Friday, November 27, 2009

This week in nanotechnology, Nov.27, 2009

Scientists at the Carnegie Institution have found for the first time that high pressure can be used to make a unique hydrogen-storage material. The discovery paves the way for an entirely new way to approach the hydrogen-storage problem. The researchers found that the normally unreactive, noble gas xenon combines with molecular hydrogen (H2) under pressure to form a previously unknown solid with unusual bonding chemistry.

hydrogen storage material Xe(H2)7

This schematic shows the structure of the new material, Xe(H2)7. Freely rotating hydrogen molecules (red dumbbells) surround xenon atoms (yellow).

Researchers at the University of Illinois have developed a technique for fabricating three-dimensional, single-crystalline silicon structures from thin films by coupling photolithography and a self-folding process driven by capillary interactions. This is a completely different approach to making three-dimensional structures.

Researchers at the Institute of Bioengineering and Nanotechnology (IBN), A*STAR, in Singapore, have developed a new protocol for the synthesis of tiny metal and semiconductor crystals that are a few nanometers in size. The efficiency and structural control provided by this method could revolutionize the production of nanocrystals and their hybrids, which have diverse applications in medicine, electronics and energy.

Scientists from the MESA+ Institute for Nanotechnology of the University of Twente and the FOM Foundation have succeeded in transferring magnetic information directly into a semiconductor. For the first time, this is achieved at room temperature. This breakthrough brings the development of a more energy efficient form of electronics, so-called ‘spintronics’ within reach.

A new generation of ultrasmall transistors and more powerful computer chips using tiny structures called semiconducting nanowires are closer to reality after a key discovery by researchers at IBM, Purdue University and the University of California at Los Angeles. The researchers have learned how to create nanowires with layers of different materials that are sharply defined at the atomic level, which is a critical requirement for making efficient transistors out of the structures.

nanowires with sharply defined layers of silicon and germanium

The researchers have grown the nanowires with sharply defined layers of silicon and germanium, offering better transistor performance. As depicted in this illustration, tiny particles of a gold-aluminum alloy were alternately heated and cooled inside a vacuum chamber, and then silicon and germanium gases were alternately introduced. As the gold-aluminum bead absorbed the gases, it became "supersaturated" with silicon and germanium, causing them to precipitate and form wires.

A lot of the scientific knowledge in chemistry and biology comes from experiments on ensembles of molecules by which a vast number of duplicate behaviors are investigated and averaged responses are recorded. Researchers have now, for the first time, demonstrated direct and amplification-free single molecule detection of biomolecules in sub-nanolitre droplets through application of Cylindrical Illumination Confocal Spectroscopy (CICS) and droplet confinement within a retractable microfluidic constriction.