Christian Joachim, has lead a research team that has made a molecular rack-and-pinion device for which an STM tip drives a single pinion molecule at low temperature. The pinion is a 1.8-nm-diameter molecule functioning as a six-toothed wheel interlocked at the edge of a self-assembled molecular island acting as a rack. They monitor the rotation of the pinion molecule tooth by tooth along the rack by a chemical tag attached to one of its cogs.
Foresight has some more details They have observed a molecular ‘rack-and-pinion’ mechanism at work with an atomic-scale precision. They obtained this by a full sequence of steps comprising the careful design and synthesis of the molecule, the surface preparation and the assembly of the molecular pinion on its molecular rack. Combined with the atomic-scale understanding of the physics of its movement, the piece-by-piece assembly of such a device opens a new way of exploring the functioning of a molecular machine.
The work was funded by the Volkswagen Foundation Project ‘Single molecule synthesis’ and the European Projects NANOMAN and AMMIST.