Generalized Efficiency and its Application to Microscopic Engines

Abstract

We generalize the definition of the energy output of an engine as the minimum energy input required to accomplish the same task as the engine. Applying this new concept to molecular motors makes it possible to measure their efficiency even without attaching any external load to them. This way we can compare and characterize the operation of molecular motors in various situations. We also investigate how the thermally driven motors differ from other motors.