Open menu
Nanowerk

Nanotechnology Spotlight

Behind the buzz and beyond the hype:
Our Nanowerk-exclusive feature articles

Nanotechnology Spotlight – Latest Articles

RSS Subscribe to our Nanotechnology Spotlight feed

Showing Spotlights 769 - 776 of 2049 in category (newest first):

 

Compelling evidence for silicene - the silicon analogue to graphene

siliceneThe fascination with two-dimensional (2D) materials that has started with graphene has spurred researchers to look for other 2D structures like for instance metal carbides and nitrides. One particularly interesting analogue to graphene would be 2D silicon - silicene - because it could be synthesized and processed using mature semiconductor techniques, and more easily integrated into existing electronics than graphene is currently. However, silicene does not seem to exist in nature nor is there any solid phase of silicon similar to graphite. Nevertheless, silicene has been predicted by theory as early as 1994. Researchers have now presented the first clear evidence for the synthesis and thus the existence of silicene - a two-dimensional material, with a honeycomb-like arrangement of silicon atoms.

Posted: Mar 23rd, 2012

Dynamically controlling graphene's properties with engineered piezoelectricity

graphene_latticeOne of the greatest challenges in harnessing the power of nanotechnology is achieving dynamic control of mechanical, electronic, optical and chemical properties of nanoscale structures and devices. Dynamic control can be achieved through the use of piezoelectric materials. These are materials where applying a mechanical strain results in an electrical voltage or conversely, application of an electric field induces mechanical deformation. While piezoelectricity has mainly been shown for 3D bulk materials, the piezoelectric effect has also been demonstrated and exploited at the nanoscale. Researchers have now demonstrated through density functional theory calculations that piezoelectricity can be engineered into non-piezoelectric graphene by selective surface adsorption of atoms on only one side, which breaks inversion symmetry.

Posted: Mar 22nd, 2012

Ultrasensitive chemical nanocoax sensor based on carbon nanotubes

nanocoax_sensorVarious types of nanostructures are used in the development of nanosensors: nanoparticles, nanotubes, nanorods, two-dimensional materials like graphene, embedded nanostructures, porous silicon, and self-assembled materials. For instance, gas sensors often operate by detecting the subtle changes that deposited gas molecules make in the way electricity moves through a surface layer. Researchers have fabricated gas sensors based on carbon nanotube-based field effect transistors, which can detect electrical potential changes around them. While these and related sensing schemes can be all-electronic - i.e., not requiring optical readout - they all require sophisticated nanolithographic techniques to isolate, identify, and integrate electrical contact to the active nanosensor. Researchers have now presented a nanoscale 3D architecture that can afford highly sensitive, room temperature, rapid response, and all-electronic chemical detection.

Posted: Mar 21st, 2012

Explosibility of nanoparticles

explosionRecent studies have found that nanomaterials - in this case dusts and powders having nanosize particles - exhibit an explosion severity which is not disproportionate to micrometer-sized materials, but the likelihood of explosion is quite high due to very low ignition energies and temperatures. A recent review concludes that nanomaterials present a dust explosion hazard, with metallic nanoparticles being particularly reactive. Nanomaterials have been shown to display lower ignition energy and temperature requirements than larger particles. Due to this high sensitivity, explosion hazards may exist for many processes including, but not limited to, mixing, grinding, drilling, sanding, and cleaning.

Posted: Mar 20th, 2012

A precise nanothermometer for intracellular temperature mapping

axonsGreen Fluorescent Protein (GFP) - originally found in a jellyfish - has played a crucial role in life science research, providing insights to many fundamental questions that have paved the way to the biology and medicine of the future. Since the mid-1990s, when the protein was successfully cloned, GFP can be found in research laboratories worldwide used as a visual marker of gene expression and protein localization, easily observed via light (optical) microscopy. GFP can be linked to other proteins and is primarily used to track dynamic changes in living cells. In 2008, biologists who discovered and developed the protein as a laboratory tool won a Nobel Prize for their work. Researchers in Spain have now demonstrated how GFP can also act as an efficient nano-thermometer inside cells.

Posted: Mar 19th, 2012

Nanotechnology Braille display could make Web accessible to the blind

Braille If you are a blind computer user you have to rely on electronic Braille displays which typically allow you to see only one line at a time, no matter what you were doing. Such a Braille display is a tactile, electro-mechanical device for displaying Braille characters, consisting of a row of special 'soft' cells. A soft cell has 6 or 8 pins made of metal or nylon; pins are controlled electronically to move up and down to display characters as they appear on the computer display. A number of cells are placed next to each other to form a soft or refreshable braille line. As the little pins of each cell pop up and down they form a line of braille text that can be read by touch. Researchers have now have fabricated a Braille sheet display by integrating organic thin-film transistor drivers, organic static random-access memory, and carbon nanotube-based actuators.

Posted: Mar 16th, 2012

New secrets of spider silk - its high thermal conductivity beats most materials

spiderResearchers and material scientists have been fascinated by spider silks for a long time - ultra-strong and extensible self-assembling biopolymers that outperform the mechanical characteristics of many synthetic materials, including steel. Atomistic studies have contributed to a better understanding of the source of the strength and toughness of this amazing biological material. Now, researchers have come up with another set of very surprising findings: The highly periodical structure of spider silk can sustain super fast thermal transport that surpasses those of most organic and inorganic materials. This discovery shows that highly organized organic materials can feature extremely high thermal conductivity.

Posted: Mar 15th, 2012

DNA reference tags allow single-molecule research on complex genomes

tagged_DNAKnowing the distribution of DNA binding proteins along the genome is very informative and can tell scientists about the state of gene expression at the time of measurement. These DNA-binding proteins include transcription factors which modulate the process of transcription, various polymerases, nucleases which cleave DNA molecules, and histones which are involved in chromosome packaging in the cell nucleus. Previously, researchers demonstrated the viability of a single-molecule approach to directly visualize and map protein binding sites on DNA using fluorescent quantum dots, allowing multicolor, nanometer-resolution localization. Now, they have shown that proteins bound to DNA can be located very accurately by direct imaging. The precision of these measurement presents new opportunities for contextual genomic research on the single-molecule level.

Posted: Mar 12th, 2012