Impact and wetting behaviors of impinging microdroplets on superhydrophobic textured surfaces

The impact and wetting behaviors of impinging microdroplets on textured surfaces are investigated using high-speed imaging. Microdroplets with diameters less than 50 μm are ejected using a piezoelectric printhead with controlled Weber numbers. The impact behaviors are clearly observed, and the detailed mechanisms are explained according to the Weber number and wetting states of the impinging droplets. Moreover, the transition phenomena from bouncing to non-bouncing are clearly observed. The impalement transition, which has been explained by wetting pressures, is also examined in this study.