  Developing the non-equilibrium thermodynamics of friction is required for
systematic design of low friction surfaces for a broad range of technological
applications. Intuitively, the thermodynamic work done by a material sliding
along a surface is expected to be partially dissipated as heat and partially
transformed into the change of the internal energy of the system. However,
general non-equilibrium thermodynamic principles governing this separation are
presently unknown. We develop a theoretical framework based on the transition
state theory combined with the conventional Prandtl-Tomlinson model, allowing
to set explicit expressions for evaluating the heat dissipation and internal
energy change produced during the frictional stick-slip motion of a tip of a
typical friction force microscope (FFM). We use the formalism to quantify the
heat dissipation for a range of parameters relevant to materials in practical
applications of nanoscale friction.
