Responsible Nanotechnology: Impressive Scientific Progress

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Two additional developments in the news today fit into our category of 'enabling nanotech':

World's Best Microscope Can Produce Images Less Than Diameter of Single Hydrogen Atom
TEAM 0.5, the world's most powerful transmission electron microscope — capable of producing images with half‑angstrom resolution (half a ten-billionth of a meter), less than the diameter of a single hydrogen atom — has been installed at the Department of Energy's National Center for Electron Microscopy (NCEM) at Lawrence Berkeley National Laboratory. . .

In preliminary tests at the FEI Company, before the TEAM 0.5 was shipped, NCEM's Christian Kisielowski tested the microscope's ability to resolve individual atoms and precisely locate their positions in three dimensions. He made a series of images of two gold crystals connected by a "nanobridge" only a few dozen atoms wide. From each exposure to the next, individual gold atoms could be seen changing positions.

To achieve this extraordinary resolution, TEAM 0.5 embodies technical advances that have only recently become possible, including ultra-stable electronics, improved aberration correctors, and an extremely bright electron source. . .

Correcting spherical aberration makes it possible to use the TEAM 0.5 not only for broad-beam, "wide-angle" images but also for scanning transmission electron microscopy (STEM), in which the tightly focused electron beam is moved across the sample as a probe, capable of performing spectroscopy on one atom at a time — an ideal way to precisely locate impurities in an otherwise homogeneous sample, such as individual dopant atoms in a semiconductor material. . .

It's not just high resolution that makes TEAM 0.5 the world's best microscope, says Ulrich Dahmen, director of the NCEM. When all the electrons in the beam focus at the same plane, image contrast and signal-to-noise ratio improve tremendously.

"It's because the signal-to-noise ratio is so good that you can adjust focus atom by atom, with enough sensitivity to obtain information about the three-dimensional atomic structure of a single nanoparticle." Dahmen adds, "This brings us within reach of meeting the great challenge posed by the famous physicist Richard Feynman in 1959: the ability to analyze any chemical substance simply by looking to see where the atoms are."

Scientists Make 'Perfect' Nanowires

Scientists have created silicon nanowires that are perfect—at least atomically. Down at the single-atom level, the identical wires have no bumps, bends, or other imperfections. They are perfectly crystalline, even more so than bulk silicon. The full array of nanowires is also highly parallel, and each wire is an excellent metallic conductor.

This research may be an important step forward for nanotechnology. Nanowires play a key role in developing nanoelectronics applications, and silicon nanowires are particularly important because of the central function that silicon plays in the semiconductor industry and current technologies. Some scientists believe that silicon nanowires will overtake carbon nanotubes in popularity, and they are being eyed for a variety of electronics applications and even quantum computing.

Therefore, the ability to create straight, identical, parallel, and atomically smooth nanowires could lead to new developments in nanoelectronics. . .

Neither of these advances directly portends a realization of molecular manufacturing, of course. But both could represent significant steps toward enabling the full range of MM's needed technical capabilities.

(Double hat tip to KurzweilAI.net)

Mike Treder

Tags: nanotechnology nanotech nano science technology ethics blog