A large-area, all-plastic, flexible electroosmotic pump

Abstract

A large-area, fabric-like pump would potentially have applications, for example, in controlling water transport through a garment, such as a rain jacket, regardless of the external temperature and humidity. This paper presents an all-plastic, flexible electroosmotic pump, constructed from commercially available materials: A polycarbonate membrane combined with the electrochemically active polymer poly(3,4-ethylenedioxythiophene) polystyrene sulfonate that actively transports water using an electric potential that can be supplied by a small battery. By using electrochemically active polymer electrodes instead of metal electrodes, the electrochemical reaction that drives flow avoids the oxygen and hydrogen gas production or pH changes associated with water electrolysis. We observe a water mass flux up to 23 mg min−1 per cm2 polycarbonate membrane (porosity 10–15%), at an applied potential of 5 V, and a limiting operating pressure of 0.3 kPa V−1, similar to previously reported membrane-based electroosmotic pumps.