Brownian free energy ratchets

The directed motion of a Brownian particle subject to a unequilibrium fluctuation which moves in a two-dimensional ratchet potential is studied. Thus, a working model of the free-energy ratchet is proposed through eliminating no-transport variables. The properties of the present model such as the current, the efficiency, the diffusion coefficient and the Pe number are discussed. Comparison with the previous one-dimensional models, some novel phenomena are observed.