  Examples of self propulsion in strongly fluctuating environment is abound in
nature, e.g., molecular motors and pumps operating in living cells. Starting
from Langevin equation of motion, we develop a fluctuating thermodynamic
description of self propelled particles using simple models of velocity
dependent forces. We derive fluctuation theorems for entropy production and a
modified fluctuation dissipation relation, characterizing the linear response
at non-equilibrium steady states. We study these notions in a simple model of
molecular motors, and in the Rayleigh-Helmholtz and energy-depot model of self
propelled particles.
