Sliding of water droplets on micropillar-structured superhydrophobic surfaces

Abstract

Understanding the specific behavior of water droplet detachment from a micropillar-structured superhydrophobic surface is essential in a variety of potential applications. Herein, the sliding behavior of water droplets on three different micropillar-structured superhydrophobic surfaces was studied. From tilting plate experiments and retention force measurements, we probed the motion of water droplets with different volumes. The effects of droplet sizes and contact angle hysteresis on the roll-off angle were also investigated. Furthermore, three different models are proposed to estimate a roll-off angle. The lateral retention force-based model agrees well with the roll-off angle measurements, and the other two contact angle hysteresis-based models capture the trend in the variation of the roll-off angle.