Seen here is a gear that's just 1.2 nanometers in diameter. For comparison, a human hair is about 80,000 nanometers in diameter. Developed by researchers from A*STAR’s Institute of Materials Research and Engineering in Singapore, the gear is reportedly the smallest in the world with controllable rotation. From ScienceDaily:
(Professor Christian) Joachim and his team discovered that the way to successfully control the rotation of a single-molecule gear is via the optimization of molecular design, molecular manipulation and surface atomic chemistry. This was a breakthrough because before the team’s discovery, motions of molecular rotors and gears were random and typically consisted of a mix of rotation and lateral displacement. The scientists at IMRE solved this scientific conundrum by proving that the rotation of the molecule-gear could be well-controlled by manipulating the electrical connection between the molecule and the tip of a Scanning Tunnelling Microscope while it was pinned on an atom axis.Said Dr Lim Khiang Wee, Executive Director of IMRE, “Christian and his team’s discovery shows that it may one day be possible to create and manipulate molecular-level machines. Such machines may, for example, walk on DNA tracks in the future to deliver therapeutics to heal and cure.
World's First Controllable Molecular Gear At Nanoscale Created