No Standing Still for Nanotechnology

The first story discusses the use of carbon nanotubes as tiny extruders and jigs, for small scale fabrication.

The research builds on the team's earlier findings detailing how bombarding electrons at carbon "onions" -- tiny, multilayered balls of carbon -- essentially knocks the carbon atoms out of their lattice. Surface tension then causes the balls to contract with great force, which allows carbon onions to act as high-pressure cells for creating diamonds.

In the new report, the team discovered that the same thing happens with nanotubes, producing enough pressure to deform, extrude, and even break solid materials that are encapsulated within.

The researchers filled carbon nanotubes with nanowires made from two extremely hard materials: iron and iron carbide. When irradiated with an electron beam, the collapsing nanotubes squeezed the materials through the hollow core along the tube axis, as in an extrusion process. In one test, the diameter of iron carbide wire decreased from 9 nanometers to 2 nanometers as it moved through the tube, only to be pinched off when the nanotube finally collapsed. Source.

Next, we learn that scientists at NIST (National Institute of Standards and Technology) are growing nanowires that can be used as nano-light sources, for small scale sensors and detectors.

NIST is one of few laboratories capable of growing such semiconductor nanowires without using metal catalysts, an approach believed to enhance luminescence and flexibility in crystal design. The wires are generally between 30 and 500 nanometers in diameter and up to 12 micrometers long. When excited with a laser or electric current, the wires emit an intense glow in the ultraviolet or visible parts of the spectrum, depending on the alloy composition.

A paper in the May 22 issue of Applied Physics Letters* reports that individual nanowires grown at NIST produce sufficiently intense light to enable reliable room-temperature measurements of their important characteristics. For example, the peak wavelength of light emitted with electric field parallel to the long axis of a nanowire is shifted with respect to the peak wavelength emitted with electric field perpendicular to the wire. Such differences in emission are used to characterize the nanowire materials and also may be exploited to make sensors and other devices. Source.

Finally, we are told that "Panasonic today announced the development of a novel VCSEL (Vertical Cavity Surface Emitting Laser) utilizing an epoch-making physical phenomenon called as surface plasmon resonance."

The surface Plasmon resonance drastically enhances optical transmission through the silver nano-holes array at an optimized pitch of the holes resulting in high optical output of 2mW. The used silver is known as the metal exhibiting the maximum resonant effect as well as very high reflectance. The enhanced reflectance at the mirror successfully reduces the threshold current down to 0.5mA.

In addition, fabrication process of the silver nano-holes is successfully established using electron beam lithography. In order to avoid any degradation of the silver, the nano-holes are entirely covered by dielectric films such as silicon nitride. Source.

So we see advances in nanotechnology involving nano-fabrication, nano-sensors, and nano-laser devices for rapid data communications. When we read books such as Drexler's Engines of Creation, then look at the state of the art in nanotech, we might wonder "where are all those miracles we were promised?" But miracles do not come from nothing. They come from clear and clever thinking, and hard persistent work. And time and luck.

And do you really think the militaries of the world would publicly announce nanobots that could be dropped over a country such as Iran, to seek out and dismantle any nuclear devices and materials found?

Update: Here is a nano invisibility cloak. Maybe there is some magic in the air after all.