Adhesive lift method for patterning arbitrary-shaped thin ion-selective films in micro/nanofluidic device

Area of Science:

• Electrokinetics
• Nanofabrication
• Microfluidics

Background:

• Nanoporous films are crucial for studying electrokinetic phenomena in systems like electro-desalination and biomolecular preconcentration.
• Current fabrication methods limit studies to film properties (charge, pore size), neglecting the significant impact of membrane morphology.

Purpose of the Study:

• To introduce an economical and feasible nanofabrication method, the "adhesive lift method", for patterning arbitrarily-shaped nanoporous films.
• To enable the integration of these patterned films into micro/nanofluidic platforms for advanced electrokinetic studies.

Main Methods:

• Utilized spin coating, oxygen plasma treatment, and the "adhesive lift technique" for conformal patterning of nanoporous films (Nafion, PEDOT:PSS).
• Fabricated micro/nanofluidic platforms incorporating these patterned films.

Main Results:

• Demonstrated the initiation of ion concentration polarization along nanoporous films of various shapes.
• Successfully characterized electrokinetic behaviors, including overlimiting conductance, influenced by microchannel length scales.

Conclusions:

• The adhesive lift method provides a versatile platform for fabricating patterned nanoporous films.
• This technique facilitates the study of electrokinetic phenomena in systems that closely mimic macro-scale fluidic applications.