Repeated geometrical T-junction breakup microfluidic filter device by injection of premixed emulsion for microdroplet production

In this study, we propose a repeated geometrical T-junction breakup microfluidic filter device for fabricating microspheres from premixed emulsions. The proposed microfluidic filter device is composed of multiple repeated T shapes in the microchannel for droplet splitting. Microdroplets are guided along the microchannel and divided symmetrically at the T-junction in the microchannel. The results obtained herein show that as the number of filters was increased, the droplet diameter decreased and the droplet size distribution improved significantly. The behaviors of the microdroplets in the microchannel were inspected as a function of the viscosity of the premixed emulsion solution. The microdroplet diameter increased significantly as the emulsion viscosity increased. Furthermore, the microfluidic filter device was tested by using it to prepare chitosan microspheres. Chitosan microspheres of a narrow size distribution with coefficient value of 6.2% were prepared successfully.