Effective method for measuring structural influence through changes in droplet spreadability

Abstract

Conventional contact angle and hysteresis measurements often fail to distinguish structural differences between surfaces of the same material. In this study, a new analytical approach is designed to overcome these limitations. The proposed method involves observing the behavior of droplets upon their impact on the surface for different target material structures, thereby measuring the velocity of the droplet boundary during spreading (high Weber number and kinetic energy conditions) or receding (low Weber number and kinetic energy conditions). These velocity characteristics dynamically reflect structural influences, offering a highly sensitive approach for differentiating surfaces based on their structure. We anticipate that this method, which provides a reliable and effective way for characterizing surface structures in various applications, will be widely adopted in research and industry.