High pressure EWOD digital microfluidics

Abstract

We are developing new electrowetting-on-dielectric (EWOD) digital microfluidic systems for operating at non-atmospheric conditions. The first generation is a compact pressure chamber with an electric feed-through, enabling EWOD operation within a gaseous medium of well-controlled pressure and composition. EWOD performance is insensitive to chamber pressure because the chip is of open-channel architecture. We demonstrate two different types of previously unachievable processes - (i) controlling evaporation rates of common solvents (water, methanol, acetonitrile) by adjusting the pressure of an inert gaseous medium (N ₂ ), and (ii) controlling the reaction rate of a solid-liquid-gas-phase reaction by adjusting the pressure of a gas-phase reagent (H ₂ ).