A combined bi-ionic polymer actuator with unidirectional extension against bipolar excitations

Polyphenol sulfonic acid-doped polypyrrorle films and dodecyclo benzene sulfonic acid-doped polypyrrorle films display volumetric expansions in response to positive and negative excitation voltages, respectively. This fundamental behavior is utilized with a new fabrication procedure to devise an artificial muscle capable of displaying a longitudinal expansion with an excitation voltage applied with either polarity. Therefore, this all polymer bi-ionic actuator can be used with ac excitation signals to make a positive displacement. The cyclic voltammogram and percentage deformation graphs showing a good match between the theoretical prediction and the practical outcome. This type of an artificial muscle is useful in situations where the actuation to be proportional only to the magnitude of the excitation voltage irrespective to the polarity.