Kleegamefan
K. LEE GAIDEN
http://www.eetimes.com/article/showArticle.jhtml?articleId=46200732&sub_taxonomyID=
All the relevent TV stuffs bolded..
This article is from 3 days ago.....I hear Sony's CNT FEDs will be first shown @ CES...don't know about Sammy, Motorola and the others, though....
All the relevent TV stuffs bolded..
Nanotube processes refined for commercial apps
By Chappell Brown
EE Times
September 06, 2004 (9:00 AM EDT)
HANCOCK, N.H. Although carbon nanotubes are quickly finding their way into a variety of products, some basic technical issues still need to be addressed before the full advantages of nanostructured materials can be realized.
One of the chief concerns is how to align the tubes efficiently at the nanoscale. While it is now possible to manufacture many carbon nanotube types, they emerge from reactors as a tangled mat. Most applications, from superstrong materials to nanotube semiconducting memory chips, require the tubes to be aligned-stretched out in the same direction in two or three dimensions.
The major line of attack has centered on various chemical strategies. By treating a mass of nanotubes with a surfactant, for example, individual tubes become un-tangled and can be manipulated with techniques such as electrophoreses.
Now, NanoDynamics Inc., a company specializing in the production of nanotubes, believes it has a practical industrial process for chemically untangling bulk nanotubes and arranging them in one-, two- and three-dimensional arrays.
We have established a proprietary synthesis technology and a number of strategic partnerships," Blakely said. "Under the umbrella of those relationships, we are using functionalized nanotubes." At this point, all of the NanoDynamics partners are still at the developmental stage with nanotube-based materials, he added.
The company just obtained a patent for its process, which is an adaptation of sol-gel processing that was developed in the ceramics industry. The patent is open for nonexclusive licensing since, Blakely said, he does not want to slow the implementation of carbon nanotubes, which could usher in fundamentally new types of materials.
Theoretically, carbon nanotube materials could be a hundred times stronger than steel at about a sixth of steel's weight. Electronically, the tubes have a lower resistance than copper and conduct heat better than diamonds. But to achieve the figures of merit, the tubes need to be carefully aligned.
"You will still get some of the advantages of nanotubes with nonaligned structures," Blakely said. "But if you have these masses of entangled and intertwined tubes, they are not of much use and can actually be detrimental to the properties of a composite material."
Blakely expects a whole host of processes ultimately will be developed, depending on the end application. Experimental approaches have used electrophoresis, chemical chromatography and even the attachment of DNA strands to tubes to induce them to self-assemble.
"For industrial development, you will probably need a more-scalable and high-volume and high-throughput process than some of the approaches we have been hearing about at this point," he said.
Custom fit
Nanotubes are specifically tailored to fit different applications. Tubes can be built in single-wall or multiple-wall architectures and the specific spiral configuration of the tube's wall-its "chirality"-can vary greatly.
"At the end of the day, you end up with milligrams or micrograms of a specific material, but it's very specific material, which may have high-value applications-for example, in drug delivery," he said. Many materials applications, however, will require much larger quantities, which must be available at a reasonable price.
Part of NanoDynamics' business strategy is to find scalable, high-volume processes for nanotubes with specific properties. Combined with a feasible process for separating them, commercial products using nanotubes will begin to appear.
But with market pressures and the high degree of competition in mass market applications, manufacturers may not have time to wait for such refined and tailored approaches.
HDTV stampede
One example of that acceleration is the sudden rush to develop carbon nanotube-based field emission flat-panel displays for high-definition television that can beat liquid crystal and plasma products already on the market.
Several companies, including Samsung, Sony and Motorola, have been developing carbon nanotube displays. And a joint project between Canon and Toshiba(EDIT: this is the SED TV being shown @ CEATEC next month) is developing a field emission display that does not require any structured emitter at all. Instead, two electrodes are separated by a narrow gap, and electrons tunnel across the gap to turn on a pixel.
Vertically aligned nanotubes form a superior electron emitter. The tiny tip reduces the required voltage and the tubes are much more durable than metal tips, which tend to degrade. But there are additional difficulties involved because the tubes have to be aligned inside tiny vacuum chambers, one for each pixel in the display.
A technology development company, Applied Nanotech Inc. (Austin, Texas), formed a consortium of Japanese companies last October to build a high-volume, low-cost approach to nanotube field }emission displays. The process actually sidesteps the nanotube alignment issue. Using nanotubes in the form of a print-on paste produces enough of a performance enhancement over metal tips to make the consortium's flat panels competitive.
Zvi Yaniv, president and chief executive officer of Applied Nanotech, said that Cannon's approach, called surface emission displays (SEDs), is closest to his own.
"To be honest, we don't know exactly how the nanotubes emit electrons, and it would be too costly to do transmission electron microscope studies to find out," said Yaniv. However, he said, company researchers have a fairly good idea of how the nanotubes emit electrons, and basically the thrust is toward pragmatic implementation of the effect, rather than research analysis.
"Our strategy in large-area displays is focused on very large diagonal displays. To really enjoy HDTV, studies have shown that the diagonal dimension must be around 80 to 100 inches," he said. "So the question is, how can you get there at a price that consumers can afford?"
LCDs need semi processes that are similar to silicon but on glass and cannot get to a size larger than 50 inches in manufacturing. Plasma technology has some image problems, is power-hungry and probably will not go to over 70 inches on the diagonal, he said.
"Price differentiation eventually will come from the two important variables-capital investment and cost of electronics. LCD is leading over plasma due to the cost of electronics. However, a manufacturing plant that could turn out 1 million 60-inch diagonal LCDs would cost between $3 billion and $4 billion," he estimated.
For the process being developed at Applied Nanotech-using a print-on paste-Yaniv expects capital investment to be approximately 80 percent less than that for large-area LCD and plasma televisions, and the resulting 60-inch carbon nanotube TV will sell for less than $1,200 in full-volume production.
'Low capital'
"We have shown that we can create a high-resolution, color 40-inch diagonal display with a low capital investment process. No CVD machines, no lithography, just printable processes," he said. "What we discovered is that people are fighting the process. If you try to align the nanotubes, a low-cost manufacturing process would be impossible. Instead, use functionalized tubes in a printable process and eliminate the microscopic alignment."
The big disadvantage for field emission display manufacturing is the need for a vacuum chamber. Yaniv designed the process so that all the fabrication-defining the electronic interconnect and the emitters for each pixel-could be done outside a vacuum chamber. Once processed, the two pieces of glass that define the front and back of the display are sealed inside a vacuum chamber.
If Yaniv's gamble on nonaligned nanotubes wins, no doubt the more refined processes being developed by companies such as NanoDynamics will be useful in follow-on designs.
Scaling down the size of the pixels or scaling up the macro dimensions of the display will require additional refinements in the nanotube emitters, and a bulk solution approach that offers better performance might help the technology stay in the running.
This article is from 3 days ago.....I hear Sony's CNT FEDs will be first shown @ CES...don't know about Sammy, Motorola and the others, though....
