Laser-based surface microtexturing for advanced liquid guidance

Controlling the movement of liquids across solid surfaces is essential for applications such as microfluidics, anti-fouling and heat-transfer technologies. Laser-based microtexturing, particularly Direct Laser Interference Patterning (DLIP), offers a highly versatile approach for tailoring surface wettability and enabling the precise manipulation of fluid behavior on materials such as glass, polymers, and metals. In this work, advanced strategies for liquid guidance enabled by surface microstructures fabricated using DLIP are presented. In a first example, superhydrophobic PTFE surfaces are fabricated by replicating a microtexture from a DLIP-treated metal master to the polymer surface by hot embossing. Another application is the directional liquid transport driven by extreme wettability contrasts. In this case, soda-lime glass was structured by ns-DLIP using a UV laser source to produce hydrophilic surfaces and spraying with a chemically active perfluoropolyether compound to selectively induce hydrophobicity. A third example of advanced liquid manipulation is showcased by fabricating surface microtextures with varying spatial periods which induce spontaneous and directional motion of droplets. Together, these results indicate that DLIP is a powerful and scalable tool for surface functionalization aimed at flexible fluid manipulation. Additionally, the combination of high-throughput structuring and broad material compatibility hints at a robust platform for engineering surfaces with advanced liquid-guidance capabilities.