Effect of microchannel structure on droplet size during crossflow microchannel emulsification

A monodispersed oil-in-water emulsion was continuously produced using a cro ssflow-type silicon microchannel plate in which a liquid flow path for the continuous phase was made, and on each side of the wall of the path, an arr ay of regular-sized slits (microchannels) was precisely fabricated on a mic rometer scale by photolithography. A flat glass plate was tightly attached to the microchannel plate to cover the top of the microchannels. Regular-si zed oil (triolein) droplets were generated by pressing the oil through the microchannels into a continuous phase of 0.3 wt% aqueous sodium lauryl sulf ate. The average size of the oil droplets was regulated within a range of 1 1.3 to 28.2 mu m by changing the microchannel structural features such as t he shape of the cross section and outlet, the equivalent diameter, and the length of the terrace, which is a flat area fabricated at the outlet of the microchannels. In every case, the droplet size distribution was narrow, an d the geometric standard deviation was 1.03 or less.