To construct practical devices based on the actuating properties of conducting polymers we need to understand the underlying mechanism of the reversible length change and the effect of numerous synthetic and processing parameters on the extent of actuation, reversibility and durability. Here, we have investigated the out-of-plane actuation of polypyrrole (PPy) doped with dodecylbenzenesulfonate (DBS) in an aqueous electrolyte, and the linear actuation of PPy/DBS (aq.) and PPy/ hexafluorophosphate (PF6) in a propylene carbonate (PC) based electrolyte. The out-of-plane actuation was examined by means of AFM, and linear actuation was evaluated by a combination of electrochemomechanical deformation (ECMD) measurements, cycling voltammetry, chronoamperometry and conductivity measurements. The results revealed a very large actuation for PPy/DBS (aq.) in the out- of-plane mode, but a very limited actuation in the linear direction with low reversibility. PPy/PF6 (PC) showed much higher linear actuation than PPy/DBS, with reversible ECMD characteristics.
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