On-demand Production of Emulsion Droplets Over a Wide Range of Sizes

We have successfully produced emulsion droplets on a chip with size control and on-demand droplet generation by using a magnetically driven microtool (MMT). The MMT has a parallel plate structure to be constrained in translational motion. With a lateral motion of MMT in microchannels, the continuous phase can be cut into different size droplets and the dispersed phase flow can inflow into the microchannels by the movement of the MMT to obtain both size-controlled and on-demand droplets actively. The size range of the produced droplet was improved 3 times as large as the previous system by employing a novel hydraulic design of the chip and also leakage of the fluid was successfully prevented when it was chopped by using the MMT. (C) Koninklijke Brill NV, Leiden and The Robotics Society of Japan, 2010