Sandia researchers construct carbon nanotube device that can detect colors of the rainbowMay 01, 2009LIVERMORE, Calif. - Researchers at Sandia National Laboratories have created the first carbon nanotube device that can detect the entire visible spectrum of light, a feat that could soon allow scientists to probe single molecule transformations, study how those molecules respond to light, observe how the molecules change shapes, and understand other fundamental interactions between molecules and nanotubes. Carbon nanotubes are long thin cylinders composed entirely of carbon atoms. While their diameters are in the nanometer range (1-10), they can be very long, up to centimeters in length. The carbon-carbon bond is very strong, making carbon nanotubes very robust and resistant to any kind of deformation. To construct a nanoscale color detector, Sandia researchers took inspiration from the human eye, and in a sense, improved on the model. When light strikes the retina, it initiates a cascade of chemical and electrical impulses that ultimately trigger nerve impulses. In the nanoscale color detector, light strikes a chromophore and causes a conformational change in the molecule, which in turn causes a threshold shift on a transistor made from a single-walled carbon nanotube. "In our eyes the neuron is in front of the retinal molecule, so the light has to transmit through the neuron to hit the molecule," says Sandia researcher Xinjian Zhou. "We placed the nanotube transistor behind the molecule-a more efficient design." Zhou and his Sandia colleagues François Léonard, Andy Vance, Karen Krafcik, Tom Zifer, and Bryan Wong created the device. The team recently published a paper, "Color Detection Using Chromophore-Nanotube Hybrid Devices," in the journal Nano Letters. The idea of carbon nanotubes being light sensitive has been around for a long time, but earlier efforts using an individual nanotube were only able to detect light in narrow wavelength ranges at laser intensities. The Sandia team found that their nanodetector was orders of magnitude more sensitive, down to about 40 W/m2-about 3 percent of the density of sunshine reaching the ground. "Because the dye is so close to the nanotube, a little change turns into a big signal on the device," says Zhou. LIVERMORE, Calif. - Researchers at Sandia National Laboratories have created the first carbon nanotube device that can detect the entire visible spectrum of light, a feat that could soon allow scientists to probe single molecule transformations, study how those molecules respond to light, observe how the molecules change shapes, and understand other fundamental interactions between molecules and nanotubes. Carbon nanotubes are long thin cylinders composed entirely of carbon atoms. While their diameters are in the nanometer range (1-10), they can be very long, up to centimeters in length. The carbon-carbon bond is very strong, making carbon nanotubes very robust and resistant to any kind of deformation. To construct a nanoscale color detector, Sandia researchers took inspiration from the human eye, and in a sense, improved on the model. When light strikes the retina, it initiates a cascade of chemical and electrical impulses that ultimately trigger nerve impulses. In the nanoscale color detector, light strikes a chromophore and causes a conformational change in the molecule, which in turn causes a threshold shift on a transistor made from a single-walled carbon nanotube. "In our eyes the neuron is in front of the retinal molecule, so the light has to transmit through the neuron to hit the molecule," says Sandia researcher Xinjian Zhou. "We placed the nanotube transistor behind the molecule-a more efficient design." Zhou and his Sandia colleagues François Léonard, Andy Vance, Karen Krafcik, Tom Zifer, and Bryan Wong created the device. The team recently published a paper, "Color Detection Using Chromophore-Nanotube Hybrid Devices," in the journal Nano Letters. The idea of carbon nanotubes being light sensitive has been around for a long time, but earlier efforts using an individual nanotube were only able to detect light in narrow wavelength ranges at laser intensities. The Sandia team found that their nanodetector was orders of magnitude more sensitive, down to about 40 W/m2-about 3 percent of the density of sunshine reaching the ground. "Because the dye is so close to the nanotube, a little change turns into a big signal on the device," says Zhou. Sandia National Laboratories |
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| Related Carbon Nanotube Current Events and Carbon Nanotube News Articles A recipe for controlling carbon nanotubes Nanoscopic tubes made of a lattice of carbon just a single atom deep hold promise for delivering medicines directly to a tumor, sensors so keen they detect the arrival or departure of a single electron, a replacement for costly platinum in fuel cells or as energy‐saving transistors and wires. Friction force differences could offer a new means for sorting and assembling nanotubes Nanotubes and nanowires are promising building blocks for future integrated nanoelectronic and photonic circuits, nanosensors, interconnects and electro-mechanical nanodevices. But some fundamental issues remain to be resolved - among them, how to position and manipulate the tiny tubes. Carbon nanotubes could make efficient solar cells Using a carbon nanotube instead of traditional silicon, Cornell researchers have created the basic elements of a solar cell that hopefully will lead to much more efficient ways of converting light to electricity than now used in calculators and on rooftops. Nanotubes take flight With products that range from carpets to kites, you'd think Rice University chemist Bob Hauge was running a department store. A Billion Year Ultra-Dense Memory Chip When it comes to data storage, density and durability have always moved in opposite directions - the greater the density the shorter the durability. Inexpensive plastic used in CDs could improve aircraft, computer electronics If one University of Houston professor has his way, the inexpensive plastic now used to manufacture CDs and DVDs will one day soon be put to use in improving the integrity of electronics in aircraft, computers and iPhones. UCLA researchers develop new method for producing transparent conductors Researchers at UCLA have developed a new method for producing a hybrid graphene-carbon nanotube, or G-CNT, for potential use as a transparent conductor in solar cells and consumer electronic devices. UCLA physicists create world's smallest incandescent lamp In an effort to explore the boundary between thermodynamics and quantum mechanics - two fundamental yet seemingly incompatible theories of physics - a team from the UCLA Department of Physics and Astronomy has created the world's smallest incandescent lamp. Nanoribbons from sliced open nanotubes: new, faster, more accurate method from Stanford A world of potential may lie tied up in graphene nanoribbons, particularly for electronics applications. But researchers have been hampered in their efforts to fully explore that potential because they had no reliable way of creating the large quantities of uniform nanoribbons needed to conduct extensive studies. New 'near-field' radiation therapy promises relief for overheating laptops Our modern age has become accustomed to regular improvements in information technology, says Slava Rotkin, but these advances do not come without a cost. More Carbon Nanotube Current Events and Carbon Nanotube News Articles |
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