Robust air pocket stability of various liquids droplet on micro cavity structures
Myung‐Seo Kim, Seungmin Oh, Woo Young Kim, Seo Rim Park, Seo Na Yoon, Su Hyun Choi, Seungwoo Shin, Sin Kwon, Kyoohee Woo, Seok Kim, Young Tae Cho
Abstract
• Evaluation of textured omniphobic surfaces to control droplet wetting. • Microstructural arrays patterned on a polymer using UV nanoimprint lithography. • Comparison of micropillar, microcavity, and combined hierarchical structures. • Surface tension and viscosity affect contact angles on microstructured surfaces. • Microcavity structure prevents surface wetting with low-surface-tension liquids. Surface texturing is carried out to realize a robust liquid-repellent surface, that is, a surface with a high contact angle for various liquids. Surfaces with an array of micropillars, microcavities, or a hierarchical structure composed of micropillars and microcavities were fabricated, and their wetting behaviors were evaluated. The microstructural arrays were fabricated on a flexible polymer substrate using ultraviolet nanoimprint lithography and contact angles of liquids with different surface tensions were measured and compared. Furthermore, the long-term liquid repellency of the developed surfaces was evaluated by measuring static and dynamic contact angles. The results revealed that the microcavity structure is suitable for preventing the wetting of the surface with low-surface-tension liquids, such as hexane and silicone oil. Unlike the pillar array, the microcavity structure prevented the wetting of the surface with such liquids.