Topography printing to locally control wettability.

Area of Science:

• Materials Science
• Surface Chemistry
• Microfabrication

Background:

• Patterning techniques are crucial for creating microstructures with tailored surface properties.
• Existing methods may have limitations in substrate compatibility or pattern fidelity.
• Developing versatile and efficient patterning methods is essential for advanced material applications.

Purpose of the Study:

• To present a new, NaOH-assisted method for patterning polydimethylsiloxane (PDMS) on various substrates.
• To demonstrate the capability of this method for creating well-defined PDMS architectures.
• To explore the application of this patterning technique in controlling surface wettability.

Main Methods:

• Utilizing sodium hydroxide (NaOH) to promote irreversible binding between PDMS stamps and substrates.
• Employing cohesive mechanical failure for efficient PDMS pattern transfer.
• Applying the method to a range of substrates including Si100, glass, gold, polymers, and SU8 photoresist.

Main Results:

• Achieved high substrate tolerance with successful PDMS pattern transfer on diverse materials.
• Demonstrated the ability to print various PDMS geometries with high fidelity.
• Successfully altered surface wettability by printing PDMS architectures on patterned SU8 photoresist.

Conclusions:

• The developed NaOH-assisted patterning method offers a versatile approach for microfabrication.
• This technique allows for precise control over surface properties, enabling differential wetting and dewetting.
• The method has significant potential for applications in microfluidics and surface engineering.