• Off-topic, these days information just goes in circles from subreddits, X, YouTube, and Hacker News to countless secondary sources, and then back again to the same original sources.
  • This seems to be the galena cat whisker stage of developing Drexler's "eutactic chemistry". It may be a parlor trick forever, or it might be the humble beginnings of mechanosynthesis, the first working tool-tips for a Drexler arm.

    https://wiki.reprap.org/wiki/Drexler_Arm

  • At the current time I see this is front page and has reasonable upvotes, but not one comment.

    My guess is that this is highly useful for either:

    * Building chips (but it's on a silicon surface, not with silicon)

    * Carbon nanotubes (looking forward to a space elevator, folks, one day ;))

    * It's a more notable movement forward in nano construction in general and I just know too little to understand its impact.

    Given the zero comments to date: would someone who knows this area like to accept an invitation to share something really interesting about this paper, please? :)

    • This is an experimental demonstration of the technology that makes Neal Stephenson's "Diamond Age" possible. They place an individual carbon atom pair(dimer) on silicon. Silicon has the same crystal structure as diamond, so adding carbon in this manner is similar to building diamond. There is potential for eventually making 3D atomically precise structures of diamond with this tech although that is far off.

      This is a very, very basic demonstration, but it's showing for the first time that atoms can be controllably and programmably covalently bonded in something that can probably be extended to 3D. There was a lot of skepticism that this process was possible at all, so an experimental demonstration is important

    • Inside a vacuum chamber cooled at very low temperatures, they move a scanning tunneling microscopy probe over the surface of a silicon wafer, and with it, in the locations that they choose, they can build some carbon atom structures attached to the silicon surface, atom by atom, in a reproducible way.

      This kind of control of atomic structures, where the position of every individual atom can be controlled, is very impressive, but for now this is pure research. Any practical applications are more than a decade in the future.

      Techniques derived from this might be used some day either for making some kind of integrated circuits or for making some kind of masks for the production of such circuits, but there is no way to use this directly for the production of some material needed in great quantities, like nanotubes for a space elevator.

      For a material needed in great quantities, if you build it atom by atom, there must be billions of such building processes done concurrently, like in a living being, in order to achieve an acceptable growth rate. For now, they use a microscopy probe to attach the atoms one by one and you could not make a sufficient number of these that work concurrently.