THERMODYNAMICAL AND MECHANICAL EFFICIENCY OF A RATCHET PUMP

The mechanical and thermal behaviors of a model ratchet were studied a nd its efficiency calculated when subjected to external changes in tem perature or potential. For dichotomic changes we succeeded in analytic ally establishing the values of the current and the efficiency. It is remarkable that, when operated mechanically, the pump efficiency may b e considerably lower than under thermal changes; the maximal mechanica l efficiency is attained at a finite temperature. (C) 1998 Elsevier Sc ience B.V. All rights reserved.