Regression analysis of wetting characteristics for different random surface roughness of polydimethylsiloxane using sandpapers

This paper studies various wetting characteristics on different surfaces of Polydimethylsiloxane (PDMS) polymer. The random roughness of the surface is engineered by using sandpapers to introduce different order of hydrophobic properties to understand the temporal evolution of drying droplets. We develop statistical models to predict temporal evolution of the base diameter, height, surface, and contact angle of drying droplets with varying grit size or surface roughness. Five different robust polynomial regression models have been compared for the prediction of three dependent variables base diameter, height, and surface of drying droplets for random rough surfaces. In a nutshell, we here identify the best statistical model to capture the dynamics of drying droplets on hydrophobic surfaces of random roughness characteristics.