The transport performance of condensate droplets on inclined superhydrophobic surfaces

Abstract

Coalescence-induced droplet jumping on superhydrophobic surfaces has significant potential for various applications, such as enhanced condensation, water harvesting, self-cleaning, and thermal management of electronic devices. Existing research focuses primarily on the coalescence and jumping of two or more droplets on the horizontally placed superhydrophobic surface, but the transport behavior of condensate droplets caused by coalescence-induced jumping on the inclined superhydrophobic surface is insufficiently understood. In this work, we investigate the impact of the surface inclination angle on the dynamic behavior of condensate droplets and derive the relationship between the transport distance, transport height, jumping direction of droplets, and the surface inclination angle. Additionally, we establish a droplet motion equation to describe the trajectory of droplets after they jump off the surface. Furthermore, we demonstrate the phenomenon of multi-hop jumping on the inclined superhydrophobic surface, which can increase the droplet transport distance, and the established mathematical model can better predict the multi-hop jumping transport distance. This work exposes the effect of superhydrophobic surface inclination angle on droplet dynamics and droplet directional transport performance, which has significant implications for the application of droplet jumping.