Short Communication

Force-free motion in an asymmetric environment: a simple model for structured objects

(Received 3 August 1994, accepted 12 September 1994)

Abstract
Recent models have shown how dissipation of energy can set into directed motion a point-like particle in an environment of vectorial symmetry, even in the absence of macroscopic forces. This statement is extended to the case of an object with an internal structure, focusing on the simplest model: an elastic dumb-bell. We briefly show that specific mechanisms then come into play, able to set the object into directed motion even if thermal diffusion is negligible.