Computer simulation of Feynman's ratchet and pawl system.

In this work, we introduce two models of Feynman's ratchet and pawl system. Molecular dynamics is carried out to simulate the two designs for Feynman's ratchet and pawl systems followed by a Langevin dynamics simulation of the reduced system. We find that the ratchet will rotate as designed when the temperature of the pawl chamber is lower than that of the ratchet chamber, which is consistent with the second law of thermodynamics. Different parameters and configurations are tested, and the results show that the efficiency of the ratchet depends on the applied torque. We find further that efficiencies of the Feynman's ratchet and pawl systems depend greatly on the details of the systems.