**Reversible reaction dynamics of self-diffusiophoretic Janus motors
**

The dynamics of a Janus motor with reversible surface reactions that is

driven out of equilibrium fluxes of reactants and products will be described.

Coupled Langevin equations for the motor velocity and reaction rate that are

consistent with microscopic reversibility are used to derive a fluctuation

formula for the joint probability to find the motor at position r after n

reactive events have occurred in a time t. Thermodynamic consistency requires

the existence of a contribution to the Langevin equations that is reciprocal

to self-propulsion by diffusiophoresis and causes the reaction rate to depend

on an externally applied force. A reversible microscopic model that can be

used to study such phenomena will be discussed.