Synthesis of scalable micro-droplets with heat-driven effect in flow-focusing device

This paper reports a new method for controlling micro- and nano-droplets by the aid of heat. Computational fluid dynamics (CFD) simulation results suggest this technique is capable of conveniently controlling the droplets sizes down to several micrometers or even nanometers. This pilot research offers the possibility of fabricating micro-droplet with specific size and without changing the fluid. Three factors are studied, including the temperature of continuous phase, the temperature of discrete phase and the temperature gradient on the orifice. The results show that heat transfer between the two phases is fast as characteristic length is in micron level. Increase in temperature can lead to the increase of the droplet radius, wherein the effect of the continuous phase temperature is the most significant.