Out-of-equilibrium nanosystems

Recent advances in the nonequilibrium statistical mechanics and thermodynamics of out-of-equilibrium nanosystems are reviewed. Nanosystems can be out of equilibrium either during their relaxation toward an equilibrium state, or when maintained in a nonequilibrium steady state imposed by external reservoirs of heat or particles at different temperatures or chemical potentials. Examples are sliding carbon nanotubes, evaporating nanoclusters, fluids in nanohydrodynanlics, mesoscopic conductors, and biological molecular motors. Remarkable relations have been recently discovered in the properties of their fluctuating paths or histories during some time interval. These advances give a new understanding to the second law of thermodynamics in terms of the time asymmetry in the dynamical randomness of these paths or histories.