Statistical optimization and surface engineering for hydrophobicity in DLP-printed textures

Abstract

This study presents a systematic approach for fabricating hydrophobic and superhydrophobic polymer surfaces using digital light processing (DLP) additive manufacturing. A commercially available water-washable resin was employed to improve the scalability and practical applicability of the method without modifying resin chemistry. Surface textures with varying feature height, dimension, spacing, and angle were fabricated and optimized using a central composite design (CCD). Wettability was evaluated through static water contact angle measurements. Statistical analysis revealed that texture spacing and angle were the most influential parameters, with spacing contributing to a 62% increase in contact angle. Optimized textures achieved contact angles up to 142° ± 2°. To further enhance hydrophobicity, a spray coating containing photo-resin, fumed silica, and alumina particles was applied, generating hierarchical micro-scale roughness and increasing the contact angle to 156° ± 2°, reaching the superhydrophobic regime. The results demonstrate that geometry-driven surface engineering combined with scalable coating techniques can effectively tailor wettability using commercially available DLP materials, offering strong potential for self-cleaning, anti-wetting, and microfluidic applications.

Graphical abstract

Keywords

digital light processing (DLP) / superhydrophobicity / surface texturing / central composite design (CCD)

Rights & permissions

Higher Education Press