Tailoring surface wettability through laser speckle patterning

The hydrophobicity of a material surface is crucial for its self-cleaning, antifouling, and anticorrosion properties. In this paper, a novel approach for enhancing surface hydrophobicity is presented, in which laser speckle grayscale lithography combined with soft embossing is employed to fabricate microstructures on polydimethylsiloxane (PDMS). By adjusting the exposure dose and laser speckle size, the surface morphology and, consequently, the wettability of the PDMS showed regular changes. Without any post-treatment, the patterned PDMS exhibited the higher water contact angle (144.2°) than the intrinsic contact angle of PDMS (100.6°). This approach offers a simple and cost-effective route for enhancing hydrophobicity of surfaces.