Sudden Contraction Promotes the Rebound of Droplets on an Inclined Microflower Superhydrophobic Surface

Abstract Natural freezing at a low temperature poses fatal threats to aircraft, cables, and plants. Accelerating the rebound of the impacting droplet is an important approach to reduce ice accretion on the solid surface. Herein, a superhydrophobic copper myristate surface with a static contact angle of 158° is prepared to study the dynamic behaviors of the impacting droplet on the inclined surface. For the first time, the sudden contraction of the impacting droplet, especially in the cases at a high Weber number, is reported. With the increase of the Weber number, after reaching the maximum wetting diameter, the contraction process changes from direct contraction to sliding at first and then contracting while maintaining the maximum wetting diameter. Further investigations confirm that the sudden contraction of the trailing edge is the underlying mechanism for accelerating the droplet rebound. This discovery provides new insight and explanation for the dynamic evolution of impacting droplets on the inclined superhydrophobic surface.