Basic Evaluation for Dynamic Behavior of Waterdrop on Line-patterned Silicone Surface using Equation of Motion
Kenji Yanagisawa* and Chinatsu Saito
Published: April 15, 2022
DOI: 10.55162/MCET.02.037
Abstract
Inspired by the water-repellent and self-cleaning properties of the lotus leaf in the natural world, artificial superhydrophobic surfaces have generated extensive attention in academia and industry. Hydrophobicity and the sliding behavior of waterdrops is a very important phenomenon in our daily life as well as in many industrial processes. However, the difference between these two phenomena is not well understood. This study was performed to predict movement of waterdrop on surfaces of silicone sheet and was focused on interface resistive forces between waterdrop and surfaces. Various hydrophobic sheets having different the waterdrop contact ratio (the ratio of the contact area between the waterdrop and the sheet) were prepared. And the relationships between the sliding angles, the sliding velocities and the surface structure were investigated. Equation of motion is used to calculate the interface resistive forces from the sliding angle and the sliding velocities. As the result of calculation, interface resistive forces between waterdrop and the surfaces are equivalent to force of the gravity. The interface resistive forces decrease with decreasing the waterdrop contact ratio. Sliding velocities seems to affect interface resistive forces. This research clarifies that sliding velocity and interface resistive forces are related to positive correlation by the waterdrop contact ratio. The relationship may help prediction of movement of drops on surfaces.