Study of the electro-responsiveness and surface texturing of PEDOT:PSS for smart MEMS interface applications

In this study, we characterize the impact of electrical stimuli on the wettability and volume of thin films of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) in aqueous solution. At low voltage (<;1V), we demonstrate a 20° to 30° modulation of the contact angle controlled by an electrowetting phenomenon and not by electrochemical reactions like usually seen for other common conducting polymers. Consequently, the contact angle range can be tuned by chemical functionalization of its interface. Besides, we show that the polymer presents a small swelling (<;4%) when the potential is turned from 0.2V to -0.8V. Finally, we develop fabrication processes to texture the PEDOT:PSS surface at microscale and nanoscale.