Multiple Bounces and Oscillatory Movement of a Microdroplet in Superhydrophobic Minichannels

A droplet jumping intensification device of droplets surrounded by gas has effectively integrated small droplets (d = 0.30-0.60 mm) generated by an electrohydrodynamics system (EHD) and super hydrophobic minichannel to enhance gas absorption or chemical reaction due to the multiple bounces of the droplets. Droplet internal circulation was formed after impact on the superhydrophobic surface in the process of droplet bounce back and forth, with deformation in the superhydrophobic minichannel, which was like a liquid slug moving in the meandering channels. It was shown that the bouncing frequency went up with the decreasing height of the minichannel, meaning that the bouncing movement became stronger in the confined space. The droplet trajectory could be better controlled by the height of the minichannel, droplet size, and impact Weber number, which was investigated experimentally and analytically.