Production of uniform emulsion droplets using a simple fluidic device with a peristaltic pump

We fabricated a simple fluidic device consisting of a needle, a glass capillary, and a Tygon® tube to produce oil-in-water (O/W) emulsion droplets. In the fluidic device, the flow rate of the continuous phase was adjusted by a syringe or peristaltic pump, where a syringe pump was used for the discontinuous phase. We compared the performance of the syringe and peristaltic pump for the continuous phase in terms of the average diameter and coefficient of variance of the resultant O/W emulsion droplets. It was found that uniform droplets could be obtained when the production frequency was well matched. In addition, the flow behavior of the discontinuous phase during droplet formation was monitored using a high-speed camera, observing the back pressure in the peristaltic pump. By employment of a peristaltic pump for the continuous phase, it was possible to prepare a large amount of emulsion droplets.