Experimental study of single-plate EWOD device for a droplet based PCR system

The requirements for a polymerase chain reaction (PCR) microchip are reduction in reaction time and PCR reagent volume. In this paper, we describe the design and experimental studies of a droplet-based PCR by electrowetting on a dielectric (EWOD) chip by using the droplet basis to reduce PCR reagent volume. The droplet-based PCR system consists of a single-plate EWOD device and serpentine-shape microheaters integrated underneath to maintain temperature for denaturation, annealing, and extension. The EWOD-based PCR system consists of 1.4 mm wide, 11 mm long and 470 μm deep microchannel and serpentine-shape microheater integrated underneath to maintain temperature at each stage. DNA was driven by moving droplet through each electrode (dimension of 2 mm width and 2 mm long) that maintains temperature at denaturation, annealing, and extension region. The single-plate EWOD based PCR device has been successfully fabricated and tested. The tested results confirm that ionized droplet can be moved with fully controlled manner by applying voltage less than 50 V. The obtained experimental datum shows that the optimized applied voltage of three microheaters for the temperature of PCR are 1.04, 0.53, and 0.91 V.