Conductin polymers have been investigated for the use as active component in polymer actuators. Addition of I-pentanol as co-surfactant to the polymerisation solution is shown to increase the reversible linear strain that can be achieved with polypyrrole films doped with dodecyl benzene sulfonate (PPy-DBS). When such films are prepared without pentanol, the length change between the oxidised and the reduced state is 2.5%. If pentanol is added to the synthesis solution in concentrations above 2.4 vol%, a linear extension of 5.6% was measured at a constant load of 0.6 MPa. The morphology of the film is changed considerable upon pentanol addition, although electrochemical quartz crystal microbalance measurements indicate that pentanol is only incorporated in the polymer to a small extent. The mechanical properties, conductivity and doping level of PPy-DBS films show little or no changes with the addition of pentanol. The use of pentanol as co-surfactant during polymerisation will, therefore, be beneficial for the use of PPy-DBS as active component material in polymer actuators.