Initial studies into the development of a self-powered controlled release system using ionic liquid electrolyte were performed via galvanic coupling of a conducting polymer doped with dye and a zinc anode. The conducting polymer employed was polypyrrole (PPy) doped with phenol red (PR) dye. The electrochemical properties of the polymer as well as the dye release process initiated by a Zn electrode were investigated. A bilayer conducting polymer structure wherein polypyrrole–polystyrene sulfonate (PPy-PSS) coated on top of PPy-PR ensured no leakage of dye, yet allowed efficient release of PR on galvanic coupling in a temperature sensitive electrolyte.
Wang, C. Y., Ashraf, S., Too, C. O. & Wallace, G. G. (2009). Ionic liquid as electrolyte in a self-powered controlled release system. Sensors and Actuators B: Chemical: international journal devoted to research and development of physical and chemical transducers, 141 (2), 452-457.