Active-Matrix Digital Microfluidic Device Based on Surfactant-Mediated Electro-Dewetting

Abstract

Based on electro-wetting mechanism, digital microfluidics (DMF) today utilizes both direct-drive and active-matrix (AM) control of electrodes. Recently, DMF with surfactant-mediated electro-dewetting that electrically induces hydrophobic repulsion of droplets containing ionic surfactant has also been demonstrated. However, the existing electro-dewetting DMF devices are on a direct-drive controlled electrode array, which limits the number of independent electrodes. Reported in this work is an electro-dewetting DMF device on an AM array by providing the continuous current needed for electrodewetting. Indium-tin-zinc oxide top-gate self-aligned thin-film transistors are employed in the cell circuit to address and drive droplets with low voltage. The resulting AM electro-dewetting DMF devices are confirmed to transport, split, and merge droplets by using low voltage, opening the path for electro-dewetting DMF that offers a large number of independent electrodes.