Microstructured SiO/COP Stamps for Patterning TiO₂ on Polymer Substrates via Microcontact Printing.

Area of Science:

• Materials Science
• Microfabrication
• Surface Chemistry

Background:

• Microcontact printing (μCP) is crucial for microfabrication, but limitations exist with polydimethylsiloxane (PDMS) stamps.
• PDMS stamps are hydrophobic and soft, often requiring rigid masters or photoresist processes for replication.

Purpose of the Study:

• To develop a novel, master- and photoresist-free microcontact printing stamp.
• To demonstrate a facile and cost-effective method for creating micropatterns on flexible substrates.

Main Methods:

• Vacuum ultraviolet (VUV) lithography was used to create stamps from cyclo-olefin polymer (COP).
• Selective deposition of siloxane precursors followed by conversion to silicon dioxide (SiO2) formed hydrophilic patterns on COP.
• The resulting SiO2/COP stamps had punch heights of approximately 180 nm.

Main Results:

• A novel, hydrophilic SiO2/COP microcontact printing stamp was successfully fabricated.
• The stiffer SiO2/COP stamps demonstrated reduced deformation during pressing compared to PDMS.
• Titania precursor gel was patterned using μCP to produce TiO2 micropatterns on flexible substrates.

Conclusions:

• The developed SiO2/COP stamps offer a simple, cost-effective alternative for microfabrication.
• This technique facilitates the creation of micropatterned flexible devices.