Mechanical Transmission of Rotational Motion between Molecular-Scale Gears

Even in 2020, there's still some room at the bottom: The miniaturization of machines remains an important goal that attracts interest in many fields. In particular, making ultrasmall gears to transmit mechanical motion is a challenge, with molecular gears being the ultimate target. Motivated by recent experimental studies on molecule gears, the authors employ atomistic molecular dynamics simulations and a nearly-rigid-body model to obtain insights into the dynamics of both single gears and trains of them. A train of such gears exhibits three qualitatively different regimes of motion, depending on the magnitude of the applied torque.