December 23, 2005

Gold nanospheres show a path to all-optical computing.

New research, however, may enable engineers to build nanoscale antennae that turn light into a different sort of wave that can move through metal; the result could be data transmission speeds that are orders of magnitude higher than today's.

The key to the approach is a gold sphere just 50 nanometers in diameter. A Rice University team led by Peter Nordlander and Naomi Halas has shown that such a sphere, when positioned within a few nanometers of a thin gold film, will behave like a tiny antenna that can transmit or receive light. Light of specific wavelengths excites particles called plasmons inside the nanosphere. This in turn induces a "plasmon wave" in the gold film, which could be converted back into light when it reaches another nanosphere.

Variations on the gold nanosphere might make it possible to exploit materials already used in computer chips, such as copper and aluminum, as superfast optical interconnects, says Mark Brongersma, a materials scientist at Stanford University. A light wave encoding data would hit a metal nanosphere, generating a plasmon wave that would travel through a metal strip or wire, carrying the data with it.

DNA self-assembly used to mass-produce patterned nanostructures

Duke University scientists have used the self-assembling properties of DNA to mass-produce nanometer-scale structures in the shape of a 4x4 grids, on which patterns of molecules can be specified. They said the achievement represents a step toward mass-producing electronic or optical circuits at a scale 10 times smaller than the smallest circuits now being manufactured. Instead of using silicon as the platform for tiny circuits, as is done in the current manufacturing technique of photolithography, the Duke researchers used DNA strands to create grids less than one ten-millionth of a meter square. The smallest features on these square DNA lattices are approximately five to 10 billionths of a meter (nanometers), according to the scientists, compared with about 65 nanometers in silicon circuits created using photolithography. The structure of the tiles created the molecular equivalent of puzzle pieces that would self-assemble only in a specific arrangement when mixed together, with the DNA loop loaded with a desired "cargo" molecule that would form the structure the researchers wished to create. In one experiment, the scientists specified 16 unique puzzle pieces that fit together as a 4x4 grid that formed a puzzle spelling the letter "D." Because each piece would only match up with its predetermined neighbors, the scientists could mix together a trillion of each type of tile in one batch to generate a trillion 4x4 grids.

December 19, 2005

Richard Jones lays out the hurdles to his belief in Diamondiod nanotechnology

Richard Jones has proposed 6 experiments for validating his belief in diamondoid nanotechnology

1. Stability of nanoclusters and surface reconstruction.
2. Thermal noise, Brownian motion and tolerance.
3. Friction and energy dissipation.
4. Design for a motor.
5. The eutactic environment and the feed-through problem.
6. Implementation path.

It seems that Richard Jones has clearly outlined his areas of concern with the current plans towards MNT.
He has made some efforts to understand the work being done on the dry MNT side.

I know that more work has been done on point 6 than he has indicated or is aware of.

It is at least clear what it will take for Richard Jones and scientists in his mould
will believe that diamondoid MNT is possible when those 6 points are met computationally and experimentally.
Basically when we are about 1-2 years from the Feynmann grand prize being won.