A comparison of poly (3,4-ethylenedioxythiophene) polymerized potentiostatically and galvanostatically

Abstract

Conducting polymer films, such as polypyrrole (PPy), have been extensively studied as linear actuators. Poly (3,4-ethylendioxythiophene) (PEDOT) received less attention as linear actuators, even though they show much better stability and conductivity than PPy films. In this work, we investigate the actuation of PEDOT films of comparable thicknesses electropolymerized either, potentiostatically (PEDOT (pot)) and galvanostatically (PEDOT (galv)) in the same organic electrolyte. Characterization by cyclic voltammetry and chronoamperometry revealed that the actuation direction of these films is opposite to each other: in PEDOT (pot) films show cation-driven actuation, while for PEDOT (galv) films present anion-driven actuation. The measured strain of PEDOT (pot) was found to be 1.4 times larger than that of PEDOT (galv), involving 1.5 times higher charge density and having 2.3 times higher electronic conductivity. The specific capacitance, measured by cyclic voltammetry and chronopotentiometry, showed that PEDOT (pot) has double energy storage capabilities to that of PEDOT (galv), keeping up to 86.7% of the storage capacity after 5000 charge/discharge cycles. Further characterization of the PEDOT samples was performed by means of scanning electron microscopy (SEM), energy dispersive X-Ray spectroscopy (EDX) and Raman spectroscopy.