Bouncing droplets on micro-grooved non-wetting surfaces

Water droplets impinging on micro-grooved polydimethylsiloxane surfaces were studied. Depending the impact velocity and surface roughness, different phenomena such as no bouncing, complete rebound (CR), bouncing occurring with droplet breakup (BDB), partial rebound, sticky state observed. The lower limit of for can be determined by balancing kinetic energy barrier due to contact angle hysteresis. To predict upper droplets, a high-speed camera was used record at an ultrahigh speed it found that transition from CR BDB attributed local wetting Cassie–Baxter Wenzel state. Based experimental observation, theoretical model developed taking into account penetration liquid micro-grooves. In addition, there shorter time decrease in Weber number roughness has small influence our experiments.