The book will contain two parts: * the review of microfluidic devices and the methods used for controlled preparation of droplets and bubbles. * the description of physical and chemical methods for solidification of such prepared droplets in situ on microfluidic chips. In the first part, the general aspects of microfluidics will be reviewed, the fabrication methods used for the production of microfluidic devices, and the applications of microfluidics. In particular, the focus will be on the physics of formation of droplets in microfluidics and the devices used for emulsification. In the second part, different polymerization and fabrication processes will be reviewed that are used for solidification of droplets and hence continuous production of particles. The methods for production of solid and soft particles with different compositions, shapes and morphologies and their potential applications will also be presented.