Feeding upon negative entropy in a thermal-equilibrium environment

The validity of the Second Law of thermodynamics, indisputable in the macroscopic world, is challenged at the mesoscopic level: a mesoscopic isolated system, possessing spatial dimensions of the order of a few microns, is capable, as shown by a straightforward kinetic analysis, to exhibit a perpetuum mobile behavior associated with large negative variations of the Clausius entropy of the system. This violation of the Second Law is expedient for devising a cyclic process through which an isolated system can extract energy from a surrounding thermal bath.