Light-induced Patterning and Grafting for Slippery Surfaces based on Silane-coated Nanoporous Structures.

Area of Science:

• Materials Science
• Surface Chemistry
• Nanotechnology

Background:

• Developing patterned surfaces with controlled wettability is crucial for advanced fluidic devices.
• Existing methods for creating slippery surfaces often lack spatial precision or scalability.

Purpose of the Study:

• To develop a high-resolution, maskless method for fabricating spatially patterned slippery surfaces.
• To create surfaces with tunable liquid repellency and controlled droplet behavior.

Main Methods:

• Utilized digital light processing (DLP) and polymerization-induced phase separation to pattern polyurethane acrylate (PUA) resin with a porogen (PEG-200).
• Employed UV-ozone activation and silanization for surface hydrophobization, followed by UV-initiated grafting of a polydimethylsiloxane (PDMS) brush layer.
• Characterized surface wettability using contact angle and hysteresis measurements with various liquids, including water, octane, honey, and artificial saliva.

Main Results:

• Achieved spatially patterned slippery surfaces with strong liquid repellency and low contact angle hysteresis.
• Demonstrated selective slipperiness by directing water-based droplets between slippery and hydrophilic regions, creating well-defined liquid patterns.
• Confirmed high optical transparency of the fabricated surfaces, suitable for various applications.

Conclusions:

• The developed DLP-based method offers a versatile platform for fabricating complex liquid-repellent patterns with high precision.
• The patterned slippery surfaces show significant potential for applications in microfluidics, droplet manipulation, and water harvesting.
• This approach enables scalable, maskless patterning on flexible substrates, broadening the scope of surface engineering possibilities.