The emulsification of the monomer phase is achieved in capillary-based microreactors without any surfactant or surface treatment. Polymer beads are obtained after UV irradiation while polymer capsules are directly generated in the microfluidic device through an interfacial polycondensation reaction.
A preliminary study has shown that in the dripping regime the variation of particle diameter with respect to operating parameters (flow rates and viscosities of the dispersed and continuous phases) is fairly well described by an empirical relationship between two dimensionless numbers, the normalized particle diameter and the Capillary numbers ratio .
Application of these microsystems concerns O/W or W/O emulsions for the preparation of inorganic-organic hybrid beads as well as hollow and doped capsules. By confining the particles in the microsystem, we have also successfully prepared polymer beads necklaces  with different arrangements.
 C. Serra, N. Berton, M. Bouquey, L. Prat and G. Hadziioannou, Langmuir, 23 (14) (2007) 7745-7750.
 M. Bouquey, C. Serra, N. Berton, L. Prat and G. Hadziioannou, Chem. Eng. J. (In press, doi:10.1016/j.cej.2007.07.043).