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Conducting polymers serve as electrically conductive actuators via ion diffusion in and out of the polymer when voltages are applied. Their actuation performance can be largely affected by deposition setup, post-deposition processing, type of electrolyte, applied voltage for actuation, and temperature. It was shown that increasing temperature caused higher active stress in polypyrrole, an attractive conducting polymer actuator material. However, detailed characterizations were lacking to determine whether the improved active stress was caused by structural change in the polymer and/or charging effect. A temperature-controlled solvent bath was integrated with a custom-built electrochemical dynamic mechanical analyzer to conduct isometric and isotonic tests on polypyrrole under elevated temperature. Experimental results showed that heating increased the charge transport through the polymer and thermal expansion in the polymer allowed more room for charge uptake. As a result, increase in ion movement largely contributed to improvements in actuation stress (rate) and strain (rate), while the decrease in stiffness due to heating had limited effect. Moreover, actuation performance wa