10th International Conference on Surface Engineering (ICSE 2026)

Dropwise condensation is a highly efficient phase-change heat transfer process crucial for industrial thermal management and water harvesting. However, conventional superhydrophobic surfaces often fail under high humidity, while rigid slippery liquid-infused porous surfaces (SLIPS) suffer from lubricant depletion and poor adaptability to curved surfaces. This study presents a flexible and transparent SLIPS based on a microstructured polydimethylsiloxane (PDMS) elastomer. Silicon masters featuring micropillar and microcavity arrays were fabricated via photolithography and etching processes. Subsequently, PDMS was employed to replicate these masters, thereby precisely controlling the surface topography. The PDMS structures were then immersed in perfluoropolyether (PFPE) lubricant within a vacuum chamber, and the excess oil was removed using a spin coater thereafter. The resulting soft SLIPS exhibited superior wettability (water contact angle: ~105.7°, contact angle hysteresis: ~2°), enabling rapid droplet removal and continuous condensation. Due to the microstructures, lubricant loss per unit area was reduced by 28.2% compared with conventional SLIPS. Furthermore, the water collection efficiency of the soft SLIPS was 27.4% higher than that of ordinary superhydrophobic surfaces. This work demonstrates that the integration of soft materials and microstructures provides a robust solution for stable condensation on substrates of various shapes, offering new insights into the design of advanced interfacial materials for energy-efficient thermal management and atmospheric water harvesting.
 

SLIPS,Dropwise condensation,Soft material,Water harvesting