**4.1 Introduction**

Hoshino et al. tried to immerse TFSI-doped PPy films into several organic chemicals, and found that the PPy films showed notable swelling in 2-propanol. They reported that the PPy actuators showed the increased electrochemical strains in aqueous LiTFSI solutions containing 20 to 40% of 2-propanol as described in the previous section (Hoshino et al., 2011).

In this section, the dynamic electrochemical deformation characteristics of TFSI-doped PPy soft actuators under potential sweep rates between 10 and 25 mVs-1 in aqueous LiTFSI solutions with different 2-propanol concentrations are reported.
