Controlled transport of droplets using conducting polymers.

The controlled transport and delivery of dichloromethane through platinum mesh coated with dodecylbenzenesulfonate-doped polypyrrole is demonstrated upon in situ electrochemical redox switching. Droplets of dichloromethane were observed to pass freely through the mesh upon reduction of the polymer as a result of the release of the surfactant dopant into the dichloromethane and the change in the surface energy of the polymer. Planar and liquid-filled tube configurations are investigated. These concepts are envisaged to prove useful for fluid control in microfluidic devices, in the preparation of microparticles for drug delivery, and in the development of organic microreactors.