CNT structures.
May 21st, 2010
The development of artificial muscles is one of the key areas for bionic enhancements or replacements. The discovery of the electromechanical actuation properties of single-walled carbon nanotubes and the complex behavior of multi-walled carbon nanotubes has led to the development of various carbon nanotube actuators. Besides artificial muscles, potential applications include microelectro-mechanical systems (MEMS), biomimetic micro-and nanorobots, and micro fluidic devices. Recently, a new class of active system, carbon nanotube/polymer composite actuators, has received great attention with regard to macroscopic artificial muscle applications. It has been demonstrated that successful introduction of the highly conductive CNTs could significantly enhance the polymer nanocomposite's electrical, thermal, mechanical, and interface properties, thus providing a suitable material for novel artificial muscle-like actuator investigations.
May 19th, 2010
The ability to extract, dispense and manipulate very small amounts of liquids on the micro- and nanoscale is important in biotechnology, chemistry and also for patterning inorganic, organic and biological inks. Several methods for dispensing liquids exist, but many require complicated electrodes and high-voltage circuits. Researchers in Italy have now demonstrated a pyroelectrohydrodynamic droplet dispenser based on pyroelectric forces.Researchers in Italy have developed and demonstrated a completely new method for extracting and dispensing very small amounts of liquid - as small as few attoliters - from liquid droplet reservoirs or thin liquid films by a method called pyroelectrohydrodynamic (Pyro-EHD).
May 18th, 2010
Ferroelectric materials have unique properties - spontaneous, switchable polarization, piezoelectricity, and pyroelectricity - that makes them attractive for a host of applications, ranging from medical ultrasound to examine fetuses and internal organs, military sonar for underwater navigation and detection, to energy harvesting devices for powering mobile gadgets. Recently, memory storage devices utilizing ferroelectrics have gained much attention due to their nonvolatility and fast switching speed. It was theoretically predicted that a nanodisk with a diameter of 3.2 nm could maintain spontaneous polarization. However the fabrication of ferroelectric nanostructure at this size level is extremely difficult and the smallest diameter for ferroelectric nanostructure with narrow size distribution obtained from experiments so far has been 60 nm. Researchers have now managed to prepare an ultrahigh density array of lead titanate nanoislands with a lateral dimension of 22 nm and a height of 7 nm.
May 17th, 2010
'Smart' windows, or smart glass, refers to glass technology that includes electrochromic devices, suspended particle devices, micro-blinds and liquid crystal devices. Their major feature is that they can control the amount of light passing through the glass and increase energy efficiency of the room by reducing costs for heating or air-conditioning. In the case of self-powered smart windows the glass even generates the energy needed to electrically switch its transparency. A new type of smart window proposed by researchers in The Netherlands makes use of a luminescent dye-doped liquid-crystal solution sandwiched in between electrically conductive plates as an energy-generating window.
May 12th, 2010
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