Virtual electrowetting channels: electronic liquid transport with continuous channel functionality

Abstract

Reported is a new mechanism for electronic transport of liquid in virtual channels. These virtual channels are formed by application of voltage to an array of polymer posts. The posts are coated with a conducting electrode and hydrophobic dielectric, and thereby capable of electrowetting. Directional channel formation, as well as splitting and merging, is also demonstrated using specific arrangements of posts. The channel dimensions are ∼20 µm in cross-section, are scalable, and at the threshold for channel formation the minimum transport speed is ∼1 mm s⁻¹. The virtual electrowetting channels are further unique as they can retain any channel geometry even in the absence of voltage. With the addition of arrayed voltage controls, the virtual electrowetting channels have the potential to combine the advantages of programmable electrowetting and continuous channel functionality into a single lab-on-chip platform.