Abstract
A microfluidic device includes a substrate, first and second capillary inlets, a microfluidic channel unit, an outlet disposed downstream of the microfluidic channel unit, and a suction member disposed downstream of the outlet. A first liquid is drawn into a first sub-channel and a main channel of the microfluidic channel unit through the first capillary inlet. A second liquid is drawn into a second sub-channel of the microfluidic channel unit through the second capillary inlet. The suction member provides a predetermined suction force to permit the second liquid to penetrate into the first liquid and to break up into droplets in the first liquid, thereby generating monodisperse emulsions.