Reproducible PDMS flexible superhydrophobic films: A method utilizing picosecond laser-etched templates

Abstract

This paper provides a convenient, efficient and repeatable method for the preparation of flexible PDMS superhydrophobic films. The stainless steel template was etched with picosecond laser to create textures, which was then filled with PDMS and thermally cured to produce PDMS superhydrophobic films featuring corresponding microstructures. By constructing computational models of the microstructures and exploring the influence of laser scanning spacing on contact angle, the process parameters were optimized to obtain superhydrophobic PDMS films while ensuring the stability of microstructures. The microstructures showed straight lines spaced 55 μm apart, with each line connected by regular truncated cone structures. These structures formed Cassie contacts with the droplets, exhibiting a contact angle of 152.1° and a sliding angle of 9°. In addition, this study demonstrates the reproducibility of the PDMS superhydrophobic film preparation method and its effectiveness in delaying icing. The results indicate that the templates can be used for more than twenty replications, and the obtained PDMS superhydrophobic films have a delayed icing time of 3.3 times. These findings suggest that the PDMS superhydrophobic films have excellent performance and repeatable characteristics, making them suitable for various applications.