In this paper, we present a novel method to generate ultra-small droplets via volatile component evaporation. By regulating the composition of the binary solvent, the volume ratio of the high saturated vapor pressure component, and the flow rate ratio of the two phases, monodisperse ultra-small water or nonvolatile organic droplets can be formed. This method is flexible, versatile, and compatible with tip-streaming or nanofluidics, and may have potential applications in single molecule assay, colloid synthesis, and block copolymer assembly.

We present a novel method to synthesize anisotropic elongated particles via the combination of a droplet based microsphere synthesis method and colloidal assembly in a microchannel. By programmable controlling of the integrated microvalve, the elongated particles with different length, bonding angle, size sequence and composite order can be produced and regulated individually. The established method is flexible and easy to operate, which will find applications for rheological modifier and drug delivery carrier design.