An active-matrix digital microfluidic device based on surfactant-mediated electro-dewetting

Abstract

Based on electrowetting mechanism, digital microfluidics (DMF) 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 an ionic surfactant has also been demonstrated. However, existing electro-dewetting DMF devices are on a direct-drive controlled electrode array, which limits the number of independent electrodes. This work presents an AM electro-dewetting DMF device with continuous current to drive droplets. 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.