Microfluidic Dispensing Device Using Wettability Gradient and Electrowetting

Abstract

We have designed a novel microfluidic dispensing device using automatic droplet transportation on a wettability gradient surface that is sequentially followed by electrowetting-based liquid handling. While a droplet moves along the wettability gradient in a main channel, a portion of the droplet is drawn into a side channel and stored in a reservoir temporarily. Next, the stored liquid is dispensed into a mixing channel when a voltage is applied between two electrodes. The fabricated device succeeded in dispensing two liquids of different nanoscale volumes after extracting them from a microscale volume droplet.