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A molecule printer for nanotechnology based on spinning carbon nanotubes

Detailed calculations show that electrons passing through a ‘turbine’ in which one type of carbon nanotube (CNT) is suspended inside another type of CNT would cause the inner CNT to rotate, forming an electron ‘windmill’ or turbine. The researchers also suggest that atoms or molecules could be pumped through the spinning inner CNT to form patterns of atoms or molecules—a nanotech inkjet printer. From NewScientist.com news service, written by Kate McAlpine: “‘Electron turbine’ could print designer molecules“, via KurzweilAI.net

A carbon nanotube that spins in a current of electrons, like a wind turbine in a breeze, could become the world’s smallest printer or shrink computer memory, UK researchers say.

The design is simple. A carbon nanotube 10 nanometres long and 1 nm wide is suspended between two others, its ends nested inside them to form a rotating joint. When a direct current is passed along the tubes, the central one spins around.

That design has as yet only been tested using advanced computer simulations by Colin Lambert and colleagues at Lancaster University, Lancashire, UK.

But Adrian Bachtold of the Catalan Institute for Nanotechnology, who was not involved in the work, intends to build the electron turbines and says it should be straightforward.

Researchers have made or designed a range of small-scale motors in recent years, using everything from DNA to light sensitive molecules to cell-transport proteins.

…The Lancaster researchers say their motor could be used to pump atoms and molecules through the spinning middle tube. Multiple pumps could precisely control a chemical reaction, driving atoms in a pattern to engineer new molecules. “It’s like a nanoscale inkjet printer,” says Lambert.

The News Scientist article includes a link to the preprint of the research publication. The preprint presents the calculations on electron flow through the CNTs that justify the conclusion that the inner CNT will rotate. However, as far as I can see, it does not provide much information about how this device could be used to arrange atoms and molecules into patterns for designer molecules. The only statement I could find on this topic:

For example, if the electrical contacts in Fig. 1 are replaced by reservoirs of atoms or molecules and a pressure difference applied to drive the atoms or molecules from left to right, then the resulting transfer of angular momentum may also be sufficient to drive the motor, as could a flux of phonons resulting from a temperature difference between the ends of the device.

No doubt the researchers have ideas for how to build a molecule printer beyond what they present in this paper. Let’s hope that they follow with more on this concept and that someone soon succeeds in building such a device and testing it as a molecule printer.
—Jim

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