In biology, many natural systems have evolved to reverse this trend, enabling the flow of energy from the small to the large, with examples including photosynthesis or motor protein motion.
The desire to recreate this ability in artificial systems motivates a search for strategies and concepts that enable energy harvesting from very small subsystems. Lotze et al. (1) show how the motion of a macroscopic cantilever beam can be excited using the driven motion of only a single molecule. The H2 motion was activated by tunneling electrons and caused fluctuations of the forces sensed by the tip of a noncontact atomic force microscope. The stochastic molecular noise and the periodic oscillation of the tip were coupled in a concerted dynamic that drives the system into self-oscillation. This phenomenon could be a way for enhancing the transfer of energy from incoherent sources into coherent dynamics of a molecular engine, says Lotze.