Low-voltage manipulation of an aqueous droplet in a microchannel via tunable wetting on PPy(DBS).

This paper presents experimental results and analyses on the controlled manipulation of a liquid droplet. The droplet was manipulated upon local reduction and oxidation (redox) of dodecylbenzenesulfonate doped polypyrrole (PPy(DBS)) in an immiscible organic fluid of bulk dichloromethane (DCM, CH(2)Cl(2)). The electrochemically tunable wetting property of PPy(DBS) permitted liquid droplet manipulation at very low voltages (-1.5 V to 0.6 V). In particular, the actuation behavior of a salt water droplet upon redox of PPy(DBS) in a microchannel configuration was characterized and analyzed. The controlled lateral transport of the droplet was successfully demonstrated in a slightly tilted microchannel configuration.